Resource limitation, intra‐group aggression and brain neuropeptide expression in a social wasp

Paper wasps: A model clade for social cognition

Paper wasps are a highly intelligent group of socially flexible insects with complex lives and variation in social structures. They engage in sophisticated communication within their small societies using olfaction, vibration, and even visual signals of quality or individual identity in some species. Here we describe the social biology of paper wasps as well as the impressive visual and cognitive abilities seen in this group. We summarize the recent discoveries about where and how social information is processed in the wasp brain and highlight the potential of this clade to further our understanding of the neural underpinnings of complex social cognition, its development, and its evolution.

Population size and structure of Grant's gazelle and lesser kudu in Geralle National Park, Southeastern Ethiopia

Background

Grant's gazelle and lesser kudu remain widespread within and outside protected areas. Current pressures on their populations, human encroachment and disturbance associated habitat modifications, and excessive grazing pose further threats to the species. The estimation of density and abundance of species has significant value for sustainable wildlife management in Geralle National Park (GNP) and also contributes towards a more accurate global population estimate.

Result

Using distance sampling methods, the lowest Akaike Information Criterion (AIC) (close to zero) and Chi-square tests (P value > 0.05) showed that the hazard rate key function with an un-equal interval group model was selected for estimation of density and abundance. The density of species was 1.7 ± 0.5, 2.07 ± 0.7, gazelle/km2 and 1.39 ± 0.3, 1.92 ± 0.42, lesser kudu/km2 during the dry and wet seasons, respectively. Population density, abundance, and structure showed habitat and seasonal differences in observation. More individuals of both species were recorded during the wet season as compared to the dry season. Grassland was favored by Grant's gazelle, while lesser kudu preferred woodlands. Both species exhibited a female-biased sex ratio, indicating potential for future population growth prospects.

Conclusion

It can be concluded that GNP is home to viable populations of Grant's gazelle and lesser kudu, and season has influenced population abundance and distribution due to resource availability variations among seasons. The female-biased sex ratio indicates the future population growth prospects for the two species.

Neuropeptide regulations on behavioral plasticity in social insects

Social insects demonstrate remarkable behavioral flexibility in response to complex external and social environments. One of the most striking examples of this adaptability is the context-dependent division of labor among workers of bees and ants. Neuropeptides, the brain's most diverse group of messenger molecules, play an essential role in modulating this phenotypic plasticity related to labor division in social insects. Integrated omics research and mass spectrometry imaging technology have greatly accelerated the identification and spatiotemporal analysis of neuropeptides. Moreover, key roles of several neuropeptides in age- and caste-dependent behavioral plasticity have been uncovered. This review summarizes recent advances in the characterization, expression, distribution, and functions of neuropeptides in controlling behavioral plasticity in social insects, particularly bees and ants. The article concludes with a discussion of future directions and challenges in understanding the regulation of social behavior by neuropeptides.

Impact of the social environment in insect sensory systems

The social environment has a direct impact on sensory systems and unquestionable consequences on allocation of neural tissue. Although neuroplasticity is adaptive, responses to different social contexts may be mediated by energetic constraints and/or trade-offs between sensory modalities. However, general patterns of sensory plasticity remain elusive due to variability in experimental approaches. Here, we highlight recent studies in social Hymenoptera showing effects of the social environment on sensory systems. Further, we propose to identify a core set of socially mediated mechanisms that drive sensory plasticity. We hope this approach is widely adopted in different insect clades under a phylogenetic framework, which will allow for a more direct integration of the how and why questions exploring sensory plasticity evolution.

Nutritional inequalities structure worker division of labor in social insects

Eusocial insect societies are fundamentally non-egalitarian. The reproductive caste 'wins' in terms of resource accumulation, whereas non-reproductive workers 'lose'. Here, we argue that the division of labor among workers is also organized by nutritional inequalities. Across vastly different social systems and a variety of hymenopteran species, there is a recurrent pattern of lean foragers and corpulent nest workers. Experimental manipulations confirm causal associations between nutritional differences, associated molecular pathways, and behavioral roles in insect societies. The comparative and functional genomic data suggest that a conserved toolkit of core metabolic, nutrient storage, and signaling genes has evolved to regulate the social insect division of labor. Thus, the unequal distribution of food resources can be considered a fundamental organizing factor in the social insect division of labor.