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Social aggression is a pervasive feature of insect societies. In eusocial Hymenoptera, aggression among females can affect task performance and competition over direct reproduction (egg laying); in most species males participate in social interactions relatively rarely. Males of the independent-founding paper wasp Mischocyttarus mastigophorus are exceptional: they are aggressive toward female nestmates, leading us to explore the function of this unusual behavior. We applied social network analyses to data on M. mastigophorus social aggression to quantify sex differences in giving and receiving social aggression. The network analyses supported the pattern of biased male aggression toward female nestmates; females are relatively rarely aggressive to males. We then asked whether male aggression toward females was biased by females’ relative ovary development. Males were more aggressive toward females with better-developed ovaries, opposite to patterns of aggression among females. Because food brought to the colonies is often monopolized by dominant females, we suggest that males direct aggression toward socially dominant females with better-developed ovaries to obtain food. The implications of biased male aggression for female task performance and physiology are unknown.

The dominance-nutrition hypothesis predicts that nutritional intake and energetic costs in adulthood interact to drive behavioral and physiological differences between females in primitively eusocial insects, and thereby affect reproductive caste. We tested predictions of this hypothesis in independent-founding Mischocyttarus pallidipectus paper wasps. We measured stable isotope tissue composition to compare nutritional status before adult emergence and among adult females. Adult tissue δ15N content (an indicator of feeding at a higher trophic level because it is enriched in animal prey relative to plant-based foods) was significantly higher in adults than at the end of pupal development, suggesting adult nutrition affects δ15N content after the end of pupal development. We then asked if behavior and nutritional status predicted ovary development. We measured ovary development, nitrogen and carbon stable isotope ratios, dominance behavior, and task performance (foraging, as indicated by time spent on the nest) for adult female wasps. We used social network analysis to quantify differences in social status between females with developed and undeveloped (filamentous) ovaries. Dominant females spent more time on the nest and were significantly more enriched in δ15N than subordinate females. These data support the dominance-nutrition hypothesis: adult behavior and energy expenditure, and access to animal-based diets, correspond to female reproductive physiology, and may play a role in adult-stage caste determination. Within animal social groups, differential access to resources can affect differences in reproductive success. This may affect caste determination in eusocial colonies, where reproductive tasks are divided between female castes, with a queen (or multiple queens) capable of egg-laying and helped by sterile workers. Female sterile workers and reproductives of some social Hymenoptera are morphologically similar at adult emergence, suggesting that adult experience may impact caste status. We asked whether patterns of nutritional physiology in Mischocyttarus pallidipectus paper wasps matched adult-stage caste determination by testing predictions of the dominance-nutrition hypothesis, which states that adult nutrition and energetic costs of tasks shape reproductive female development through behavioral and physiological changes.

Urine contains multiple water-soluble hormones, which are valuable non-invasive biomarkers for the monitoring of reproductive status and health. An effective method for drying urine on filter paper was previously developed to preserve wildlife urine samples where electrical equipment was not available for this; however, the stability of samples preserved in this way remains to be verified. Here, we developed and validated a method to elute multiple water-soluble reproductive hormones from filter paper that had been stored for an extended period of time. Aliquots of urine from chimpanzees were adsorbed on filter papers, air dried and stored for 1 year at room temperature. Estrone-3-conjugate (E1C), pregnanediol-3-glucuronide (PdG), estriol-3-glucuronide (E3G), and chorionic gonadotropin (CG) were eluted into deionized water from the filter papers and measured using enzyme immunoassays (EIAs). The mean recoveries of E1C, PdG, and creatinine from filter papers stored for 1 year were 69.5%, 128.7%, and 83.8%, respectively. The profiles of E1C and PdG from preserved filter papers significantly correlated with those derived from a direct analysis of the frozen urine of menstruating chimpanzees. We detected E3G and CG from 1-year-old filter papers for urine collected during early pregnancy, but the recovery of E3G was low and CG profiles did not correlate with those of the original frozen urine samples. The method proposed here for the elution and measurement of reproductive hormones in urine preserved for a long period of time on filter paper provides a practical and simple way to monitor the reproductive status of chimpanzees. We propose that this method can also be utilized in field studies of other wild nonhuman primates.

