Cryptic female choice in crickets and relatives (Orthoptera: Ensifera)

In his pioneering work on cryptic female choice , Eberhard identified a wide range of mechanisms that potentially allow multiply-mated females to bias paternity in favour of certain types of male following the start of copulation. The aim of this chapter is to review critically the empirical evidence for a range of these mechanisms of cryptic female choice in crickets and relatives (Orthoptera : Ensifera ), while taking into account coevolutionary interactions between the sexes. There is compelling evidence that female crickets control the duration of spermatophore attachment and/or the uptake of sperm to the sperm storage organ to bias paternity in favour of males expressing a variety of favourable traits, or in favour of non-kin males. There is also some evidence that females can bias paternity to favour males with certain traits by choosing to remain with them for repeated mating. For other potential mechanisms of cryptic female choice, such as differential allocation of resources to the production of eggs, there is currently insufficient evidence to distinguish male-induced effects from cryptic female choice (if, indeed, such a distinction can be made). The evidence that mechanisms of cryptic female choice have resulted in coevolutionary adaptations in males is strong: males have evolved a wide range of behaviours to facilitate ejaculate transfer by deterring the female from removing the ampulla of the spermatophore prematurely, for example. How such adaptations affect the form and intensity of cryptic female choice and whether or not they result in ongoing sexually antagonistic coevolution deserve further investigation.