Abstract
A detailed morphological study of the immature stages of Contarinia pseudotsugae Condr., C. constricta Condr. and C. cuniculator Condr., along with their description, is presented in this paper. This work is based on examinations of several hundred larvae of each species, with numerous observations of larvae in the act of moulting and pupating which confirmed the morphological indications of three larval instars. Included also is a brief description of the galls associated with each midge species. Terminology used in the larval descriptions follows that of Möhn 1955.