CYTOGENETIC EVIDENCE FOR 3 SIBLING SPECIES IN ANOPHELES-FLUVIATILIS (DIPTERA, CULICIDAE)

Three arrangements of chromosome arm 2 occur as homozygotes, without o bservable heterozygotes, in populations of Anopheles fluviatilis James . This indicates positive assortative mating between populations havin g different arm 2 arrangements and is taken as evidence for three sibl ing species within A.fluviatilis. This finding confirms an earlier hyp othesis that the taxon is a mixture of biological forms, which was ind icated by heterogeneity between populations in their malaria transmiss ion potential on the Indian subcontinent. Rearrangement of arm 2 invol ves two paracentric inversions, 2q1 and 2r1, giving three types of arm 2:2 + q1 + r1, 2q1 + r1, and 2 + q1r1. Photomaps of the ovarian polyt ene chromosomes are presented.