When helpers from cooperative breeding animals have some expectation of direct reproduction, there is potential for conflict over how much aid they should provide to the colony. For example, if food is shared among all colony members, then higher levels of foraging by a helper would be desirable for the colony as a whole. However, because foraging is risky and physiologically costly, hopeful reproductive helpers could avoid foraging. Evidence suggests that this work-conflict could be resolved if helpers are aggressively coerced by their nestmates to provide aid. Here, we showed that in the primitively eusocial paper wasp Polistes versicolor, colony food starvation leads to an increasing in aggression that results in an increasing activity level (including foraging). We propose that aggression affects forage levels because (i) attacks from nestmates are directed toward known foragers rather than non-foragers; and (ii) resting wasps generally respond to aggression by becoming more active while already active wasps generally respond by switching the task they were doing. In P. versicolor, direct reproduction is an option for helpers. It means that they can be considered as hopeful reproductive individuals seeking to avoid performing risky behaviours, like foraging. In this sense, decentralized aggression from nestmates could be a coercive mechanism to force wasps performing undesirable tasks, while simultaneously enhancing the performance of a variety of other tasks.

In cooperative breeders, subordinates that have alternative reproductive options are expected to stay and help dominant breeders only as long as they contribute to group productivity, if their fitness is linked with colony success. Female Polistes dominula paper wasps live as cooperative breeders in small groups of typically fewer than 10 females. Subordinates tend to have high-quality outside options, and so could choose alternative breeding tactics if their work efforts increased productivity negligibly. In the founding stage before workers emerge, we tested the effect of various predictors on nest growth, as a proxy for group productivity, and explored the shape of the relationship between group size and nest growth. We found group size to be the only significant predictor of nest growth: variation among body sizes within the group showed no effect, suggesting a lack of size-dependent task specialization in this species. Average body size and average genetic relatedness between group members similarly showed no effects on nest growth. Group size had a non-linear effect so that per-capita benefits to nest growth decreased in larger groups, and groups of 10 or more would benefit negligibly from additional group members. Hence, females might be better off pursuing other options than joining a large group. This finding helps to explain why P. dominula groups are usually relatively small in our study population. Further studies may illuminate the mechanisms behind the smaller per-capita nest growth that we found in larger groups. Significance statement Identifying which factors influence the productivity of animal groups is key to understanding why different species breed cooperatively in groups of varying sizes. In the paper wasp Polistes dominula, we investigated the growth rate of nests as a measure of group productivity. We found that average body size, the variation in body sizes within the group, and average genetic relatedness between group members did not affect nest growth, while group size had a strong, positive effect: nests grew faster with more group members, but the per-capita benefit decreased in larger groups. The addition of extra group members in groups of 10 or more had negligible effects on nest growth. Hence, wasps may be better off pursuing other options than joining large groups. This finding helps to explain why groups normally consist of fewer than 10 wasps in this population. Electronic supplementary material The online version of this article (10.1007/s00265-018-2502-x) contains supplementary material, which is available to authorized users.

