Paternity assurance and altered roles in the mating behaviour of a giant water bug, Abedus herberti (heteroptera: Belostomatidae)

Abstract

Natural selection theory predicts that male brooding giant water bugs, Abedus herberti Hidalgo, should possess paternity assurance mechanisms and have altered roles in courtship. Mating behaviour of this species was studied to check these predictions. Females were aggressive in courtship, but male ‘display’ was an essential element. Copulation always preceded oviposition, and copulation and oviposition were cyclical events under male control. Females engaged in cyclical polyandry in the laboratory, and this threat under natural conditions presumably favoured the male-dominated system of alternating bouts of copulation and oviposition. Male and gravid female bugs seemed equally eager to exchange brooding services for eggs under laboratory conditions. Courtship roles are discussed in relation to relative parental investment and availability of eligible males.