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Torymidae

Torymidae

Torymus bedeguaris female IMG_7672a_edited.jpg

Description & Statistics

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Torymidae is a moderately sized family. The family currently includes 68 genera and 986 species placed in 2 subfamilies, Megastigminae (12 genera with 174 species) and Toryminae (55 genera with 808 species). In the past the family had been referred to as the Callimomidae.

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Most Torymidae are solitary, primary, ectoparasitoids of gallicolous (gall-forming) cecidomyiid and cynipid larvae. A few species parasitize larvae of Lepidoptera, some species are found in the cocoons of moths and puparia of flies, as well as insect eggs. Typical phytophages are also present among torymids. The family has both phytophagous and entomophagous species, the latter predominating. They have not been used in biological control.

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A number of species are associated with seeds and plant galls. Some are phytophagous but the majority develop in various galls and are usually regarded as parasites, but some may be inquilines consuming the gall tissues and thus competing with the actual gall-maker. Xenostigmus species are recorded as gall-makers. Phytophagous species include seed-eaters belonging to the genera Megastigmus, Bootania, Bootanellus and Torymus. Other Megastigmus and Torymus, and some or all species of Neomegastigmus, Paramegastigmus, Mangostigmus, Torymoides, Liodontomerus and Odopoia are associated with various galls, mainly on leaves. A least 2 species of Megastigmus develop in figs, while others seem to be entomophagous. Four genera of the Podagrionini are parasitic in mantid eggs, species of Rhynchoticida and Chrysochalcissa attack heteropterous eggs. A few other Monodontomerinae parasitise the cocoons of Lepidoptera and Hymenoptera. Amoturoides was found to develop in a tachinid attacking polistine wasps. The Diomorus and Ecdamua species are associated with sphecid wasps in old burrows in dead wood and firm plant stems.

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Important morphological characters include;

They are metallic green or bronze, sometimes yellow, except for the Megastigminae, which are primarily yellowish or brownish, though often with black markings, and have complete, well-formed, parapsidal sutures, and a forewing with setal tracts.

Medium-sized chalcids with a body generally elongate, excluding ovipositor about 1.1-7.5mm in length, averaging 5mm, including ovipositor up to 16.mm in length

Cercal plates not flat, slightly raised and papillar in form

The ovipositor is exserted, thread-like, and often several times longer than the body.

a 12-13 segmented antenna with 1-2 annuli present.

Hind coxae are 3X larger than fore coxae, more or less triquetrous and triangular in cross section rather than round. Hind tibiae straight.

Petiole strongly transverse, not distinct

Stigmal vein very short (although sometimes with stigma very enlarged) so that apex of uncus almost touches anterior margin of forewing

Pronotum more or less long, attenuated slightly in front, or rectangular.

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2516090727_8e31b9a5f3_o_edited.jpg

Checklist of UK Recorded Torymidae

Classification: Torymidae (Family) chalcids

  • Cryptopristus caliginosus (Walker, 1833)
  • Diomorus armatus (Boheman, 1834)
  • Glyphomerus stigma (Fabricius, 1793)
  • Glyphomerus tibialis (Forster, 1859)
  • Megastigmus aculeatus (Swederus, 1795)
  • Megastigmus atedius Walker, 1851
  • Megastigmus bipunctatus (Swederus, 1795)  
  • Megastigmus brevicaudis (Ratzeburg)
  • Megastigmus dorsalis (Fabricius, 1798)
  • Megastigmus pictus (Forster, 1841)
  • Megastigmus pinus Parfitt, 1857
  • Megastigmus spermotrophus Wachtl, 1893
  • Megastigmus stigmatizans (Fabricius, 1798)
  • Megastigmus suspectus Borries, 1895
  • Monodontomerus aereus Walker, 1834
  • Monodontomerus obscurus Westwood, 1833
  • Monodontomerus obsoletus (Fabricius, 1798)
  • Monodontomerus rugulosus Thomson, 1876
  • Monodontomerus vicicellae (Walker, 1847)
  • Pseudotorymus apionis (Mayr, 1874)
  • Pseudotorymus frontinus (Walker, 1851)
  • Pseudotorymus medicaginis (Mayr, 1874)
  • Pseudotorymus militaris (Boheman, 1833)
  • Pseudotorymus nephthys (Walker, 1848)
  • Torymus aceris Boucek, 1994
  • Torymus affinis (Fonscolombe, 1832)
  • Torymus amurensis (Walker, 1874)
  • Torymus angelicae (Walker, 1836)
  • Torymus arundinis (Walker, 1833)
  • Torymus auratus (Moller, 1764)
    Torymus auratus (synonym) (Geoffroy in Fourcroy, 1785)
  • Torymus azureus Boheman, 1834
  • Torymus basalis (Walker, 1833)
  • Torymus baudysi Boucek, 1954
  • Torymus bedeguaris (Linnaeus, 1758)
  • Torymus brachyurus Boheman, 1834
  • Torymus breviscapus spec. nov.
  • Torymus calcaratus Nees, 1834
  • Torymus caledonicus spec. nov.
  • Torymus campanulae Cameron, 1880
  • Torymus caudatalus spec. nov.
  • Torymus caudatus Boheman, 1834
  • Torymus chlorocopes Boheman, 1834
  • Torymus chloromerus (Walker, 1833)
  • Torymus chrysocephalus Boheman, 1834
  • Torymus cingulatus Nees, 1834
  • Torymus confinis (Walker, 1833)
  • Torymus corni Mayr, 1874
  • Torymus cultiventris Ratzeburg, 1844
  • Torymus cupratus Boheman, 1834
  • Torymus curtesi nom. nov.
  • Torymus curticauda spec. nov.
  • Torymus cyaneus Walker, 1847
  • Torymus druparum Boheman, 1834
  • Torymus eadyi spec. nov.
  • Torymus erucarum (Schrank, 1781)
  • Torymus fagineus Graham, 1994
  • Torymus fastuosus Boheman, 1834
  • Torymus filipendulae spec. nov.
  • Torymus flavipes (Walker 1833)
  • Torymus formosus (Walker, 1833)
  • Torymus fuscicornis (Walker, 1833)
  • Torymus fuscipes Boheman, 1834
  • Torymus galeobdolonis spec. nov.
  • Torymus galii Boheman, 1834
  • Torymus geranii (Walker, 1833)
  • Torymus gloriosus spec. nov.
  • Torymus grahami Boucek, 1994
  • Torymus hederae (Walker, 1833)
  • Torymus heterobiae spec. nov.
  • Torymus heyeri Wachtl, 1883
  • Torymus hylesini Graham, 1994
  • Torymus igniceps Mayr, 1874
  • Torymus impar Rondani, 1877
  • Torymus juniperi (Linnaeus, 1758)
  • Torymus laetus (Walker, 1833)
  • Torymus lathyri spec. nov.
  • Torymus microcerus (Walker, 1833)
  • Torymus microstigma (Walker, 1833)
  • Torymus moelleri (Thomson, 1876)
  • Torymus nigricornis Boheman, 1834 misident
  • Torymus nigritarsus (Walker, 1833)
  • Torymus nitens (Walker, 1833)
  • Torymus nitidulus (Walker, 1833)
  • Torymus nobilis Boheman, 1834
  • Torymus notatus (Walker, 1833)
  • Torymus pallidicornis Boheman, 1834
  • Torymus paludum spec. nov.
  • Torymus pascuorum Boucek, 1994
  • Torymus perisicariae Mayr, 1874
  • Torymus phillyreae Ruschka, 1921
  • Torymus posticus (Walker, 1833)
  • Torymus pretiosus (Walker, 1833)E
  • Torymus problematicus spec. nov.
  • Torymus pulchellus Thomson, 1876
  • Torymus quadriceps spec. nov.
  • Torymus quercinus Boheman, 1834
  • Torymus regalis (Walker, 1833)
  • Torymus roboris (Walker, 1833)
  • Torymus rubi (Schrank, 1781)
  • Torymus salicis Graham, 1994
  • Torymus scutellaris (Walker, 1833)
  • Torymus spilopterus Boheman, 1834
  • Torymus stenus Graham, 1994
  • Torymus strenuus (Walker, 1871)E
  • Torymus tilicola Ruschka, 1921
  • Torymus tipulariarum Zetterstedt, 1838
  • Torymus ulmariae Ruschka, 1921
  • Torymus vallisnerii Cameron, 1901E
  • Torymus varians (Walker, 1833)
  • Torymus ventralis (Fonscolombe, 1832)
  • Torymus veronicae Ruschka, 1921


