Descriptions and Habits of Cecidomyiidae (Diptera) from White Spruce Cones

Abstract

Taxonomically, the Cecidomyiidae (Gall Midges) are a difficult group. Many species have been described using colour of freshly killed specimens as the principal criterion for identification (Felt, 1907a). As dead specimens seldom retain their original colour, subsequent determinations based on this characteristic are almost impossible. Morphological characteristics which separate the genera are fairly distinct and therefore acceptable but those used to separate the species, namely, the number and shape of the antenna1 segments (Barnes, 1932), were found to be quite variable in the species studied. Species are more easily identified if, in addition to their morphology, something is known of their biology. In this paper, descriptions and notes on the biology of five gall midges from white spruce cones are given. In addition, the literature on all species from white spruce is reviewed.