Pre-copulatory and copulatory courtship in male-dimorphic arthropods

Abstract

Male dimorphism is an emblematic example of disruptive selection, commonly found in arthropods. However, few studies compared pre-copulatory and copulatory courtship between morphs. Our review shows that pre-copulatory courtship may be markedly different between morphs. Four processes may explain these differences: only one morph expresses traits used in pre-copulatory courtship; only the morph in good body condition can pay the courtship costs; female resistance to mating attempts of one morph leads to an increase in courtship; one morph abbreviates pre-copulatory courtship to avoid interference or injuries by the other morph. Morphs also differ in copulatory courtship, but information is restricted to copulation duration, which is usually longer for the morph exhibiting alternative reproductive tactics. Males may be spending more time in sperm removal and/or genital stimulation, which may lead to within-species genitalic divergence. We hope our review stimulates further studies on the behavior and genital morphology of male-dimorphic arthropods.