Citation: UK Species Checklist for Torymidae ; www.mapmate.co.uk/checklist

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The extent of this family has undergone several changes, especially since the description of some puzzling tropical forms. Earlier all chalcids with a long ovipositor were regarded as torymids but gradually it became evident that this character developed independently in several groups. More recently it was found that the true torymids have relatively long cerci (sometimes unnecessarily called 'pygostyles') and again some alien forms were misplaced in Torymidae, e.g. the pteromalid Roptrocerus Ratzeburg in the North American catalogues. For the same reason Ormyrus was removed from the family either to the pteromalids (Riek, 1970) or as a family of its own.

The limits of the family can now be settled by the presence or absence of the horseshoe-like occipital carina. The presence of this character clearly separates the torymids from other forms having protruding ovipositors, especially from the fig wasps, Agaonidae, unusual Pteromalidae, and also from the Chalcididae. The separation of torymids from chalcidids seemed sometimes vague because of the enlarged and toothed hind femora in Podagrionini, but these parasites of mantids are clearly torymoid and differ from Chalcididae by the presence of the occipital carina, long ovipositor together with the short last two tergites and long cerci, and by the absence of the genotemporal carina. The occipital carina does occur in some other groups, e.g. in Tetracampidae and in several subfamilies of Pteromalidae (Diparinae, Spalangiinae, Cerocephalinae, Asaphinae), so it can be regarded as a symplesiomorphy. However, in the evolutionary line of torymids it seems to be in harmony with other characters, such as the shortened stigmal vein compared with the long marginal vein; the relatively large hind coxae and their attachment to the thorax; the mentioned terminal terga with cerci; the complete notauli; the undifferentiated clypeal area; the invariably 13-segmented antennae, etc., although the occipital carina may become obliterated in some extralimital genera (absent in the American Erimerus Crawford), notauli become very shallow in a few species, the marginal vein may become shortened (e.g. extralimital Liodontomerus Crawford and Chalcimerus Steffan & Andriescu).  Notwithstanding this it seems reasonable to regard Torymidae as a monophyletic group as delimited here.

 

The horseshoe-like occipital carina should not be confused with a secondary transverse fold of some pteromalids, e.g. Trichomalopsis Crawford, Dibrachys Förster.  The mentioned terminal terga are abdominal terga IX and X, counted as gastral tergites 7 and 8, following the spiracle-beraring sixth tergite. In Torymidae the seventh tergite is dorsally extremely short but separated from the eighth tergite by a membranous line, on sides the membrane widens and bears the mobile elongate cercus with long sensorial setae.  The eighth tergite is also short, flap-like, often only weakly sclerotised.  it is followed by the membranous anus (faeces may be stuck there in some dead specimens) situated just above the base of the ovipositor and its sheaths.  This arrangement is similar to some forms of Agaonidae, but in these (e.g. Apocrypta) the cerci are moved ventrad and are placed within the sclerotized side part of the seventh tergite, and the occipital carina is invariably absent, the marginal and stigmal veins are different, etc.

 

Torymidae share one character with Agaonidae which seems to separate them both from Pteromalidae and from the groups regarded as possibly derived from the last family.  In torymids and agaonids (as here defined) the back of the head has the postgenae expanded to the median line so that the hypostomal margins are medially strongly constricted or even fused some distance below foramen magnum...  In pteromalids the hypostomal margins are generally almost straight from the mandibular base to the sides of the foramen.

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Immature Stages of Torymidae

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The normal egg form in the Torymidae is elongate-oval to kidney-shaped, with the anterior end broadest and terminating in a short, rounded protuberance (Clausen 1940, noted as Callimodidae).  The posterior end is somewhat attenuated, and in occasional instances it terminates in a sharp point.  The egg of Epimegastigmus brevivalvus described by Noble is markedly different, for it possesses a slender stalk about 2X the length of the egg body.  The illustrations of eggs of this species in different stages of embryonic development show the had of the larva at the end of the egg opposite the stalk, and the latter must thus be posterior, as opposed to its anterior position in the normal stalked egg of the superfamily.  In this species and in Callimome cyanimum, the chorion is unsculptured and glistening, while in Ditropinotus aureoviridisMonodontomerus aereus, Eridontomerus isosomatis and Callimome abbreviatus it is densely clothed with minute papillae except, in some species, for a small area at the posterior end.  These papillae often give the egg a grayish color.

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​The stalked type of egg described above for Epimegastigmus is of general occurrence among the phytophagous members of the family, although the stalk is normally at the anterior end.

Torymus affinis female 2314294902_d726e2

The 1st instar larvae are hymenopteriform, with 13 distinct body segments, and bear rather large, cylindrical antennae and sensory setae on the head, heavy and long sensory setae on the body segments, particularly the thorax, which may equal the length of several segments, and spiracles on the 2nd thoracic and 1st 3 abdominal segments.  Each body segment also bears a band of short integumentary setae.

 

Several species show departures in one or more characters from the above.  The larva of Epimegastigmus brevivalvus is very stout, is devoid of sensory and integumentary setae, and has no spiracles or internal tracheal system.  In D. aureoviridis, there are thought to be 5 pairs of spiracles, the additional pair being on the metathorax, and there are indications of this pair in Eridontomerus isosomatis, also.

 

Five larval instars have been observed and described in D. aureoviridis, E. isosomatis, M. aereus and Epimegastigmus brevivalvus.  In the first two species, the 2nd instar larvae are readily distinguished from the first by the reduction in size of the sensory setae and the absence of the bands of integumentary setae.  The sensory setae then become progressively larger and the integumentary setae more abundant in the following instars.  The full complement of spiracles appears on the 2nd instar larva, situated on the last two thoracic and the first seven abdominal segments.  In E. brevivalvus, the internal tracheal system is first evident in the 3rd instar, but open spiracles do not occur until the 5th.

