Cooperative breeding decreases the direct reproductive output of subordinate individuals, but cooperation can be evolutionarily favored when there are challenges or constraints to breeding independently. Environmental factors, including temperature, precipitation, latitude, high seasonality, and environmental harshness have been hypothesized to correlate with the presence of cooperative breeding. However, to test the relationship between cooperation and ecological constraints requires comparative data on the frequency and variation of cooperative breeding across differing environments, ideally replicated across multiple species. Paper wasps are primitively social species, forming colonies composed of reproductively active dominants and foraging subordinates. Adult female wasps, referred to as foundresses, initiate new colonies. Nests can be formed by a single solitary foundress (noncooperative) or by multiple foundress associations (cooperative). Cooperative behavior varies within and among species, making paper wasps species well suited to disentangling ecological correlates of variation in cooperative behavior. This data set reports the frequency and extent of cooperative nest founding for 87 paper wasp species. Data were assembled from more than 170 published sources, previously unpublished field observations, and photographs contributed by citizen scientists to online natural history repositories. The data set includes 25,872 nest observations and reports the cooperative behavioral decisions for 45,297 foundresses. Species names were updated to reflect modern taxonomic revisions. The type of substrate on which the nest was built is also included, when available. A smaller population-level version of this data set found that the presence or absence of cooperative nesting in paper wasps was correlated with temperature stability and environmental harshness, but these variables did not predict the extent of cooperation within species. This expanded data set contains details about individual nests and further increases the power to address the relationship between the environment and the presence and extent of cooperative breeding. Beyond the ecological drivers of cooperation, these high-resolution data will be useful for future studies examining the evolutionary consequences of variation in social behavior. This data set may be used for research or educational purposes provided that this data paper is cited.

In social Hymenoptera, fertility and fertility signalling are often under identical hormonal control, and it has been suggested that such hormonal pleiotropies can help to maintain signal honesty. In the common wasp Vespula vulgaris, for example, fertile queens have much higher juvenile hormone (JH) titers than workers, and JH also controls the production of chemical fertility cues present on the females’ cuticle. To regulate reproductive division of labour, queens use these fertility cues in two distinct ways: as queen pheromones that directly suppress the workers’ reproduction as well as to mark queen eggs and enable the workers to recognize and police eggs laid by other workers. Here, we investigated the hormonal pleiotropy hypothesis by testing if experimental treatment with the JH analogue methoprene could enable the workers to lay eggs that evade policing. In support of this hypothesis, we find that methoprene-treated workers laid more eggs, and that the chemical profiles of their eggs were more queen-like, thereby causing fewer of their eggs to be policed compared to in the control. Overall, our results identify JH as a key regulator of both reproduction and the production of egg marking pheromones that mediate policing behaviour in eusocial wasps.

In the highly eusocial wasp, Vespula vulgaris, queens produce honest signals to alert their subordinate workers of their fertility status, and therefore they are reproductively suppressed and help in the colony. The honesty of the queen signals is likely maintained due to hormonal regulation, which affects fertility and fertility cue expression. Here, we tested if hormonal pleiotropy could support the hypothesis that juvenile hormone controls fertility and fertility signaling in workers. In addition, we aimed to check oocyte size as a proxy of fertility. To do that, we treated V. vulgaris workers with synthetic versions of juvenile hormone (JH) analogue and a JH inhibitor, methoprene and precocene, respectively. We dissected the treated females to check ovary activation and analyzed their chemical profile. Our results showed that juvenile hormone has an influence on the abundance of fertility linked compounds produced by workers, and it also showed to increase oocyte size in workers. Our results corroborate the hypothesis that juvenile hormone controls fertility and fertility signaling in workers, whereby workers are unable to reproduce without alerting other colony members of their fertility. This provides supports the hypothesis that hormonal pleiotropy contributes to keeping the queen fertility signals honest.

Some effort had been made concerning the social biodiversity of wasps in Brazil; however, few approaches have been made relating to how this taxa have adapted their nesting behavior to anthropic mixed environments. Thus, the present work aimed to survey the occurrence of social wasps in an anthropic area and their relationship with different types of nesting substrates. Increasing the knowledge of social wasps in anthropic areas would allow us to develop strategies for their conservation and management. Twenty long-term surveys were made at the Universidade de São Paulo, Ribeirão Preto campus, São Paulo State. During the searches, we collected information about wasp species and nesting substrate. A total of 20 species of 8 genera were identified, and a total of 431 active colonies were registered. Epiponini was the richest in terms of species richness. On the other hand, Mischocyttarini was represented by more active colonies. Mischocyttarus cerberus had a remarkably greater number of colonies, which agreed with the idea of preference of anthropic environments by independent founding wasps. Nesting behavior was associated with eight substrate categories. We observed that some species might express certain plasticity regarding their nesting substrate usage, whereas some expressed certain specificity. Facing the increase in the actual urbanization process and, consequently, habitat loss, this type of study might contribute towards better understanding how these insects are affected by altered environment.

In social insects, it has been suggested that reproduction and the production of particular fertility-linked cuticular hydrocarbons (CHC) may be under shared juvenile hormone control, and this could have been key in predisposing such cues to later evolve into full-fledged queen pheromone signals. However, to date, only few studies have experimentally tested this “hormonal pleiotropy” hypothesis. Here we formally test this hypothesis using data from four species of Polistine wasps, Polistes dominula, Polistes satan, Mischocyttarus metathoracicus and Mischocyttarus cassununga, and experimental treatments with JH (juvenile hormone) using the JH analogue methoprene and the anti-JH precocene. In line with reproduction being under JH control, our results show that across these four species, precocene significantly decreased ovary development when compared to both the acetone solvent-only control and the methoprene treatment. Consistent with the hormonal pleiotropy hypothesis, these effects on reproduction were further matched by subtle shifts in the CHC profiles, with univariate analyses showing that in P. dominula and P. satan the abundance of particular linear alkanes and mono-methylated alkanes were affected by ovary development and our hormonal treatments. The results indicate that in primitively eusocial wasps, and particularly in Polistes, reproduction and the production of some cuticular hydrocarbon cues are under joint JH control. We suggest that pleiotropic links between reproduction and the production of such hydrocarbon cues have been key enablers for the origin of true fertility and queen signals in more derived, advanced eusocial insects.

1. Recent studies have demonstrated that the richness of pollinators in crop systems can improve productivity due to the effect of functional trait differences between species. These findings reinforce the potential effectiveness of integrated management of both Apis and non‐Apis bees to ensure global crop yields. 2. Thus, we used meta‐analysis techniques to synthesise published literature on crop pollination and verify whether Apis and non‐Apis bees perform equivalent contributions to worldwide crop production considering the differences in both functional traits of these bees and pollination requirements of the crops. We expected that pollination by both Apis and non‐Apis bees would contribute to enhancing all crop production measures (fruit/seed weight, fruit/seed yield, no. fruit/seed, and pollination/fertilisation) independently of levels of pollination dependency. 3. The final database used in the meta‐analysis included 33 published studies, reporting 72 independent pollination experiments of A. mellifera and non‐Apis bees on crop production, including fruits, vegetables, spices, and oil crops. As expected, our results demonstrated that crop production was greater with bee pollination regardless of being provided by Apis or non‐Apis species. We also observed a stronger positive effect on flower pollination/fertilisation and production of crops with essential/great dependency on pollination. 4. The overall analysis of the contribution of Apis and non‐Apis bees to crop production indicated that both groups are essential for the maintenance of agricultural production.

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