Pteromalidae
Description & Statistics
Pteromalidae is one of the largest families of Chalcidoidea, with circa 570 valid genera and 2900 species. They are cosmopolitan in distribution. Important morphological characters include a usually 13-segmented antenna; parapsidal sutures distinct, but often incomplete; propodeum usually well developed. Pteromalids have been considered the most difficult Chalcidoidea to identify; morphologically they are exceedingly diverse, and thus no combination of taxonomic characters is reliable for identification.
Most Pteromalidae are primary parasitoids, but hyperparasitic species are common. Most species are ectoparasitic, but endoparasitic species are common also. Solitary and gregarious species and races are common. Generally, this family has a wide host range. Most species are gregarious ectoparasitoids of larvae and pupae of Lepidoptera and Coleoptera, but a number of species attack larvae and pupae of Diptera as well. Some are predaceous on eggs of Coccidae. There are no phytophagous species. Considerable importance has been placed on pteromalids for biological control of Lepidoptera, Coleoptera and synanthropic Diptera. A few species have also been used for the biological control of Coccidae.
​
Further Description.
Pteromalidae now also includes the former separate families, Cleonymidae, Miscogasteridae and Spalangiidae, which have been designated subfamilies Cleoneminae, Miscogasterinae and Spalangiinae, respectively. For the present, discussions of the various subfamilies will be separate because of considerable distinctness among them. The families consist of Asaphinae, Austroterobiinae, Austrosystasinae, Brachyscelidiphaginae, Ceinae, Cerocephalinae, Chromeurytominae, Cleonyminae, Coelocybinae, Colotrechinae, Cratominae, Diparinae, Ditropinotellinae, Eunotinae, Erotolepsiinae, Eunotinae, Eutrichosomatinae, Herbertinae, Keiraninae, Leptofoeninae, Louriciinae, Macromesinae, Miscogasterinae, Neodiparinae, Nefoeninae, Ormocerinae, Panstenoninae, Parasaphodinae, Pireninae, Pteromalinae, Spalangiinae and Storeyinae.
Among Chalcidoidea, the Pteromalidae are one of the most common families containing many genera and species of frequent encounter as parasitoids or hyperparasitoids of various insect pests. Dominant genera include Pteromalus, Habrocytus, Dibrachys and Pachyneuron. The family Spalangiidae is frequently included under Pteromalidae and is represented by many species of Spalangia (Bou…ek 1963). Most species are external gregarious parasitoids of larvae and pupae of Lepidoptera and Coleoptera, but some also attack pupae of Diptera and larvae of Hymenoptera. Genera such as Spintherus, Enargopelte and Peridesmia are egg predators. External and internal parasitism within a genus is found in Dibrachys, Pteromalus and Stenomalus. Ophelosia crawfordi Riley occurs as a predator on the eggs of Pulvinaria, Pseudococcus and Icerya (Smith & Compere 1931), and as a hyperparasitoid of these genera and sometimes of larvae of Coccinellidae. It has been reared from Icerya females where hyperparasitism seemed possible through Cryptochaetum. Some species of Asaphes are hyperparasitoids of Aphididae through various braconids, aphelinids and encyrtids that behave as primary parasitoids (Griswold 1929). Dibrachys cavus Wlk. (= boucheanus Ratz.) attacks a wide range of hosts with over 45 host species comprising 2 Coleoptera, 2 Diptera, 27 Hymenoptera and 14 Lepidoptera (Faure & Zolstorewsky 1925).
Pteromalus puparum L., a gregarious internal parasitoid of cabbage butterfly pupae and Ascia rapae L. in New Zealand have been credited with marked reductions in host population densities in biological control efforts. Species of Muscidifurax, Urolepis and Pachycrepoideus have been deployed successfully against synanthropic Diptera (Legner et al. 1976, Rueda & Axtell 1985).
​
The terminology with reference to the body structure of pteromalids is unique in some respects. The abbreviation POL designates the distance between the inner margins of the posterior ocelli, and OOL designates the distance between the posterior ocellus and the margin of the eyes. Counting of the antennal segments begins from the basal segment (scape not included). The maximum number of segments in the antennal clava is three.
​
The broad apical part of the radial vein in the forewings of pteromalids has been termed the stigma, and the ascending apical section of the submarginal vein, the parastigma. Traces of veins which have disappeared are shown by dotted lines... and extant veins depicted as rows of hairs. Traditionally, these veins have retained the names of their correspondents (cubital and basal). The name of the areas enclosed by these "veins" on the wing disk has been retained, i.e., "cell" (for example, basal cell). The glabrous part of the wing disk, located immediately behind the basal vein is called the "speculum." The speculum may be either closed or open; in the former case it is restricted on the lower side by a row of hairs.
Most species are metallic in color and are recognized by the following characters: Head and thorax usually densely sculptured, with notauli complete, or incomplete; antennae 11-13-segmented (0-3 anelli, 4-7 funicle segments, 3 club segments). Propodeum usually with plicae (sublateral carinae), a median carina, and some species with a narrowed convex neck (nucha) extending posteriorly. Some of the smaller pteromalids are superficially similar to the Eulophidae but may be separated by the five-segmented tarsi, by the greater number of antennal segments (11-13), and by the long curved fore tibial spurs.
​
Males of this family may be confused with those of the genus Eupelmus (Eupelmidae), in which the mesopleuron is divided by a distinct suture into mesepisternum and mesepimeron. Pteromalid males can easily be distinguished from eupelmus males, however, by the poorly developed mid tibial spur, which is enlarged and thickened in the latter. Females are indistinguishable.
​
​
Moderate to large chalcidoids; colour often blackish or metallic green, but also paler; antenna usually with more than one ring-segment; mesoscutum with complete or incomplete parapsidal sulci; fore wing with venation well developed, the marginal vein usually relatively long; shape of abdomen varying considerably: gaster broadly joined to propodeum or petiolate, the petiole sometimes long and slender; gaster ranging from short and broad to long, slender, acutely pointed at apex; tarsi five-segmented, the fore legs rarely with femur enlarged, swollen, or with hind femur swollen as in Chalcididae.
​
Biology. - The great diversity of body forms partly reflects the wide variety of biological aspects. Pteromalids include parasites in eggs, larvae and pupae from many orders of insects; a few species even oviposit into adults of some beetles (Curculionidae, Scolytidae). The great majority of pteromalids are primary or secondary parasitoids, attacking a large range of insects in their various stages of development, whereas a few are known to be gall-formers. One such species is Asparagobius braunsi Mayr which is endemic to South Africa, and which is a gall-former on the stems of Asparagus stricta. A number of pteromalids are important enemies of Diptera, and several species of Spalangia have been recorded as solitary external parasitoids of the puparia of fruit flies, whereas S. endius Walker is a common cosmopolitan parasitoid of housefly puparia; Nasonia vitripennis (Walker) is another widespread species which is a primary pupal parasitoid of various Diptera, mainly of the families Calliphoridae and Muscidae, and Muscidifurax raptor Girault & Saunders [= Sanders] readily attacks housefly puparia in many parts of the world. Species of Pachyneuron are primary parasitoids of syrphid flies, but have also been recorded as hyperparasitoids of braconid wasps attacking aphids. Many pteromalids are parasitic in Coleoptera, some of which belong to economic important groups. Members of the Chalcidectinae attack xylophagous beetles; Choetospila elegans Westwood, which is cosmopolitan in distribution, develops from a number of stored grain beetles of the families Curculionidae, Anobiidae, Bruchidae and Bostrichidae, and also from moths of the family Gelechiidae, whereas species of Dinarmus are well known parasitoids of bruchid beetles. Many species of Lepidoptera also serve as hosts. Species of Pteromalus and Habrocytus are often reared from butterflies, and the cosmopolitan P. puparum (L.) is known to attack the lucerne butterfly, Colias electo (L.) in South Africa. Scutellista is one of the few genera that parasitize Coccoidea, and its species are important natural enemies of injurious soft scale insects and mealybugs. Species of this genus are also predaceous on the eggs and larvae of their hosts. The larvae of some other pteromalid species develop as predators on eggs, e.g. of coccids (Eunotinae) or of spiders.
Many pteromalids are known to be primary parasites, secondary and sometimes even tertiary or quaternary parasitism is known. Pteromalids inhabit almost all terrestrial ecosystems. A number of groups, including Ditropinotellinae, Ormocerinae, Austrosystasinae and possible Coelocybinae and partly Colotrechninae are known to be, or surmised to be, phytophagous. Some of them develop in seeds of plants, many are reared from galls and some Ormocerinae are known to be gall-makers, e.g. an Australian Trichilogaster species which controls an Acacia growing as a weed in South Africa. Some other species may be inquilines in galls caused by other insects, consuming the tissues at the expense of the actual gall-maker. Of the entomophagous forms on the other hand Cleonyminae, Leptofoeninae, Macromesinae and Cerocephalinae are probably exclusively parasites of beetles, mainly of species developing in woody plants. Diparinae as far as is known attack curculionids (and perhaps other beetles) on roots or parts of plants close to the ground. Asaphinae, Elatoidinae and Eunotinae are mainly associated with homopterous insects, especially coccids, aphids and psyllids. Spalangiinae, Herbertiinae, Miscogasterinae and many 'petiolate' Pteromalidae develop at the expense of dipterous larvae and puparia. The subfamily Pteromalinae attack hosts belonging to several orders, the more plesiomorphic forms attack mainly beetles. In general the plesiomorphic forms of the family belong to two different ecological groups: the beetle parasites and the phytophagous species. it is, however, very difficult to judge from the morphology which of the two is more ancestral. Probably it is the phytophagous groups, but in that case phytophagy would seem to have a plesiomorphic character, not really useful in phylogenetic speculations.
​
Development of Larvae.
The larvae of practically all species are hymenopteriform with 13 distinct body segments, the head often large, and the integument bare except for three pairs of setae on each of the thoracic segments and two pairs on those of the abdomen, the four pairs of spiracles are situated on the second thoracic and the first three abdominal segments. There appears to be a variation among the species in the number of sensory setae. The body of Stenomalus micans is covered with minute integumentary setae, and the last abdominal segment is modified to form a "furca" which serves to hold the larva in a favored feeding position. Habrocytus sp. reared from braconid cocoons by Voukassovitch (1927) has a sucker like organ ventrally on the second thoracic segment, which is stated to serve a locomotory function. Merisoporus chalcidiphagus W. & R. has an additional pair of spiracles, which is on the third thoracic segment. Certain of the endophagous species, such as Pteromalus puparum, lack an open tracheal system.
The larva of Pirene graminea, described and figured by Kutter (1934), departs from the normal of the family and Is distinctly mandibulate in form. The head is large, the body segmentation indistinct, the integument without setae, and the large, extruded, falcate mandibles are very widely spaced and lie transversely. Marchal (1907) described a larva of similar form in Tridymus piricolaa Marchal.
First instar larvae of species that feed externally are usually very active, moving about readily on the body of the host and in the cell containing it. However, Smith (1930) found that larvae of D. dynastes which hatch from eggs not placed directly on the host, usually die without reaching it. In solitary species, there is a pronounced cannibalistic tendency, and the larva that hatches first often destroys any remaining eggs. In cases where a number are able to hatch, the youngest, due to its greater mobility, is usually victorious in the combat for the host. Such an elimination of surplus individuals seems necessary because of the indiscriminate oviposition of the parent female, which is apparently unable to recognize hosts that are already parasitized.