 

The mature larva of most species bears heavy and long sensory setae and one or more rows of long integumentary setae in a band encircling each segment, giving it a distinctly hairy appearance.  In D. aureoviridis and Eridontomerus isosomatis, the head is also densely clothed with setae and spines of varying length.  The larva of Epimegastigmus brevivalvus bears a closer resemblance to those of the phytophagous members of the family, the integument being smooth and shining except for a transverse row of very minute setae on each segment.  That of P. pachymerum is distinguished by a heavy band of minute setae, set upon tubercles, on each segment.

 

In a considerable number of species, the mandibles of the 5th instar are simple, as are those of the earlier instars, but in E. brevivalvus they are tridentate, and in Megastigmus dorsalis F. and Epibootania nonvitta Gir. they are 4-dentate.

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Torymus bedeguaris female 2516103545_18c

Torymidae species

Torymus bedeguaris male 2415798317_5a855
Torymus auratus

Torymus auratus (=nitens)

A member of the family Torymidae, this wasp is parasitoid of cynipid wasps. Synonyms; T. nitens, T. nigricornis

 

The common gall hosts of this species are; 

Andricus curruptrix agamic,

A. fecundator agamic,

A. kollari agamic,

A. lignicola agamic,

A. quercuscalicus agamic,

Aphelonyx cerricola agamic,

Biorhiza pallida sexual,

Cynips divisa agamic,

C. longiventris agamic,

C. quercusfolii agamic,

Neuroterus quercusbaccarum sexual.

 

The flight times for this wasp are all year round.

Torymus auratus female 2516090727_8e31b9

The female wasp measures in at 2-5.3mm, excluding ovipositor, with an average of 3.5mm.

The head is a metallic blue-green, and reticulated. The eyes are quite large, red with an internal dark latticework and dark red-brown ocelli. The antennae have are dark grey-brown with longitudinal sensillae and a yellow marked scape. There is one ring and 7 funicular segments, with no obvious club.

The bright metallic green thorax has gold and red tints and sparse pale hairs. The mesoscutem is granulate and a high gloss coppery mesepimeron and deep full length notaulices. The tegulae are straw coloured leading to the wings which are clear and have mid yellow veins and hairs, with a very short stigmal vein with a well developed stigma and uncus. The legs are pale yellow, with metallic coxae, with a number of bright white hairs above the hind coxae. Metallic femora, sometimes bronze-green. and the tarsel segments, of which there are 5, are yellow.

The gaster (abdomen) is a bronzy metallic green. Triangular from the side, lightly punctate and shiney. The ovipositor sheaths are long dark brown and hairy.

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The male is 1.7-4.2mm averaging at 2.6mm in length.

The head is metallic green, sculputered with white hairs all over. The eyes are a very bright red with red ocelli. The antennae are dark grey-brown with no obvious club. The scape is all dark and the third segment is longer then the pedicle. There is one ring and 7 funicular segments covered in pale longitudinal sensillae.

The thorax is a metallic green, with light scuplting all over and covered in short hairs. Deep full length notaulices, like the female, and a rugose cross-striae mesoscutem, along with high gloss mesepimeron. The tegulae are neutral brown, and the wings are clear, slightly yellowish with hair all over and strong veining. The stigmal vein is very short with quite a heavy stigma. The legs are variable yellow with, from a metallic green rear coxae, to metallic green coxae, femora and tibia. The rest is brown with paler yellow joints. There are 5 tarsel segments. There are a number of hairs on top of the rear coxae.

The bronze gaster has a testaceous band in the final third, slightly hairy and lightly whirled and ridged all over.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

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Torymus affinis

Torymus affinis

A member of the family Torymidae, this wasp is a  parasitoid of cynipid wasps.

Synonym; Syntomaspis apicalis

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The common gall hosts of this species are; Biorhiza pallida sexual.

The flight times for this wasp are from April through to October.

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The female wasp measures in at 2-3.8mm, excluding ovipositor, with an average of 3mm.

The head is a bright metallic blue-green, sometimes strongly gold tinted, and sculptured with

white hairs. The eyes are medium sized, red-brown with red ocelli. The antennae have a metallic

green scape and pedicle, but the rest is dark bronze gold, with long sensillae. There is one ring

and 7 funicular segments.

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Torymus affinis female IMG_5050_edited.j

The metallic brilliant green thorax has white hairs. The mesoscutem is cross sculpured and a high gloss mesepimeron and short notaulices. The tegulae are dark leading to the wings which are clear and have mid yellow veins and hairs, with a very short stigmal and post marginal vein. The legs have brilliant green coxae, femora and the tibia and the tarsel sgments, of which there are 5, are yellow with darker ends.

The gaster (abdomen) is a brilliant metallic green with some translucent brown below. Triangular from the side, and with faint coriaceus microsculpure. The ovipositor sheaths extremely long and slender, often twice the body length. It has a dark top, with pale underneath and is hairy.

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The male is 1.3-3.3mm averaging at 2.3mm in length.

The head is metallic bright green, sometimes with a gold tint, and sculputered with white hairs.

The eyes are red/brown in colour and medium sized with red ocelli. The antennae have a metallic

scape and pedicle but the rest is neutral bronze and hairy. There is one ring and 7 funicular

segments.

The thorax is a metallic brilliant green, though some have golden lights, with white hairs. Short

notaulices, like the female, and a cross sculptered mesoscutem, along with high gloss

mesepimeron. The tegulae are dark and metallic, and the wings are clear with mid yellow veins

and hairs. The stigmal and post marginal veins are short. The legs have brilliant green coxae,

femora and the tibia and the tarsel segments, of which there are 5, are yellow with darker ends.

There are no hairs on top of the coxae.

The brilliant metallic gold-green gaster is short and tubular with a point.

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More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.

Torymus affinis female 2314294902_d726e2b3ef_o_edited.jpg
Torymus bedeguaris

Torymus bedeguaris

Classification ;

Parasitica,

Chalcidoidea,

Torymidae,

Toryminae,

Torymus bedeguaris.

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A hyper-parasite of Diplolepis rosae, the Bedeguar gall wasp, although it is not averse to parasitizing any inquilines or other hyperparasites that have already attacked the gall.

 

Torymidae are solitary, primary, ectoparasitoids of gallicolous (gall-forming) cynipid larvae. Important morphological characters include a 12-13 segmented antenna with 1-2 annuli present. Hind coxae are 3X larger than fore coxae. The ovipositor is exerted, thread-like, and often several times longer than the body. They are metallic green or bronze, and have complete, well-formed, parapsidal sutures, and a forewing with setal tracts. Fore wing with venation not

Torymus bedeguaris female 2516104563_71a

especially modified, the marginal vein long, much longer than the short stigmal and postmarginal veins. The hind femur is weakly to greatly swollen, the ventral margin with one or more teeth.

