POLYTENE CHROMOSOMES IN PUPAL AND ADULT BLACKFLIES (DIPTERA-SIMULIIDAE)

A number of pupal and adult tissues of 8 Australian blackfly species representing 3 genera, Austrosimulium [A. bancrofti, A. victoriae, A. torrentium], Cnephia [Cnephia spp., C. tonnoiri, C. strenua] and Simulium [S. ornatipes, S. melatum], were examined for the presence of polytene chromosomes. Banded polytene chromosomes were found in Malpighian tubules, hind gut, fat body and ovary, but only those from the Malipighian tubules of female adults and pupae were of good quality. A detailed comparison of polytene chromosomes from larval salivary glands and adult Malpighian tubules was made in S. ornatipes and, to a limited extent, in S. melatum. The banding patterns of chromosomes from both tissues were identical with minor differences in puffing patterns in S. ornatipes and chromocenter characteristics in S. melatum. A survey of the remaining 6 spp. shows 5 with Malpighian chromosomes suitable for detailed cytological analysis. Simultaneous studies of larval, pupal and adult polytene chromosome systems offer a novel approach to the analysis of population problems in blackflies. The ability to recognize sibling species in adults also has potential practical significance in efforts to control vectors on onchocerciasis.