''Neuroterus anthracinus'' is a widely distributed

gall wasp Gall wasps, also incorrectly called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1,300 species of this generall ...

that forms chemically induced leaf

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external Tissue (biology), tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissu ...

s on oak trees. ''N. anthracinus'' has both sexual and

agamic Religion *Āgama (Buddhism), a collection of Early Buddhist texts *Āgama (Hinduism), scriptures of several Hindu sects *Jain literature (Jain Āgamas), various canonical scriptures in Jainism Other uses * ''Agama'' (lizard), a genus of lizards ...

generations and in consequence forms two distinct galls, the oyster gall and April-bud gall. Darlington, Page 160

Synonyms

''Ameristus'' Förster 1869, ''Diplobius'' Kinsey 1923, ''Dolichostrophus'' Ashmead 1887, ''Neospathogaster'' Kinsey 1923, ''Spathegaster'' Hartig 1840, furunculus Beyerinck 1882, ''ostreus'' Giraud 1859, ''ostria'' Hartig 1840, ''Andricus ostreus'', ''Neuroterus schlechtendali'' and ''Andricus furunculus'' are all previous nomenclatures found in the literature.

Galls

The oyster gall is found on the leaf underside, rarely above, and is around 0.3 cm across, located between the midrib and the lateral veins. It develops under the lower epidermis and when it emerges it has two flaps of valve-like tissue which remain, even after the gall has fallen. The gall has also been recorded as green, brown, pink and even with red spots. The April-bud gall is of brief duration, the bud swelling and the insect emerging within a week from the smooth and oval 0.8 cm gall, tucked up within the bud scales. The old galls show the escape aperture clearly.

Life cycle

Eikennapjesgal Neuroterus albipes forma laeviusculus-levelsadjust-mask

Agamic generation

Emerging in autumn the parthenogenetic female of the agamic generation developed in the unilocular and unilarval bean-shaped structure, which is about 0.8 cm across, known as the 'oyster gall'; they lay eggs within the buds which result in the bisexual generation.Stubbs, Page 48

Sexual generation

The males and females emerge from the unilocular and unilarval April-bud galls in the terminal or axillary buds around May; their fertilised eggs placed in the leaf lamina result in the Oyster gall.

Parasites and inquilines

Several

parasites Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

and

inquiline In zoology, an inquiline (from Latin ''inquilinus'', "lodger" or "tenant") is an animal that lives commensally in the nest, burrow, or dwelling place of an animal of another species. For example, some organisms such as insects may live in the h ...

s are found in both the sexual and agamic phases.

References

;Notes ;Sources * Darlington, Arnold (1975) ''The Pocket Encyclopaedia of Plant Galls in Colour.'' Pub. Blandford Press. Poole. . * Stubbs, F. B. Edit. (1986) ''Provisional Keys to British Plant Galls''. Pub. Brit Plant Gall Soc. .

External links

Checklist of Cynipid wasps
{{Taxonbar, from=Q14529693 Cynipidae Gall-inducing insects Hymenoptera of Europe Insects described in 1838 Oak galls Taxa named by John Curtis