 

Torymidae share one character with Agaonidae which seems to separate them both from Pteromalidae and from the groups regarded as possibly derived from the last family. In torymids and agaonids, the back of the head has the postgenae expanded to the median line so that the hypostomal margins are medially strongly constricted or even fused some distance below foramen magnum.

 

Subfamily Toryminae, usually large, metallic greenish in colour with long ovipositors, sometimes with bronze or purple reflections. The body more or less finely sculptured, with the groove between mesopleuron and metapleuron (below hind wing) straight. The gaster is more or less compressed from side to side, not depressed so that the gaster is flattened dorsally.

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The female Torymus bedeguaris wasp measures in at (2.2-5.3mm), with an average of 4.0mm

excluding ovipositor. Its colour is bright metallic green from above but brilliant glossy bronze

from side. A brilliant coppery mesepimeron. A brilliant metallic green head with red eyes and

ocelli, dark brass-tinted antennae with 7 funicular segments. The legs are testaceous with all

bronze or green metallic front coxae (look only at the front coxa, not the trochanter below-which

is quite separate and may be yellow). The wings are clear and the stigmal vein is shorter than the

post stigmal vein. The gaster is metallic green with fiery-red or fiery-bronze tints over at least the

back and long, slender ovipositor sheaths. The ovipositor is actually longer than her body, this is

so long that when she lands on the gall, she can push it through the long tangled hairs and into

the hard woody shell. Then she lays her eggs and when the larvae emerge they feed as

ectoparasitoides on the Robin's Pincushion gall wasps Diplolepis rosae.

 

The male Torymus bedeguaris wasp measures in at (1.8-4mm), with an average of 3.0mm. Like

the female its colour is bright metallic green from above but brilliant glossy bronze from side. A

brilliant coppery mesepimeron. A brilliant metallic green head with red eyes and ocelli, dark

brass-tinted antennae with 7 funicular segments. The legs are testaceous or translucent-yellow

with all bronze or green metallic front coxae (look only at the front coxa, not the trochanter below

which is quite separate and may be yellow). The wings are clear and the stigmal vein is shorter

than the post stigmal vein. The gaster is metallic green with fiery-red or fiery-bronze tints.

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More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.

Torymus bedeguaris female IMG_7672a_edited.jpg
Torymus bedeguaris male 2416619108_4a322

Torymus erucarum

Torymus erucarum

A member of the family Torymidae, this wasp is parasitoid of cynipid wasps. 

 

The common gall host of this species is; Andricus quercusradicis agamic.

 

The flight time for this wasp is August. 

 

The female wasp measures in at 1.9-2.5mm, excluding ovipositor, with an average of 4.1mm.

The head is purple bronze, sculpted and with white hairs. The eyes are mid sized red/brown coloured. The antennae are very dark with a touch of metallic green and a hint of gold between the segments. The scape is yellow and brown. There is one ring and 7 funicular segments.

The thorax is metallic purple with white hairs and sculpted. The notaulices are deep and full length. The wings which are clear and have yellowish veins and hairs, with a very short stigmal and post marginal vein. The legs are pale yellow, with dark metallic purple green coxae. There are 5 tasel segments.

The gaster (abdomen) is a dark bronze/brown at the base, followed by a tesaceous yellow band that extends right round the body with a blob of brown at the top. Triangular from the side with a broad pointed top. The ovipositor sheaths are very long (about 138% body length) and dark brown.

 

The male is 2.7-3.1mm averaging at 2.8mm in length.

The head is purple bronze, sculpted and with white hairs. The eyes are mid sized red/brown coloured. The antennae are dark brown. The scape is yellow and dark brown. There is one ring and 7 funicular segments and the club is yellow and brown.

The thorax is metallic purple with white hairs and sculpted. The notaulices are deep and full length. The wings which are clear and have yellowish veins and hairs, with a very short stigmal and post marginal vein. The legs are pale yellow, with dark metallic purple green coxae. There are 5 tasel segments.

The bronze/brown gaster has a testaceous band runnign around the body but stopping at the top of the sides, which shows as a constriction in the darker colouring.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

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Torymus chloromerus

Torymus chloromerus

A member of the family Torymidae, this wasp is parasitoid of cynipid wasps.

 

The gall hosts of this species is; Macrodiplosis pustularis (=dryobia), which is a small non biting midge and member of the order Diptera. Although a lot is known about the gall and the larva, not a lot is known about the adult. The larvae is the causer of a gall on Oak leaves which is evident by a tight folding of the leaf lobe at the tip of a vein. It is green at first then turns brown and is evident from June to September. The gall contains a white larva.

 

The flight times for Torymus chloromerus are from May to July and the again in September.

 

The female wasp measures in at 2.5-2.9mm, excluding ovipositor, with an average of 2.7mm.

The head is a metallic green with some blue tints, and coriaceous. The eyes are moderatly large and red with large red ocelli. The antennae are dark brassy coloured with prominent pale sensillae and a yellow scape and metallic pedicel. There is one ring and 7 funicular segments, with a distinctive club.

 

The bright metallic green and blue thorax has plenty of short pale hairs. The  notaulices are full length. The tegulae are testaceous leading to the wings which are clear and have pale hairs and pale yellow veins, with a short stigmal vein and a long post marginal vein. The legs have bright metallic green coxae and femora, with brown tibia. The ends of each leg section and the joints are yellow and the tarsel segments, of which there are 5, are brown.

 

The gaster (abdomen) is a bright metallic green with blue. The underneath fades to a translucent testaceous colour. It is glossy with some sculpture in parts. The ovipositor sheaths are mid length (about 80% length of head and body), mid brown and hairy with short hairs.

 

The male is 1.5-2.6mm averaging at 2.2mm in length.

The coriaceous head is bright metallic green with strong white hairs. The eyes are moderatly large and red with large deep red ocelli. The antennae are brassy with a bright metallic scape and brown pedicel and prominent pale sensillae. There is one ring and 7 funicular segments leading to a distinctive club.

 

The thorax is a metallic green with occasional blue tints and sparse white hairs. Full length notaulices and the tegulae are dark and pale brown. The wings are clear, with unobtrusive hairs and pale yellow veins. It has a short stigma and a long post marginal vein. The legs have bright metallic green coxae and femora, with brown tibia. The ends of each leg section and the joints are yellow and the tarsel segments, of which there are 5, are brown.  

 

The gaster is variable in colour from all bright metallic green with some blue tints through to a mix with mid brown. It is narrow, deep and, of a compact shape.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.

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Torymus cyaneus

Torymus cyaneus

A member of the family Torymidae, this wasp is parasitoid of cynipid wasps.

Synonyms; Syntomaspis cyaneus

 

The common gall hosts of this species are;

Andricus quercuscalicis agamic, 

Cynips divisa agamic,

C. longiventris agamic,

C. quercusfolii agamic.

The flight times for this wasp are from May to July.  

 

The female wasp measures in at 2.6-4mm, excluding ovipositor, with an average of 3.4mm.

