''Rabdophaga marginemtorquens'' is a

gall midge Cecidomyiidae is a family of diptera, flies known as gall midges or gall gnats. As the name implies, the larvae of most gall midges feed within plant tissue, creating abnormal plant growths called galls. Cecidomyiidae are very fragile small in ...

which forms

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or war ...

s on

willow Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

s (''Salix'' species) and is found in Europe. It was described by

Johann Jacob Bremi-Wolf Johann Jacob Bremi-Wolf (25 May 1791, Dübendorf – 27 February 1857, Zürich) was a Swiss entomologist and ''Kunsthandwerker'' (artist wood turner) in Zürich.Guyet, E. V., 1974 ''Vom Naturalienkabinett der Naturforschenden Gesellschaft in Zür ...

in 1847.

Appearance of the gall

The eggs are laid between the bud scales in the spring. The gall is a short or long downward, hairless, roll containing one or several yellowish-red or orange larvae. The galls are of varying lengths, often run together and often have orange, red or white patches. There are two or three generations in a year, with the summer generations pupating in the gall and the autumn generation pupating in the soil. It is found on white willow ( ''S. alba''), goat willow ( ''S. caprea''), grey willow ( ''S. cinerea''), violet willow ( ''S. daphnoides''), olive willow ( ''S. elaeagnos''), purple willow ( ''S. purpurea'') and common osier ( ''S. viminalis''). According to Redfern et al (2011) the gall is only found on ''S. viminalis'' in Great Britain.

Distribution

The insect has been found in

Armenia Armenia, officially the Republic of Armenia, is a landlocked country in the Armenian Highlands of West Asia. It is a part of the Caucasus region and is bordered by Turkey to the west, Georgia (country), Georgia to the north and Azerbaijan to ...

, Germany, Great Britain, Lithuania, the Netherlands, and Sweden.

Inquiline

'' Rabdophaga roskami'' (Stelter, 1989) is probably an

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 ...

of ''R. marginemtorquens''.

References

marginemtorquens Gall-inducing insects Insects described in 1847 Nematoceran flies of Europe Taxa named by Johann Jacob Bremi-Wolf Willow galls {{Bibionomorpha-stub