Division of labor in social groups can be influenced by differential nutrition. Consumption of more food or higher-quality food often affects individuals’ capacities for reproduction. In social insects, nutrients consumed during immature (e.g., larval) stages often affect adult reproductive capacity, but adult nutrition may also impact reproductive status. This study tested whether ovary development, an indicator of reproductive status, corresponded to higher trophic-level feeding for adults in the primitively eusocial paper wasp Mischocyttarus mastigophorus. Our main prediction was that females’ ovary development would correlate positively with evidence of feeding at higher trophic levels, as indicated by stable isotope ratios of nitrogen (δ15N) and carbon (δ13C). We first asked whether isotope ratios of mature females co-varied with ovary development. δ15N values were higher for mature females with better-developed ovaries, as expected if they fed on a diet richer in animal tissue. There was a negative relationship of δ13C with ovary development in mature females, as would be expected if females with developed ovaries had higher body lipid stores. To test for evidence of nutritional biasing of caste during immature development, we measured changes in isotope ratios across pupal development leading up to early adulthood (i.e., immediately before and after adult eclosion). The δ15N and δ13C values for mature pupae were similar to those of newly emerged adults and to those of mature adults lacking developed ovaries. In contrast, mature females with developed ovaries showed N-isotope signatures of a more prey-based diet and C-isotope signatures of elevated lipid content. We conclude the N and C isotopic signatures of ovary-developed mature females diverged from their levels at the end of immature development. The findings suggest reproductive caste status was associated with differences in nutrient acquisition and reflects differences in consumption of animal-derived versus plant-based foods during adulthood. Pre-adult nutrition is known to affect caste development, and thereby influence division of labor, in diverse insect societies. In temperate independent-founding (IF) paper wasps, the effects of larval nutrition on adult caste may reflect adaptations for overwintering and diapause by reproductive females. We asked whether adult nutritional content showed caste-related trophic differences in the Neotropical IF paper wasp Mischocyttarus mastigophorus. Previous studies suggested interactions among adult nest-mates affected food sharing and caused biased nutrient flow within colonies. Our data suggest adult nutrition affected reproductive physiology. We propose this pattern may be widespread in tropical IF paper wasps, where opportunities for adult reproductive plasticity are favored by long colony cycles and relatively aseasonal nest founding.

Inter-specific variation in the occurrence of individual recognition (IR) has mostly been examined in species that differ with respect to two critical conditions necessary for such ability: presence of complex social behaviours and sender’s distinctiveness. However, variation in IR when species share such conditions is lesser known. We tested for IR in the paper wasp Polistes versicolor and compared the results with published information on IR in Polistes fuscatus. Both species have a flexible nest-founding behaviour and form dominance hierarchies. Additionally, both have individually distinctive facial patterns. P. versicolor faces are highly variable, and they do not appear to be associated with individual quality, consistent with the role as cues in IR. However, the wasps did not discriminate between nestmates with familiar and unfamiliar faces. Besides, wasps did not discriminate between familiar and unfamiliar social partners. Familiar discrimination (discrimination of individuals based on prior social interactions) is considered the first stage toward IR; therefore, P. versicolor wasps, unlike P. fuscatus, lack the ability for IR. Our results suggest that the high variation in colour pattern may not be a good proxy for the occurrence of IR in paper wasps and that neutral variation may be an underestimated factor promoting phenotypic variability. High inter-individual phenotypic variability in primitively eusocial paper wasps has sometimes been considered to be a result of selection for efficient individual identity signalling, especially because senders may benefit from being individually recognised. P. versicolor paper wasp females have highly variable inter-individual facial patterns. However, we demonstrated that they lack individual recognition. After excluding some potentially confounding hypothesis, we conclude that selection for efficient individual identity signalling is not the only factor promoting phenotypic variability in paper wasps and that at least in some species, neutral variation may play a role.

We investigated the effect of kinship on mate selection by males of the neotropical primitively eusocial paper wasp Polistes versicolor. By conducting short-time, paired, consecutive, dyadic encounters, in which a male was randomly introduced separately to a related and an unrelated female in a small glass arena, we were able to observe and measure the male sexual display. We found that male sexual interest toward a female was not affected by kinship, even after controlling the differences in female behavior. Despite our finding that males were as eager to harass females, regardless of kinship, previous evidence suggested that incestuous copulation (inbreeding) in natural populations of P. versicolor appeared to be avoided. We suggest that in the natural mating habitat of the native population that we studied, in which many colonies were able to produce males and reproductive females in a short time window, the probability of finding related sexual partners was low, hence, intersexual kin discrimination did not evolve.

