Alternation of sex ratio in a partially bivoltine bee, Megachile rotundata (Hymenoptera: Megachilidae)
Annals of the Entomological Society of America
Parental investment and sex ratio theory. Spring-emergent adults produce two types of offspring: those that develop directly to adult stage by mid-summer, and those that diapause to the following spring. Sex ratio of summer-emergent progeny biased toward females (because some spring-emergent males should still be around, although they found this to be highly unlikely), sex ratio of diapausing progeny biased toward males (regardless of whether they came from spring or summer generation). Importantly, diapausing progeny are 50% larger than summer-emergent brood
Tepedino, V. J., and F. D. Parker. 1988. Alternation of sex ratio in a partially bivoltine bee, Megachile rotundata (Hymenoptera: Megachilidae). Annals of the Entomological Society of America 81:467-476.