Sex Ratios and the Status of the Male in Pseudococcinae (Hem. Coccidae)

Abstract

1. The male of Pseudococcus is co-equal in importance with the female for the propagation of the species. Virgin females of P. citri, Risso (both aerial and root forms), P. maritimus, Ehr., P. gahani, Green, P. longispinus, Targ., and T. peregrinus, Green, are incapable of producing offspring. No form of parthenogenesis occurs in these five species. Only fertilised eggs develop.2. The relative abundance of the male sex varies greatly from species to species. The specific sex ratio of citri is 101·62± 1·54 ♂♂ per 100 ♀♀, estimated from 11,413 progeny from 47 females; that of maritimus is 59·65± 9·39 ♂♂ per 100 ♀♀, estimated from 4,630 progeny from 42 females; that of gahani is 43·025± 2·28 ♂♂ per 100 ♀♀ estimated from 12,092 progeny from 61 females; that of longispinus (for bisexual families only) is 19·28± 2·27 ♂♂ per 100 ♀♀, estimated from 4,084 progeny from 19 females; and that of peregrinus 37·01± 7·906 ♂♂ per 100 ♀♀, estimated from 3,946 progeny from 24 females.