Many individuals of Pteromalus puparum develop within a single host pupa, which results in the colony being too large for the available food supply. Numerous dead larvae are often found at the extremities of the pupa, these having died from starvation (Hardy 1933). It is evident that the food material at these points is exhausted more quickly than at the middle of the body, as Faure (1926) found that development of individuals in the extremities of the host is retarded. But Voukassovitch (1926) concluded that the retardation in emergence of a portion of the brood is independent of nutrition. It was found that emergence from pupae that had been parasitized on known dates often extended over several months. This appears to be a larval diapause of uncertain duration and affects a varying portion of each colony. Clausen (1940) regarded it unusual for the individuals comprising a single colony of an internal parasitoid to emerge so irregularly, and noted that it contrasts sharply with the synchronous development and emergence of polyembryonic Encyrtidae, which encounter the same adverse conditions through overcrowding, etc. However, Legner (1969) found that a spread of emergence was characteristic of a number of parasitic Hymenoptera in several families even though oviposition was limited to a 24h period. The spread was the result of differential rates of development in different stages; and which stage differed varied with the species.
Some solitary ectophagous species show a considerable adaptability with regard to the size of host individuals upon which development can be successfully completed. Noble found that Habrocytus cerealellae, when developing on small Sitotroga larvae, is able to pass through the final larval stage without feeding and to attain the adult stage. In such cases the larval stage was prolonged with resulting adults of minute size.
The second instar larvae of all species are of simple form, with the sensory and integumentary setae reduced in size; the latter are often absent. The nine pairs of spiracles occur on the last two thoracic and the first seven abdominal segments. In H. cerealellae, only the four pairs that persist from the first instar are open immediately after the molt, and the additional five, which are smaller, appear later in the stage. The larva of P. graminea is indistinctly segmented, and the head is much reduced, with the mandibles small, curved, and very widely spaced.
The full complement of five larval instars has been described for Eupteromalus nidulans, E. fulvipes Forbes, Dibrachoides dynastes, Pachycrepoideus dubius Ashm., S. micans, and Merisus destructor Say. Dibrachys cavus and H. cerealellae, both of which have been studied in detail, apparently have only four, and Habrocytus sp. discussed by Dustan has only three. Kutter described only two for Pirene graminea, though his prepupa shows distinctive characters representing presumably a third instar.
The fourth instar larva of S. mican is distinguished from other larvae of the family by a heavily sclerotized boring armature on the head. This consists of a transverse plate with a serrate edge situated immediately above the labrum and one or two heavy conical spines on the median line below the antennae.
The mature larvae of the different species are uniform in their characters and present no general distinguishing features. The mandibles are simple, and the integument is smooth, with the sensory setae reduced in size. In H. cerealellae, there are three pairs of prominent spines at the end of the last abdominal segment. This species and Pseudocactolaccus asphondyliae, show pronounced intersegmental ridges dorsally. The tracheal system usually has nine pairs of spiracles, situated as on the second instar. However, Haviland (1922b) recorded 10 pairs for Asaphes vulgaris Wlk.; the first of these is situated on the intersegmental membrane between the first and second thoracic segments, and those following are on the third thoracic and the first eight abdominal segments. There is a vestigial tenth pair on the eighth abdominal segment in H. trypetae Thoms. The spiracles of S. micans first appear on the fourth instar, and rudimentary spiracular stalks are also present on the first thoracic and the eighth abdominal segments. Kutter's figure of the prepupa of Pirene graminea, which bears the external structures of the mature larva, shows the last segment produced into tubelike form and bearing two pairs of strong setae at the distal end. This tube is stated to be retractile.
Kearns describes an unusual development of the internal tracheal system in the endophagous first and second instar larvae of S. micans. Both instars possess the usual longitudinal trunks, with dorsal and ventral commissures at the anterior and posterior ends, respectively, and blunt spiracular stalks in the last two thoracic and the first eight abdominal segments. In addition, a pair of visceral tracheal trunks arise from the anterior commissure and extend over the dorsum of the intestine to the eighth abdominal segment, where they unite. These visceral trunks were not detected in the third to fifth instar larvae. A comparable modification of the tracheal system was not known in any other hymenopterous larva in 1940 (Clausen 1940).
Another departure from the normal respiratory system is described by Dustan (1923) for the larva of Habrocytus sp. parasitic in Rogas pupae. His description of that of the mature larva is as follows: " Perhaps the most amazing thing about this parasite is its immense tracheal system which, as was said previously, almost fills the body cavity. It has a tracheal trunk running down each side of the body and spiracles that can be made out under the 4 mm. objective, which appear to be closed, however; but more unusual than all, it possesses myriads of tracheids packed into every conceivable part of the body. These tracheids are collected into bundles or areas which are held in place by a definite wall or membrane. Just inside the wall of each bundle we find a ring of tracheids, varying somewhat in size but alike in having extremely thin walls. All the space inside the tracheids is packed with blood corpuscles and plasma, so that each bundle really consists of a tracheal sheath, the inside of which instead of being hollow is filled full of blood.... These tracheids open at the hypodermal wall and in this way secure an abundant supply of oxygen from the blood stream of the host. This oxygen is then carried in the tracheal bundles to all parts of the parasite and distributed by the blood stream to the different organs and tissues."
Stenomalus micans Ol., 4th instar larvae, which are parasitic in larvae of Chlorops taeniopus Meig., bears a specialized boring apparatus on its head that is used to break up the internal organs of the host and to effect emergence through the hardened shell of the host larva, which has died just as it was undergoing pupation (Kearns 1931). No feeding occurs during the 5th larval stage, which is very short in duration. Parasitism by Stenomalus results not only in appearance changes of the host larva, but in its activity. Healthy larvae move downward in a barley stem and, prior to pupation, turn about and ascent to a point just below where the leaf leaves the stem. Reddish-brown puparia are then formed. Parasitized individuals do not make this position reversal, and partly formed puparia are colourless.
Normally pupation in Pteromalidae occurs in the cell, cocoon or other cavity in which the host resided. However, Eupteromalus nidulans forms a naked pupa in the web of its lepidopterous host. Nasonia vitripennis pupae retain the larval exuviae about the posterior portion of the abdomen, and this, adhering to the meconium, attaches the pupa to the host puparium wall. Enargopelte ovivora Ishii is one of the few Chalcidoidea showing a tendency toward normal cocoon formation (Ishii 1928). Mature larvae, of which there may be circa 10 in the egg chamber of Lecanium sp., spin individual, yellowish-brown cocoons.
In some species many individuals are able to develop on a single host. Martelli (1907) recorded 165 adults of Pteromalus puparum from a single pupa of the cabbage butterfly, and Picard (1922) reared 212 males from the same host and 47 Tritneptis klugii Ratz. (= P. nematicidus Pack.) have been secured from a cocoon of Lygaeonematus erichsonii Htg. (Hewett 1912). Roubaud reared 105 N. vitripennis from a single dipterous puparium. Such figures undoubtedly represent maximums for which food material was available. However, in most gregarious species development to maturity is possible even if only a portion of the available food material is utilised. The different species of Dibrachys usually develop in numbers of <10 on each host, and all the recorded species of Habrocytus are solitary. Muscidifurax raptorellus K. & L. has both solitary and gregarious races, the habit being under the control of polygenic loci (Legner 1987d, 1988a, 1989b, 1991). The gregarious races produce individuals of a characteristic size (Kogan & Legner 1970).
Life Cycle
Pteromalids usually have short life cycles, averaging circa 3 weeks from egg to adult at room temperature. There was a minimum of 10 days recorded for Habrocytus cerealellae and Nasonia vitripennis. The females of many species require 1-2 days longer for development than do the males. The incubation of the egg requires from less than 1 day to 3 days, the larval stage 4-10 days and the pupal stage 4-14 days. A notable exception is E. ovivora, in which the egg, larval, and pupal stages take 7 days, 20 days and circa 11 months, respectively (Clausen 1940/1962).
The availability of suitable host stages influences the number of generations per year. Most species produce generation after generation as long as hosts are available, but some species are limited to a fixed number. E. ovivora has only one generation per year which corresponds to the host cycle. Pirene graminea and Stenomalus micans have two generations, as do their respective hosts. However, Aplastomorpha calandrae (Cotton 1923) and H. cerealellae are able to produce several generations to each one of the host. In these species there is no need for synchronization of the cycles of parasitoid and host, for they attack insects infesting stored grains which have all stages present continuously. Trineptis klugii has circa 6 generations each year on one brood of the host.
Most species that hibernate do so in the mature larval stage within the host cocoon, puparium or cell. But, Eupteromalus nidulans is found in the hibernation webs of the satin and brown-tail moths. E. ovivora, Rhopalicus suspensus Ratz., and Merisus febriculosus Gir. pass the winter in the pupal stage, while Dibrachoides dynastes and Pseudocatolaccus asphondyiiae Masi persist through the winter as adults. Other may pass winter as either mature larvae or adults.
A number of Pteromalidae are able to undergo long periods of inactivity as either larvae or adults when conditions are unfavorable. The relation of food to reproduction in Spintherus and Peridesmia was already noted, and it was shown that phasic castration in females may continue for a long time. This is one way of maintaining a species during periods of adverse conditions; another is larval diapause, such as is found in H. medicaginis Gahan and Nasonia vitripennis. In the former individuals have been observed to pass almost two years in the larval stage, as compared to the normal two weeks. Nasonia vitripennis may even pass several years in dipterous puparia when conditions are unfavorable (Clausen 1940/1962).
Adults live much longer than many other chalcidoid parasitoids. Species which normally pass the winter as adults are exceptionally hardy, and D. dynastes has been kept alive for >8 months at temperatures of 5-13°C. Species without diapause usually live 6-8 weeks.
​
Sex Ratio & Parthenogenesis
Females predominate in ratios up to 30:1 in Habrocytus medicaginis. Clausen (1940) noted that ratios for N. vitripennis vary from 1:1 to 10:1. The normal ratio for P. puparum is circa 2:1; but George (1927) noted a seasonal variation, the ratio being 2.8:1 in springtime and 1.1:1 in autumn. In H. cerealellae, the field sex ratio is circa 3:2. Experimental determinations give an increasing proportion of male progeny toward the end of the life of females (Clausen 1940/1962; Legner & Gerling 1967), even in thelytokous populations (Legner 1987c). Griswold (1929) recorded an excess of males in the ratio of circa 3:1 in some rearings of Asaphes americana from aphids collected in glasshouses.
Extended studies in thelytoky have been done on Muscidifurax uniraptor Kogan & Legner, showing the presence of extranuclear influences (Legner 1985a,b; 1987b,c; 1988c). Certain bacteria have been found in the male and female reproductive tracts which are capable of inducing endomitosis in unfertilized eggs, thereby causing them to be diploid and female (E. F. Legner unpub. data, R. Stouthamer unpub. data).
​
Cleoneminae (Pteromalidae)
The subfamily was once considered as a separate family, Cleonymidae. Pteromalidae now includes the former separate families, Cleonymidae, Miscogasteridae and Spalangiidae, which have been designated subfamilies Cleoneminae, Miscogasterinae and Spalangiinae, respectively. For the present, discussions of these various subfamilies will be separate because of considerable distinctness among them.
Three species for which some information is available are Schizonotus sieboldi Ratz. (Cushman 1917, Dowden 1939), S. paillotti F. & F. (Faure 1926) and Cheiropachys colon L. (Russo 1926, 1938).
