Paternal signature in kin recognition cues of a social insect: concealed in juveniles, revealed in adults

Abstract

Kin recognition is a key mechanism to direct social behaviours towards related individuals or avoid inbreeding depression. In insects, recognition is generally mediated by cuticular hydrocarbon (CHC) compounds, which are partly inherited from parents. However, in social insects, potential nepotistic conflicts between group members from different patrilines are predicted to select against the expression of patriline-specific signatures in CHC profiles. Whereas this key prediction in the evolution of insect signalling received empirical support in eusocial insects, it remains unclear whether it can be generalized beyond eusociality to less-derived forms of social life. Here, we addressed this issue by manipulating the number of fathers siring clutches tended by females of the European earwig, Forficula auricularia, analysing the CHC profiles of the resulting juvenile and adult offspring, and using discriminant analysis to estimate the information content of CHC with respect to the maternal and paternal origin of individuals. As predicted, if paternally inherited cues are concealed during family life, increases in mating number had no effect on information content of CHC profiles among earwig juveniles, but significantly decreased the one among adult offspring. We suggest that age-dependent expression of patriline-specific cues evolved to limit the risks of nepotism as familyliving juveniles and favour sibling-mating avoidance as group-living adults. These results highlight the role of parental care and social life in the evolution of chemical communication and recognition cues.

Kin discrimination increases with odor distance in the German cockroach

“…Our study in a gregarious (noneusocial) insect shows that such kin recognition abilities based on odor-gene covariance (Todrank and Heth 2003) can evolve and be maintained in simple societies where the costs of nepotism are low relative to the benefits of avoiding inbreeding. The idea that the accuracy of social recognition systems may be linked to the cost/benefit balance of nepotism in insect societies is consistent with the observation that kin informative cues can be selectively masked or expressed in socially flexible species, as for instance in the European Earwig (Forficula auricularia) where CHCs specific to patrilines are concealed in juveniles but not in adults (Wong et al 2014). In this subsocial insect, odor masking may minimize kin biased competition and cannibalism among nymphs from different patrilines constituting the brood, whereas kin informative cues may favor inbreeding avoidance in adults (Wong et al 2014).…”

“…The idea that the accuracy of social recognition systems may be linked to the cost/benefit balance of nepotism in insect societies is consistent with the observation that kin informative cues can be selectively masked or expressed in socially flexible species, as for instance in the European Earwig (Forficula auricularia) where CHCs specific to patrilines are concealed in juveniles but not in adults (Wong et al 2014). In this subsocial insect, odor masking may minimize kin biased competition and cannibalism among nymphs from different patrilines constituting the brood, whereas kin informative cues may favor inbreeding avoidance in adults (Wong et al 2014). Evidence of accurate kin recognition in solitary insects also supports this hypothesis (e.g., crickets: Thomas and Simmons 2011).…”

“…Although most research on insect kin recognition has focused on eusocial Hymenoptera, it has been proposed that accurate kin recognition based on relatedness should be more common in socially simpler (noneusocial) species, with no division of labor, lowlevels of cooperation, and therefore lower costs of nepotism (Fellowes 1998;Costa 2006;Lihoreau et al 2012;Wong et al 2014). In such groups, fine scale kin recognition may favor altruistic behavior and allow for inbreeding avoidance via disassortative mating.…”

Kin recognition in a subsocial treehopper (Hemiptera: Membracidae)

“…However, their existence has never been tested. plant identity) (Panek et al, 2001;Fan et al, 2008;Yoon et al, 2012;Wong et al, 2014). In this paper, we identified for the first time cuticular non-volatile compounds of female adults and nymphs of a treehopper species.…”

“…cuticular compounds) are among the most frequently used types of communication in insects and have been mainly studied in the context of sexual selection and social recognition in bees, termites and ants (Singer, 1998;Howard & Blomquist, 2005;Mas & Kölliker, 2008;Lihoreau & Rivault, 2009;Blomquist & Bagnères, 2010;Wong et al, 2014). cuticular compounds) are among the most frequently used types of communication in insects and have been mainly studied in the context of sexual selection and social recognition in bees, termites and ants (Singer, 1998;Howard & Blomquist, 2005;Mas & Kölliker, 2008;Lihoreau & Rivault, 2009;Blomquist & Bagnères, 2010;Wong et al, 2014).…”