Periclistus brandtii
An inquiline of several species commonly found in Bedeguar galls, caused by Diplolepis rosae and Smooth Pea galls, caused by Diplolepis eglanteriae.
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This wasp is a member of the family Cynipidae but is not a gall causing wasp, like many others. In fact it is incapable of forming a gall of its own so acts as an inquiline. This is basically a wasp that lays its egg into an existing gall at an early stage to share the same food store as the gall causer. Although the causer is not directly targeted, the fight for food resource can sometimes cause the death of the gall causer, especially if the inquiline is sharing the same cavity as the causer. Normally the chambers are separate and the difference between D. rosae cells and P. brandtii cells are easily noticed. Those of D. rosae are large, round and not much coalesced, as opposed to those of P. brandtii which are smaller, thick walled and frequently fused and appear irregular in shape, sometimes forming a solid mass. Blair (1945) noted that the small or medium sized galls infested by P. brandtii where harder to cut into with a knife than the unifested galls.
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The adult P. brandtii wasps emerge from the galls from early june through to late july in the UK.
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The female wasp has a dark brown to black head and body with testaceous gold legs and dark slender antennae consisting of 12 segments. The gaster has a ventral spine but not extended enough for a ploughshare to be present. The whole wasp measures 2.4-3.3mm averaging at 2.7mm.
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The male is deep bodied with a black head thorax and gaster. The legs, like the female are testaceous gold however, unlike the female, the antennae are also testaceous gold and consisting of 14 segments, of which the third segment is curved.
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The females carry on average 73 eggs (range 50-98). The egg is banana shaped and distinclty divided into an egg body and a long narrow peduncle. The egg body is three times longer than wide, and the peduncle can be twice as long as the egg. The exochoroin is divided into two parts. The outer part contains closely packed crystalline rods arranged in rows which are perpendicular to the egg surface. The inner part is less electron dense and also contains irregularly spaced crystalline elements. The endochoroin is electron tranluscent and uniform in structure, and about ten times thicker than the exochorion. (2003 The Linnean Society of London, Zoological Journal of the Linnean Society, 2003, 139, 247–260). Blair (1945) made observations of P. brandtii eggs found in Smooth pea galls, which were opened in mid august. A number of elongate, clear, almost colourless eggs were found lying on the wall of the central chamber. Each egg had a stalk at one end that was the length of the egg itself. The other end of the stalk was attached to the wall of the chamber. The larvae when hatched were also colourless and clear with large knobbly looking heads that they repeatedly jerked up and down. When full grown, the larva is stout and hairless with very little or no tapering at either end. The intersegmental divisions are not as obvious as in D. rosae larvae, and the tail end is bluntly rounded with no terminal narrow segment. At each side of the thoracic segments there is a slight dorso-lateral swelling, which creates the appearance of the dorsum being flattened. Another difference from D. rosae is their jaws which have a more pronounced apex but which the teeth less deveoloped.
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Periclistus brandtii is commonly attacked by three parasitoids; Glyphomerus stigma, Eurytoma rosae and Caenacis inflexa and thought to be targeted by Eupelmus urozonus.
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More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
Periclistus brandtii larva in Diplolepis rosae gall.
Ramshorn Gall Wasp
Andricus aries
A recent arrival in Britain, first recorded in Maidenhead Thicket, Berkshire
in 1997. The first colony of them was recorded at Hamstead Heath in 1999.
It is now common in most of the South East and rapidly spreading
northwards. At the current time of writing (2008) it is found as far north as Cheshire's northern border.
It is found on lateral and terminal buds of oak trees (Quercus robur and
probably Q. petraea) from July to December. It has a globular base with 2
long, slender, tapering projections, which may sometimes be only points,
or may fuse together as one. Its shape may be variable especially when
attacked by inquilines, eg Synergus spp. which causes an enlargement of
the bulbous area at the base. The gall is green at first but as it matures,
goes brown, hard and woody. The galls are unilocular (containing a single
larvae), but there may be upto 3 galls per bud, and can grow to 7mm
across and 30mm in length (including horns).
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As far as is known, there is no sexual generation, only agamic females.
The gall matures in August and the wasp emerges from august to october
or april/may the following year. The wasps head is small, hairy, pale
chestnut gold in colour with a reticulated vertex. The eyes are medium
sized and black. The antennae have 13 segments, is orange brown in
colour and covered in inconspicuous hairs.
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The thorax is orange brown and hairy. the propodeum is dark brown. The
legs are translucent orange with a lot of white hair. The wings are clear
with pale veins and hairs and with an open radial cell.
The gaster (abdomen) is bulky, glossy orange brown and segmented. Bands of long pale hairs are present on the edges of the segments. There is a long, slender ventral spine with sparse hairs.
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Inquilines of Andricus aries include; Ceroptres arator, Synergus albipes, S. gallaepomiformis, S. pallicornis, S. pallidipennis, S. reinhardi, and S. rotundiventris.
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Hyperparsites of Andricus aries include; Megastigmas dorsalis, Ormyrus nitidulus, Sycophila biguttata and S. flavicollis.
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More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
Oak Bud Gall Wasp
Andricus corruptrix
Andricus corruptrix is spreading rapidly and is one of the many
species has 2 generations per year, one sexual and one
agamic (female only, and capable of laying eggs without
mating), and one of the several species that relies on both
common oak (Quercus robur) and turkey oak (Q. cerris) for its
life cycle.
The sexual generation was previously named A. larshemi
before it was realized to be two generations of the same
species. The sexual generation bud gall is located on the
terminal or lateral buds of turkey oaks (Quercus cerris) and
are visible from late January to early February. They are
usually found separately although occasionally there may be
two galls to a bud. The size of the gall can vary from 2.4x1.4mm
- 2.6x1.6mm. The galls appearance is of a wide based, shouldered cone with a point. This point differentiates it from A. lignicola which has a rounded tip. The gall has a rough, fibrous surface and there are usually remnants of the bud scale at the base. The colour of the gall starts as off-white, but during February or march changes to pale green, then becoming tinged with rose pink. This pink flush then spreads across the whole gall and deepens until becoming a warm burnt sienna or orangy brown of the mature gall in late march. The apical ring darkens, becoming inky black, then tones down to leave a darkened ring around the tip, often with a tiny dark mark at the very tip. Occasionally the apical ring may be white, or paler than the surrounding gall. The adult wasps pupate in the gall and start to emerge in mid April.
The female A. corruptrix wasp measures in at 1.7-2mm in length and has a black head
with short sparse hairs, the vertex being heavily reticulated. The eyes are black and mid
sized with mid brown ocelli. The 13 segmented antennae vary in colour of the flagellum
from dark brown to light brown in different insects, with pale hairs present. The pedicel
is translucent brown and the scape is black.
The thorax is black with translucent dark brown tegulae. The wings are clear with dark
brown veins and short brown hairs. The radial cell is open. The legs have dark brown
and hairy coxae and femura, tapering to dirty yellow, although this is variable between
insects.
The deeply segmented, almost square shaped gaster (abdomen) is a shiny black-brown
with pale edges and a band of pale hairs at the back. There is a long ovipositor sheath
but no obvious ploughshare beneath.