Schizonotus sieboldi is gregarious and external on the pupae of Plagiodera versicolor Laich. and closely related chrysomalid beetles in the northeastern U.S. and Europe. Dowden (1939) indicated that it is an important factor in natural control of this host. Adult parasitoids occur in protected places and winter and attack the first brood of hosts in springtime. During oviposition the ovipositor is thrust beneath the pupa from the side, and one or more eggs are laid on the thorax between the appendages, although sometimes also on the abdomen or dorsum. Adult females feed upon host body fluids that exude from the puncture made in the dorsum after oviposition. Clausen (1940) commented that this is one of the few parasitic species that can develop externally upon exposed hosts, although the larvae are found between the body of the fixed host and the leaf, so that such conditions simulate the confined quarters of a burrow or cocoon.
Schizonotus paillotti differs from S. sieboldi in being hyperparasitic on some Lepidoptera through Apanteles in Europe. It is a solitary external parasitoid of the mature larva in the cocoon. Females feed on host body fluids prior to oviposition through a constructed feeding tube.
Solitary Cheiropachys colon parasitizes mature larvae of Scolytidae in Europe externally. Hosts are paralyzed at the time of oviposition, and the large egg is deposited on the body. Sex ratios favor females 5.5:1.
Immature Stages of Pteromalidae (Cleonyminae)
​
The eggs of Cleonymidae had been described for only the three species by 1940 (Clausen 1940). Those of S. paillotti and S. sieboldi are elongate-oval or somewhat cylindrical in outline, and that of C. colon is narrowed at both ends, with the anterior and drawn out into stalk-like form and at times folded back upon the main body after deposition. In S. paillotti and C. colon, the chorion is clothed with minute spicules though sparsely so in the last named species, whereas S. sieboldi bears instead a fine reticulation on one side.
The first instar larvae of the family are hymenopteriform, with small sensory setae and the integumentary setae may be uniformly distributed or in bands at the segmental margins. The respiratory system is equipped with spiracles on the mesothorax and first three abdominal segments.
The second to fifth instar larvae present no distinctive characters. The sensory setae and integumentary spines are minute. Nine pairs of spiracles appear on the fifth instar, these being situated on the second and third thoracic and the first seven abdominal segments.
​
Miscogasterinae (Pteromalidae)
​
A relatively small family with species of Tomocera, Scutellista, Aphobetoideus and Anysis being essentially predators on the eggs of lecaniine Coccidae. Miscogaster is an internal parasitoid of the larvae of leaf-mining Agromyzidae, and Megorismus is parasitic in Aphididae, and several genera are known from Hymenoptera. Some species of Dinarmus are known as solitary external parasitoids of the larvae of Tephritidae. Host preferences are varied, and host relationships include a wide range extending from predation on eggs and larvae of other insects to true internal and external parasitism. Miscogasteridae are closely related to the Pteromalidae.
Scutellista cyanea Motsch. has been used extensively in biological control. This parasitoid was originally introduced from Italy to Louisiana in 1898 to combat Ceroplastes and from South Africa to California in 1901 for biological control of black scale, Saissetia oleae Bern. Establishment occurred in some areas, and although the parasitoids became abundant, there was very little reduction in the host population density because the parasitoid larvae did not consume the entire batch of eggs beneath the host and consequently a sufficient number of survivors remained to infest trees. In California S. cyanea has largely replaced Tomocera californica How., which had similar habits and which previously had effected about the same degree of natural control.
​
Scutellista cyanea is predaceous on eggs of various lecaniine Coccidae contained in the cell beneath the parent female's body. When eggs are unavailable, the larva is able to develop as an external parasitoid of the female scale. Preferred hosts are Saissetia oleae and Ceroplastes rusci L., although occasionally Coccus and Phenacoccus, etc. are utilized.
During host selection the female shows a preference for mature females, usually those which have just laid a portion or all of their eggs. The scale is first examined with the antennae until the posterior arch is found, after which the position is reversed and the ovipositor is inserted by a backward thrust through the arch. Sometimes eggs are laid under scales from which all young have already emerged and also under those which have just completed the second molt and are without eggs. Normally the parasitoid eggs are found among those of the host, where they may be distinguished by their larger size and white color as compared to the pinkish host eggs. If no host eggs are present, the parasitoid egg adheres to the scale's ventral portion.
On hatching the young larva begins feeding on host eggs. At maturity a pupation cell is formed among the mass of empty eggshells and debris. The debris is matted together with small amounts of silk, which strands also bind the inner edge of the scale to the substratum. The meconium is case and pupation occurs. At emergence the adult parasitoid cuts a circular opening in the dorsum of the dead host, similar to but larger than those of true internal parasitoids. Old parasitized scales may adhere closely and remain on the tree longer than unparasitized scales. They may persist for 2-3 years.
The life cycle is about 41 days, of which 4-6 days are required for egg incubation, 15-21 days for the larval stage and 15-20 days for the pupa. Newly transformed adults may remain under the scale for several days before leaving.
Scutellista's seasonal cycle is correlated with the host. In areas of California where the host has a distinct annual cycle, the parasitoids are abundant only during June and July, for there is no suitable alternate host available in sufficient abundance to maintain a high density. Optimum conditions for the parasitoid require a continuous supply of maturing scales, condition which is approached only in coastal areas. There is no definite hibernation stage in California, and development continues, although at a reduced rate, through winter. In Italy there are circa 5 generations each year, the first being on Ceroplastes and the remaining four on Ceroplastes, Philippia and Saissetia.
​
On small Saissetia females, that can produce 500 eggs, a single parasitoid larva may consume the entire lot, thereby being able to halt reproduction. However, in large scales, which may deposit 2,500 or more eggs, only a portion can be consumed by a single parasitoid larva. Thus, control is considerable greater on small than large hosts (Clausen 1940/1962).
There are distinct biological forms which are not easily transferable from one host to the other. In Australia, the parasitoid attacks only Saissetia, while the African form is on Ceroplastes. The first introduction into the United States was of the wax-scale form from Italy to Louisiana, while the California introductions were of the black scale form from South Africa. Both of these hosts are heavily attacked in Italy, although it is not known if there are distinct parasitoid forms present.
Behavior of other Miscogasteridae attacking coccids is similar to that of Scutellista cyanea. Tomocera californica (Smith & Compere 1928) on the same host sometimes oviposits through the posterior arch and other times around the periphery of the scale. Like Scutellista the larva is able to develop as an external parasitoid of the female scale if eggs are unavailable. Aphobetoideus comperei Ashm. inserts the ovipositor underneath the lateral scale margin (Smith & Compere 1928).
Miscogaster sp. in France develops as a solitary internal parasitoid of the larvae of Agromyza mining the leaves of lucerne (alfalfa) (Parker & Thompson 1925). The ovipositor is inserted through the leaf surface and into the body cavity of the host. The tip of the egg stalk remains fixed in the puncture in the host integument, but the larva does not maintain a connection with it after hatching.
The behavior of immature stages of Systasis dasyneurae Mani differ in several respects from those of other Miscogasteridae by being predaceous on 2nd instar larvae of the midge, Dasyneura lini Barnes in linseed buds in India (Ahmad & Mani 1939). Eggs are deposited singly within the crumpled and unopened flower buds containing well developed midge larvae, although not always in their immediate vicinity. The newly hatched larva is active and in most cases quickly finds the midge larvae. The predators requires 3-4 midge larvae to complete development, but if more are present all are killed, although they are not completely consumed. Pupation is within the bud, and the cycle from egg to adult is 25-32 days at 18°C.
​
Immature Stages of Miscogasterinae
The ovarian eggs of the Miscogasteridae are of the two bodied type, but at deposition the anterior body disappears and only a stalk or peduncle remains. In Scutellista, Miscogaster and Anysis, this stalk or peduncle is circa 1/2 the length of the egg body; but in Aphobetoideus it is broad and stub like and in Tomocera nipple like and minute. The egg of Dinarmus dacicida Masi is ovate in form and lacks either a stalk or a peduncle.
The first instar larvae are hymenopteriform, with a variable number and arrangement of segmental spines. That of S. cyanea bears no spines whatever, while Miscogaster sp. has a complete ring of 30-40 heavy spines about each segment. In T. californica, there are only two pairs on each segment, whereas in Systasis dasyneurae three rows encircle each segment. Spiracles are found on the second and third thoracic and the second and third abdominal segments in Scutellista cyanea, on the second thoracic and first three abdominal segments in Anysis saissetiae, and on the second thoracic and first and fifth abdominal segments in T. californica. No spiracles are described or figured for Miscogaster sp., which is further distinguished from others of the family by the bilobed form of the last abdominal segment, each lobe terminating in a heavy spine.
The intermediate instar larvae have not been described for any species, nor has the number of stages been determined as of 1940 (Clausen 1940).
The mature larva has been described only for S. cyanea. The cuticular spines are minute or lacking and the respiratory system now possesses nine pairs of spiracles, situated on the last two thoracic and the first seven abdominal segments.
