Keys for the identification of British Cecidomyiidae

These are the gall midges. They are small delicate flies often with few veins on the wings. The larvae of some subfamilies cause galls in plants and identifying the gall is often the best way of identifying the insect. A good start to this is Redfern & Shirley (2011) British Plant Galls published by the Field Studies Council, £28 available from http://www.field-studies-council.org/publications/pubs/british-plant-galls-%282nd-edition%29.aspx.

Venturing into the identification of adults is very difficult and is not for the faint-hearted. Some of the keys to genus require you to have a male and a female of the same species as couplets sometimes refer to one and then the other sex.

The British species have for some time been arranged in three subfamilies, Lestremiinae, Porricondylinae and Cecidomyiinae. Recent work has split the first subfamily into Lestremiinae and Micromyinae and the second subfamily into Porricondylinae and Winnertziinae. The key below differentiates Lestremiinae, Micromyinae, Porricondylinae (in the wider sense) and Cecidomyiinae. The Porricondylinae/Winnertziinae key doesn't separate the subfamilies but keys the genera of both subfamilies.

Subfamily Micromyinae

Subfamily Cecidomyiinae

In the most recent classification this subfamily has been divided into four supertribes - Brachineuridi, Cecidomyiidi, Lasiopteridi and Stomatosematidi. These are keyed in the first key here. This is tentative and I would value any feedback on it in order to improve it.

Supertribe Brachineuridi