The male wasp measures 1.4-2.1mm and has a heavy reticulated black head with short
sparse hairs. The eyes are large and black with bright chestnut ocelli. The antennae
have 14 tear shaped segments with a very dark brown scape, mid brown pedicel and
dark brown flagullum.
The thorax is black with much reticulation and the tegulae are brown. The wings are clear with coarse, short dark hairs and neutral brown veins. The radial cell is open. The legs dark brown coxae and femora with pale joints, the rest being dirty yellow.
The slender and pointed gaster is black and glossy with a single segment and few large hairs at the front.
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The bud galls are invaded by 4 Pteromolidae hyperparasites, which are; Mesopolobus dubious, M. fuscipes, M. tibialis, and M. xanthocerus.
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The agamic generation lobed gall is found in the buds of common oaks (Quercus robur) from May to July onwards. There are three to five lobed galls found in the buds that have a characteristic shape even when young and upto 8mm across. The gall matures in July and the adult wasps emerge either in October of that year or July to August of the following year.
The agamic generation wasp measures 2.8-4.2mm and has a small orange brown head, which is granulate and has pale hairs. The eyes are black and mid-sized with small mid-brown ocelli. The antennae have 13 segments and are slender and slightly tapered, orange brown and hairy.
The hunched thorax is orange brown with a black propodeum. It is hairy on the side but less so on the top. The legs are orange brown and hairy and the wings are clear with dark brown veins and pale hairs.
The gaster (abdomen) is glossy, fat and orange brown except for a small dark brown blended in spot at the front of the top. It is translucent with faint puntuations on the rear and beneath. It is segmented with bands of pale hairs at the back of each segment. A thin ventral spine with sparse hairs.
The lobed gall is invaded by inquilines and hyperparasites. The inquilines include; Ceroptres arator, Synergus apicalis, S. gallaepomiformis, S. reinhardi, and S. umbraculus.
The hyperparasites include; Cecidostiba fungosa, Eupelmus urozonus, Eurytoma brunniventris, Megastigmus dorsalis, Mesopolobus amaenus, M. dubious, M. fasciiventris, M. fuscipes, M. sericeus, M. tibialis, Ormyrus pomaceus, Sycophila biguttata, S. variegata, Torymus auratus(=nitens), and T. flavipes.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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Curved leaf Gall,
Collard bud Gall
Andricus curvator
Andricus curvator, like many gall wasps, has 2
generations per cycle. One being sexual and the
other being agamic (all female who can lay fertile
eggs without the need to mate). Each of these
two generations creates a different gall on the
host tree which is oak (Quercus spp.).
The sexual generations gall is known as the
Curved leaf gall, and is common on oaks from
May to July onwards, on the leaf or sometimes
in the twig. On the leaf it can be described as a
globular swelling, of about 8mm across, that
distorts the leaf and midrib. Sometimes several
galls may coalesce. The twig galls form a swelling
in the twig about 13x9mm across which courses
bending of the twig. Each gall has 2 cells, a thin
walled cavity with an inner gall containing a single wasp larva. The wasp pupates in the gall whilst on the tree. The gall matures in July and the wasp will then emerge from July through August.
The female wasp is 1.9-2.8mm in length and has a black shiny head with large dark eyes with the antennae being pale chestnut but darkening after the first few segments. 14 segments in total.
The thorax is glossy black with dark brown tegulae. The legs having black coxae and and the rest being yellow brown with browning in the middle of the tibia and femur. The wings have neutral brown wings and hairs.
The gaster (abdomen) is fat, deep and segmented. Black and glossy with some paler tinges on the edges of the segments.
The male wasp is 2-2.3mm in length. The head is gloosy black with sparse pale hairs. The eyes are large and very dark brown. The antennae are yellow chestnut, darkening after the first few segments, with a dark scape, fifteen segments in total.
The thorax is black and glossy with dark brown tegulae. The legs are dirty brown yellow with darker tinged patches in the centre of the tibia and femur, and darker coxae. The wings are clear with strong brown to paler viens and medium brown hairs.
The gaster is segmented, though not obviously. Smaller than the females, it is glossy black with a short chestnut petiole.
Inquilines found in the curved leaf gall as as follows; Synergus albipes, S. crassicornis, S. galaepomiformis, and S. nervosus
Hyperparasites of this gall are; Aulogymnus arsames, A. pallarum, A. gallarum f. pulchra, Eupelmus urozonus, Eurytoma brunniventris, Megastigmus dorsalis, Mesopolobus albitarsus, M. amaenus, M. fasciiventris, M. fuscipes, M. sericeus, M. tibialis, Torymus flavipes, T. geranii and T. notatus.
The agamic generation was previously named A. collaris before it was realized to be two generations of the same species. The agamic generations gall, known as Collard bud gall, measures about 3x2mm and is found on terminal and lateral buds of oak trees, and occasionally on Artichoke gall (Andricus fecundator) scales from August to September.
The gall is well hidden until maturity, which is at the end of September, and shows the tip only which is brown in colour, often encircled by a pale ring. It contains a single cell and the wasp pupates in the gall on the ground, emerging March to April of the following year.
The agamic wasp is about 2.8mm in length. Its head is small, dark brown to black and moderately hairy. The eyes are small, dark brown in colour and the ocelli are small and pale. The antennae are chestnut coloured with 14 segments.
The thorax is glossy with very dark brown/black to paler black striped. the tegulae is pale chestnut. The legs are pale chestnut with darkened coxae. The wings are clear with pale neutral viens and hairs.
The diamond shaped gaster is segmented, deep chesthut with dark markings.
The gall is often invaded by 2 inquilines; Synergus albipes and S. nervosus, and a hyperparasite; Mesopolobus amaeneus.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society
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Hairy Catkin Gall,
Artichoke Gall
Andricus fecundator
Andricus fecundator has a life cycle which encompasses a sexual generation as well as an agamic (all female with no need to mate) generation which cause different galls in different locations of the common oak trees Quercus robur and Q. petreae.
The sexual generation was previously named A. pilosus before it was realized to be two generations of the same species. The hairy catkin gall is the sexual generation gall and can be found from May to June on oak catkins. It measures about 2x1.5mm in size. It is pointed and covered in long, dense, white hairs. The surface is not ridged and the catkin is usually not distorted. It contains a single cell and the gall matures towards the end of may. The wasp pupates in the gall usually on the tree, and emerges from the end of may through to august.
The female measures 1.4-1.8mm
Its head is shiney black and lightly sculptured with mid sized, very dark brown eyes and translucent yellow ocelli. The antennae have dark brown scapes with darker bases and the other 13 or 14 segments are gold, darkening to the tip.
The thorax is black and semi glossy, with light sculpture in parts and afew hairs towards the back. The tegulae are black and the wings clear with heavy, mid brown veins and short brown hairs. The legs consist of a dark brown femora and the rest is dark yellow.
The gaster (abdomen) is segmented and blocky but not compressed sideways. Its colour is black with dark chestnut at the rear and extreme front. It is semi glossy and slight sculpture and has a longish testaceous ovipositor sheath.