Spalangiinae (Pteromalidae)
​
Checklist of UK Recorded Pteromalidae
​
Ablaxia anaxenor (Walker, 1845)
Ablaxia megachlora (Walker, 1835)
Ablaxia parviclava (Thomson, 1878)
Ablaxia squamifera (Thomson, 1878)
Ablaxia temporalis Graham, 1969
Acrocormus semifasciatus Thomson, 1878
Aggelma spiracularis (Thomson, 1878)
Anisopteromalus calandrae (Howard, 1881)
Anogmoides fumipennis Askew, 1970
Anogmus strobilorum (Thomson, 1878)
Anogmus vala (Walker, 1839)
Apelioma pteromalinum (Thomson, 1878)
Apelioma restrictum Graham, 1961
Apsilocera bramleyi Graham, 1966
Ardilea convexa (Walker, 1833)
Arthrolytus discoideus (Nees, 1834)
Arthrolytus maculipennis (Walker, 1836)
Arthrolytus ocellus (Walker, 1834)
Asaphes suspensus (Nees, 1834)
Asaphes vulgaris Walker, 1834
Atrichomalus trianellatus Graham, 1956 Bairamlia fuscipes Waterston, 1929
Bairamlia nidicola Ferrière, 1934
Bugacia arenaria Erdös, 1946
Bugacia classeyi Boucek, 1965
Bugacia submontana Boucek, 1955
Caenacis divisa (Walker, 1836)
Caenacis inflexa (Ratzeburg, 1848)
Caenacis lauta (Walker, 1835)
Callimerismus fronto (Walker, 1833) Callimerismus suecicus Graham, 1969 Calliprymna bisetosa Graham, 1966
Callitula bicolor Spinola, 1811
Callitula ferrierei Boucek, 1964
Callitula pyrrhogaster (Walker, 1833)
Capella cecidomyiae (Ratzeburg, 1844)
Capella orneus (Walker, 1839)
Catolaccus ater (Ratzeburg, 1852)
Cea pulicaris Walker, 1837
Cecidostiba fungosa (Geoffroy in Fourcroy, 1785)
Cecidostiba geganius (Walker, 1848)
Cecidostiba hilaris (Walker, 1836)
Cecidostiba leucopeza (Ratzeburg, 1844)
Cecidostiba semifascia (Walker, 1835)
Cerocephala cornigera Westwood, 1832
Cerocephala rufa (Walker, 1833)
Cheiropachus quadrum (Fabricius, 1787)
Chlorocytus agropyri Graham in Graham & Claridge, 1965
Chlorocytus breviscapus Graham in Graham & Claridge, 1965
Chlorocytus deschampsiae Graham in Graham & Claridge, 1965
Chlorocytus diversus (Walker, 1836)
Chlorocytus formosus (Walker, 1835)
Chlorocytus harmolitae Boucek, 1957 Chlorocytus inchoatus Graham in Graham & Claridge, 1965
Chlorocytus laogore (Walker, 1839)
Chlorocytus longicauda (Thomson, 1878)
Chlorocytus longiscapus Graham in Graham & Claridge, 1965
Chlorocytus phalaridis Graham in Graham & Claridge, 1965
Chlorocytus pilosus Graham in Graham & Claridge, 1965
Chlorocytus pulchripes (Walker, 1836)
Chlorocytus spicatus (Walker, 1835)
Chlorocytus ultonicus Graham in Graham & Claridge, 1965
Chrysolampus rufitarsis (Förster, 1859)
Chrysolampus thenae (Walker, 1848)
Cleonymus laticornis Walker, 1837
Cleonymus obscurus Walker, 1837
Coelopisthia areolata Askew, 1980 Coelopisthia caledonica Askew, 1980
Coelopisthia extenta (Walker, 1835)
Coelopisthia pachycera Masi, 1924
Colotrechnus subcoeruleus Thomson, 1878
Conomorium patulum (Walker, 1835)
Coruna clavata Walker, 1833
Cratomus megacephalus (Fabricius, 1793)
Cricellius gracilis (Walker, 1836)
Cricellius repandus Graham, 1969
Cryptoprymna atra (Walker, 1833)
Cyclogastrella clypealis Boucek, 1965
Cyclogastrella deplanata (Nees, 1834)
Cyclogastrella flavius (Walker, 1839)
Cyrtogaster britteni Askew, 1965
Cyrtogaster vulgaris Walker, 1833
Dibrachoides cionobius Graham, 1969
Dibrachoides dynastes (Förster, 1841)
Dibrachys affinis Masi, 1907
Dibrachys boarmiae (Walker, 1863)
Dibrachys cavus (Walker, 1835)
Dibrachys fuscicornis (Walker, 1836)
Dibrachys linicola Graham, 1969
Diglochis sylvicola (Walker, 1835)
Dimachus discolor (Walker, 1836)
Dinarmus acutus (Thomson, 1878)
Dinotiscus aponius (Walker, 1848)
Dinotiscus colon (Linnaeus, 1758)
Dinotiscus eupterus (Walker, 1836)
Dinotoides tenebricus (Walker, 1839)
Dipara petiolata Walker, 1833
Dirhicnus pirus (Walker, 1839)
Ecrizotes filicornis (Thomson, 1876)
Ecrizotes longicornis (Walker, 1848)
Ecrizotes monticola Förster, 1861 Endomychobius endomychi (Walker, 1836)
Epicopterus choreiformis Westwood, 1833
Erdoesia tessellata Boucek, 1957
Erythromalus nubilipennis (Walker, 1835)
Eryturomalus rufiventris (Walker, 1835)
Eulonchetron scalprum (Askew, 1962)
Eulonchetron torymoides (Thomson, 1878)
Eumacepolus obscurior Graham, 1961
Eumacepolus pulcher Graham, 1961
Euneura augarus Walker, 1844
Eunotus cretaceus Walker, 1834
Eunotus parvulus Masi, 1931
Eupteromalus acuminatus Graham, 1969
Eupteromalus caricicola Graham, 1969
Eupteromalus exiguus (Walker, 1834)
Eupteromalus fucicola (Walker, 1835)
Eupteromalus hemipterus (Walker, 1836)
Eupteromalus lasiocampae Graham, 1969
Eupteromalus laticeps Graham, 1969
Eupteromalus littoralis Graham, 1969
Eupteromalus maurus Graham, 1969
Eupteromalus micropterus (Lindemann, 1887)
Eupteromalus peregrinus Graham, 1969
Eupteromalus pompilicola Graham, 1969
Eupteromalus potatoriae Graham, 1969
Eupteromalus scaposus Graham, 1969
Eupteromalus tigasis (Walker, 1939)
Gastracanthus pulcherrimus Westwood, 1833
Gastrancistrus ?pyrico/a (Marchal, 1907)
Gastrancistrus acontes Walker, 1840
Gastrancistrus acutus Walker, 1834
Gastrancistrus aequus Graham, 1969
Gastrancistrus affinis Graham, 1969
Gastrancistrus ainabocus Walker, 1848
Gastrancistrus alectus Walker, 1848
Gastrancistrus atropurpureus Walker, 1834
Gastrancistrus autumnalis (Walker, 1834)
Gastrancistrus clavatus (Thomson, 1876)
Gastrancistrus clavellatus Graham, 1969
Gastrancistrus coactus Graham, 1969
Gastrancistrus compressus Walker, 1834
Gastrancistrus coniferae Graham, 1969
Gastrancistrus consors Graham, 1969
Gastrancistrus crassus Walker, 1834
Gastrancistrus cupreus Graham, 1969
Gastrancistrus dispar Graham, 1969
Gastrancistrus fulvicornis (Walker, 1874)
Gastrancistrus fulvicoxis Graham, 1969
Gastrancistrus fumipennis Walker, 1834
Gastrancistrus fuscicornis Walker, 1834
Gastrancistrus glabellus (Nees, 1834)
Gastrancistrus hamillus Walker, 1848
Gastrancistrus hemigaster Graham, 1969
Gastrancistrus hirtulus Graham, 1969
Gastrancistrus indivisus Graham, 1969
Gastrancistrus laticeps Graham, 1969
Gastrancistrus laticornis Walker, 1834
Gastrancistrus latifrons (Thomson, 1876)
Gastrancistrus longigena Graham, 1969
Gastrancistrus obscurellus Walker, 1834
Gastrancistrus oporinus Graham, 1969
Gastrancistrus praecox Graham, 1969
Gastrancistrus puncticollis (Thomson, 1876)
Gastrancistrus pusztensis (Erdös, 1946)
Gastrancistrus salicis (Nees, 1834)
Gastrancistrus terminalis Walker, 1834
Gastrancistrus torymiformis (Ratzeburg, 1852)
Gastrancistrus triandrae Graham, 1969
Gastrancistrus unicolor Walker, 1834
Gastrancistrus vagans Westwood, 1833
Gastrancistrus venustus Graham, 1969
Gastrancistrus vernalis Graham, 1969
Gastrancistrus viridus Walker, 1834
Gastrancistrus vulgaris Walker, 1834
Gastrancistrus walkeri Graham, 1969
Gbelcia crassiceps Boucek, 1961
Glyphognathus flammeus (Delucchi, 1953)
Glyphognathus umbelliferae Graham, 1956
Gyrinophagus aper (Walker, 1839)
Habritys brevicornis (Ratzeburg, 1844)
Halticoptera aenea (Walker, 1833)
Halticoptera aureola Graham, 1972
Halticoptera brevicornis Thomson, 1876
Halticoptera circulus (Walker, 1833)
Halticoptera collaris (Walker, 1836)
Halticoptera crius (Walker, 1839)
Halticoptera flavicornis (Spinola, 1808)
Halticoptera hippeus (Walker, 1839)
Halticoptera laevigata Thomson, 1876
Halticoptera letitiae Askew, 1972
Halticoptera patellana (Dalman, 1818)
Halticoptera polita (Walker, 1834)
Halticoptera poreia (Walker, 1848)
Halticoptera violacea Askew, 1972
Hemitrichus seniculus (Nees, 1834)
Heteroprymna camma (Walker, 1848) Heteroprymna longicornis (Walker, 1835)
Hobbya kollari Askew, 1959
Hobbya stenonota (Ratzeburg, 1848)
Holcaeus calligetus (Walker, 1839)
Holcaeus compressus (Walker, 1836)
Holcaeus gorgasus (Walker, 1839)
Holcaeus stenogaster (Walker, 1836)
Holcaeus stylatus Graham, 1969
Holcaeus varro (Walker, 1839)
Homoporus apharetus (Walker, 1839)
Homoporus arestor (Walker, 1848)
Homoporus chalcidiphagus (Walsh & Riley, 1869)
Homoporus destructor (Say, 1817)
Homoporus febriculosus (Girault, 1917)
Homoporus fulviventris (Walker, 1835)
Homoporus gibbiscuta (Thomson, 1878)
Homoporus luniger (Nees, 1834)
Homoporus semiluteus (Walker, 1872)
Homoporus subniger (Walker, 1835)
Hyperimerus pusillus (Walker, 1833)
Isocyrtus laetus Walker, 1833
Janssoniella ambigua Graham, 1969
Janssoniella caudata Kerrich, 1957
Kaleva corynocera Graham, 1957
Lampoterma bianellatum Graham, 1969
Lampoterma viride (Thomson, 1878)
Lamprotatus annularis (Walker, 1833)
Lamprotatus brevicornis Thomson, 1876
Lamprotatus crassipes Thomson, 1876
Lamprotatus picinervis Thomson, 1876
Lamprotatus pschorni Delucchi, 1953
Lamprotatus simillimus Delucchi, 1953
Lamprotatus splendens Westwood, 1833 Lariophagus distinguendus (Förster, 1841)
Leptomeraporus nicaee (Walker, 1839)
Macromesus amphiretus Walker, 1848
Melancistrus mucronatus (Thomson, 1876)
Melancistrus specularis Graham, 1969
Meraporus alatus Walker, 1834
Meraporus allutius (Walker, 1848)
Meraporus crassicornis Kurdjumov, 1914 Meraporus gigon (Walker, 1848)
Meraporus graminicola Walker, 1834
Meraporus hebes (Walker, 1834)
Meraporus iners (Walker, 1834)
Meraporus micropterus (Förster, 1861)
Meraporus modestus (Walker, 1834)
Meraporus myle (Walker, 1848)
Meraporus pulex (Förster, 1861)
Meraporus temperatus (Walker, 1834)
Meraporus tenuiscapus (Förster, 1841)
Merismus lasthenes (Walker, 1848)
Merismus megapterus Walker, 1833
Merismus nitidus (Walker, 1833)
Merismus rufipes Walker, 1833
Merismus splendens Graham, 1969
Merisus splendidus Walker, 1835
Mesopolobus aequus (Walker, 1834)
Mesopolobus agropyricola von Rosen, 1960
Mesopolobus albitarsis (Walker, 1834)
Mesopolobus amaenus (Walker, 1834)
Mesopolobus anogmoides Graham, 1969
Mesopolobus aspilus (Walker, 1835)
Mesopolobus citrinus (Ratzeburg, 1848)
Mesopolobus clavicornis (Forster, 1878)
Mesopolobus diffinis (Walker, 1834)
Mesopolobus dubius (Walker, 1834)
Mesopolobus fasciiventris Westwood, 1833
Mesopolobus fuscipes (Walker, 1834)
Mesopolobus graminum (Hårdh, 1950)
Mesopolobus incultus (Walker, 1834)
Mesopolobus jucundus (Walker, 1834) see Mesopolobus sericeus
Mesopolobus laticornis (Walker, 1834)
Mesopolobus longicollis Graham, 1969
Mesopolobus mediterraneus (Mayr, 1903)
Mesopolobus mesostenus Graham, 1969
Mesopolobus morys (Walker, 1848)
Mesopolobus nobilis (Walker, 1834)
Mesopolobus phragmitis (Erdös, 1957)
Mesopolobus pinus Hussey, 1960
Mesopolobus prasinus (Walker, 1834)
Mesopolobus pseudofuscipes von Rosen, 1958
