2024-03-29T11:42:08Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/496002022-11-17T02:08:08Zhdl_2115_20046hdl_2115_138Female-biased sex allocation in wild populations of the eriosomatine aphid Prociphilus oriens: local mate competition or transgenerational effects of maternal investment?1000030175161Akimoto, Shin-ichiMitsuhashi, RyotaYoshino, Tomokoopen accessThe final publication is available at www.springerlink.comEriosomatinaeParental investmentParthenogenesisPatchPolymorphismSex ratio468Several aphid species exhibit female-biased sex allocation. Local mate competition (LMC) has been postulated to be the evolutionary factor of the female-biased sex allocation. We estimated individual sex allocation in the eriosomatine aphid Prociphilus oriens and explained the observed pattern of sex allocation based on a hypothesis other than LMC. On the basis of the relationship between maternal body size and brood size, we estimated the cost of producing a female to be 1.85 times the cost of producing a male. The population-wide allocation to males was 22%-24 %. Winged mothers exhibited a large variation in the number of male and female embryos they had, including 23%-30 % of winged mothers producing only female embryos. There was polymorphism in the sex-ratio expression. Thus, the constant male hypothesis assuming LMC was not supported. Winged mothers that produced an all-female brood contained larger female embryos than did mothers that produced a bisexual brood. Previous studies have indicated that a large sexual female produces a single large egg, which hatches into a first-instar larva containing a larger amount of gonads. Thus, in eriosomatine aphids, maternal investment in daughters directly affects the potential fecundity of granddaughters, whereas investment in sons does not. We propose a hypothesis that higher fitness returns from maternal investment in daughters than in sons may have primarily led to the evolution of highly female-biased sex allocation in P. oriens.Springer Japan2012-07engjournal articleAMhttp://hdl.handle.net/2115/49600https://doi.org/10.1007/s10144-012-0312-y1438-3896Population Ecology543411419https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/49600/1/PE54-3_411-419.pdfapplication/pdf704.04 KB2012-07