Reproductive and brood-rearing strategies in Alchisme grossa (Hemiptera: Membracidae): genetic analyses of kinship relationships

Abstract

Alchisme grossa is a treehopper species showing maternal care until at least the third nymphal instar. A secondary female treehopper has frequently been observed near a family (primary female guarding its egg clutch). Intraspecific brood parasitism, communal breeding or alloparental care may be suggested as possible mechanisms to explain secondary female presence. To distinguish between these phenomena, we performed relatedness analyses of genetic samples of groups including one A. grossa primary female, a secondary female and the associated offspring using polymorphic microsatellites. Furthermore, we characterized the behavioral interaction between both females during maternal care and the reproductive strategy (monandry or polyandry) of A. grossa females by estimating the number of male parents. We observed the presence of secondary females in 35.9% of monitored families. The behaviors characterized suggest the occurrence of brood parasitism in the interaction between both females. Nevertheless, all offspring within a family were descendants only of the primary female and a single male, thus showing that A. grossa females are monandrous. The results, taken together with data on the reproductive biology reported for other treehoppers, are consistent with the occurrence of brood parasitism in A. grossa.