The head is a metallic green with a leathery sculpture and plenty of white hairs. The eyes are large and red large red ocelli. The antennae have are grey brown and covered in pale hairs. The scape is dirty orange and metallic on the side. There is one ring and 7 funicular segments.

The polished metallic green thorax has little scuplture and pale hairs.It has deep full length notaulices. The tegulae are blue green coloured leading to the wings which are clear and have colourless hairs and brown veins, with a very short stigmal vein. The legs have green metallic coxae and femora, brown tibia and yellow tarsi, of there are 5 segments.

The gaster (abdomen) is a brilliant metallic green and blue with variable amounts of testaceous beneath. The ovipositor sheaths are mid length (about 61% of body length) and dark.

 

The male is mm averaging at 2.mm in length.

The head is bright metallic blue green with a leathery sculpture and long white hairs. The eyes are large and red with red ocelli. The antennae are dark and there is one ring and 7 funicular segments covered in pale longitudinal sensillae.

The thorax is a bright metallic green and blue with traces of red and long white hairs. Deep full length notaulices, like the female. The tegulae are blue green, and the wings are clear, with pale veins and hairs. The stigmal vein is short with a strong stigma and a short but wide post marginal vein. The legs have metallic green coxae, femora and part of the tibia. The joints are pale and the basitarsus is yellow but the rest are dark. There are 5 tarsel segments.

The dark gaster has varying amounts of metallic green and rich blue. The first sement is smooth but the rest have a central line of long golden hairs as well as cross striae.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

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Torymus fastuosus

Torymus fastuosus

A member of the family Torymidae, this wasp is parasitoid of cynipid wasps.

Synonyms; Syntomaspis fastuosa

 

The common gall hosts of this species are;

Triginaspis megaptera sexual.

 

The flight times for this wasp is March.

The female wasp measures in at 3-3.9mm, excluding ovipositor, with an average of 3.6mm.

The head is a metallic bright green, sculpted with white hairs. The eyes are bright red. The antennae have are dark grey with longitudinal sensillae and a yellow/brown marked scape and metallic scape. There is one ring and 7 funicular segments.

The metallic coppery green thorax has white hairs and deep full length notaulices. The wings are clear with brown veins and hairs, with very short stigmal and post marginal veins. The legs have metallic copper coxae and femora, brown tibia and the tarsel segments, of which there are 5, are yellow.

The gaster (abdomen) is a high gloss copper metallic. It is triangular from the side and the ovipositor sheaths are hairy and moderate in length( about 66% of body length), dark brown above and pale yellow.

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The male is 1.9-3.1mm averaging at 2.6mm in length.

The head is metallic green, sculputered with white hairs. The eyes are bright red. The antennae are dark grey with a dark metallic scape and pedicel. There is one ring and 7 funicular segments covered in pale longitudinal sensillae.

The thorax is metallic green, sculptured with hairs and the notaulicesare deep and full length.  The wings are clear with brown veins and hairs, with very short stigmal and post marginal veins. The legs have metallic green coxae and femora, brown long, swollen tibia and the tarsel segments, of which there are 5, are yellow and banded yellow joints.  

The short and wide gaster is metallic green.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

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Torymus formosus

Torymus formosus

A member of the family Torymidae, this wasp is parasitoid of cynipid wasps.

Synonyms; T. amaenus

 

The common gall hosts of this species are; Andricus quercusradicis agamic.

The flight times for this wasp is August.

 

The female wasp measures in at 2.3-4.1mm, excluding ovipositor, with an average of 3.1mm.

The head is metallic green with gold hints and the eyes are mid size and brown with pale brown ocelli. The antennae are neutral brown apart from the first segment which is yellow. There is one ring and 7 funicular segments which are covered in short hairs.

The thorax is copper with gold and green tints, granular and hairy. It has deep full length notaulices and the tegulae are pale neutral brown. The wings are clear with mid brown veins and paler hairs. The stigmal vein is short and the post stigmal veins are shortish also. The legs are yellow brown with metallic green coxae. There are 5 tarsel segments.

The rounded gaster (abdomen) is polished coppery golden brown with a green metallic tinit in the first segment and the ovipositor is brown, hairy and of medium length (approximatly 66% of body length).

 

The male is about 3.4mm in length.

The head is metallic green and hairy with a leathery structure. The eyes are mid size and brown with large brown ocelli. The antennae are dark and have one ring and 7 funicular segments. The scape is long and the pedicel is short and round.

The thorax is metallic green with bronze tints and hairy. The notaulices are deep and full length and the tegulae are dark testaceous. The wings are clear with dark hairs and pale brown veins. The legs have reticulated metallic green coxae with the rest being golden yellow and hairy. There are 5 tarsi.

The gaster has a leathery microsculpture and the first segment is a glossy metallic dark green with the remainder being purple tinged.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

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Torymus flavipes

Torymus flavipes

Previously known as Torymus auratus (Geoffrey 1785) and renamed T. flavipes by Walker in 1833, this wasp is a parasitoid of the following gall causers;

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The female wasp measures 1.7-3.3mm which averages out at 2.5mm excluding the ovipositor.

The head is coriaceous, metallic green with red/brown tints. The eyes are large and bright red, however the ocelli are almost colourless. The antennae are dark brown with a yellow marked scape and pale sensillae running along the segments. There is one ring and 7 funicular segments which have a slight taper to the continuous club.

The Thorax is metallic gold green and bronze with the notaulices nearly full length. The tegulae are straw coloured which lead on to the wings which are clear and hairy, with pale brown hairs. The veins are yellow brown and although the stigmal vein is only short the stigma and uncus are both well formed. The legs have metallic green coxae with only afew long, pale hairs on the top of the rear pair. The rest of the legs are coloured pale yellow with 5 tarsel segments and darker claws.

The gaster (abdomen) is a shiny brilliant metallic gold green with visible segments that are lightly sculptured and punctured. It is thin from above and from the side view appears triangular. The ovipositor sheaths are hairy, dark above and yellow below, and are mid sized to about just over half of the body length.

 

The male measures in at 1.6-2.9mm with an average of 2.4mm

The head is slightly different from the female being coriaceous, bright metallic green and hairy. The eyes are large and bright red, however the ocelli are almost colourless, as in the females. The antennae are grey brown in colour, with a glossy pedicel and yellow markings on the scape and longitudinal sensillae. There is one ring and 7 funicular segments. Unlike the female the antennae are not tapered.

The thorax is a bright metallic green with some gold or bronze tinges. It is hairy and the notaulices are deep and full length. The tegulae are straw coloured leading to clear wings with grey brown hairs and pale yellow brown veins. The stigmal vein is short but the stigma is sizable. The legs have metallic green coxae with afew long, pale hairs on the top of the rear pair. The rest is yellow with dark brown or metallic markings on the middle of the femora and tibia, with bright yellow joints. There are 5 tarsel segments and darker claws.

The gaster is bright metallic green at the front, changing to bronze in the rear half with some hairs. It is slender from above but appears to be quite full from the side.

 

The flight times for this wasp are from March through to October.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.