The male measures 1.3-1.8mm
The head is black and heavily reticulated with large black eyes and chestnut ocelli. The antennae consist of 14 segments and the flagellum are mid brown, as is the pedicel but the scape is dark brown.
The thorax is black with black brown tegulae. The wings are clear with dark neutral brown veins and short dark brown coarse hairs, although they can be sometimes paler. The legs consist of dark brown coxae and femora tapering to dirty yellow pale joints.
The gaster is slender pointed and tiny with a single main segment, glossy dark brown in colour with few large hairs at the front.
There is one recorded hyperparasite associated with this gall, Mesoplobus xanthocerus.
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The artichoke gall is caused by the agamic generation. It is common
and found on the terminal and auxillery buds of oak trees from June
to September. The gall is in appearance similar to an artichoke or hop.
It is pointed (though not always and can be football shaped) and
covered with bud scales and varies tremendously in size from
20x12mm to 30x20mm. Its colour is green, although after maturity at
the end of July this changes to a light brown.
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The outer scales of the gall conceals a large cavity, inside which is a
small inner gall which is occupied by a single wasp. This small inner
gall drops out of the exterior covering at maturity, leaving the empty
artichoke part of the gall remaining on the trees for several years
sometimes. After the inner gall has fallen to the ground the larva
inside then pupates, emerging the following spring in March to April.
Longer periods of waiting emerge have been recorded on many
occasions and may sometimes take 2-3 years.
The agamic wasp has a large variation in size and measures 2.2-4.8mm with an average of 3.5mm.
The head is black, lightly sculptured, with dark hairs. The eyes are small and mid brown and the ocelli are dark. The antennae are dark brown to black and covered with short hairs. There are 14 segments.
The shiney black thorax is very hairy and lightly sculptured. The tegulae are chestnut and the wings are clear with pale brown veins and hairs. The legs are hairy and dark brown, getting slightly paler lower down.
The gaster (abdomen) is bright chestnut with diagonal darker stripes from half way down, semi translucent.
One inquiline, Synergus crassicornis, and several hyperparasites of this gall include, Aulogymnus trilineatus, Eupelmus urozonus, Megastigmus dorsalis, Torymus auratus (=nitens)
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
Oak Marble Gall
Andricus kollari
Oak Marble gall wasp (Andricus kollari) has 2
generations per year. The first of which is sexual,
whereas the second is agamic (all female, and
needs no male to reproduce). This wasp also
needs two species of Oak in which to breed. The
sexual Gall is found on the buds of the Turkey
Oak (Quercus cerris), whereas the agamic galls
are found in West and Central Europe at the buds
of various species of Quercus including the
Common oak (Quercus robur), as well as Q.
petraea, Q. pubescens, Q. frainetto, Q. virgiliana.
In Spain and North Europe they develop also on
Q. pyrenaica, Q. faginea, Q. fruticosa, and Q.
canariensis.
The sexual generation was previously named A. circulans before it was
realized to be two generations of the same species. The sexual gall is easily
confused with some of the other bud galls from the Andricus family and is first
visible in late January to early February on the Turkey Oak. It has the
appearance of an apple green bud with a pinkish flush along one side of the
gall. This rarely covers the gall and can even occasionally appear deep purple.
As the gall grows and matures the flush reduces towards the tip and tends to
turn black. It reduces to the point of becoming a tiny black spot at the tip or
even vanishing completely when the gall is mature.
Gall maturity tends to occur at the end of March. The mature gall tends to be
about 2x1mm to 3x1.5mm in size and there are often several galls per bud.
The shape is rather bud shaped for want of a better description, however
when there are several together they can be misshapen to the point of being
banana shaped in some cases. Each gall has a single cell, which produces one
wasp either male or female.
The colour of the mature gall itself, is yellow or yellowy brown with small tufts
of hair sometimes found on the upper parts. They can however, appear varied in colour, with darker patches from the remains of the bud scales. The tip often has dark or black markings and a raised ridge runs up many of them.
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The wasp stays in the gall to pupate and will exit from March to June. Parasites that may kill and feed on the wasp and may exit instead of the Andricus kollari, consist of 4 Pteromalids from the Mesopolobus genus. These wasps are ; M. dubious, M. fuscipes, M. tibialis and M. xanthocerus.
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The male wasp is very dark brown to black on the head and hunched thorax, with a black gaster (abdomen), The legs are yellowy brown and the antennae are a translucent yellow or pale brown colour and consist of 14 segments. The head and body length varies from 1.5 to 2mm.
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The female has a dark brown head and thorax, which again is hunched, but has a dark brown gaster which does not have the typical Cynipid ploughshare. The legs are tapered brown/yellow. The dirty brown antennae comprise of 13 segments. The head and body measurements are similar to the males at 1.5-2mm.
After exiting the bud galls the adults will mate and then the
female will seek out a common oak (Quercus robur) and lay her
eggs in the bud where the agamic generation galls are then
formed. These agamic galls can generally be seen from June
onwards. The gall is smooth and round, green in colour and very
soft to begin with, and will grow upto 20mm across, although
some may be larger. There may be lumps or bumps, or even
slightly mishapen ones which is often caused by inquilines
around the edges of the centre chamber. There may also be
scarring on the outside which is sometimes caused by aphids
feeding off the gall as it grows. Occasionally two galls growing
very close together may combine to form a double gall in effect.
Occasionally they will not grow very large and this could well be
a sign of paratisation although I have had several fully grown
A. kollari from small galls.
The larva that lives within is white and legless and infact
resembles a very typical cynipid larval form. The internal structure
of this gall consists of the smooth exterior surrounding a sponge
like interior, which in turn sometimes surrounds several air
chambers with the larval chamber in the centre, where the larva
feeds and grows. The air pockets are believed to possibly be a
way of preventing parasites such as Torymidae by fooling them
into thinking that when they break through into the air pocket they are in the central chamber and laying there egg in a sealed off empty space, not on the larvae itself. However the multichambers that are in the picture below are the effects of inquilines of the Synergus genus in the centre where they have squeezed out the original occupant and created 6 segments. To the right is the exit hole and just above that is another chamber from a different Cynipidea inquiline.
As the gall matures the outer surface turns from green to brown and hardens to a very dense structure, making it very hard. This usually occurs in August and September and this is when the wasp larva inside will pupate prior to exiting. It then chews a tunnel out from the centre to the outside and after cleaning itself will then fly off in search of a Turkey oak to start the whole process again. In some cases though the wasp will not emerge in the first year, and will infact wait for the 2nd or even upto the 4th year before emerging. Old galls that have been exited can often be seen still on the tress for some years after, complete with circular exit holes. The larger ones are generally from the gall creater wereas the smaller ones tend to be from parasites or inquilines. In fact it is possible to get a rough guess of the ratios of successful A. kollari, if there is one large exit hole, or one large exit hole plus several smaller holes, then these would be inquilines. If there are smaller holes but no large hole then the gall was probably parasitised. It is very difficult however to differentiate from inquiline and parasite holes so the ratios between them would be difficult to document.
The adult is very similar to some of the other Andricus sp and coloured yellowy
brown or chestnut beige with an orangey brown gaster (abdomen) and a black or
dark brown triangle area at the top front of the gaster. It also has bands of hairs on
the edges of the segments. The size is an average of c. 5mm and the number of
antennal segments is 13.
