Facial markings in the hover wasps: quality signals and familiar recognition cues in two species of Stenogastrinae

Abstract

Keywords:animal communication badge of status conventional signal dominance hierarchy hover wasp Liostenogaster flavolineata Liostenogaster vechti quality signal recognition system social behaviour Both recognition and conventional signals are widespread in the animal kingdom. Chemical communication plays a major role in invertebrates, and especially in social insects. In the last decade, observational and experimental evidence has shown the existence of visual quality signals and individual recognition cues in Polistes paper wasps, meaning that visual communication might also be common in insect societies. Here we show that two species of facultatively eusocial hover wasps (Vespidae, Stenogastrinae) use the visual channel for social communication. By combining morphoanatomical measurements and behavioural assays, we found that the size of the dark facial markings was related to reproductive status and dominance in colonies of Liostenogaster vechti, thus representing a badge of status. By contrast, no correlation between facial coloration and reproductive status was found in Liostenogaster flavolineata, which instead used facial markings as familiar visual recognition cues. Our results reveal that visual communication in social insects might be more widespread than previously thought and has evolved independently in distinct wasp taxa facing similar selection pressures. Ó

Speed and accuracy in nest-mate recognition: a hover wasp prioritizes face recognition over colony odour cues to minimize intrusion by outsiders

“…A pioneering experiment demonstrated that males of the stenogastrinae wasp Parischnogaster mellyi use a visual status badge during flying duels for winning a perch in aerial leks [14]. It was since found that visual communication plays a key role in the social interactions between colony members and indeed, a facial badge of status has been shown to convey information on the agonistic qualities in foundresses of the North American population of Polistes dominula and to regulate dominance hierarchies in the stenogastrinae wasp Liostenogaster vechti [10,11], but see [15,16]. Polistes fuscatus wasps are more aggressive to individuals with unfamiliar appearances landing on the nest [9] and they are able to remember the individual identity of partners after one week of interactions with several other wasps [17].…”

“…Cuticular hydrocarbons (hereafter CHCs) together with pheromones are assumed to regulate almost all social interactions, implying the chemical senses as the predominant channels of communication in insect societies [6,8]. In the last two decades, however, visual communication abilities have been discovered in two subfamilies of social wasps [9][10][11][12][13]. A pioneering experiment demonstrated that males of the stenogastrinae wasp Parischnogaster mellyi use a visual status badge during flying duels for winning a perch in aerial leks [14].…”

“…Newly emerged females may become helpers on natal nests or disperse and join other colonies where they have higher probability to jump the queue for reproduction and to monopolize reproduction (reviewed in [26]). Individuals differ in CHCs profiles according to their colony membership and each female also has a unique facial marking [11,28] (figure 1). Both chemical and visual channels mediate nest-mate recognition, and wasps presenting unfamiliar odours or faces are rejected aggressively from the nests [11,28,29].…”

“…Individuals differ in CHCs profiles according to their colony membership and each female also has a unique facial marking [11,28] (figure 1). Both chemical and visual channels mediate nest-mate recognition, and wasps presenting unfamiliar odours or faces are rejected aggressively from the nests [11,28,29]. Liostenogaster flavolineata represents a unique opportunity to understand how these senses are combined and to which extent wasps prioritize one channel over the other to discriminate aliens and nest-mates.…”

Revision of the Afrotropical species of Pristomerus (Ichneumonidae: Cremastinae), with descriptions of 31 new species

“…We suggest that the markings are involved in intra-specific communication, as contrasting markings are known to be used for this purpose in other Hymenoptera. For example, social Vespidae use individual markings for kin recognition (Baracchi et al 2013) or minimization of conflict costs (Tibbets & Lindsay 2008). Even though they are taxonomically distantly related, from a functional perspective many lepidopterans exhibit "white" surfaces reflecting UV flashes, hence favoring mate location (Brunton & Majerus 1995).…”