Faculty Opinions recommendation of Social insects: Cuticular hydrocarbons inform task decisions.

AbstractChemical communication is common across all organisms. Insects in particular use predominantly chemical stimuli in assessing their environment and recognizing their social counterparts. One of the chemical stimuli used for recognition in social insects, such as ants, is the suite of long-chain, cuticular hydrocarbons. In addition to providing waterproofing, these surface hydrocarbons serve as a signature mixture, which ants can perceive, and use to distinguish between strangers and colony mates, and to determine caste, sex, and reproductive status of another individual. They can be both environmentally and endogenously acquired. The surface chemistry of adult workers has been studied extensively in ants, yet the pupal stage has rarely been considered. Here we characterized the surface chemistry of pupae of Formica exsecta, and examine differences among sexes, castes (reproductive vs. worker), and types of sample (developing individual vs. cocoon envelope). We found quantitative and qualitative differences among both castes and types of sample, but male and female reproductives did not differ in their surface chemistry. We also found that the pupal surface chemistry was more complex than that of adult workers in this species. These results improve our understanding of the information on which ants base recognition, and highlights the diversity of surface chemistry in social insects across developmental stages.

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Rapid up- and down-regulation of pheromone signalling due to trail crowding in the ant Lasius niger

Behaviour ◽

10.1163/1568539x-00003157 ◽

2014 ◽

Vol 151 (5) ◽

pp. 669-682 ◽

Cited By ~ 6

Author(s):

Tomer J. Czaczkes ◽

Christoph Grüter ◽

Francis L.W. Ratnieks

Keyword(s):

Cuticular Hydrocarbons ◽

Social Insects ◽

Glass Beads ◽

Lasius Niger ◽

Base Line ◽

Baseline Levels ◽

Line Level ◽

Pheromone Signalling ◽

Repeat Visits ◽

Pheromone Trail

Social insects often respond to signals and cues from nest-mates, and these responses may include changes in the information they, in turn, transmit. During foraging, Lasius niger deposits a pheromone trail to recruit nestmates, and ants that experience trail crowding deposit pheromone less often. Less studied, however, is the time taken for signalling to revert to baseline levels after conditions have returned to baseline levels. In this paper we study the behaviour of L. niger foragers on a trail in which crowding is simulated by using dummy ants — black glass beads coated in nestmate cuticular hydrocarbons. Ants were allowed to make four repeat visits to a feeder with dummy ants, and thus crowding, being present on the trail on all visits (CCCC), none (UUUU) or only the first two (CCUU). If dummy ants were always present (CCCC), pheromone deposition probability was low in the first two visits (54% of ants deposited pheromone) and remained low in visits 3 and 4 (51%). If dummy ants were never present (UUUU) pheromone deposition probability was high in the first two visits (93%) and remained high in visits 3 and 4 (83%). If dummy ants were present on the first two visits but removed on the second two visits (CCUU) pheromone deposition probability was low in the first two visits (61%) but rose in the second two visits (69%). This demonstrates that even after pheromone deposition has been down-regulated due to crowding in the first two visits, it is rapidly up-regulated when crowding is reduced, although it does not immediately return to the base line level.

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Differences in Long-Chained Cuticular Hydrocarbons between Males and Gynes in Cataglyphis Desert Ants

10.1101/538926 ◽

2019 ◽

Author(s):

Shani Inbar ◽

Eyal Privman

Keyword(s):

Sexual Selection ◽

Mate Choice ◽

Sex Ratio ◽

Mating Behavior ◽

Cuticular Hydrocarbons ◽

Social Insects ◽

Sex Pheromones ◽

Polar Fraction ◽

Virgin Queens ◽

First Time

AbstractCuticualar hydrocarbons play an important role in chemical communication in social insects, serving, among other things, as nestmate, gender, dominance and fertility recognition cues. In ants, however, very little is known about the precopulatory signals cuticular hydrocarbons carry. These signals may serve as affecting sex pheromones and aphrodisiacs or as reliable signals for idiosyncratic traits, which indirectly affect sexual selection. In this study, we examined, for the first time, in the Cataglyphis genus, sex-specific variability in cuticular hydrocarbons. We focused on a species that exhibits split sex-ratio and found significant quantitative differences between virgin queens and their potential mates. In an analyses of both absolute amounts and relative amounts, we found different compounds to be significantly displayed on gynes and drones, suggesting absolute and relative amounts may carry different signals influencing mating behavior and mate choice. We discuss the possible signals advertised by the non-polar fraction of these hydrocarbon profiles.

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Linear alkanes as a tool to evaluate intraspecific differences in social wasps

Ciência e Natura ◽

10.5902/2179460x33546 ◽

2018 ◽

Vol 40 ◽

pp. 62

Author(s):

Kamylla Balbuena Michelutti ◽

Claudia Andrea Lima Cardoso ◽

William Fernando Antonialli-Junior

Keyword(s):

Cuticular Hydrocarbons ◽

Social Insects ◽

Significant Variation ◽

Developmental Stages ◽

Social Wasp ◽

Social Wasps ◽

Branched Alkanes ◽

Linear Alkanes ◽

Intraspecific Relationships

Cuticular hydrocarbons are found in the epicuticle of insects and act during interactions between nestmates in social insects. Among the classes of these compounds, branched alkanes stand out acting as flags during intracolonial interactions, therefore, varying significantly intraspecificaly. However, there is evidence that linear alkanes can also act as signals in these interactions and therefore would also be important to assess intraspecific differences in colonies of social insects. Thus, the hypothesis of this study is that linear alkanes can be used as a tool to establish intraspecific relationships in a species of social wasp. Linear alkanes of all developmental stages were evaluated from colonies of the species Mischocyttarus consimilis Zikán (Hymenoptera, Vespidae). 21 linear alkanes were detected, with the majority ranging from n-C26 to n-C33. There is significant variation between the compounds of all developmental stages, both from samples of different colonies and populations. Therefore, the results validate the hypothesis that variation in composition of linear alkanes can be useful to assess intraspecific differences in social wasps.