Common inquilines species found in marble galls include; Ceroptres arator,
Saphonecrus connatus, Synergus albipes, S. gallaepomiformis, S. pallicornis,
S. pallidipennis, S. reinhardi, S. umbraculus.
Parasite species of marble galls include; Eurytoma brunniventris, Sycophila biguttata,
S. variegata, Megastigmus dorsalis, M. stigmatizans, Torymus auratus (=nitens),
T. geranii, Ormyrus nitidulus, Caenacis lauta, Cecidostiba fungosa, C. semifascia,
Hobbya stenonota, Mesopolobus amaenus, M. dubius, M. fasciiventris, M. fuscipes,
M. sericeus, M. xanthotherus, Eupelmus annulatus, E. urozonus, and
Aulogymnus trilineatus.
Other associated species include; Brachymeria rugulosa, Aulogymnus gallarum, Baryscapus berhidanus, Eupelmus vesicularis, Eurytoma pistaciae, Sycophila iracemae, Sycophila submutica, Caenacis inflexa, Cecidostiba adana, Cyrtoptyx robustus, Eumacepolus obscurior, Mesopolobus tibialis, Adontomerus crassipes, Torymus angelicae, Torymus calcaratus, Torymus cingulatus, Torymus erucarum, Torymus nobilis.
Another hole in a gall, this time bearing the tell tale signs of a field mouse that gnaws a circular hole
searching for the grubs inside.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
Cola Nut Gall
Andricus lignicola
Andricus lignicola, like many other Andricus
species, has 2 generations per year. The first of which is sexual, whereas the second is agamic (all female, and needs no male to reproduce). This wasp also needs two species of Oak in which to breed. The sexual Gall is found on the buds of the Turkey Oak (Quercus cerris), whereas the agamic galls are found in the buds of various species of Quercus including the Common oak (Quercus robur), as well as Q. petraea, Q. pubescens. The sexual generation was previously named A. vanherni before it was realized to be two generations of the same species.
The sexual gall is widespread across the country, on the buds of the turkey Oak and measures about 1.5x3mm. It is difficult to spot and share some similarities with some of the other closely
related gall wasps. There are several galls in a bud and each one is a single cell containing a single larva. In contrast with the other similar galls, which do not become visible until spring, they reach half size in late September to early October.
The colour of the gall changes from bright green to pink which then deepens to a blood blister purple and remains this colour throughout the winter. In early February, as the gall matures, the colour changes again to the characteristic fawn brown of the mature gall. Its shape is conical, although there are often flat side where the galls touch each other with a rounded tip. The height of the galls is generally very similar, with the tops being all level with each other. The gall is closely attached to the bud segments, which may well cover the lower half of the gall.
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The larva pupates in the gall on the tree and the adults start to emerge from February, to seek out a mate, with the females then searching for a common Oak in which to lay there eggs in the buds and create a new generation of, this time, agamic females. The flight period for these wasps begins in February and lasts through to June, with another in September for the galls that had not already emerged that spring.
The wasps that emerge from the sexual gall are difficult to tell from other sexual gall wasps in that the male has a black body at 1.5-2mm in length, with dirty yellow legs and brown antennae which comprises of 14 segments. The female is about the same length with a black head and thorax and a black- brown gaster (abdomen). Tapered brown to yellow legs and dark brown antennae with 13 segments.
Parasites of this gall includes; Mesopolobus dubius, M. Fuscipes, M. tibialis, M. xanthocerus, and Aulogymnus skianeuros.
The agamic generation gall is known as a Cola gall and is found on the buds of Common Oaks. It is spherical in shape like the marble gall but is smaller (upto 10mm across) and with a rough surface. It can be seen from July onwards and matures in October, with the wasp pupating inside the gall and emerging in November to December of the 1st year or April to July of the following year.
The adult agamic female is again very similar to other Andricus species with basically a yellow/brown or biege colouration all over and 13 antennae segments.
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Inquilines of this gall include; Ceroptres arator, Saphonecrus cannatus, Synergus albipes, S. apicalis, S. crassicornis, S. gallaepomiformis, S. reinhardi, S. umbraculus, Periclistus brandtii.
Parasite species of the cola gall include; Eurytoma brunniventris, Sycophila biguttata, Megastigmus dorsalis, Torymus auratus (=nitens), T. geranii, Ormyrus nitidulus, Mesopolobus amaenus, M. fasciiventris, M. fuscipes, M. sericeus, M. xanthocerus, Eupelmus urozonus, Aulogymnus skianeuros.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society
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Knopper Gall
Andricus quercuscalicis
Andricus quercuscalicis has 2 generations per year. The first of which is sexual, whereas the second is agamic (all female, and needs no male to reproduce). It is the second agamic generation that gives the wasp its common english name as the causer of the Knopper gall. This wasp also needs two species of Oak in which to breed. The sexual Gall is found on the buds of the Turkey Oak (Quercus cerris), whereas the agamic galls are found in West and Central Europe at the buds of various species of Quercus including the Common oak (Quercus robur), as well as Q. petraea, Q. pubescens, Q. frainetto, Q. virgiliana. The sexual generation was previously named A. cerri before it was realized to be two generations of the same species.
The mature sexual gall is common and can be found in the buds or catkins of the Turkey oak (Quercus cerris). It is bud shaped and easily missed or can be confused for other bud galls on the tree. In general it is pale, bright gold in colour, with a finely reticulated surface, slender and pointed in shape, and more or less covered by a golden brown slightly hairy husk. It measures from 1.7x1mm to 2.5x1.4mm and contains a single wasp, but there may be several galls per bud. It matures in early April and the adults fly April to June when they mate and lay there eggs in the common oak acorn buds.
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The female Andricus quercuscalicis has a black, heavily reticulated head with dark brown medium sized eyes and chestnut ocelli. Its antennae have 13 segments and are a translucent gold colour except for the last 4 tip segments which are darker.
The hunched thorax is black and glossy with yellow brown tegulae. The wings are clear with yellow brown hairs and veins and the radial cell is open. The legs are translucent apart from darker tarsi and coxae tips.
The segmented gaster (abdomen) is round and fat with out a ploughshare, black and glossy with a faint yellow surround to the ventral spine. The whole wasp measures 1.2-1.5mm head and body length.
The male Andricus quercuscalicis has a black heavily reticulated head, like the female however its eyes are black and the ocelli are straw coloured. The 14 segmented antennae are translucent gold with the last 3/4 segments a darker neutral brown and a dark scape.
The thorax is black and reticulated with dirty gold coloured tegulae, with dirty yellow legs and darker coxae. The wings, as with the female, are clear with yellow brown hairs and veins and the radial cell is open.
The black, glossy gaster is small, pointed and hairless, with a single main segment. The head and body measurements are from 1-1.5mm.
Hyper parasites of the sexual galls are; Aprostocetus aethiops, Mesopolobus dubious, M. fuscipes, M. tibialis, M. xanthocerus and Pediobus clita.
