Underlying Chemical Communication in Maternal Care of a Sub-social Parasitoid Sclerodermus guani

Family life is a common phenomenon in nature and is usually associated with substantial fitness benefits for offspring. Despite the critical importance of this distinction for life history and conflict resolution theory, there is still limited knowledge of alternative functions of offspring signals. In this study, we investigated the communication between offspring and caring females of sub-social parasitoid, Sclerodermus guani, hypothesizing that potential chemical cues from their cuticular hydrocarbons (CHCs) display information about developmental stage and needs to which females respond in terms of maternal caring. The behavioral features of S. guani were systematically monitored during the different developmental stages of their offspring. The development-dependent character of CHCs enable their use as potential indicators of trade-offs between maternal care and offspring development. We found that mothers significantly preferred to chemical cues from mature larvae and pupae and took more time caring compared with solvent or chemical cues from other developmental stages. Chemical analysis revealed significant differences in the relative quantities of CHCs among different developmental stages of offspring. The characteristic odours from mature larvae, Hexadecanoic acid ethyl ester, (Z)-9-Tricosene and 1-Heptacosanol can induce the maternal transporting behavior. This study demonstrates for the first time that an offspring chemical signal reflects caring needs and influences maternal care during offspring’s developmental process. The development-dependent character of CHCs enable their use as potential indicators of trade-offs between maternal care and offspring development. This implies that the differences in CHCs facilitate and regulate interspecific communication between the parent and offspring in S. guani.