Various animals build nests with defensive structures to deter predation on offspring. Construction of nest defensive structures can reduce the probability of predation but will involve various costs. Here, we examined both the costs and benefits of the construction of a nest defensive structure in a paper wasp, Polistes chinensis antennalis, and clarify whether the paper wasp changes the level of defensive structures of nests depending on predation risk. A foundress (queen) of the paper wasp starts a colony in spring and maintains her nest alone until the emergence of workers. At this stage, pupae in the nests are sometimes preyed on by conspecifics of other nests. The intruder needs to break the cocoon, which seals the entrance of the cell, to extract the pupa from the cell. Foundresses often apply nest material (pulp) to the surface of cocoons in their nests. We found that pulp on a cocoon increased the time an intruder required to break the cocoon. This result shows that the pulp structure on cocoons helps to prevent predation on pupae. On the other hand, pulp on cocoons involved costs, including time required to collect pulp and being a potential obstacle to the emergence of workers from the cocoon. Additionally, we found that the amount of pulp on cocoons was greater in nests under higher predation risk than nests under lower predation risk. These results suggest that pulp on cocoons is a nest defensive structure, and foundresses adjusted the construction of the defensive structure depending on predation risk.

The intentional reintroduction and translocation of animals and plants has, over the last few decades, become an integral part of the panoply of conservation tools. In a recent published paper in J. Insect Conserv. (doi: 10.1007/s10841-016-9911-9 ), Khelifa et al. (2016) claimed to have restored the last relict population of Urothemis edwardsii (Selys) in the Mediterranean. Here, I provide evidence that their claims are unwarranted, and that what has occured is a natural process of colonisation by a Critically Endangered population which was confined to a single known site. In addition to several inaccuracies contained in the paper, I will demonstrate that the work was inappropriate and question the adopted methodology that may imperil the type population of U. edwardsii. I urge for the translocation initiative to be discontinued and discuss other safe approaches that may benefit the newly expanding population.

Cuticular hydrocarbons (CHCs) are information-rich signals in social insects that coordinate behaviors within nests. However, in some taxa, the precise information conveyed by CHCs is poorly understood. In particular, there is a debate over whether CHCs convey information about their bearer's dominance or fertility. Distinguishing between dominance and fertility signaling is difficult because fertility and rank are frequently correlated within social insect colonies. This study disentangles those relationships by examining CHCs of Polistes dominulus paper wasps during the early nest-founding stage before dominance and fertility become correlated. First, we confirm that dominance and fertility are not associated in early spring foundresses. Then we show that CHCs are more strongly associated with fertility than dominance. There was no relationship between cuticular hydrocarbon profiles and a wasp’s ability to dominate rivals through aggression, suggesting that CHCs are unlikely to provide information about dominance. However, there was a significant correlation between ovarian development and the CHC profile, suggesting that CHCs could convey valuable information about their bearer's fertility. Furthermore, our data provide a potential mechanism for chemical signaling of fecundity, as there is a relationship between endogenous juvenile hormone titer (a gonadotropin), degree of ovarian development, and the CHC profile. Hormonal regulation of CHC profile expression offers a physiological mechanism to coordinate behavior, physical state, and signal expression.

Female Polistes paper wasps are capable of independent nesting, yet many populations demonstrate a mixture of solitary and cooperative nest foundation. Previous studies of Polistes have found survival and/or productivity advantages of cooperative nest foundation compared to solitary nesting, and reproductive skew models have been designed to predict the dynamics of such flexible cooperation. In this paper, we examine the success of different nesting strategies in a previously unstudied population of Polistes aurifer in southern California. The colony cycle of this population is less synchronous than that of other temperate species, and the frequency of solitary nesting averages 86.2%. Our data suggest that this low rate of cooperative nest founding is adaptive, as demonstrated by the lack of survival or productivity advantages for cooperative foundress associations. Due to foundress turnover and nest foundation later in the season, many nests produce only one set of offspring. This results in a loss of the eusocial nature of some nests in the population. Data from a small sample of multifoundress nests show significant positive reproductive skew, despite concession model predictions that skew should be low in populations with low ecological constraints on independent nesting. This lack of support for the concessions skew model reflects a diminished incentive for cooperation.