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Knopper galls are very common in localised areas where turkey oaks are present along side common oaks. They grow on average to about 20mm across, although occasionally some very large examples can be found. They are seen on the trees from May to October and are either green or red in colour. They are of irregular shape (as can be seen on the accompanying photos), and are covered by a sticky resin. The galls themselves contain a large inner cavity with a smaller inner gall containing one wasp. When they mature in September they start to brown, lose the sticky substance from around it and will fall off the tree just before or along with the acorns. The wasp will sometimes emerge in October to December but more usually in the following year from January to April. If conditions are not correct then they may remain in the gall for another 12 months or so.
The agamic generation of Andricus quercuscalicis is considerably larger at 4.5-5.4mm in length. The head is orange with black vertex and back as well as around the mouth and with masses of pale hairs. The mandibles are also shiny black with touches of orange at the base and orange appendages. The eyes are small and neutral brown with chestnut ocelli. The 14 antennae segments are black with a swollen scape and orange base.
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The thorax is striped black and orange with a dense covering of hairs. The wings are clear except for a bleeding of the viens around the areolet, and with dark brown veins and hairs. The radial cell is open. The coxae are dark, fading to orange and a distinctively striped femora, dark on top and orange below.
The bulky, segmented gaster is black with some orange at the bottom of segments and masses of pale hairs in bands at the edge of the segments. The hypogium is long and slender with sparse short hairs.
Inquilines of the knopper gall are as follows; Synergus gallaepomiformis, S. nervosus, S. pallicornis and S. umbraculus.
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Hyperparasites of the knopper galls are; Arthrolytus ocellus, Cecidostiba fungosa, C. semifascia, Eupelmus urozonus, E. vesicularis, Eurytoma brunniventris, Gelis formicarius, Mastrus deminuens (=castaneus), Megastigmus dorsalis, M. stigmatizans, Mesopolobus amaenus, M. sericeus, M. tibialis, Ormyrus nitidulus, Spilomicrus stigmaticalis, Sycophila biguttata, Torymus auratus (=nitens), T. cyaneus, and T. geranii
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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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Hairy spindle Gall, Bisected Gall
Andricus solitarius
Andricus solitarius has a life cycle with encompasses a sexual generation as well as an agamic (all female with no need to mate) generation which cause different galls in different locations of the common oak trees Quercus robur and Q. petreae.
The sexual generation was previously named A. occultus before it was realized to be two generations of the same species. The gall, known as the Bisected gall, is common and can be found in the base of stunted catkins. It measure about 3x2mm, is oval in shape and has a ridge on each side of the gall, meeting at the tip, splitting the gall, hence the name, and coloured hairs of red brown or yellow. The gall is found in April, with the gall reaching maturity and the wasp emerging in the same month, usually through an exit hole which is commonly in the side of the tip.
The female measures 1.9-3.2mm averaging 2.8mm
Its head is a slightly glossy, very dark brown/black and granular with mid sized, very dark brown eyes. The antennae consist of 13 segments and are yellow, darkening to the tip. The sensillae and hairs are pale.
The thorax is very dark brown with a semi glossy mesocutum. The wings are clear with pale brown veins and hairs. The legs are translucent deep yellow and lightly hairy.
The gaster (abdomen) is a deep, bulky, non segmented, glossy, deep translucent chestnut and a few hairs are present at the front of the segment. The ovipositor sheath is long and thin with a tuft of hairs at the tip.
The male measures 3.3mm
The head is black and granular with mid sized very dark brown/black eyes. The antennae consist of 15 segments and the flagellum are dark yellow, darkening to the tip.
The thorax is semi glossy black. The wings are clear with pale yellow veins and hairs. The legs are deep yellow with darker coxae and hairy.
The gaster is pointed and not segmented or sculptured, high glossy chestnut in colour.</p><p>There is no recorded inquilines or hyperparasites associated with this gall.
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The Hairy spindle gall is caused by the agamic generation. It is common and found on the terminal and axillery buds of oak trees from June to September and measures about 9x3mm. The gall is in appearance pear shaped with a pointed tip. It is normally smooth and hairless, although may have red or golden hairs when young and contains a single cell. The gall reaches maturity at the end of August and the adult wasp emerges August and September.
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The agamic wasp measures 3mm in length.
The head is yellow brown and granulate. The eyes are mid sized yellow brown and the ocelli are dirty yellow. The antennae are dark yellow brown and there are 14 segments.
The thorax is dark and chestnut, lightly granulate, with a chestnut mesoscutum, with a largely dark top and a yellow brown mesopleuron. The tegulae are chestnut and the wings are clear and the legs are dirty yellow brown.
The gaster (abdomen) is yellow brown and paler underneath. It is smooth and segmented.
Two inquilines, Synergus gallaepomiformis and S. nervosus, and four hyperparasites of this gall include; Eupelmus urozonus, Eurytoma brunniventris, Mesopolobus amaenus and M. sericeus.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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Oak apple Gall,
Oak Potatoe Gall
Biorhiza pallida
Like many Cynapidae species, Biorhiza pallida has 2 generations in its life cycle. One being sexual and the other is agamic (females who can reproduce without mating). Both stages of B. pallida take place on common oaks, the more commonly seen "Oak apple gall" is the sexual generation on the buds and the agamic generation root gall is found on the roots of the tree.
Oak apple galls are very noticable, large galls that can be 50mm across. They start forming on terminal and lateral buds in may and are cream with bright pink and red with a soft spongy texture. As they mature towards the end of June,
they turn light brown and loose their spongy texture to become very papery. The adult wasps emerge July to September. The adult wasps may be confused with the smaller Andricus quercusramuli.
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The female Biorhiza pallida at about 2.1-3.4mm in length, has a translucent dark brown to a paler translucent gold brown with pale hairs. The eyes are quite large and prominent and dark brown in colour. The ocelli are chestnut. The antennae have 14 segments, are golden brown in colour.
The thorax is semi translucent yellow chestnut with darker panelling. The legs are translucent chestnut gold and hairy and the wings are clear with gold to dark brown veins and pale brown short hairs.
The gaster (abdomen) is golden brown to dark chestnut, swollen and smooth, not obviously segmented. The ventral spine is short with protuding hairs that go beyond the tip. The ovipositor sheath does not protrude.
The male, 2.1-3.5mm, has a dark chestnut yellow head that is slightly granulated with large pale eyes and chestnut ocelli. The 15 segmented antennae vary from mid brown to paler chestnut yellow.
The thorax is a semi translucent yellow chestnut with darker panelling as with the female. The legs are all translucent pale chestnut yellow and hairy. The wings are clear with prominent dark chestnut veins and hairs.
The gaster is narrow, deep and triangular, and a shiny chestnut yellow to rich chestnut.
Two inquilines are commonly found in oak apple galls; Synergus gallaepomiformis and S. umbraculus.
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Hyperparasites, however, are more numerous and include; Aprostocetus aethiops, A. skianeuros, Baryscapus diaphantus, Cecidostiba fungosa, C. semifascia, Eupelmus urozonus, Eurytoma brunniventris, Hobbya stenonota, Megastigmus dorsalis, Mesopolobus amaenus, M. dubius, M. sericeus, M. tibialis, M. xanthocerus, Ormyrus pomaceus, Sycophila variegata, Torymus affinis, T. auratus (=nitens), T. flavipes and T. geranii.