Mesopolobus pseudolaticornis von Rosen, 1966
Mesopolobus rhabdophagae (Graham, 1957)
Mesopolobus semiclavatus (Ratzeburg, 1848)
Mesopolobus sericeus (Förster, 1770)
Mesopolobus spermotrophus Hussey, 1960
Mesopolobus squamifer (Thomson, 1878)
Mesopolobus teliformis (Walker, 1834)
Mesopolobus tibialis (Westwood, 1833)
Mesopolobus xanthocerus (Thomson, 1878)
Metacolus unifasciatus Förster, 1856
Metastenus concinnus Walker, 1834
Micradelus acutus Graham, 1969
Micradelus rotundus Walker, 1834
Miscogaster elegans Walker, 1833
Miscogaster hortensis Walker, 1833
Miscogaster maculata Walker, 1833
Miscogaster rufipes Walker, 1833
Mokrzeckia obscurus Graham, 1969
Muscidifurax raptor Girault & Sanders, 1910
Nasonia vitripennis (Walker, 1836)
Neodipara masneri Boucek, 1961
Nephelomalus conspersus (Walker, 1835)
Nodisoplata diffinis (Walker, 1874)
Ormocerus latus Walker, 1834
Ormocerus vernalis Walker, 1834
Pachycrepoideus vindemmiae (Rondani, 1875)
Pachyneuron aphidis (Bouché, 1834)
Pachyneuron concolor (Förster, 1841)
Pachyneuron cremifaniae Delucchi, 1953
Pachyneuron formosum Walker, 1933
Pachyneuron groenlandicum (Holmgren, 1872)
Pachyneuron planiscuta Thomson, 1878
Pachyneuron vitodurense Delucchi, 1955
Pegopus inornatus (Walker, 1834)
Pegopus leptomerus Graham, 1969
Peridesmia congrua (Walker, 1836)
Peridesmia discus (Walker, 1835)
Perniphora robusta Ruschka, 1923
Phaenocytus glechomae (Förster, 1841)
Pirene bouceki Graham, 1969
Pirene chalybea Haliday, 1833
Pirene conjungens Graham, 1969
Pirene decipiens Graham, 1969
Pirene eximia Haliday, 1833
Pirene graminea Haliday, 1833
Pirene herbacea Graham, 1969
Pirene microcera (Haliday, 1844)
Pirene paludum Graham, 1969
Pirene penetrans (Kirby, 1800)
Pirene varicornis (Haliday, 1833)
Platneptis laeta (Walker, 1848)
Platygerrhus affinis (Walker, 1836)
Platygerrhus dolosus (Walker, 1836)
Platygerrhus ductilis (Walker, 1836)
Platygerrhus longigena Graham, 1969
Platygerrhus subglaber Graham, 1969
Platygerrhus tarrha (Walker, 1848)
Platygerrhus unicolor Graham, 1969
Plutothrix cisae Redqvist, 1966
Plutothrix coelius (Walker, 1839)
Plutothrix scenicus (Walker, 1836)
Plutothrix trifasciatus (Thomson, 1878)
Polycystus clavicornis (Walker, 1833)
Pseudocatolaccus nitescens (Walker, 1834)
Psilocera atra (Walker, 1834)
Psilocera crassispina (Thomson, 1878)
Psilocera obscura Walker, 1833
Psilonotus achaeus Walker, 1848
Psilonotus adamas Walker, 1834
Psilonotus hortensia Walker, 1846
Psychophagoides crassicornis Graham, 1969
Psychophagus omnivorus (Walker, 1835)
Pteromalus aeson Walker, 1848
Pteromalus albipennis Walker, 1835
Pteromalus altus (Walker, 1834)
Pteromalus apum (Retzius in Degeer, 1783)
Pteromalus aureolus (Thomson, 1878)
Pteromalus bedeguaris (Thomson, 1878)
Pteromalus berylli Walker, 1835
Pteromalus bifoveolatus Förster, 1861
Pteromalus brachygaster (Graham, 1969)
Pteromalus capreae (Linnaeus, 1761)
Pteromalus caudiger (Graham, 1969)
Pteromalus chlorospilus (Walker, 1834)
Pteromalus chrysos Walker, 1836
Pteromalus cioni (Thomson, 1878)
Pteromalus conformis (Graham, 1969)
Pteromalus decipiens (Graham, 1969)
Pteromalus dispar (Curtis, 1827)
Pteromalus dolichurus (Thomson, 1878)
Pteromalus elevatus (Walker, 1834)
Pteromalus grandis Walker, 1835
Pteromalus helenomus (Graham, I 969)
Pteromalus hieracii (Thomson, 1878)
Pteromalus intermedius (Walker, 1834)
Pteromalus isarchus Walker, 1839
Pteromalus janssoni (Graham, 1969)
Pteromalus mediocris Walker, 1835
Pteromalus microps (Graham, 1969)
Pteromalus musaeus Walker, 1844
Pteromalus myopitae (Graham, 1969)
Pteromalus ochrocerus (Thomson, 1878)
Pteromalus papaveris Förster, 1841
Pteromalus parietinae (Graham, 1969)
Pteromalus patro Walker, 1848
Pteromalus platyphilus Walker, 1874
Pteromalus procerus Graham, 1969
Pteromalus puparum (Linnaeus, 1758)
Pteromalus semotus (Walker, 1834)
Pteromalus sequester Walker, 1835
Pteromalus sophax Walker, 1839
Pteromalus squamifer Thomson, 1878
Pteromalus tereus Walker, 1839
Pteromalus tibiellus Zetterstedt, 1838
Pteromalus tiburtus Walker, 1839
Pteromalus tripolii (Graham, 1969)
Pteromalus vibenulus (Walker, 1839)
Rakosina deplanata Boucek, 1955
Rhaphitelus maculatus Walker, 1834
Rhicnocoelia constans (Walker, 1836)
Rhicnocoelia coretas (Walker, 1848)
Rhicnocoelia impar (Walker, 1836)
Rhopalicus brevicornis Thomson, 1878
Rhopalicus guttatus (Ratzeburg, 1844)
Rhopalicus tutela (Walker, 1836)
Rohatina denticulata Graham, 1969
Rohatina inermis Boucek, 1954
Roptrocerus mirus (Walker, 1834)
Roptrocerus xylophagorum (Ratzeburg, 1844)
Sceptrothelys deione (Walker, 1839)
Sceptrothelys grandiclava (Walker, 1835)
Sceptrothelys intermedia Graham, 1969
Sceptrothelys parviclava Graham, 1969
Schimitschekia populi Boucek, 1965
Schizonotus latus (Walker, 1833)
Schizonotus sieboldi (Ratzeburg, 1852)
Seladerma aeneum (Walker, 1833)
Seladerma annulipes (Walker, 1833)
Seladerma antennatum (Walker, 1833)
Seladerma berani (Delucchi, 1953)
Seladerma bicolor Walker, 1834
Seladerma breve Walker, 1834
Seladerma caledonicum Graham, 1969
Seladerma convexum Walker, 1834
Seladerma diffine (Walker, 1833)
Seladerma euroto (Walker, 1839)
Seladerma gelanor (Walker, 1839)
Seladerma geniculatum (Zetterstedt, 1838)
Seladerma laetum Walker, 1834
Seladerma parviclava (Thomson, 1876)
Seladerma sabbas (Walker, 1848)
Seladerma saurus Walker, 1848
Seladerma scaea (Walker, 1844)
Seladerma scoticum (Walker, 1833)
Seladerma simplex (Thomson, 1876)
Seladerma tarsale (Walker, 1833)
Semiotellus diversus (Walker, 1834)
Semiotellus fumipennis Thomson, 1876
Semiotellus laevicollis Thomson, 1876
Semiotellus mundus (Walker, 1834)
Skeloceras clavigerum (Thomson, 1876)
Skeloceras novickyi Delucchi, 1953
Skeloceras socium (Zetterstedt, 1838)
Skeloceras truncatum (Fonsco1ombe, 1832)
Spalangia cameroni Perkins, 1910
Spalangia crassicornis Boucek, 1963
Spalangia erythromera Förster, 1850
Spalangia nigra Latreille, 1805
Spalangia nigripes Curtis, 1839
Spalangia nigroaenea Curtis, 1839
Spalangia rugulosa Förster, 1850
Spalangia subpunctata Förster, 1850
Spalangiopelta alata Boucek, 1953
Spalangiopelta procera Graham, 1966
Spaniopus dissimilis Walker, 1833
Spaniopus peisonis (Erdös, 1957)
Sphaeripalpus fuscipes (Walker, 1833)
Sphaeripalpus laevigatus (Delucchi, 1953)
Sphaeripalpus laevis (Delucchi, 1953)
Sphaeripalpus microstolus (Graham, 1969)
Sphaeripalpus viridis Förster, 1841
Sphegigaster aculeata (Walker, 1833)
Sphegigaster brevicornis (Walker, 1833)
Sphegigaster glabrata Graham, 1969
Sphegigaster interstita Graham, 1969
Sphegigaster nigricornis (Nees, 1834)
Sphegigaster obliqua Graham, 1969
Sphegigaster pallicornis (Spinola, 1808)
Sphegigaster truncata Thomson, 1878
Spilomalus quadrinotata (Walker, 1835)
Spintherus dubius (Nees, 1834)
Staurothyreus cruciger Graham, 1956
Stenomalina continua (Walker, 1836)
Stenomalina dives (Walker, 1835)
Stenomalina epistena (Walker, 1835)
Stenomalina favorinus (Walker, 1839)
Stenomalina fervida Graham in Graham & Claridge, 1965
Stenomalina fontanus (Walker, 1839)
Stenomalina gracilis (Walker, 1834)
Stenomalina illudens (Walker, 1836)
Stenomalina laticeps (Walker, 1850)
Stenomalina liparae (Giraud, 1863)
Stenomalina micans (Olivier, 1813)
Stenomalina oxygyne (Walker, 1835)
Stenophrus compressus Förster, 1841
Stictomischus gibbus (Walker, 1833)
Stictomischus groschkei Delucchi, 1953
Stictomischus lamprosomus Graham, 1969
Stictomischus obscurus (Walker, 1833)
Stictomischus scaposus Thomson, 1876
Stictomischus tumidus (Walker, 1833)
Stinoplus etearchus (Walker, 1848)
Stinoplus pervasus (Walker, 1836)
Synedrus transiens (Walker, 1835)
Syntomopus agromyzae Hedqvist, 1972
Syntomopus incisus Thomson, 1878
Syntomopus incurvus Walker, 1833
Syntomopus oviceps Thomson, 1878
Syntomopus thoracicus Walker, 1833
Systasis angustula Graham, 1969
Systasis annulipes (Walker, 1834)
Systasis encyrtoides Walker, 1834
Systasis parvula Thomson, 1876
Systasis tenuicornis Walker, 1834
Telepsogina adelognathi Hedqvist, 1958
Theocolax formiciformis Westwood, 1832
Thinodytes cyzicus (Walker, 1839)
Tomicobia promulus (Walker, 1840)
Toxeuma acilius (Walker, 1848)
Toxeuma fuscicorne Walker, 1833
Toxeuma paludum Graham, 1959
Toxeuma subtruncatum Graham, 1959
Trichomalus apertus (Walker, 1835)
Trichomalus bracteatus (Walker, 1835)
Trichomalus campestris (Walker, 1834)
Trichomalus conifer (Walker, 1836)
Trichomalus coryphe (Walker, 1839)
Trichomalus curtus (Walker, 1835)
Trichomalus elongatus Delucchi & Graham, 1956
Trichomalus flagellaris Graham, 1969
Trichomalus fulvipes (Walker, 1836)
Trichomalus gracilicornis (Zetterstedt, 1838)
Trichomalus gynetelus (Walker, 1835)
Trichomalus helvipes (Walker, 1834)
Trichomalus inops (Walker, 1835)
Trichomalus inscitus (Walker, 1835)
Trichomalus lepidus (Förster, 1841)
Trichomalus lonchaeae Boucek, 1959
Trichomalus lucidus (Walker, 1835)
Trichomalus nanus (Walker, 1836)
Trichomalus oxygyne Graham, 1969
Trichomalus perfectus (Walker, 1835)
Trichomalus pexatus (Walker, 1835)
Trichomalus placidus (Walker, 1834)
Trichomalus posticus (Walker, 1834)
Trichomalus repandus (Walker, 1835)
Trichomalus robustus (Walker, 1835)
Trichomalus rufinus (Walker, 1835)
Trichomalus rugosus Delucchi & Graham, 1956
Trichomalus tenellus (Walker, 1834)
Tricyclomischus celticus Graham, 1956
Trigonoderus cyanescens (Förster, 1841)
Trigonoderus filatus Walker, 1836
Trigonoderus princeps Westwood, 1832
Trigonoderus pulcher Walker, 1836
Tritneptis klugii (Ratzeburg, 1844)
Trychnosoma punctipleura (Thomson, 1878)
Urolepis maritima (Walker, 1834)
Vrestovia fidenas (Walker, 1848)
Xestomnaster chrysochlorus (Walker, 1846)
Xiphydriophagus mayerinckii (Ratzeburg, 1848)
​
Legner (unpub. data) working with parasitoids of synanthropic Diptera has observed what he regards as a higher degree of intelligence among species of Spalangia than of various pteromalid parasitoids, as manifested by more intense searching of the host's environment and examination of the host prior to parasitization. Also, during numerous laboratory experiments with various species of this genus, they have shown a degree of learning toward the ultimate goal of escape from the experimental environment. After repeated handling their ability to feign death, for example, is remarkable, which frequently results in their escape from the observer.
