Courtship behavior in the Hawaiian cricket Laupala cerasina: Males provide spermless spermatophores as nuptial gifts

摘要

The role of sexual selection in the crickets (family Gryllidae) is well known but new forms of courtship behavior continue to be discovered. Here we describe the elaborate mating behavior of the Hawaiian endemic Laupala cerasina (subfamily Trigonidiinae) on the basis of both laboratory and field observations. We found that courtship and mating involve multiple copulations during which repeated spermatophores are transferred. Initial copulations involved the transfer of relatively small 'microspermatophores'. The final copulation results in the transfer of a considerably larger 'macrospermatophore'. We tested and rejected the hypothesis that the number of spermatophore transfers results in greater offspring sired by a given male. Matings involving only microspermatophores resulted in no offspring, whereas most matings involving micros and a macrospermatophore, or a macrospermatophore only, produced offspring. A direct examination of the contents of the microspermatophore revealed an absence of sperm, whereas examination of the macrospermatophore revealed the presence of sperm. Given that females consume the spermless microspermatophores, we conclude that the microspermatophores are a form of nuptial feeding of females by males. We discuss possible hypotheses to explain this unusual courtship system.