FLAGELLAR AXONEMES WITH 10 MICROTUBULAR DOUBLETS IN SPERMATOZOA FROM GALL-MIDGES (DIPTERA, CECIDOMYIIDAE)

The spermatozoa of some gall-midges (Cecidomyiidae, Lestremiinae), bel onging to the tribe Micromyini, were seen to have an axoneme that cons ists of 10, instead of nine, microtubular doublets surrounding a centr al cylinder. In some related species within the same tribe the axoneme was found to contain a similar cylinder but to have nine doublets, as in typical flagella, or to have nine doublers and no central structur e. These three types of axonemes can be given the shorthand designatio ns ''10+cyl'',''9+cyl'', and ''9+0''. The tribe Lestremiini is charact erized by a giant axoneme having 150 doublets in two rows reversely or iented. Other characteristics of examined spermatozoa are the electron density of the B-tubules of the axoneme, a feature shared by all memb ers of the subfamily Lestremiinae, and the presence of a prominent cyt oplasmic droplet containing numerous, regularly spaced microtubules, w hich is shared by all Micromyidi. These axonemal models are discussed from a phylogenetic point of view.