​
There are only a few genera, of which Spalangia is the most commonly encountered. Richardson (1913) listed six species from dipterous hosts, one from Lepidoptera and two with myrmecophilous habits. The recording from the lepidopterous host is probably in error, for the species concerned, S. nigra Latr, has been frequently recorded from housefly puparia (Bou…ek 1963). Silvestri (1914) recorded several species from Trypetidae in West Africa. Those which attack Diptera utilize puparia and are solitary and external in habit. Clausen (1940) noted that these are parasitoids of dipterous pupae and consequently are considered hyperparasitoids only when the particular host species that they attack are themselves of parasitic habit, although S drosophilae Ashm., attacking dung-infesting Diptera, is recorded as attacking Alysia and Psilodora, which are primary parasitoids of the same hosts. Entomophagous Diptera which form their puparia on or near the soil surface are frequently attacked by Spalangiidae. Cerocephala develops on larvae and pupae of the coleopterous families Scolytidae, Curculionidae, etc. (Clausen 1940/1962).
Biology and Behavior
Richardson (1913) did an extensive study on S. nigroaenea Curtis (= S. muscidarum) as a solitary parasitoid of the pupae of housefly, Musca domestica L. In oviposition, the female crawls over the host puparium, examines it carefully with the antennae, and then inserts the ovipositor through the puparial wall, usually in the posterior half. The body of the larva or pupa within the puparium is not penetrated, and the egg is placed externally.
The 1st instar larva is very active and capable of extended movement over the surface of the host, which is for the purpose of finding a suitable feeding point, which usually proves to be the dorsum or dorsolateral areas of the abdomen (Gerling & Legner 1968). The pupal integument is much thinner at these points and is more easily punctured than elsewhere. The 2nd and 3rd instar larvae are relatively more fixed in their feeding positions in S. cameroni Perkins (Gerling & Legner 1968). When feeding is complete, the mature larva moves toward the anterior end of the puparium, casts its meconium and then pupates. The adult emerges through a hole cut in the anterior end of the puparium (Clausen 1940/1962).
An account of S. nigroaenea as a parasitoid of stablefly, Stomoxys calcitrans L. was given by Pinkus (1913), which differs in several respects from that by Richardson. Oviposition took place in the anterior portion of the puparium, usually through a suture. The female was able to detect prior parasitization and would not deposit a second egg on a host already bearing one. Many of the pupae attacked died, even though no egg was deposited, which would indicate that the body had been penetrated by the ovipositor. The adults mate soon after emergence, and females are able to deposit eggs the same day.
A minimum life cycle under cool laboratory conditions was found to be circa 88 days, but under warmer summer conditions outdoors the cycle is less than half this duration. Hibernation was thought to take place in any immature stage, and development progressed at any time that the temperature became higher again.
Spalangia parasitizing the pupae of Lyperosia were studied by Handschen (1932, 1934). These were S. sundaica Graham of Java and S. orientalis Graham from Australia. S. sundaica deposited an average of 160-170 eggs during a 4-weeks period. The cycle from egg to adult was completed in 18-21 days, and males emerged two days earlier than females. Adults were attracted to dung in which the hosts develop. S. orientalis had the same general habits and life cycle but produced an average of only 85 eggs during 15 days. These two "species" were hybridized in an effort to produce a more effective "race" that was better adapted to Australian conditions. Female S. orientalis when mated with male S. sundaica produced progeny more prolific than either parent form, the average egg deposition being 240 in 32 days. The reverse cross produced 100 eggs during 10 days. The fact that the hybrids were fertile and highly fecund, it is indicative that races instead of species had been studied. Yet Bou…ek (1963) considered S. orientalis a synonym of S. endius Walk. and S. sundaica a synonym of S. nigroaenea Curtis. During three decades of research on Spalangia and related genera, Legner (unpub. data) has never obtained hybrids between S. cameroni and S. nigroaenea. Studies with Australian Spalangia nevertheless have raised some interesting questions, as for example the reproductive isolation of a race of S. endius secured from the southeastern portion of the continent from that of morphologically indistinguishable isolates from North America. A morphologically and biologically distinct race from New Zealand, however, although isolated from the Australian isolate fully interbred with North American S. endius (Legner 1983).
In Cerocephala cornigera Westw., parasitoid of scolytid larvae and pupae, the female first paralyzes the host and then places an egg either directly on it or in its immediate vicinity. The ovipositor is usually inserted into the entrance of the host's oviposition tunnel.
Adult feeding habits in the family were studied by Lindquist (1936) who found that Spalangia muscidarum var. stomoxysiae paid little attention to artificial foods, and the length of life when confined with puparia suggested host feeding. Parker & Thompson (1925) found such feeding in S. nigra Latr, where they noted the construction of a feeding tube.
Life cycles in Spalangiidae are short, ranging from 17 days in S. muscidarum var. stomoxysiae and S. drosophilae to 25-30 days in C. cornigera. More than one generation is produced each year, and winter is passed in the mature larval stage, although Richardson found that S. muscidarum is in the pupal stage during winter.
The developmental life history of Spalangia cameroni Perkins was presented by Gerling & Legner (1968), with observations on physiology of ovum formation, and sperm translocation through the male reproductive system. Pertinent aspects treated in detail were host-feeding and selection, oviposition, superparasitization, length of developmental stages, oocyte development, ovisorption and sperm activation. Particularly interesting were the interinvolvement of host-feeding and oviposition, the high moisture requirement for embryonic development and the 100+ feeding punctures made by a larva while feeding ectophagously on the host pupa encased in the puparium. There was a prolongation of female pupal development with respect to the male, a deposition of partially resorbed eggs, two chambers in the seminal vesicle, and a short duration of testes function.
The sex ratio varies with environmental conditions (Legner 1967a,b; 1969, 1979a,b; Legner & Gerling 1967), but females tend to predominate in a ratio of 2:1 in S. muscidarum var. stomoxysiae. There has been no thelytoky discovered in this family.
​
Immature Stages of Spalangiinae
Clausen (1940) noted that the 1st instar larva is very active and capable of extended movement over the surface of the body of the host pupa. This is for the purpose of finding a suitable point for feeding, which varies, but usually is around the dorsum or dorsolateral areas of the abdomen. The skin of the pupa is much thinner at these points and more easily punctured than elsewhere. The 2nd and 3rd instar larvae have a fixed feeding position.
The eggs of Spalangia muscidarum and S. nigra are elongate ovate in outline and broader at the anterior end, which bears a nipple like protuberance. That of Cerocephala is of similar form except that the anterior protuberance is lacking.
The first instar larvae are hymenopteriform and elongate oval in outline and have a relatively large head. In S. nigra (Parker, 1924), each body segment bears a band of minute setae at the anterior margin. An open tracheal system is found in S. nigra with the spiracles occurring on the second thoracic segment, or on the membrane between the first and second, and on the first three abdominal segments. Richardson emphasized that not only does the first instar larva of S. muscidarum lack spiracles, but the intermediate and mature larvae are likewise apneustic.
The number of larval instars in the family is uncertain, with only three mentioned for S. muscidarum and four for S. nigra. The second and third instar larvae of the latter species bear nine pairs of spiracles, situated on the second and third thoracic and the first seven abdominal segments.
The mature larvae of the genus Spalangia are distinguished by the possession of distinct conical protuberances or tubercles at each dorsolateral margin of the first eight abdominal segments. A minute pair is found on the first thoracic segment. These tubercles have not been noted upon larvae of other genera. They are considered by Richardson to have neither an ambulatory nor sensory function, but appear to relate to prepupal growth. The mature larva of C. cornigera is more elongated than that of Spalangia, and each body segment bears four pairs of setae, those of the last segment being longest.
​
Pteromalidae species
Caenacis inflexa
The female wasp measures 2.4-4mm, averaging out at 2.8mm.
The head and thorax are dark green and bronze with gold tints. The bottom edge of the clypeus is clearly incised. The antenna are part way up the eye line, dark in colour with 6 funicular segments and a long conspicuous scape. The wings have well developed stigmal and post marginal veins and the basel cell has many microtichia (tiny hairs). The legs are brown tapering down to pale with 5 tarsel segments. They have a golden bronze gaster (abdomen).
​
The male wasp measures 1.8-2.7mm, averaging out at 2.4mm.
The head and thorax are very dark green with gold gleams. The bottom edge of the clypeus is clearly incised. The antenna are part way up the eye line, dark in colour with 6 funicular segments and a long bright conspicuous scape. The wings have well developed stigmal and post marginal veins and the basel cell has many microtichia (tiny hairs). The legs are brown tapering down to pale with 5 tarsel segments. They have a golden bronze gaster (abdomen).
​
​
​
Hobbya stenonota
Hobbya stenonata has a synonym and was at one time called H. kollari. It is a parasitoid of the family Pteromalidae. As such it parasitises many members of the gall forming family of Cynapidae such as;
Andricus kollari agamic,
Aphelonyx cericola agamic
and Biorhiza pallida sexual galls.
The flight times of this wasp are from March through to September.
The female measures from 1.5-2.9mm with an average of 2.1mm head and body.
​
The head is over sized and dark metallic gold green in colour and hairy. The face has fanned striae radiating out to the face and cheeks and is patterned by small reticulations. The eyes are largish and dark netral with toning in, and the ocelli are dark brown. The antennae have 2 rings and 6 funicular segments which are tranverse and brassy in colour. They are stout, short and tapered with dark sensillae and short, pale, decumbant hairs. The pedicel is short and fat whereas the dull yellow scape is long and set deep into the head.
​
The thorax is very dark metallic green and hairy with the notaulices incomplete. The tegulae are dark straw coloured and lead to the wings which are clear with mid neutral brown veins and neutral hairs. There is a wide marginal vein with a slight break (which is difficult to see) between the marginal and sub marginal veins. The stigmal vein is longish, with a visable sharp stigma. The legs have metallic reticulated coxae and femora with contrasting yellow trochanter, the rest being a pale translucent yellow and dark claws. There are 5 tarsi.