Temperature characteristics in paper models of Polistes wasp nests with various numbers (N = 7, 19, 37, or 61 cells) and lengths (L = 10–50 mm) of cells were measured in the field. Temperature distribution in a N61L50 model showed that the central cell provided the best thermal conditions in terms of gained temperature and its fluctuation. The mean temperature excess (difference between cell and ambient temperatures) observed in the diel trial 1 (L50 models with different cell numbers) was 1.5°C in N7 model and 2.3°C in N61, whereas in trial 2 (N37 models with different cell lengths) it was 0.6°C in the L10 model (with 10-mm-long cells) and 2.4°C in L50. In these trials, models with larger numbers of cells or longer cells attained a higher temperature. It seemed that length was more effective in gaining higher maximum temperature than the number of cells. By their heat insulation effect, peripheral cell rings ameliorated the temperature fluctuation in cells at the central part of the comb. Models with more and longer cells maintained temperature slightly higher than the ambient level even during the nighttime.

Made available in DSpace on 2018-11-26T17:06:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-08-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Based on species endemism, three biodiversity centers, called Ecological Corridors have been proposed as one of the main conservation strategies for the Atlantic Rain Forest. This study tested whether the organization of the social paper wasp assemblage fits those centers. A standardized protocol was used for sampling the social paper wasp fauna. The structural organization was estimated by Nonmetric Multidimensional Scaling (NMDS) based on the similarity indexes of Sorensen (qualitative data) and Morisita-Horn (quantitative data). Regressive models were applied to the first axes' site scores of the NMDS, to the latitudinal and altitudinal variations, and to the speciation and immigration probabilities predicted by the neutral theory for a metacommunity. Our results indicated that the social paper wasp assemblage is organized in a continuum, with two distinct biodiversity centers. The organization of the assemblage along the gradient was dependent on latitudinal and altitudinal variations and their interactions, and also on the speciation and immigration probabilities. Several studies have demonstrated that the current biodiversity patterns of the Atlantic Forest might be explained by the past climate and, consequently, by the connection between the Amazon and the Atlantic Forest. In addition, speciation and immigration probabilities strongly influence the compositional and structural variations of the social paper wasp assemblage along the latitudinal gradient. Univ Estadual Paulista, Inst Biociencias Letras & Ciencias Exatas, Dept Zool & Bot, Rua Cristovao Colombo 2265, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil Univ Sao Paulo, Museu Zool, Ave Nazare 481, BR-04263000 Sao Paulo, SP, Brazil Univ Estadual Paulista, Inst Biociencias Letras & Ciencias Exatas, Dept Zool & Bot, Rua Cristovao Colombo 2265, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil FAPESP: 98/05083-0 FAPESP: 01/08060-5

A recent study (Izzo et al., Behav Ecol Sociobiol 64: 857–864, 2010) reported that cuticular hydrocarbons (CHCs) correlate with fertility, not dominance, in the paper wasp Polistes dominulus thus contradicting the results of recent investigations which concluded that social dominance is the main determinant for CHC signatures in this species. We suggest here that different forms of dominance in the pre-nesting and post-nesting phases caused the apparently contradictory results. Thus the assumption that dominance behaviour in the pre-nesting stage is synonymous with dominance after colony foundation is incorrect. We provide standardised definitions for forms of “dominance” observed in the P. dominulus life cycle to avoid apparent discrepancies in the future among studies dealing with the same topics in different annual stages.

Successful Polistes dominulus nests can be started by one or more nest founding queens (foundresses). Consequently, there is much interest in the specific benefits that induce cooperation among foundresses. Here, we experimentally demonstrate one major benefit of cooperation, namely that multiple foundresses increase colony productivity. This increase is close to the value predicted by subtracting the productivity of undisturbed single-foundress colonies from the productivity of undisturbed multiple-foundress colonies. However, we found no evidence that an associating foundress' contribution to colony growth is preserved if she disappears (assured fitness returns). Our correlational data suggest that cooperation provides survival benefits, multiple-foundress colonies are more likely to survive to produce offspring than are single-foundress colonies, and individual foundresses in multiple-foundress groups are less likely to disappear before worker emergence than foundresses nesting alone. Therefore, association provides substantial productivity and survival benefits for cooperating foundresses. Copyright 2003.

