Data from: Male-female chemical interactions in a facultatively parthenogenetic stick insect

Facultative parthenogenesis is a form of reproduction in which females can
either lay unfertilised eggs that typically develop into female offspring
only, or mate and lay fertilised eggs that develop into male and female
offspring. Facultative parthenogens often occur in mixed-sex
populations where reproduction is mostly sexual, and all-female
populations where reproduction is asexual. How all-female populations
avoid invasion by males remains unknown. Here, we
investigated the role of volatile and non-volatile (cuticular
hydrocarbons, CHCs) pheromones in the persistence of all-female
populations in the facultatively parthenogenetic stick
insect, Megacrania batesii. We found that M. batesii exhibits
slight sexual dimorphism in antenna morphology, and
behavioural assays provided little evidence that males could
locate females solely by volatile pheromones. However, CHC profiles
differed substantially between different types of
females. Analysis of CHC structure and
abundance indicated a clear genetic difference between females
from all-female versus mixed-sex populations, as well as a maternal
effect of female parthenogenesis versus sexual development.
Together, our results suggest that males might rely more
on close-range chemical cues to differentiate females, and chemical
communication could play a role in the persistence of
all-female populations.