Opposing effects of mortality factors on progeny operational sex ratio may thwart adaptive manipulation of primary sex ratio.

ABSTRACT: Despite extensive research on mechanisms generating biases in sex ratios, the capacity of natural enemies to shift or further skew operational sex ratios following sex allocation and parental care remains largely unstudied in natural populations. Male cocoons of the sawfly Neodiprion abietis (Hymenoptera: Diprionidae) are consistently smaller than those of females, with very little overlap, and thus, we were able to use cocoon size to sex cocoons. We studied three consecutive cohorts of N. abietis in six forest stands to detect cocoon volume-associated biases in the attack of predators, pathogens, and parasitoids and examine how the combined effect of natural enemies shapes the realized operational sex ratio. Neodiprion abietis mortality during the cocoon stage was sex

SUBMITTER: Moreau G 

PROVIDER: S-EPMC5496525 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature