Among the insects which do serious damage to grasses grown for seed, the larvae of gall midges (Cecidomyidae) are of great importance. Very little is known about their bionomics, except in the case of the Sorghum midge (Contarinia sorghicola), and the Meadow Foxtail midges (Dasyneura alopecuri, Contarinia merceri, and Stenodiplosis geniculati). In view of this and the fact that several grasses are grown for seed with advantage in Great Britain, it has been thought advisable to collect together all the available information.