The egg, three larval stages and the puparium of C. aprica have been described for the first time. Each larval stage is distinctly different in size, shape of cephalopharyngeal skeleton, structure of anterior and posterior spiracles, and the distribution of spinules. The third larval stage and puparium of C. aprica were compared to the same development stages of C. minima. The most conspicuous difference in the structure of adult larvae and puparia of both species is the shape of posterior spiracles. The range of morphological features that have been taken into consideration in determining the larvae of the third stage and puparia of genus Calamoncosis was extended.
The host plant for C. aprica is common reed (Phragmites australis) This dipteran develops in galls formed on tops of this plant's stems by Platycephala planifrons (Chloropidae). Information concerning the life‐cycle of C. aprica, as well as some remarks on its biology are included in this paper.