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Andricus corruptrix agamic,

A. curvator sexual,

A. inflator sexual,

A. quadrilineatus agamic,

A. quercusramuli sexual,

A. seminationis agamic,

Aphelonyx cerricola,

Biorhiza pallida sexual,

Cynips disticha agamic,

Cynips divisa agamic,

Cynips longiventris agamic,

Cynips quercusfolii agamic,

Diplolepis eglanteriae,

Diplolepis mayri,

Diplolepis nervosa,

Diplolepis rosae ?,

Diplolepis spinosa,

Neuroterus albipes,

Neuroterus numismalis,

Neuroterus quercusbaccarum,

Neuroterus tricolor,

Plagiotrochus quercusilicis.

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It also parasitoid the following inquilines;

Periclistus brandtii,

Synergus albipes,

Synergus gallaepomiformis 

and Synergus nervosus.

 

Other parasitoids that it may be a hyperparasite of include;

Olynx arsames,

Pediobius lysis,

Eurytoma brunniventris,

Mesopolobus tibialis,

Syntomaspis notata and

Torymus notatus.

 

Other target species outside hymenoptera are Diptera and include; Cecidomyiidae -  Cecidomyia baccharicola, Dasineura asperulae,  Kiefferia pimpinellae, Putoniella marsupialis, Rabdophaga dubia. Tephritidae - 
Chaetostomella onotrophes, Urophora jaceana
and Urophora quadrifasciata.

 

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Torymus geranii

Torymus geranii

Previoulsy known as Torymus cingultus,  Torymus geranii is a member of the family Torymidae whose females are easy to distinguish from there bright metallic green colourations and very long ovipositors. The ovipositor is used to inject an egg into a gall chamber and the insects that they prey upon include;

Helicomyia saliciperda a member of the Cecidomyiidae family in the order of Diptera along with,

from the order of Hymenoptera

Andricus curvator sexual,

A. kollari agamic,

A.lignicola agamic,

A. quercuscalicis agamic,

Biorhiza pallida sexual,

Cynips divisa agamic,

Cynips longiventris agamic,

Diplolepis nervosa,

Dryocosmus kuriphilus,

Neuroterus anthracinus (=Neuroterus anthracina) agamic

and Trigonaspis synaspis.

 

As such the wasp tends to be located around Oaks, sweet chestnut and rose.

The flight times of T. geranii are from January through to October. 

 

The female measures 2.8-4.6mm averaging 3.4mm excluding the ovipositor.

The head is blue and green metallic in colour with hairy cheeks with red eyes and dark neutral brown ocelli. The short and stout antennae are dark brown with a yellow tinged scape and have one ring and 7 funicular segments.

The thorax is a metallic blue, bronze and green with deep full length notaulices and straw coloured tegulae. The wings are transparent with dark yellow brown veins and pale hairs. The stigmal vein is short but the stigma and uncus are well developed. The legs have metallic green coxae which are reticulated. The rear coxae have a fringe of long white hairs above. The rest of the legs are pale yellow and it has 5 tarsi.

The gaster (abdomen) is metallic green and bronze with more or less testaceous pink at the front and underneath. If no pink is present then it will probably be Torymus auratus. The ovipositor sheaths are dark brown and hairy and measure about 98% of the body length.

 

The male measures in at an average of 2.5mm with a range of 1.5-4.2mm.

The head is metallic green and lightly sculptured. It has short hairs all over. The eyes are bright red with chestnut to dark coloured ocelli. The antennae are dark grey brown with pale longitudinal sensillae and there is a yellow socket to the scape. The 3rd segment is shorter than the pedicel (see T. auratus).

The thorax is metallic green and covered in short hairs. The notaulices are deep and full length The tegulae are straw coloured leading to the wings which are slightly yellowish and hairy all over. The veining is strong a stigmal vein is very short with a quite heavy stigma. The legs are variable in the coxae, of which the rear pair have many long white hairs above, which range from reticulate metallic green rear coxae only, the rest being brown, to all metallic coxae, femora and tibia, with pale yellow joints. The remainder of the legs are a variable yellow and there are 5 tarsel segments. 

The gaster is hairy, lightly whirled and ridged all over with a bronze colouring and a testaceous band near the base.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.

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Torymus nobilis

Torymus nobilis

A member of the family Torymidae, this wasp is parasitoid of cynipid wasps.

 

The common gall hosts of this species are; Andricus quercusradicis agamic,

A. testaceipes agamic,

Biorhiza pallida sexual,

Diplolepis rosae.

 

The flight times for this wasp is February to May and again in September.

 

The female wasp measures in at 2.5-3.3mm, excluding ovipositor, with an average of 3mm.

The head is sculpted and dark metallic green with purple tints and white hairs. The eyes are red and the antennae are dark neutral brown with long sensillae and a yellow/brown scape. There is one ring and 7 funicular segments.

The thorax is a dark metallic purple/green with white hairs and sculptured with the notaulices being deep and full length. The wings are clear with mid brown veins and hairs. The stigmal veinn is shortish and the post marginal vein is also short. The legs have metallic purple coxae with testaceous ends with the rest being mid yellow brown. There are 5 tarsal segments.

The gaster (abdomen) is testaceous with a darker top at the base or with a band of purple bronze at the front and rear. The ovipositor sheath is mid length at 58% body length. It is hairy and dark brown at the top and paler below.

The male is 1.8-2.9mm averaging at 2.1mm in length.

The head is sculptured and very dark purple metallic with white hairs and red eyes. The antennae are all dark, hairy and with sensillae.

The thorax is again dark metallic purple, sculpted with white hairs and deep full length notaulices. The wings are transparent with mid brown hairs and veinswith short stigmal and post marginal veins. The legs have a metallic purple coxae with a pale end and the rest being brown/yellow and with 5 tarsi.

The gaster is quite long, broad and pointed. It is testaceous, banded with brown and with tinting to purple at the rear and a short patch of purple at the front.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

 

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Torymus rubi

Torymus rubi

This wasp is a parasite of Diastrophus rubi although it has been recorded exiting bedeguar galls on numerous occasions.

 

The female measures 1.8mm-4mm, averaging at 3.2mm in length, excluding the ovipositor

The wasp has a brilliant metallic green body with the mesepimeron being all copper in colour. The legs are translucent yellow with 5 tarsal segments. The coxae are green with at least the lowest part being yellow and the hind coxae being at least twice the length of the middle coxae. The wings are clear with the stigmal vien shorter than the post stigmal vein. The antennae are dark brassy or black with 7 funicular segments. The ovipositor sheaths are longish (mid length compared to other torymids) at about 70% of body length.

 

The male measures 1.8-2.9mm averaging at about 2.3mm

The wasp has a brilliant metallic green head and thorax with the mesepimeron being all copper in colour. The gaster (abdomen) is green and sometimes slightly tinted with bronze at the rear. The legs are translucent yellow with 5 tarsal segments. The coxae are green with at least the lowest part being yellow and the hind coxae being at least twice the length of the middle coxae. The wings are clear with the stigmal vien shorter than the post stigmal vein. The antennae are dark brass tinted with 7 funicular segments.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

 

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Torymus scutellaris

Torymus scutellaris

A member of the family Torymidae, this wasp is parasitoid of cynipid wasps.

