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Social wasps build their nests using plant material and can thereby occupy different types of habitats. The organization of their colonies is generally based on complex communication systems that include chemical compounds of the cuticle that are shared with the material of their nests thus contributing to the specific chemical signature of their colony. These compounds can vary by environmental factors, in this case the nesting substrate may interfere with this composition. However, no study to date has investigated whether there is any relationship between the chemical signature of the colony and the nesting substrate of their nests. Therefore, in this study we investigated the relationship between the colonial chemical signature and the plant in which the colonies were nesting. Colonies of three species of social wasps and samples of plants where they nested were collected, then extractions of the chemical composition of adult wasps, nest material and plants were performed. The results show that the colonies of social wasps investigated here share their chemical composition with the plants where their nests were built. Our results suggest that the plant can provide the colony with more than just a place with ideal physical conditions and safety, but also compounds that compose the colonial chemical signature.

Chemical communication is fundamental to maintain cohesion in social insect colonies, and in this communication process, cuticular hydrocarbons act as cues exchanged during interactions between nestmates. However, few studies have investigated intraspecific variation of these compounds in Neotropical swarm-founding wasps. We undertook the present investigation by performing two assessments. First, we assessed whether the cuticular chemical composition of females in Polybia sericea varies according to the degree ovarian development, relative age and different body parts. Second, we assessed whether the cuticular chemical profile of colony members and compounds found in nest materials could be used as complementary tools to assess population differences. To make these determinations, samples were collected from three different populations, and the compounds were analyzed by gas chromatography coupled with mass spectrometry. Linear alkanes were found to be the most abundant compounds in the cuticle of females and nest material. Considering the cuticular composition, it was possible to distinguish the females according to degree of ovarian development, relative age and different body parts. In addition, cuticular compounds and nest material were different in the three analyzed populations; therefore, both the cuticular chemical profile of colony members and the chemical profile of nest material can be used as complementary tools to assess population differences.

Made available in DSpace on 2020-12-10T20:09:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Nests of independent-founding primitively eusocial paper wasps are founded by one or a few females. Before worker emergence, foundresses must forage, sometimes leaving the nest unattended. Chemical defence - the application of ant repellent secretions of the Van der Vecht organ (VdVO) on the nest surface - allows brood protection when active defence is weak or not possible. After worker emergence, it is more likely that some wasps stay in the nest, so active nest defence may be more common. Given this constraint on the nest defence, selection for increasing the cuticular secretory area of the VdVO, to improve chemical defence, may be stronger in foundresses (queens) than in workers - morphological castes are hypothesized to evolve. We investigated the occurrence of morphological castes in the Neotropical paper wasp Mischocyttarus. Confirming our prediction, we found that in some (but not all) species, foundresses have a distinct increase in the secretory area of the VdVO in relation to workers; even though there is a strong overlap between caste phenotypes (incipient morphological castes). Implications of these findings for the evolution of morphological castes in primitively eusocial wasps are discussed. Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Biol, BR-14040901 Sao Paulo, Brazil Univ Fed Vicosa, Dept Biol Celular & Estrutura, BR-36570900 Vicosa, MG, Brazil Univ Estadual Paulista, Inst Biociencias Letras & Ciencias Exatas, Dept Zool & Bot, BR-15054000 Sao Jose Do Rio Preto, Brazil Univ Estadual MatoGrosso do Sul, Lab Ecol Comportamental LABECO, BR-79804970 Dourados, MS, Brazil Univ Fed Juiz de Fora, Dept Zool, Lab Ecol Comportamental & Bioacust LABEC, BR-36036900 Juiz De Fora, Brazil Univ Estadual Paulista, Inst Biociencias Letras & Ciencias Exatas, Dept Zool & Bot, BR-15054000 Sao Jose Do Rio Preto, Brazil FAPESP: 2015/05302-0

The social wasps have a remarkable system of organization in which chemical communication mediate different behavioral interactions. Among the compounds involved in this process, cuticular hydrocarbons are considered the main signals for nestmate recognition, caste differentiation, and fertility communication. The aims of this study were to describe the cuticular chemical compounds of the species Mischocyttarus consimilis, Mischocyttarus bertonii, and Mischocyttarus latior, and to test whether these chemical compounds could be used to evaluate differences and similarities between Mischocyttarus species, using gas chromatography coupled to mass spectrometry (GC–MS). Workers from these three species presented a variety of hydrocarbons ranging from C17 to C37, and among the compounds identified, the most representative were branched alkanes, linear alkanes and alkenes. The results revealed quantitative and qualitative differences among the hydrocarbon profiles, as confirmed by discriminant analysis. This study supports the hypothesis that cuticular chemical profiles can be used as parameters to identify interspecific and intercolony differences in Mischocyttarus, highlighting the importance of these compounds for differentiation of species and populations. Keywords: Chemical profile, Cuticular hydrocarbons, Mischocyttarus, Polistinae, Surface pheromones

The foraging activity in social wasps is complex behavior that involves the ability to locate and transport the resources necessary for the colony. The activity is opportunistic and generalist, sometimes adapting to the availability of the resources when the colonies are exposed to critical environmental conditions. The aim of this study was to evaluate the opportunistic behavior of two species of wasps of the genus Polybia for the capture and storage of prey in the form of flights of winged. Five colonies of Polybia occidentalis (Olivier) and two colonies of Polybia paulista (L.) were collected. Six of them contained stored winged of termites, and one contained winged of ants. The results indicated that these two species practice an opportunistic foraging strategy and are able to store large quantities of protein resources in their colonies.

SUMMARYSocial wasps can face many challenges during their colony cycle, including the presence of parasites. The order Strepsiptera is among the main parasites of the wasp genus Polistes. The aim of this study was to evaluate the effect of an endoparasite species on the host Polistes ferreri, with the hypothesis that females of this social wasp would undergo morphophysiological alterations as well as changes in their cuticular chemical profile caused by the obligate endoparasite. On average, parasitism was found in 10% of the colonies studied. All the parasitized females showed filamentous ovarioles without developing oocytes, which indicates a physiological castration. Moreover, the endoparasites present in the gaster of females caused its volume to increase, and the presence of endoparasites changed the cuticular chemical profiles of females, confirming our hypothesis. It is likely that this parasitism effect could hamper the maintenance of wasp colonies.