​
The gaster (abdomen) has the first segment a polished dark metallic green with the rest being a dark coppery bronze. It is heavily triangular from the side and is narrow but high with some faint microsculpture and is hairy at the edges and in bands across. The ovipositor sheaths are not visable.
​
The male measures 1.5-2.2mm averaging out at 1.8mm
​
The head again is oversized, reticulated dark metallic bronzey green and hairy with fanned striae radiating out to the face and cheeks. The eyes are largish and neutral brown, dark toning in with large pale ocelli. The antennae have 2 rings and 6 funicular segments which are brassy in colour. They are slightly longer than female antennae and slightly tapered with dark sensillae and short, pale, decumbant hairs. The pedicel is darker than the female and the dull yellow scape is set deep into the head.
​
The thorax is metallic bronzy green and hairy with the notaulices incomplete and barely visible. The dark neutral brown tegulae lead on to the wings which are clear with pale veins and neutral hairs on a transparent and wide marginal vein. A slight break (barely visible) between the marginal and the sub marginal vein. It has a longish stigmal vein with a visible sharp stigma. The legs have metallic reticulated coxae and dark brown femora tinged with metallic, yellow trochanter and joints with the rest being a biege/yellow and dark claws. There are 5 tarsi.
​
The gaster appears tiny and is pointed from above and from the side very thin. It is a shiney golden bronze and is hairy.
​
Mesopolobus amaenus
Mesopolobus amaenus is a parasitoid of the family Pteromalidae. As such it parasitises many
members of the gall forming family of Cynapidae such as;
Andricus corruptrix agamic,
A. curvator sexual and agamic,
A. kollari agamic,
A. lignicola agamic,
A. quercuscalicis agamic,
A. solitarius agamic
and Biorhiza pallida sexual galls.
​
The flight times of this wasp are from March to April then from June through to January.
​
The female measures from 2.3-2.8mm with an average of 2.6mm head and body.
​
The head is reticulated, largely hairless and coloured bright metallic gold green with the clypeus slightly notched at the centre of the margin. The eyes are red brown in colour and moderatly sized and the ocelli are pale red. The antennae are brown and blend into golden segments towards the club, which is the lightest part, and the heavy taper also blends smoothly into the club. The scape and pedicel are bright dark yellow and there 3 rings and 5 funicular segments.
​
The thorax is bright metallic green and largely hairless and reticulate with incomplete notaulicesand the pronotal collar has a ver large reticulation. The tegulae are pale yellow and lead to the wings which are clear with neutral hairs and veins and a long pale stigmal vein. The legs have coarsely reticulate metallic green coxae with brown femora and the rest being yellow, ecept for the bottom joints of the 5 tarsel segments and the claws.
The gaster (abdomen) is a glossy metallic gold green with bands of long hairs towards the rear and on the sides. The ovipositor sheaths are not visable.
​
The male measures 1.8-2.2mm averaging out at 2mm
​
The head is reticulated with some hairs and a bright metallic green in colour. there is a light notch in the centre of the clypeus margin with carina fanning out over the face. The eyes are large and red brown and the ocelli are also red brown. The antennae have 3 rings and 5 funicular segments that are a striking orange gold with the funicular segment 3 and the last 2 of the club being dark. The long and fat scape is orange and the pedicel is smaller.
The thorax is bright metallic green and largely hairless and with the pronotal collar having a large reticulation and the notaulices being incomplete. The tegulae are pale yellow and lead to the wings which are clear with neutral hairs and veins and a long pale stigmal vein. The legs have a coarsely reticulated metallic green coxae, with the rest being a pale bright yellow. The middle tibia is enlarged and there are 5 tarsel segments.
The gaster is slender from the side and the first segment is a glossy dark metallic green with the remainder being a dark brown bronze with a varible amount of dirty yellow just behind the first segment, which can vary from a vague central spot through to a narrow and ill defined band. There are bands of hair towards the back and on the sides.
​
Mesopolobus fasciiventris
This Chalcid parasitoid is a member of Pteromalidae and on Oak, parasitises;
Andricus corruptrix agamic,
A. curvator sexual,
A. kollari agamic,
A. lignicola agamic,
Cynips divisa agamic,
C. longeventris agamic,
C. quercusfolii agamic,
Neuroterus albipes agamic,
N. numismalis sexual
and N. quercusbaccarum agamic
and Diplolepis rosae on dogrose (Rosa canina)
This is from one account which is thought to be the first record in Europe, and was from a gall found by Toddy Cooper in Beer, Devon in 2005.
The female measures 2.2-3.7mm, averaging out at 2.6mm.
The head is bright metallic green, hairy and reticulate. The eyes are red brown with very pale red ocelli. The clypeus has a small incision on the margin. The antennae are yellow brown with a long yellow scape and a dark pedicel. There are 2 rings and 6 funicular segments, of which segments 5 and 6 are darker. The club is a paler yellow brown.
The thorax is a metallic bright green or metallic blue green, and hairy. The notaulices are incomplete and the mesepimeron is glossy on top and reticulate below. The tegulae are dark testaceous and lead to the wings which are clear. The veins and hairs are mid coloured and the stigmal and post marginal veins are long. The legs have reticulated metallic green coxae, with the rest of the legs being bright pale yellow. The tarsi have 5 segments.
The gaster (abdomen) is pointed and longer than the head and thorax. It is brilliant blue green in colour with bands of pale hairs at the segment edges. The ovipositor sheaths are not visible.
The male measures in at 1.8mm, with a range of 1.4-2.4mm.
The head is bright metallic green, hairy and reticulate. The eyes are red brown with very pale red ocelli. The antennae are bright yellow with 2 rings and 6 funicular segments.
The thorax is bright metallic green with blue tints and hairy. The notaulices are incomplete and the mesepimeron is glossy on top and reticulate below. The tegulae are pale yellow and lead to the wings which are clear with mid coloured veins and hairs and long stigmal and post marginal veins. The legs have reticulated metallic green coxae, with the rest of the legs being a glowing pale yellow with brown marks near the joints of all the tibiae. The middle tibiae have a highly visible dark, triangular projection at the end. The tarsi have 5 segments.
The gaster has a metallic green front, followed by a narrow band of yellow, which carries on round and below, with the last half of the gaster being brown. These markings are not as definate as the ones on Mesopolobus sericeus
​
Mesopolobus sericeus
This Chalcid parasitoid is a member of Pteromalidae and was peviously known as Mesopolobus jucunus. It is normally associated with Cynipidae galls on Oak were it has a succession of three or four generations per year and over winters as fully grown larva inside a gall. It is also a rare parasitoid of Diplolepis rosae with three records to date from Oxford in 1923, Northumberland in 1958 and County Durham in 1970. All three of these wasps from D. rosae were larger than the ones usually associated with Oak galls, but it is not thought that they are a new species.
​
In Oak it parasitises;
Andricus callidoma,
A corruptrix agamic,
A. curvator sexual,
A. grossulariae agamic,
A. inflator agamic,
A. kollari agamic,
A. lignicola agamic,
A. lucidus agamic,
A. quercuscalicis agamic,
A. quercusramuli agamic,
A. solitarius agamic,
Aphelonyx cerricola agamic,
Biorhiza pallida sexual,
Cynips disticha agamic,
C. divisa agamic,
C. longeventris agamic,
C. quercusfolii agamic,
Neuroterus anthracinus (=Andricus anthracinus) agamic,
N. numismalis sexual
and N. quercusbaccarum sexual
and Diplolepis rosae on Dog Rose (Rosa canina).
The female wasp measures in length 2.2-4mm averaging 3.1mm
​
The head is bright metalllic green and reticulated. The clypeus has a large marginal notch in
the centre. The eyes are bright red with a latticework of darker patches inside and the ocelli
are small and dark brown in colour. The antennae are brassy olive with darker joints and longitudinal sensillae, the long scape and pedicel are deep yellow with pale yellow hairs. The antennae have 2 rings and 6 funicular segments which are tapered to a slight but definate club.
​
The thorax is bright metallic green with the notaulices being three quarters length from the front. The tegulae are pale yellow and lead to the wings which are clear with pale veins and neutral hairs. The stigmal and post marginal veins are longish and the basel cell is bare. The legs have reticulated metallic green coxae, more or less brown on pale femora with the rest being smooth yellow, There are 5 tarsel segments and the claws are dark.
​
The gaster (abdomen) appears triangular from the side and is from metallic glossy green bronze thought to brilliant gold in colour. The ovipositor sheaths are not visible.
​
The male wasp averages 2.1mm with a range of 1.4-3mm in length
​
The head is reticulated and green/red metallic in colour. The clypeus has a large marginal notch in the centre. The eyes are red and the ocelli are small and red. The antennae are bright pale yellow with some tiny darker brown spots, There are 2 rings and 6 funicular
segments which are angled and tapering and there is a distinctive hooked tip to the club.
​
The thorax is punctate and reticulated. It is coloured metallic green, golden green or purple and blue. It is hairless except at the side and rear. The notaulices are incomplete. The tegulae are pale yellow and lead to the wings which are clear with pale hairs and veins. The stigmal vein is long and the basel cell is bare. The legs have reticulated metallic coxae with the rest being bright pale yellow. There are 5 tarsel segments.
​
The gaster is brown bronze and largely hairless but with a distinctive yellow shuttle mark on the back.
​
Pteromalus bedeguaris
​
A parasite of the bedeguar gall formed by Diplolepis rosae but is not host specific and will
hyperparasitise other species, including Othopelma mediator, Torymus bedeguaris and
​
The female wasp measures 2.2-4.7mm, averaging out at 3.5mm.
​
The head and thorax are black or dark metallic green. The bottom edge of the clypeus is
waved. The antenna are part way up the eye line, thick and neutral bronze in colour with 6
funicular segments. The wings have well developed stigmal and post marginal veins and the
basel cell is virtually bare. The legs are brown tapering down to pale with 5 tarsel segments. They have a golden bronze gaster (abdomen).
The smaller male is 1.7-3.4mm averaging 2.4mm.
​
The head and thorax are dark metallic blue/green with bronze tints. The antennae are part way up the eye line, brassy brown and have 6 funicular segments. The bottom edge of the clypeus is waved. The wings have well developed stigmal and post marginal veins as well as the basel cell being virtually bare. The legs are brown tapering down to pale with 5 tarsel segments. The gaster is dark brown, short and wide.
​
​
Cecidostiba fungosa
​
Cecidostiba fungosa (Geoffrey in Fourcroy 1785)
Synonyms of this wasp include; C. hilaris (Walker 1836) and C. leucopeza (Ratzburg 1844).
Cecidostiba fungosa is a parasitoid of the family Pteromalidae. As such it parasitises many members of the gall forming family of Cynapidae such as; Andricus corruptrix agamic, A. grossulariae sexual and agamic, A. kollari agamic, A. quercuscalicis agamic, A. quercusramuli sexual, Aphelonyx cerricola agamic, and Biorhiza pallida sexual galls.
The flight times of this wasp are from March to April then from February through to December.
The female measures from 1.7-3.3mm with an average of 2.6mm head and body.
The head is metallic bright green with a reticulated sculpture and black hairs with the clypeus notched. The eyes are large and red brown in colour and the ocelli are translucent pale brown. The antennae are brassy with 2 rings and 6 funicular segments which darken at the joints. The scape is long and translucent gold and pedicel is darker and flask shaped. The flagellum are slightly tapered with an enlarged club, conspicuous sensillae and pale hairs.