Synonyms; T. pleuralis

 

The common gall hosts of this species are;

Andricus quercusradicis agamic,

Neuroterus saliens sexual.

 

The flight times for this wasp april to may.

 

The female wasp measures in at 2.3-3.5mm, excluding ovipositor, with an average of 2.9mm.

The head is golden tinted metallic green, reticulated and hairy with large red brown eyes. The antennae are long and fairly slender, dark grey brown in colour and hairy. There is one ring and 7 funicular segments.

The thorax is bright metallic green with pale hairs and complete notaulices. The tegulae are testaceous leading on to the wings which are clear with pale hairs and veins, a short stigmal vein but a longer postmarginal vein. The legs have metallic green coxae that fade to pale yellow at the end, the rest is all pale yellow and hairy with 5 tarsal segments and dark claws.

The gaster (abdomen) is deep and triangular from the side with fine microsculpture and hairy. The front half is semi glossy testaceous with the rear half being metallic green and the longish (about 80% body length) ovipositor being slender and dark brown in colour.

 

The male is about 2mm in length.

The head is darker metallic green than the female but is also reticulated and hairy. The eyes are red brown and mid sized. The antennae are mid brassy gold with one ring and 7 funicular segments and the scape has a paler yellow base.

The thorax is also darker metallic green than the female with light hairs and complete notaulices. The tegulae are testaceous and lead to clear wings with pale veins and hairs, a short stigmal vein but longer post stigmal vein. The legs have brown coxae which tapers down through the femora to the pale yellow tibia and 5 tarsel segments, with pale hairs and dark claws.

The gaster is hairy, wide and dull. The front is testaceous with a brown end.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

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Torymus microstigma

Torymus microstigma

This wasp has been recorded in bedeguar galls but it is very rare in these. The first record in Europe was by Toddy Cooper in 2005 in Beer, Devon. This was followed a year later in Somerset near Taunton.

 

The female measures 2.1-3.6mm, averaging at 3.1mm in length, excluding the ovipositor.

The wasp has a brilliant metallic green body with the mesepimeron being green in colour, with or without some bronze below. The legs are metallic and pale yellow with 5 tarsal segments. The front coxae is all metallic green and the hind coxae being at least twice the length of the middle coxae. The wings are clear with the stigmal vien shorter than the post stigmal vein. The antennae are dark with 7 funicular segments. The gaster (abdomen) is bright metallic green with bronze tints. The ovipositor sheaths are comparatively short compared to other torymids at about 45% of body length.

 

The male measures 1.8-2.9mm averaging at about 2.3mm

The wasp has a dark metallic green head and thorax with the mesepimeron being green, with or without some bronze below. The gaster (abdomen) is darker green brown. The legs are brown and pale with 5 tarsal segments. The front coxae are all metallic green and the hind coxae being at least twice the length of the middle coxae. The wings are clear with the stigmal vein shorter than the post stigmal vein. The antennae are thick and dark with 7 funicular segments.

 

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.

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Torymus notatus

Torymus notatus

A member of the family Torymidae, this wasp is parasitoid of cynipid wasps.

Synonyms; Syntomaspis notata. 

 

The gall hosts of this species are; Andricus curvator sexual.

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The flight times for this wasp are April to May. The female wasp measures in at 1.8-2.8mm, excluding ovipositor, with an average of 2.4mm.

 

The head is a bright metallic green, copper and blue, sculpted and with white hairs. The eyes are red brown. The antennae have golden brown funicles, of which there are 7 and one ring, and a metallic scape and pedicel with sensillae. The antennae is heavy but not tapered.

 

The bright metallic green thorax has copper and blue tints and white hairs. The thorax is sculpted and the notaulices are full. The scutellum has a transverse furrow. The wings which are clear and have yellow brown veins and hairs, with a short stigmal and post marginal vein with hairy fringes. The legs have metallic coxae and femorea, a dark brown tibia and the tarsel segments, of which there are 5, are pale.

 

The gaster (abdomen) is a glossy metallic green bronze with a testaceous streak underneath and is pedunculate. The ovipositor sheaths are moderate in length, about 65% body length, and dark brown and hairy.

 

The male is 1.5-1.9mm averaging at 1.7mm in length.

 

The head is bright metallic green, copper and blue, sculpted with white hairs. The eyes are red brown. The antennae are dark metallic bronze with a light green scape and pedicel. Heavy but not tapered. There is one ring and 7 funicular segments covered in pale longitudinal sensillae.

 

The thorax is a bright metallic green, copper and blue with scuplting and white hairs. Deep full length notaulices and the scutellum has a transverse furrow. The wings are clear with yellow brown veins and hairs. The stigmal vein is short, as is the post marginal vein. The legs have metallic coxae, femora and tibia. There are 5 pale tarsel segments.

 

The metallic green brown gaster is tiny and triangular.

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More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

 

 

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Torymus roboris

Torymus roboris

 

Torymus roboris (Walker 1833) A member of the family Torymidae, this wasp is parasitoid of cynipid wasps.

 

The common gall hosts of this species are; Biorhiza pallida sexual.

 

The flight times for this wasp is September.

 

The female wasp measures in at 2.8-4.1mm, excluding ovipositor, with an average of 3.4mm.

 

The head is a dark purple and smooth with a pattern of pale hairs. The eyes are medium to large and dark in colour with large brown ocelli. The antennae are dark bronze with a long orange scape, and a small pedicel that is marked with orange. There is one ring and 7 funicular segments, which are tapered and well seperated.

 

The dark metallic purple thorax has traces of green and deep full length notaulices. The tegulae are testaceous leading to the wings which are clear but have a brown tinted appearance due to the deep brown hairs. The veins are also deep brown. The legs are all brilliant orange except for the rear coxae which is part brown. There are 5 tarsel segments.

 

The gaster (abdomen) is testaceous at the front which shades into dark purple for the rest and has pale hairs. The ovipositor sheaths are longish, about 79% body length, and dark with bronze tints.

 

The male is about 2.2mm in length.

 

The head is a dark with purple notes and pale hairs. The eyes are large and dark in colour with translucent pale ocelli. The antennae are heavy and all bronze with a long reticulated scape, and a round pedicel. There is one ring and 7 funicular segments.

 

The dark metallic purple shot thorax has deep full length notaulices and the tegulae are testaceous leading to the wings which are clear. The veins and hairs are also mid density and the post marginal vein is short. The legs are yellow with dark markings on the coxae. There are 5 tarsel segments.

 

The gaster (abdomen) is dark neutral bronze brown with some purple tones and dirty orange at the front and on the sides.

 

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More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society

 

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Glyphomerus stigma

Glyphomerus stigma

Glyphomerus stigma is an ectoparasitoid of

Diplolepis rosaePericlistus brandtii 

and Eurytoma rosae in the Bedeguar gall.

