Hermaphroditism in icerya zeteki cockerell,and the mechanism of gonial reduction in iceryine coccids (coccoidea: Margarodidae morrison)

In the Panamanian iceryine coccid Icerya zetekiCockerell (Family MargarodidaeMorrison) all females become hermaphroditic early in the first instar; occasional males arise from unfertilized eggs, but self-fertilization is assured by the protandry of the hermaphrodite. In the development of the ovotestis, initiation of the male phase is brought about by haploidization of those germ cells destined for spermatogenesis. In both Icerya zeteki and Icerya purchasi this gonial reduction results from the degeneration and elimination of one genome during prophase. Except for minor variations in the coiling cycle of spermatocytes, the chromosomes (n=2) of I. zeteki correspond closely to those of all other haplo-diploid iceryines known. The present status of the species Icerya zetekiCockerell is reviewed, and on both taxonomicand cytological grounds is judged to be uncertain.Supported in part by National Science Foundation Grant GB — 1922.