Abstract
The influence of lead (lead acetate) on the cytogenetic and external morphology of Tabanus bovinus (Tabanidae) was investigated. The effect of lead acetate (9.65 mg/1) and (0.009 mg/1) treatment on five and one generations respectively of T. bovinus was studied experimentally. From F2 till F5 reduction in hatching and malformation were found. Malformations concerned the teeth of mandible, sub-mentum, colour of pupa, adults, shape of genitalia and wings. In the F4 and F5 generation individuals with elongated legs and larvae with two gular sclerites were observed. Structure and functional abnormalities of the polytene chromosomes were found; pulverization of the chromosomes, pericentric heterozygous inversions. In the 1 chromosomes a synapsis of the homologues is almost complete, probably owing to differences at a molecular level which are not reflected in the banding pattern. The presence of different degrees of polytene and different amounts of centromere heterochromatin of the homologues of this chromosome could be result of an inhabitory effect of lead on the replication activity of both homologues.
