Differences in reproductive potential of two populations of Catolaccus grandis (Hymenoptera : Pteromalidae) and their hybrids

A new colony of the boll weevil ectoparasitoid Catolaccus grandis was intro duced from Guasave, Sinaloa, Mexico to improve vigor of a 12-year-old labor atory reared stock in Weslaco, Texas. The biological characteristics of the introduced colony were compared to those of the Weslaco colony and a cross breed of these 2 colonies. Developmental time was not significantly differe nt among the 3 colonies, but the preovipositional period of the Sinaloa fem ales was 3 times as long compared to the other 2 colonies. The fecundity, n et reproductive rate (R-o), and intrinsic rate of increase (r(m)) of female s from Sinaloa were significantly lower than those of females from Weslaco and the hybrid colony. Generation time (G) and doubling time (DT) were sign ificantly longer in the Sinaloa colony. These characteristics make the Sina loa population less desirable for mass propagation and release to control b oll weevil populations than the Weslaco colony. The biological and populati on parameters of the hybrid colony were not significantly different from th ose of the Weslaco population. The implications of the observed results on the mass propagation and release strategies against the boll weevil are dis cussed and recommendations are presented.