 

It is partly phytopagous and once the host has been consumed it will revert to feeding from the gall tissue. If the inducer is killed by a parasitoid in early summer, nutritive gall cells degenerate into vacuolate parenchyma and are consumed. If the inducer is killed later in the summer, when galls begin to mature, nutritive cells persist in the chambers for about 1 week before degenerating.

 

Glyphomerus stigma kills and consumes inducer larvae when galls are maturing. New nutritive cells appear under the influence of G. stigma and are then consumed. The ability of entomophytophagous chalcids to promote the formation of gall cells provides insight into the derivation of the gall-inducing guild.

 

The wasp emerges in early June through to early August. Its distribution is in the southern half of Britain and there may be somewhat locally distributed (Blair 1943).

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The female measures an average 3.4mm with a range of 1.7-4.4mm head and body, excluding the ovipositor.

The head and body are black to dark brown, semi glossy, hairy and without any metallic colouration. The antennae are dark brown and have 7 funicular segments. The legs are brown with the hind coxae being at least twice the length of the middle coxae and have 5 tarsel segments. The wings are tinted brown all over with a large dark cloud around the stigma extending backwards. The stigmal vien is shorter than the post stigmal vein. The ovipositor sheaths are about mid length.

 

The male measures 1-3.1mm averaging 2.2mm

The head and body are black to dark brown, semi glossy, hairy and without any metallic colouration. The antennae are dark brown and have 7 funicular segments. The legs are brown with the hind coxae being at least twice the length of the middle coxae and have 5 tarsel segments. The wings are tinted brown all over with a large dark cloud around the stigma extending backwards. The stigmal vien is shorter than the post stigmal vein.

 

Blaire (1945) gives a description of the larva as white and tapering strongly towards the tail. The larva is curved into a question mark shape and the greatest thickness is about the second and third thoracic segments. The segmental divisions are not deeply constricted and a median dorsal protuberance is present on the posterior border of each of the first four abdominal segments. It has a covering of long soft hairs which are curved outwardly and ventrally. The head is transversely cordiform and is twice as wide as it is long with the middle of the frons depressed and there are two deep, elongate fossae which nearly meet above. The jaws are slender, curved and have a sharp tooth on the inner side, some distance before the apex.

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More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.

Megastigmas dorsalis

Megastigmus dorsalis

A member of the family Torymidae and is a parasitoid of the following gall causers; 

Andricus aries agamic,

A. corruptrix agamic,

A. curvator sexual,

A. fecundator agamic,

A. grossulariae sexual and agamic,

A. inflator sexual,

A. kollari agamic,

A. lignicola agamic,

A. quercuscalicis agamic,

A. quercusradicis agamic,  

Aphelonyx cerricola agamic,

Biorhiza pallida sexual,

Callirhytis erythrocephala sexual,

Cynips quercusfolii agamic.

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Megastigmas dorsalis female IMG_4680a_ed

The female wasp measures 1.9-4.1mm which averages out at 3.2mm excluding the ovipositor.

The head is a rich yellow colour with a sharply defined dark metallic green patch on the vertex. The eyes are large and red/brown, sharply contrasting with the rest of the head and the ocelli are large and dark. The antennae are hairy and yellow brown with dark joints, the scape is dark above and testaceous below. There is one ring and 7 funicular segments which have a taper to the long club.

The thorax has varying amounts of well defined dark metallic green on the top and sides and yellow with traces of brown beneath. The notaulices are deep and full length. The tegulae are straw coloured which lead on to the wings which are clear with mid brown hairs. The veins are mid brown and the stigma is dark with a cloud surrounding it that may vary in size considerably. The legs are all yellow with sometimes brown on the rear coxae. 5 tarsel segments are present and darker claws.

The gaster (abdomen) is a rich brown on the top with points running down the yellow sides and yellow underneath. The ovipositor sheaths are hairy and black and is in length about 3/4 the body length.

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Megastigmas dorsalis female IMG_4718a co

The male measures in at 1.6-3.5mm with an average of 2.8mm

The head  is yellow with a distinct dark patch on the vertex. The eyes are red/brown and large, contrasting with the other colour of the head and the ocelli are also large and chestnut red in colour. The antennae are dirty gold and slender with dark joints and a slight club. There is one ring and 7 funicular segments.

The thorax  is dark green metallic, sometimes shading to brown butter yellow below but giving a

much darker appearance than with the female. It is sparsly covered with long hairs and the

notaulices are deep and full length. The tegulae are straw coloured leading to clear, hairy wings

which have a broadly circular stigma. The cloud that encircles the stigma, like in the female,

varies considerably in size. The legs are pale yellow with brown tops to the mid and rear coxae.

There are 5 tarsel segments and dark claws.

The small gaster is dark chocolate in colour with pale underneath and a yellow bar at the tip.

 

The flight times for this wasp are all year round apart from February and December.

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More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.

Megastigmas stigmatizans

Megastigmus stigmatizans

A parasitoid of the following gall causers;

Andricus kollari agamic,

A. quercuscalicis agamic.

 

The female wasp measures 5.9-6.8mm which averages out at 6.3mm excluding the ovipositor. The head is a rich yellow colour with a sharply defined metallic red/green patch on the vertex. The eyes are large and bright red, contrasting vividly with the rest of the head, the ocelli are dark baige. The antennae are dark, short and heavy with one ring and 7 funicular segments with longitudinal hairs on each segment.

The thorax has varying amounts of well defined metallic red shot green on the top and sides contrasting with yellow with traces of brown beneath. The notaulices are deep and full length and there are some hairs present. The tegulae are colourless testaceous which lead on to the wings which are clear. The stigma is shaped like a dark capsule, twice as long as it is broad, with a cloud surrounding it that may vary in

Megastigmus stigmatizans female IMG_6488
Megastigmus stigmatizans female IMG_4720
Megastigmus stigmatizans female IMG_6494

 size considerably. The legs are all yellow with metallic hairy coxae. 5 tarsel segments are present and dark claws.

The gaster (abdomen) deeply triangular and is a mainly a dull mid yellow with touches of dark brown above. The ovipositor sheaths are long, hairy and dark and is in length at least as long as the body length, with an average of 113% of the body length.

 

The male measures in at 4.5-6.3mm with an average of 5.2mm. The head  is yellow with a distinct dark green patch on the vertex. The eyes are a conspicuous brown contrasting with the other colour of the head and the ocelli are dark beige in colour. The antennae are dark, short and heavy with one ring and 7 funicular segments with longitudinal hairs on each segment. 

The thorax varies considerably with many specimens having metallic green all over to others that have, more or less, yellow on the sides and underneath. They all are hairy and the notaulices are deep and full length. The wings which are clear have a stigma that is shaped like a dark capsule, twice as long as it is broad, with a cloud surrounding it that may vary in size considerably, like in the female. The legs are pale yellow and hairy with dark marks on the rear femora and dark rear coxae. There are 5 tarsel segments and dark claws.

The small gaster square from the side but triangular from above. It is dark chocolate in colour with pale underneath with no yellow band or bar at the tip.

 

The flight times for this wasp are February and then again in June and July.

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More detailed descriptions and identification keys are available from Robin Williams at the 

British Plant Gall Society.

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