Differences in Reproductive Potential of Two Populations of Catolaccus Grandis (Hymenoptera: Pteromalidae) and their Hybrids

Juan A. Morales-Ramos, M. Guadalupe Rojas, Edgar G. King


A new colony of the boll weevil ectoparasitoid Catolaccus grandis was introduced from Guasave, Sinaloa, Mexico to improve vigor of a 12-year-old laboratory reared stock in Weslaco, Texas. The biological characteristics of the introduced colony were compared to those of the Weslaco colony and a crossbreed of these 2 colonies. Developmental time was not significantly different among the 3 colonies, but the preovipositional period of the Sinaloa females was 3 times as long compared to the other 2 colonies. The fecundity, net reproductive rate (Ro), and intrinsic rate of increase (rm) of females from Sinaloa were significantly lower than those of females from Weslaco and the hybrid colony. Generation time (G) and doubling time (DT) were significantly longer in the Sinaloa colony. These characteristics make the Sinaloa population less desirable for mass propagation and release to control boll weevil populations than the Weslaco colony. The biological and population parameters of the hybrid colony were not significantly different from those of the Weslaco population. The implications of the observed results on the mass propagation and release strategies against the boll weevil are discussed and recommendations are presented.

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