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The paper wasp Polistes dominulus is unique among the social insects in that nearly one-third of co-foundresses are completely unrelated to the dominant individual whose offspring they help to rear and yet reproductive skew is high. These unrelated subordinates stand to gain direct fitness through nest inheritance, raising the question of whether their behaviour is adaptively tailored towards maximizing inheritance prospects. Unusually, in this species, a wealth of theory and empirical data allows us to predict how unrelated subordinates should behave. Based on these predictions, here we compare helping in subordinates that are unrelated or related to the dominant wasp across an extensive range of field-based behavioural contexts. We find no differences in foraging effort, defense behaviour, aggression or inheritance rank between unrelated helpers and their related counterparts. Our study provides no evidence, across a number of behavioural scenarios, that the behaviour of unrelated subordinates is adaptively modified to promote direct fitness interests.

International audienceCoexistence of female colour morphs in animal populations is often consideredthe result of sexual conflict, where polymorphic females benefit from reduced male sexualharassment. Mate-searching males easily detect suitable partners when only one type offemale is present, but become challenged when multiple female morphs coexist, whichmay result in frequency-dependent mate preferences. Intriguingly, in damselflies, onefemale morph often closely resembles the conspecific male in body coloration, which haslead to hypotheses regarding intra-specific male-mimicry. However, few studies havequantitatively evaluated the correspondence between colour reflectance spectra from malesand male-like females, relying instead on qualitative visual assessments of coloration.Using colour analyses of reflectance spectra, we compared characteristics of the bodycoloration of ontogenetic male and female colour morphs of the damselfly Ischnura elegans.In addition, we evaluated whether males appear to (1) discriminate betweenimmature and mature female colour morphs, and (2) whether male-like females experiencereduced male mating attention and low mating frequencies as predicted fro