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The Root gall is found underground, on the rootlets of the oak tree. It is globular, upto 8-10mm, and has one large chamber which is inhabited by 1 gall wasp larva. The individual galls often coalesce into clusters 30mm across. The gall matures by October of the second year and the agamic wasps emerge from October to December of that year or march of the following 3rd year.
The 4.8-6.3mm long wingless adult agamic wasp has a small yellow brown head with slight sculpture. The eyes are medium sized, long and mid brown yellow, with small pale orange ocelli. The 15 segmented antennae are a bright mid brown with an orange tint.
The thorax is yellow brown to orange with the legs being all yellow brown and the wings are not present.
The gaster is large, fat, shining, segmented and yellow brown in colour.
The gall suffers from 2 hyperparasites, being; Torymus nobilis and T. roboris
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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Red Pea Gall,
Red Current Gall
Cynips divisa
Cynips divisa has a life cycle which encompasses a sexual generation as well as an agamic (all female with no need to mate) generation which cause different galls in different locations of the common oak trees Quercus robur and Q. petreae.
The sexual generation was previously named C. verrucosa before it was realized to be two generations of the same species. The Red wart gall is the sexual generation gall and can be found in axillary or terminal buds on the twig, and leaf, at the end of the midrib, or on the leaf margin from April to June. It measures about 4x1.8mm in size and slender or barrel shaped. It is brightly coloured yellow, orange to brownish, glossy and hairless and often covered in tiny liquid filled putules. It is inconspicuous and only really shows when mature, which is in May. It contains a single cell and the wasp pupates in the gall usually on the tree, and emerges from the end of may.
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The female measures approximatly 2.7mm
Its small head is dark brown and largely smooth with mid sized, dark brown eyes and brown ocelli. The antennae are long, with 14 segments, and tapering and are coloured pale, darkening to the tip.
The thorax is black with a smooth mesoscutum and full length notaulices and a hairy scutellum and a glossy mesopleuron. The wings clear with dark veins and hairs. The legs are bright yellow.
The gaster (abdomen) is not segmented and dark brown, tapering to a pale tip, slightly hairy and dull.
The male measures approximatly 2.2mm
The head is very dark brown and wide with mid sized dark brown eyes. The antennae consist of 14 segments and the third segment is slightly bent.
The thorax is a dark neutral brown, dull and smooth but with some light sculpturing and the notaulices are complete. The wings are clear with conspicuous dark yellow brown veins and hairs. The legs are deep yellow.
The gaster is dark brown, short and square from the side and segmented.
There are no recorded inquilines or hyperparasite associated with this gall as yet.
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The Red pea gall is common on the underside of the oak leaf, from mid summer right through to October. It measure around 5x6mm. It is glossy, flattened slightly and has a very short stalk attaching it to the leaf vein. It starts off green or white, then changes to a noticeable flushed red, before finally turning brown as it matures in September. The gall is very thick walled and hard when mature. Each gall has a single cell and the wasp pupates inside the gall, emerging august to December in the same year or occasionally January to March of the following year.
The agamic wasp has a large variation in size and measures 2.2-4mm with an average of 3.4mm.
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The head is bright orange brown to dark brown with long, pale hairs. The eyes are neutral brown, contrasting with the rest of the head and the ocelli are translucent pale chestnut. The antennae are slender and long, dark brown and hairy. There are 13 segments.
The thorax varies from bright orange to all dark brown and black beneath, with long, pale hairs. The notaulices are full length. The tegulae are chestnut and the wings are clear with pale yellow to neutral brown veins
and brown hairs. The legs are dark chestnut with pale hairs and parts of the coxae are darker.
The gaster (abdomen) is pale to darker chestnut with diagonal darker streaks from top to bottom along the segments and a tuft of pale hairs at the end of the ventral spine.
Three inquilines, Synergus albipes, S. nervosus, and S. pallicornis, and several hyperparasites of this gall include,
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Aprostoctus aethiops, Caenacis lauta, Eupelmus urozonus, Eurytoma brunniventris, Mesopolobus dubius, M. fasciiventris, M. sericeus, Sycophila biguttata, Torymus auratus (=nitens), T. cyaneus, T. flavipes and T. geranii.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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Common Spangle Gall,
Current Gall
Neuroterus
quercusbaccarum
The gall wasp has 2 generations per year. One being sexual and the other agamic (all female, and needs no male to reproduce). The sexual generation causes current galls in catkins and singles below leaf with a red mark above. Whereas the agamic generation causes Common spangle galls on the underside of oak leaves. The agamic generation was previously named N. lenticularis before it was realized to be two generations of the same species.
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The Current Gall is common on leaves catkins and even the ends of stems on twigs and measures about 4-7mm. They are smooth, succulent and can be yellow, green, red or purple. These galls can be spotted May to June. They mature May to June and comprise of a single cell where the wasp pupates on the tree and both males and females emerge May to July.
The female wasp is winged and about 2.5-3mm in length. Its head is a very dark, shiny brown with large and long bright pale brown eyes. The antennae are yellow brown and comprise of 15 segments with a yellow scape and pedicel.
The thorax is again a very dark shiny brown with straw coloured tegulae. The wings are very long, clear with dark brown veins. The legs are semi translucent yellow with sparse pale hairs.
The Gaster or abdomen is again very dark brown, blocky and segmented with a particularly jagged appearance to the edge. The petiole is very short and tiny.
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Flying time - May to July
The male wasp is winged and slightly longer than the female, but thinner and ranges from 2.3-3.2mm in length. The head is small and dark brown with large dark brown eyes, which have a conspicuous pale circumference. The antennae comprise of 15 segments and are pale brassy in colour.
The thorax, as in the female, is a shiny very dark brown with straw coloured tegulae, and the wings are clear and long with dark brown veins. The legs are translucent straw coloured with a brown top to the coxae.
The gaster is thin and glossy dark brown with a thin, long petiole.
Common Inquiline species found in N. quercusbaccarum current galls include; Synergus albipes, S. apicalis, S. gallaepomiformis, S. nervosus and S. thaumacerus.
Common hyperparasites of N. quercusbaccarum current galls include; Aulogymnus arsames, A. gallarum, Eupelmus urozonus, Eurytoma brunniventris, Mesopolobus sericeus, M. tibialis, Torymus auratus (=nitens) and T. flavipes.
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The Common Spangle Gall is abundant on the underside of the oak leaf and can reach 5mm across. This gall holds the agamic generation and looks like a rimless disc with a rising central mound. It is usually yellow in colour but can sometimes appear more greeny yellow. There are often also red hairs. It is a single cell gall holding one wasp and can be seen from July onwards, until the leaves fall in autumn. The wasp larva will mature in august but remain in the gall on the ground throughout the winter, emerging the following year from January to May.
The agamic generation wasp is winged and measures in at 2.1-3.1mm in length. The head is small, black and bent down sharply giving it a hunched appearance, with mid sized black eyes. The antennae are dark to dark brassy with a dirty yellow scape and pedicel, with 15 OR 16 segments.
