Chemical stimuli from parents trigger larval begging in burying beetles

Abstract

In birds, nestling begging is often triggered by visual or acoustic stimuli from parents. Although begging occurs in some insects, it is not known whether it is triggered by specific parental stimuli. The burying beetle Nicrophorus vespilloides has attracted interest as an insect system for studying parent-offspring communication. Recent work on this species suggests that begging is triggered by chemical stimuli from parents. In support of this hypothesis, we found that larvae begged less toward female parents that had been washed in pentane as a means to remove chemical stimuli than toward unwashed female parents and that they begged more toward filter paper rubbed against female parents than toward untreated filter paper. Previous work on N. vespilloides suggests that chemical stimuli from parents might provide a mechanism for larval kin recognition. In support of this hypothesis, we found that larvae begged more toward breeding females than toward nonbreeding females, although there was no evidence that larvae actively avoided contact with nonbreeding females. We found no evidence that larvae discriminated between their biological female parents and unrelated breeding females. We conclude that chemical stimuli from parents trigger larval begging and may allow for larval kin discrimination. However, our results suggest that larval kin discrimination is a by-product of stimulus discrimination based on cues that are incidentally correlated with kinship rather than an adaptive mechanism for avoiding contact with nonbreeding females.