PHYSIOLOGICAL ECOLOGY Reproductive Potential of Overwintering, F1, and F2 Female Boll Weevils (Coleoptera: Curculionidae) in the Lower Rio Grande Valley of Texas

The feeding and oviposition activity of overwintering boll weevils,Anthonomus grandis grandis (Boheman), and seasonal ßuctuations in development, survival, and reproduction of progeny of overwintering and Þrstand second-generation boll weevil females were determined in the laboratory at 27 C, 65% RH, and a photoperiod of 12:12 (L:D) h. During the cotton-free period in the Lower Rio Grande Valley, female boll weevils without access to cotton resorb their unlaid eggs and enter reproductivediapause.However,when theywereprovideddailywithgreenhouse-growncotton squares, commencement of oviposition began after 7, 15, or 20 d, depending on when they were captured. Females captured later in the winter fed longer before laying eggs than those captured in the early fall, suggesting that it may take females longer to terminate diapause the longer they have been dormant. The rate of feeding by females was signiÞcantly less during thewintermonths, and this may have affected the rate of diet-mediated termination of dormancy. Females of the Þrst and second generations after the overwintering generation produced a signiÞcantly higher percentage of progeny surviving to adulthood and ahigher proportionof these progenywere females.Offspringdevelopment time from overwintering female parents was signiÞcantly longer than that from Þrst and second generations under the same laboratory conditions. The total number of lifetime eggs produced by females of the second generation during the cotton-growing season were 9.9-fold higher than for overwintering females and 1.5-fold higher than for Þrst-generation females. Life table calculations indicated that thepopulationof second-generationbollweevils increased an averageof 1.5-foldhigher each generation than for females of the Þrst generation and 22.6-fold higher than for overwintering females. Our data showed variation in boll weevil survival, development, and reproductive potential among the overwintering and Þrstand second-generation females, suggesting inherent seasonal ßuctuations in these parameters.