The black, smooth thorax has brown and gold tegulae. The long clear wings have thick brown viens and fairly dense brown hairs. The dark brown hairy legs blend into yellow joints.
The large black gaster is moderatly glossy and blends into a yellow brown ventral spine. It is evenly segmented.
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Flying time - January to May.
Common Inquiline species found in N. quercusbaccarum common spangle galls include; Synergus albipes, and S. nervosus.
Common hyperparasites of N. quercusbaccarum common spangle galls include; Aulogymnus gallarum, A. gallarum f. pulchra, Eurytoma brunniventris, Mesopolobus dubious, M. fasciiventris, M. tibialis, Pediobius clita, P. lysis and Torymus flavipes.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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Silk Button Gall,
Blister Gall
Neuroterus numismalis
The gall wasp has 2 generations per year. One being sexual and the other agamic (all female, and needs no male to reproduce). The sexual generation causes Blister galls on oak leaves. Whereas the agamic generation causes Silk button galls on the underside of oak leaves. The agamic generation was previously named N. vesicator before it was realized to be two generations of the same species.
The Blister Gall is common on leaves from May to October. It is a convex blister on both surfaces, smooth but with paler radiating lines. Its size is approximatley 3mm x 0.5mm. They usually mature towards the end of May and comprise of a single cell where the wasp pupates in the gall on the tree and both males and females emerge May to July, although sometimes they can be seen emerging in april.
The female wasp is winged and about 1.8-2.4mm in length, averaging at 2.1mm.
Its head is a shiny dark brown, lightly reticulated, with large dark neutral brown eyes. The antennae are mid yellow brown and comprise of 14 segments and a fat and hairy pedicel.
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The thorax is again a shiny brown nearly hairless and with no notaulices. The wings are clear with pale brown hairs and dark veins. The legs are hairy, mid brown, tapering to paler tarsi and pale joints.
The short and upright Gaster or abdomen is mid brown and smooth, not obviously segmented, but with fine microsculpture. A band of hairs at the back and a large ploughshare beneath.
The male wasp is winged and slightly shorter than the female, and ranges from 1.4-2.2mm in length, averaging at 1.9mm.
The head is dark neutral brown, lightly sculptured with large dark eyes. The antennae comprise of 15 segments and are pale straw coloured with a fat brown scape. The thorax has mid neutral brown side and is darker above. No notaulices and a pale tegulae. The wings are clear with heavy brown hairs and brown veins,
with an open radial cell. The legs are pale testaceous coloured with a brown back coxae.
The blocky, segmented and unsculptures gaster is mid brown in colour, going darker underneath, with a thin, long petiole.
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There is one inquiline species found in N. numismalis blister galls which is; Synergus albipes.
Common hyperparasites of N. numismalis blister galls include; Aulogymnus arsames, Aprostocetus aethiops, Eurytoma brunniventris, Mesopolobus fasciiventris, M. fuscipes, M. sericeus, M. tibialis and Torymus flavipes.
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The Silk button Gall is abundant on the underside of the oak leaf and can reach 3mm across. This gall holds the agamic generation and looks like a thick, rolled edge disk with a deep central pit and gold hairs, there is no mark on the top of the leaf. It is a single cell gall holding one wasp and can be seen from August to October, until the leaves fall in autumn. The wasp larva will mature in August but remain in the gall on the ground throughout the winter, emerging the following year from February to April.
The agamic generation wasp is winged and measures in at approxiamtly 2.5mm in length.
The head is small and pointed, black and granulated, with medium sized pale brown eyes and pale straw ocelli. The antennae are dark brown with a large rounded pedicel, and consists of 15 segments.
The black thorax has pale hairs and short notaulices at the back. The tegulae are pale. The long clear wings have dark brown viens and hairs. The dark coxae and femora gradually lightening over the rest of the legs with pale joints.
The trapezoid, segmented, bulky (from the side)
gaster is dark neutral brown and shiney, but paler underneath and along the ploughshare. The back end is hairy.
The one inquiline species found in N. numismalis silk button galls is; Synergus albipes.
Common hyperparasites of N. numismalis silk button galls include; Aulogymnus gallarum, Mesopolobus fasciiventris, M. tibialis, Pediobius lysis and Torymus flavipes.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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Synergus gallaepomiformis
Synergus gallaepomiformis is a member of the family Cynipidae, this wasp is actually an inquiline of other cynipid wasps. In fact it is incapable of forming a gall of its own so acts as an inquiline. This is basically a wasp that lays its egg into an existing gall at an early stage to share the same food store as the gall causer. Although the causer is not directly targeted, the fight for food resource can sometimes cause the death of the gall causer, especially if the inquiline is sharing the same cavity as the causer.
The common gall hosts of this species are; Andricus albopunctatus agamic, A. aries agamic, A. callidoma agamic, A. curruptrix agamic, A. curvator sexual, A. grossulariae sexual, A. kollari agamic, A. lignicola agamic, A. quadrilineatus agamic, A. quercuscalicus agamic, A. quercusramuli sexual, A. seminationis agamic, A. solitarius agamic, Aphelonyx cerricola agamic, Biorhiza pallida sexual, Cynips quercusfolii sexual, Neuroterus anthracinus agamic, N. quercusbaccarum sexual, N. tricolor sexual and Trigonaspis megaptera sexual.
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The flight times for this wasp are from mid January through to October.
Parasitoids of S. gallaepomiformis are; Torymus flavipes.
This wasp comes in two forms. S. gallaepomiformis form A which usually exits the same year as the gall is formed and S. gallaepomiformis form B which usually exits the following year.
The female form A wasp measures in at 1.4-2.9mm with an average of 2.3mm.
The head is dark yellow to brown but always with a brown vertex. The eyes are large, brown and edged with yellow. The ocelli are small and chestnut. The antennae are deep yellow throughout the 14 segments with a short pedice, and the third segment straight.
The pronotal carina is present on the black thorax, and the straw coloured tegulae lead to the wings which are clear and hairy with pale yellow veins, along with a closed radial cell. The legs are predominatly yellow brown with dark and glossy coxae and femora.
The gaster (abdomen) starts off dark brown but tapers to yellow brown. It is not punctate.
The male form A is 1.1-2.4mm averaging at 1.8mm in length.
The head is a rich, deep yellow with a brown vertex, strongly contrasting with its dark mid sized eyes and small brown ocelli. The antennae consist of 15 segments and are deep yellow with a slight taper with a short pedicel and the third segment bent.
The thorax is again black and the pronotal carina is present. The tegulae are straw coloured and the wings are transparent with mid grey/brown hairs and pale yellow veins, with a closed radial cell. The legs are a rich deep yellow which shade to a rich deep brown. The hind coxae is darker and glossy, with some brown on the front ones.
The glossy gaster is dark brown with paler colouring underneath, and is not punctate.
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The female form B wasp measures in at 1.1-2.4mm with an average of 2.3mm.
The head is dark with dark mid sized eyes and the ocelli are small and chestnut. The antennae are deep yellow throughout the 14 segments with a short pedicel and the third segment bent.