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Behaviour and chemical signature of pre-hibernating females of Polistes dominulus infected by the strepsipteran Xenos vesparum

Parasitology ◽

10.1017/s0031182006001739 ◽

2006 ◽

Vol 134 (4) ◽

pp. 545-552 ◽

Cited By ~ 17

Author(s):

L. DAPPORTO ◽

A. CINI ◽

E. PALAGI ◽

M. MORELLI ◽

A. SIMONTI ◽

...

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Cuticular Hydrocarbons ◽

Social Insects ◽

Physiological Condition ◽

Social Wasps ◽

Polistes Dominulus ◽

Chemical Similarity ◽

Cuticular Waxes ◽

Helping Behaviour

Polistes dominulus are social wasps which are the host of the strepsipteran endoparasite Xenos vesparum. In the hibernating phase, unparasitized and parasitized wasps leave natal nests and aggregate together in sheltered quarters. In aggregations, wasps are socially active, and some individuals perform helping behaviour. Here we investigated if castrated parasitized wasps perform worker tasks in mixed aggregations. Moreover, by gas chromatography and mass spectrometry, we examined the cuticular hydrocarbons of unparasitized and parasitized wasps to evaluate if the infection alters the composition of cuticular waxes that are recognition cues in social insects. In clusters, infected females do not perform helping behaviour and they are less active than unparasitized wasps. Cuticular hydrocarbons are slightly differentiated between unparasitized and parasitized wasps but, generally, unparasitized wasps are more similar to wasps infected by Xenos females compared to wasps infected by Xenos males. Wasps infected by Xenos males do not usually survive the winter. This chemical similarity is probably a consequence of the similar physiological condition of unparasitized and female-affected Polistes wasps. At this stage, it is difficult to affirm whether these modifications are a true parasite manipulation or a consequence of infection.

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Kin-informative recognition cues in ants

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2010.2295 ◽

2010 ◽

Vol 278 (1714) ◽

pp. 1942-1948 ◽

Cited By ~ 41

Author(s):

Volker Nehring ◽

Sophie E. F. Evison ◽

Lorenzo A. Santorelli ◽

Patrizia d'Ettorre ◽

William O. H. Hughes

Keyword(s):

Theoretical Prediction ◽

Cuticular Hydrocarbons ◽

Social Insects ◽

Social Insect ◽

Social Groups ◽

High Accuracy ◽

Acromyrmex Octospinosus ◽

Insect Colonies ◽

Group Members ◽

Colony Level

Although social groups are characterized by cooperation, they are also often the scene of conflict. In non-clonal systems, the reproductive interests of group members will differ and individuals may benefit by exploiting the cooperative efforts of other group members. However, such selfish behaviour is thought to be rare in one of the classic examples of cooperation—social insect colonies—because the colony-level costs of individual selfishness select against cues that would allow workers to recognize their closest relatives. In accord with this, previous studies of wasps and ants have found little or no kin information in recognition cues. Here, we test the hypothesis that social insects do not have kin-informative recognition cues by investigating the recognition cues and relatedness of workers from four colonies of the ant Acromyrmex octospinosus . Contrary to the theoretical prediction, we show that the cuticular hydrocarbons of ant workers in all four colonies are informative enough to allow full-sisters to be distinguished from half-sisters with a high accuracy. These results contradict the hypothesis of non-heritable recognition cues and suggest that there is more potential for within-colony conflicts in genetically diverse societies than previously thought.

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Experimental modulation of external microbiome affects nestmate recognition in harvester ants (Pogonomyrmex barbatus)

PeerJ ◽

10.7717/peerj.1566 ◽

2016 ◽

Vol 4 ◽

pp. e1566 ◽

Cited By ~ 19

Author(s):

Andy Dosmann ◽

Nassim Bahet ◽

Deborah M. Gordon

Keyword(s):

Cuticular Hydrocarbons ◽

Social Insects ◽

Topical Application ◽

Nestmate Recognition ◽

Behavioral Responses ◽

Past Research ◽

Harvester Ants ◽

Pogonomyrmex Barbatus ◽

Microbial Cultures ◽

Observed Behavior

Social insects use odors as cues for a variety of behavioral responses, including nestmate recognition. Past research on nestmate recognition indicates cuticular hydrocarbons are important nestmate discriminators for social insects, but other factors are likely to contribute to colony-specific odors. Here we experimentally tested whether external microbes contribute to nestmate recognition in red harvester ants (Pogonomyrmex barbatus). We changed the external microbiome of ants through topical application of either antibiotics or microbial cultures. We then observed behavior of nestmates when treated ants were returned to the nest. Ants whose external microbiome was augmented with microbial cultures were much more likely to be rejected than controls, but ants treated with antibiotics were not. This result is consistent with the possibility that external microbes are used for nestmate recognition.

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