PUPATION SITE AND EMERGENCE TIME INFLUENCE THE MATING SUCCESS OF BAGWORM FEMALES, OIKETICUS-KIRBYI

In commercial oil palm plantations in Costa Pica, we tested the hypoth eses that pupation site and emergence time affect the mating success o f protogynous female bagworms, Oiketicus kirbyi (Guilding) (Lepidopter a: Psychidae). Greater proportions of female than male pupae on upper leaves of oil palms and greater proportions of mated females in the up per rather than lower crown strata support the hypothesis that selecti on of pupation site by female larvae influences the mating success of adults. Increasing captures of males with increasing trap height furth er suggest that enhanced mating success of females in tree tops may be attributed either to most effective dissemination of sex pheromone on higher sites, or to males foraging predominantly in the upper strata of oil palms. As the majority of females pupated in the middle rather than upper crown of oil palms, selection of pupation site by females m ay be affected by additional as yet unknown factors. Emergence of fema les significantly preceded emergence of males. Increasing proportions of mated females throughout the emergence season probably resulted fro m an increased 'availability' of males. In tropical rainforests with l ocal variations in O. kirbyi developmental time and stage, protogyny m ay represent an evolutionary strategy that furthers outbreeding.