The thorax is bright metallic green with a reticulated mesoscutum with black hairs. There are no notaulices and the reticulated scutellum has 2 longitudinal rows of black hairs. The tegulae are neutral brown and lead to the wings which are clear with neutral brown long hairs and veins. The stigmal vein is long as is the post marginal vein. The stigma is as wide as it is long with a small uncus. The legs have coarsely reticulate metallic green coxae with contrasting yellow trochanter and trochantellus, a dark brown femora and the rest being pale yellow, except for the claws at the bottom of the 5 tarsel segments.
The gaster (abdomen) is segmented, the first segments is glossy metallic bronze green without sculpture, whereas the rest is dark bronze with light sculpture. The gaster is sessile and its shape is long and triangular from the side. The ovipositor sheaths are not visable.
The male measures 1.3-2.5mm averaging out at 1.9mm
The head is metallic bright green with a reticulated sculpture and black hairs with the clypeus notched. The eyes are large and brown in colour and the ocelli are translucent golden brown. The antennae are brassy with 2 rings and 6 funicular segments which darken at the joints. The scape is long and translucent gold and pedicel is darker and flask shaped. The flagellum are slightly tapered with an enlarged club, conspicuous sensillae and pale hairs.
The thorax is bright metallic green with a reticulated mesoscutum with black hairs. There are no notaulices and the reticulated scutellum has 2 longitudinal rows of black hairs. The tegulae are neutral brown and lead to the wings which are clear with neutral brown long hairs and veins. The stigmal vein is long as is the post marginal vein. The stigma is as wide as it is long with a small uncus. The legs have coarsely reticulate metallic green coxae with contrasting yellow trochanter and trochantellus, a dark brown femora and the rest being pale yellow, except for the claws at the bottom of the 5 tarsel segments.
The gaster (abdomen) is segmented, the first segments is glossy dark green without sculpture, whereas the rest is dark brown with sparse hairs. The gaster is sessile and its shape is mid width and shallow.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
​
​
Cecidostiba semifascia
​
Cecidostiba semifascia (Walker 1835)
Cecidostiba semifascia is a parasitoid of the family Pteromalidae. As such it parasitises many members of the gall forming family of Cynapidae such as; A. kollari agamic, A. quercuscalicis agamic, Aphelonyx cerricola agamic, Biorhiza pallida sexual and Neuroterus saliens sexual galls.
The flight times of this wasp are from March to April then from January through to September and then again in November.
The female measures from 1.7-3.3mm with an average of 2.6mm head and body.
The head is metallic bright green with gold tints, a reticulated sculpture in the clypeus among the striae and no notch. The eyes are large and yellow brown in colour and the ocelli are red brown. The antennae are brassy with 2 rings and 6 funicular segments which darken at the joints. The scape is long and translucent gold and pedicel is darker and flask shaped. The flagellum are not tapered but have conspicuous sensillae and decumbant hairs, and the club is not enlarged.
The thorax is bright metallic green with gold tints, a reticulated mesoscutum with black hairs. There are no notaulices and the reticulated scutellum has 2 longitudinal rows of black inward facing spines. The tegulae are dark brown and glossy, leading to the wings which are clear with a pale brown cloud behind the stigma, more or less depending on the individual and quite often not visible. The veins and hairs are dark. The stigmal vein is long as is the post marginal vein. The stigma is longer than it is wide, with a small uncus. The legs have reticulated metallic green coxae with contrasting yellow trochanter and trochantellus, a dark brown femora and the tibia being pale yellow with a darkened top (C. fungosa being all yellow). The 5 tarsel segments are yellow.
The gaster (abdomen) is segmented, the first segments is glossy dark metallic green, whereas the rest is dark bronze/purple. The gaster is sessile and its shape is triangular from the side. The ovipositor sheaths are not visable.
The male measures 1.2-2.5mm averaging out at 1.7mm
The head is metallic bright green with gold tints, a reticulated sculpture in the clypeus among the striae and no notch. The eyes are large and very dark neutral brown in colour with a paler ring around the circumference and the ocelli are large and red brown. The antennae are brassy with 2 rings and 6 funicular segments which darken at the joints. The scape is long and translucent gold and pedicel is darker and flask shaped. The flagellum are not tapered but have conspicuous sensillae and pale and decumbant hairs, and the club is not enlarged.
The thorax is dark metallic green with a reticulated mesothorax with black hairs. There are no notaulices and the reticulated scutellum has 2 longitudinal rows of black hairs. The tegulae are dark brown and glossy, leading to the wings which are clear with a pale brown cloud behind the stigma, more or less depending on the individual and quite often not visible. The veins are dark and the hairs are brown. The stigmal vein is long as is the post marginal vein. The stigma is longer than it is wide, with a small uncus. The legs have reticulated metallic green coxae with contrasting yellow trochanter and trochantellus, a dark brown femora and the tibia being pale yellow with a darkened top (C. fungosa being all yellow). The 5 tarsel segments are yellow.
The gaster (abdomen) is segmented, the first segments is glossy dark bronze brown without sculpture, whereas the rest has fine transverse sculpting. The gaster is sessile and its shape is long and thin from the side.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
​
Mesopolobus dubius
Mesopolobus dubius (Walker 1834) is a parasitoid of the
family Pteromalidae. As such it parasitises many members
of the gall forming family of Cynapidae such as; Andricus
corruptrix sexual and agamic, A grossulariae sexual, A. kollari sexual and agamic, A. lignicola sexual, A. quercuscalicis sexual, Biorhiza pallida sexual, Cynips divisa agamic, Neuroterus quercusbaccarum agamic and
Trigonaspis megaptera sexual galls.
The flight times of this wasp are from April to September
with records during January, February and November.
The female measures from 1.9-2.5mm with an average of
2.1mm head and body.
The wide and heavy head is heavily reticulated and
coloured a very dark metallic green bronze. The eyes are
dark brown in colour with a paler rim and the ocelli are red
brown. The antennae are brassy and tapered with a darker
club. The scape is long, deep and yellow and pedicel is
also long. There 3 rings and 5 funicular segments but they
are difficult to count.
​
The thorax is dark metallic green bronze with some golden tints. No
notaulices. The tegulae are testaceuous and lead to the wings which are
clear with pale yellow hairs and veins and long stigmal and post marginal
veins. The legs have metallic coxae with the remainder a mid brown yellow
with 5 tarsel segments.
The gaster (abdomen) is a glossy metallic green golden brown and is wide
and flat. The ovipositor sheaths are not visable.
The male measures 1.4-1.8mm averaging out at 1.7mm
The wide and heavy head is reticulated and a metallic green bronze in
colour. The eyes are neutral brown. The antennae have 3 rings and 5
funicular segments that are pale yellow, apart from segments 2 and 3 which are brown, and a very pale scape with a long brown pedicel.
​
The thorax is metallic green with no notaulices. The tegulae are testaceous
and lead to the wings which are clear with mid yellow hairs and veins and a long stigmal vein with a small stigma and a long post marginal vein. The legs have metallic coxae, with the rest being a pale yellow with dark claws. The middle tibia is enlarged and there are 5 tarsel segments.
The gaster is narrow from the side and wide from above. It is metallic green at the front followed with a yellow band across the middle and the remainder being a brown.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
​
Mesopolobus tibialis
Mesopolobus tibialis (Westwood 1833) is a parasitoid of the family
Pteromalidae. As such it parasitises many members of the gall forming
family of Cynapidae such as; Andricus albopunctatus agamic, A. corruptrix sexual and agamic, A. curvator sexual, A. grossulariae agamic, A. kollari sexual, A. lignicola sexual, A. quercuscalicis sexual and agamic, Biorhiza pallida sexual, Neuroterus albipes sexual and agamic, N. anthracinus sexual, N. numismalis sexual and agamic, N. quercusbaccarum sexual and agamic, N. tricolor sexual and Trigonaspis megaptera sexual galls.
The flight times of this wasp are from May through to December.
The female measures from 1.7-3.1mm with an average of 2.3mm head and
body.
The large and wide head is metallic bronze tinted green and reticulated.
The eyes are red brown in colour and the ocelli are small and red brown.
The antennae are brown yellow and tapered with a paler club. The scape
is long and yellow and pedicel is also long and yellow. There 2 rings and 6 funicular segments.
​
The thorax is metallic bronze tinted green. No visible notaulices and the tegulae are translucent yellow with a brown mark leading to the wings which are clear with pale yellow hairs and veins and longish stigmal and long post marginal veins. The legs are mid yellow with with veined fatter femora and the rear tibia are wide and flat with longitudinal red lines. There are 5 tarsel segments with darker claws.
The gaster (abdomen) is dark bronze green and glossy and is pointed. The ovipositor sheaths are not visable.
The male measures 1.5-2mm averaging out at 1.7mm
The wide reticulated head is metallic green, green gold or tinged with red. The eyes are large and red brown with pale red ocelli. The antennae are slender, hairy and have 2 rings and 6 funicular segments that are golden with a taper to a darker club, a long, pale yellow, banana shapped scape and a small yellow pedicel.
The thorax is metallic green gold with a faint impression of notaulices at the front. The tegulae are testaceous and lead to the wings which are clear with pale yellow hairs and veins and a long stigmal vein and a long post marginal vein. The legs mid yellow with with veined fatter femora. The middle tibia are enlarged with a black mark at the apex and the rear tibia are wide and flat with longitudinal red lines. There are 5 tarsel segments with darker claws.
The gaster is a glossy dark metallic bronze green at the base followed with a yellow fading into browny bronze. Some may have the appearance of M. sericeus shuttle mark although it is very vague in outline and not always present.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society
​
Mesopolobus xanthocerus
Mesopolobus xanthocerus (Thompson 1878) is a parasitoid of the family Pteromalidae. As such it parasitises many members of the gall forming family of Cynapidae such as; Andricus corruptrix sexual, A. fecundator sexual, A. grossulariae sexual, A. kollari sexual and agamic, A. lignicola sexual and agamic, A. quadrilineatus agamic, A. quercuscalicis sexual, Biorhiza pallida sexual and Neuroterus anthracinus sexual galls.
The flight times of this wasp are January and February then from April through to August.
The female measures from 1.9-2.5mm with an average of 2.1mm head and body.
The head is a dull metallic golden green and reticulated. The eyes medium to large and are a dull red brown in colour and the ocelli are tiny and brown. The antennae are brassy yellow and distinctly tapered with a long plae yellow scape and pedicel. There 3 rings and 5 funicular segments.
The thorax is dull metallic golden green. The notaulices are incomplete and the tegulae are dull straw coloured leading to the wings which are clear with pale yellow hairs and veins and longish stigmal and post marginal veins. The legs have reticulated metallic coxae with a large brown femur tapering to paler below. There are 5 tarsel segments with darker claws.
The gaster (abdomen) is pointed and is deep green shot dark bronze green with a shiney first segment and light sculpture on the remainder. The ovipositor sheaths are not visable.
The male measures 1.5-1.8mm averaging out at 1.7mm
The reticulated head is metallic bright green. The eyes are neutral brown. The antennae have 3 rings and 5 funicular segments that are deep yellow brown with a taper to a dark club, a long, pale yellow scape and pedicel.
The thorax is metallic bright green with the notaulices incomplete. The tegulae are dull straw coloured and lead to the wings which are clear with very pale hairs and veins and a longish stigmal vein and post marginal vein. The legs have reticulated metallic coxae with a large brown femur tapering to paler below. The middle tibia are enlarged with a black process on the outside edge near the apex. There are 5 tarsel segments with darker claws.
The gaster is metallic with a yellow band across the middle of the broad top. The gaster looks broad from above but thin from the side.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society
​