Pheromone relay networks in the honeybee: messenger workers distribute the queen's fertility signal throughout the hive.

Background: The harmonious operation of many insect societies depends upon colony-wide dissemination of a non-volatile pheromone produced by a single queen, which informs workers of her presence. This represents a major challenge in large colonies. Honeybee colonies, which can exceed 60,000 bees, are believed to solve this challenge using 'messenger' workers that actively relay the queen pheromone throughout the hive.

Ant social network structure is highly conserved across species.

The ecological success of social insects makes their colony organization fascinating to scientists studying collective systems. In recent years, the combination of automated behavioural tracking and social network analysis has deepened our understanding of many aspects of colony organization. However, because studies have typically worked with single species, we know little about interspecific variation in network structure.

Gut microbiota influences onset of foraging-related behavior but not physiological hallmarks of division of labor in honeybees.

Unlabelled: Gut microbes can impact cognition and behavior, but whether they regulate the division of labor in animal societies is unknown. We addressed this question using honeybees since they exhibit division of labor between nurses and foragers and because their gut microbiota can be manipulated. Using automated behavioral tracking and controlling for co-housing effects, we show that gut microbes influence the age at which bees start expressing foraging-like behaviors in the laboratory but have no effects on the time spent in a foraging arena and number of foraging trips.

2-Methoxybenzaldehyde effectively repels ants.

Ants can particularly make for harmful pests, infesting human homes and reducing crop yields. The damage caused by ants and the efforts to mitigate the damage are hugely costly. Broad-spectrum insecticides are used most commonly; however, due to their negative side effects, there is increasing interest in nontoxic alternatives.

Social isolation shortens lifespan through oxidative stress in ants.

Social isolation negatively affects health, induces detrimental behaviors, and shortens lifespan in social species. Little is known about the mechanisms underpinning these effects because model species are typically short-lived and non-social. Using colonies of the carpenter ant Camponotus fellah, we show that social isolation induces hyperactivity, alters space-use, and reduces lifespan via changes in the expression of genes with key roles in oxidation-reduction and an associated accumulation of reactive oxygen species.

A complete absence of indirect genetic effects on brain gene expression in a highly social context.

Genes not only control traits of their carrier organism (known as direct genetic effects or DGEs) but also shape their carrier's physical environment and the phenotypes of their carrier's social partners (known as indirect genetic effects or IGEs). Theoretical research has shown that the effects that genes exert on social partners can have profound consequences, potentially altering heritability and the direction of trait evolution. Complementary empirical research has shown that in various contexts (particularly in animal agriculture) IGEs can explain a large proportion of variation in specific traits.

The gut microbiota affects the social network of honeybees.

The gut microbiota influences animal neurodevelopment and behaviour but has not previously been documented to affect group-level properties of social organisms. Here, we use honeybees to probe the effect of the gut microbiota on host social behaviour. We found that the microbiota increased the rate and specialization of head-to-head interactions between bees.

Iterative evolution of supergene-based social polymorphism in ants.

Species commonly exhibit alternative morphs, with individual fate being determined during development by either genetic factors, environmental cues or a combination thereof. Ants offer an interesting case study because many species are polymorphic in their social structure. Some colonies contain one queen while others contain many queens.

Evolution of master sex determiners: TGF-β signalling pathways at regulatory crossroads.

To date, more than 20 different vertebrate master sex-determining genes have been identified on different sex chromosomes of mammals, birds, frogs and fish. Interestingly, six of these genes are transcription factors (- or - related) and 13 others belong to the TGF-β signalling pathway (, , , and ). This pattern suggests that only a limited group of factors/signalling pathways are prone to become top regulators again and again.

Ant behavioral maturation is mediated by a stochastic transition between two fundamental states.

The remarkable ecological success of social insects is often attributed to their advanced division of labor, which is closely associated with temporal polyethism in which workers transition between different tasks as they age. Young nurses are typically found deep within the nest where they tend to the queen and the brood, whereas older foragers are found near the entrance and outside the nest. However, the individual-level maturation dynamics remain poorly understood because following individuals over relevant timescales is difficult; hence, previous experimental studies used same-age cohort designs.

The evolution of altruism and the serial rediscovery of the role of relatedness.

The genetic evolution of altruism (i.e., a behavior resulting in a net reduction of the survival and/or reproduction of an actor to benefit a recipient) once perplexed biologists because it seemed paradoxical in a Darwinian world.

Kin selection and altruism.

Natural selection is predicated on the 'struggle for existence': life is short, cruel and, whether through predation, disease or starvation, often ends traumatically. It would seem that in such a dog-eat-dog world, organisms ought to act selfishly, and avoid reducing their fitness (expected survival and reproductive success) by expending time and energy helping others. Put another way, alleles that increase the probability of altruism - a behavior whose expression increases the fitness of recipients while decreasing that of the actor - should decrease in frequency across generations and ultimately disappear.

How to estimate kinship.

The concept of kinship permeates many domains of fundamental and applied biology ranging from social evolution to conservation science to quantitative and human genetics. Until recently, pedigrees were the gold standard to infer kinship, but the advent of next-generation sequencing and the availability of dense genetic markers in many species make it a good time to (re)evaluate the usefulness of genetic markers in this context. Using three published data sets where both pedigrees and markers are available, we evaluate two common and a new genetic estimator of kinship.