The pronotal carina is present on the black thorax, and the straw coloured tegulae lead to the wings which are clear and hairy with pale yellow veins, along with a closed radial cell. The legs are yellow and brown with darker, high gloss rear coxae and some brown on the front coxae, otherwise rich, deep yellow which shades to a rich brown.
The gaster (abdomen) is glossy, dark brown with paler underneath. It is not punctate.
The male form B is 1.1-2.4mm averaging at 1.8mm in length.
The head is dark with mid sized dark eyes and small chestnut ocelli. The antennae consist of 15 segments and are deep yellow with a slight taper with a short pedicel and the third segment bent.
The thorax is again black and the pronotal carina is present. The tegulae are straw coloured and the wings are transparent with mid grey/brown hairs and pale yellow veins, with a closed radial cell. The legs are yellow and brown with darker, high gloss rear coxae and some brown on the front coxae, otherwise rich, deep yellow which shades to a rich brown.
The glossy gaster is dark brown with paler colouring underneath, and is not punctate.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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Synergus reinhardi
This wasp is a member of the family Cynipidae but is not a gall causing wasp, like many others. In fact it is incapable of forming a gall of its own so acts as an inquiline. This is basically a wasp that lays its egg into an existing gall at an early stage to share the same food store as the gall causer. Although the causer is not directly targeted, the fight for food resource can sometimes cause the death of the gall causer, especially if the inquiline is sharing the same cavity as the causer.
The common gall hosts of this species are; Andricus aries agamic, A. corruptrix agamic, A. kollari agamic, and A. lignicola agamic.
The flight times for this wasp are from march through to october, as well as a short spell from December to January.
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The female measures in at 1.9-4.5mm with an average of 3.5mm.
The head is black and granular with a clear definition to the edge of the mouth. The eyes are mid sized and dark brown with large, close set, brown ocelli. The antennaehas 14 segments and are pale brown, darkening to mid neutral-brown, with a chestnut edgeing to the segments. The first half of the scape is dark.
The thorax is granular and black with pronotal carina present and a black tegulae. The wings clear with heavy dark brown veins, pale hairs and a closed radial cell. The legs are generally dark in appearence with dark brown coxae and femora, with contrasting yellow-brown joints. The tibia and tarsi are dirty yellow.
The bulky, dark black/brown gaster (abdomen) has chestnut hints beneath and to the rear and is clearly punctuate.
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The male measures 1.8-3.9mm with an average of 2.9mm
The head is black and granular with a clear cut pale mouth. The eyes are mid sized and mid brown in colour with large close set, brown ocelli. The antennae have 15 segments and are pale brown darkening to neutral brown, with a slight chestnut tint on the segment ends, and have a dark scape.
The thorax is black with the pronotal carina present. The tegulae are black and the wings are clear with prominent rich, dark brown veins, pale hairs and a closed radial cell. The legs have very dark coxae and fibulae and tibiae with contrasting yellow joints. There is some brown on the first tarsel joint.
The gaster is dark brown with a paler band underneath and clearly punctuate.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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Synergus umbraculus
This wasp is a member of the family Cynipidae but is not a gall causing wasp, like many others. In fact it is incapable of forming a gall of its own so acts as an inquiline. This is basically a wasp that lays its egg into an existing gall at an early stage to share the same food store as the gall causer. Although the causer is not directly targeted, the fight for food resource can sometimes cause the death of the gall causer, especially if the inquiline is sharing the same cavity as the causer.
Synergus umbraculus is an inquiline of Andricus corruptrix agamic, A. kollari agamic, A. lignicola agamic, A. lucidus agamic, A. quercuscalicis agamic and Biorhiza pallida sexual.
Its flight period is from February through to October.
The female has a head and body length of 1.3-3.4mm with an average length of 2.5mm
The head is a black/brown vertex fading more or less to a brown, though some are darker than others, some have only brown around the mouth but never yellow. The eyes are large and dark. The antennae are mid brown with 14 segments, slender but not tapered, and a dark scape.
The thorax is all black and with pale hairs. The notaulices are full and deep. The tegulae are mid brown which lead to the wings which are clear with neutral brown veins, inconspicuous hairs and a closed radial cell. The legs are brown, gradually becoming paler towards the tarsi and with paler joints.
The gaster (abdomen) is a single main segment which is dark brown and glossy and clearly punctate There is a large ploughshare underneath.
The male measures 1.3-3.5mm with an average of 2.2mm.
The head is often bright yellow with a black vertex and contrasting large dark eyes. Some however are like the female with a black vertex which blends into brown and maybe only showing around the mouth. The antennae are normally all translucent gold but sometimes darker, with a darker scape.
The thorax is all black with pale hairs. The notaulices are deep and full. The tegulae are mid brown and the wings are clear with at the basel halves, pale brown veins, and a closed radial cell. The legs of yellow headed insects have the first two pairs of legs translucent gold and the rear pair are brown with paler tarsi. The leg colour tends to darken with the colour of the face.
The gaster has a single main segment which is clearly punctate and dark brown a translucent rear edge.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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Synergus variabilis
This wasp is a member of the family Cynipidae but is not a gall causing wasp, like many others. In fact it is incapable of forming a gall of its own so acts as an inquiline. This is basically a wasp that lays its egg into an existing gall at an early stage to share the same food store as the gall causer. Although the causer is not directly targeted, the fight for food resource can sometimes cause the death of the gall causer, especially if the inquiline is sharing the same cavity as the causer.
Synergus variabilis is an inquiline of Aphelonyx cerricola agamic. Its flight period is from March through to September.
The female has a head and body length of 1.3-2.2mm with an average length of 1.7mm
The head is a dark chestnut colour, which fades paler around the mouth. It has a black vertex and the striae radiate from the mouth to the eyes which are large and dark, contrasting with the head. The ocelli are mid brown and translucent. The antennae are testaceous yellow with 14 segments.
The thorax is black and hairy, except for the pronotum (without pronotal collar) which is a contrasting chestnut colour. The notaulices are variable from a steeply impressed short triangle to an only faintly indicated longer line. The tegulae are translucent pale brown which lead to the wings which are clear with light yellow veins and a closed radial cell. The legs are testaceous yellow with the rear, and sometimes the mid, coxae being dark brown and dark claws.
The gaster (abdomen) is a single main segment which is smooth and hairless but not high gloss. It is very dark chesnut tinged black with puncturations on the hypopygium but no punctuations on the main segment.. There is a short, broad and visible vetral spine.
The male measures 1-2.1mm with an average of 1.6mm.
The head is dark testaceous yellow fading to paler around the mouth. Larger specimens may have chestnut traces. The vertex is again black and the stiae radiate from the mouth to the eyes. The eyes, like the females are large and dark and contrast with the head, and the ocelli are a translucent mid brown. The antennae are all yellow and have 15 segments, of which the third has an excavated inner margin and is up to twice the length of the following segment.
The thorax is black and hairy, and the pronotum is without a pronotal color. The notaulices are variable from a long, feint indentation on the cuticle to a more sharpley defined short triangle. The tegulae are light brown to yellow and the wings are clear with light yellow veins and a closed radial cell.
The gaster has a single main segment with no punturations and a very dark chestnut tinged black in colour.
More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.
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