The spermatozoa ofContarinia, Allocontarinia, LestodiplosisandMyricomyia(Diptera, Cecidomyiidae) with considerations on the systematic relationships within the group

Abstract

The sperm structure of some genera belonging to Cecidomyiidae dipterans is reported. Spermatozoa are immotile, as their axonemal doublets are devoid of dynein arms. Sperm cells of Contarinia and related genera (Allocontarinia, Lestodiplosis, Myricomya) are characterized by a flattened tail with the plasma membrane adapted to form orderly evaginations, each containing a microtubular doublet. The results do not support the inclusion of the genera among members of the subfamily Cecidomyiinae. Syndiplosis, retained to be a synonym of Contarinia, has a different sperm structure. The results are discussed in relation to the traditional taxonomy. A hypothetical evolution of the group based on the different sperm models till now described is also proposed.