Paper wasps of the family Vespidae exhibit a wide range of social lifestyles, from facultative eusocial groups to highly ritualistic swarm-founding societies. Even so, adult caste flexibility is widespread throughout the eusocial tribes. Thus, a common endocrine mechanism for caste determination and maintenance in paper wasps is expected, with Polistes dominula serving as a model for the study of mechanisms controlling phenotypic plasticity. In P. dominula, juvenile hormone (JH) and ecdysteroids have been shown to have important caste-determining functions, are important for reproductive growth, and correlate with hydrocarbon signals on the cuticle. Yet research on swarm-founding vespids has shown that JH functions are surprisingly labile, begging the question as to how conserved JH functions are within Polistes, a non-swarming genus. Here, we compared the JH and ecdysteroid titers, cuticular hydrocarbon (CHC) profiles, and prospective visual signals of dominance of free-living foundresses from two sympatric and closely related species of Polistes in South Africa, the indigenous Polistes smithii and the invasive P. dominula. In contrast to P. dominula, neither the JH titer nor the CHC profile was linked to dominance or reproduction in P. smithii, and in both species, hemolymph ecdysteroids were essentially absent. Moreover, many of the relationships between hormones, reproduction, dominance, and social signals in P. dominula are in contrast to studies performed on northern hemisphere populations. The divergence of endocrine and chemical profiles within Polistes offers an unforeseen opportunity to study the evolution of proximate mechanisms underlying phenotypic plasticity.

Polistes sulcifer is a cuckoo paper wasps, an obligate social parasite which must usurp a colony of another species in order to reproduce. Field data show thatP. sulcifer females usurp exclusively nests belonging to one species only (P. dominulus). Moreover, they are more frequently found on large and puparich nests. A series of laboratory trials, in which parasite females were offered a binary choice of nests with different characteristics, confirm both the species specificity betweenP. sulcifer andP. dominulus and the parasite's preference to usurp larger nests containing pupae. The data support the hypothesis thatP. sulcifer females choose between available nests. The biological meaning of these findings is discussed.

Diploid males in haplo-diploid insects are sterile, because they produce diploid sperm. Our previous report revealed that early males of the Japanese paper wasp Polistes chinensis antennalis are diploid but did not reveal how often this occurs. We analyzed the genotypes of early males using six microsatellite markers. Two of the 41 early males (5%) from six colonies were haploid, but the other males were diploid. This evidence suggests that we can ignore the reproductive success of the early males of P. chinensis antennalis.

Bioassays were used to study the infectivity of cytoplasmic polyhedrosis viruses (CPVs), nuclear polyhedrosis viruses (NPVs) and entomopoxviruses (EPVs) contained in 16 nests of the paper waspPolistes hebraues F. in Reunion Island. Several virosis were propagated from 6 nest contents in 5 Lepidoptera:Catopsilia thauruma Saalmuller,Catopsilia florella F.,Callixena versicolora Mabille,Polydesma umbricola Boisduval andEagris sabadius Boisduval. Each of the previous species supported the development of one or two virosis and therefore, wasp nests must be considered as accumulating centres where infectivity of occluded entomoviruses is preserved. The accurate origin of the virosis propagated through bioassays was searched for using ecological investigations on similar natural diseases, REN analysis and a cross-transmission test onSpodoptera mauritia Boisduval. The nuclear polyhedrosis and one cytoplasmic polyhedrosis appearing in bioassays can be assigned respectively to viruses produced byC. thauruma andC. versicolora; the other virosis must be considered as developing in alternate or substitution hosts. Wasp nests could therefore be used to detect the presence of specific viruses in an environment and to collect new virus isolates.

The present study aimed to investigate whether chimpanzees (Pan troglodytes) could learn a transverse pattern by being trained in the rules of the rock–paper–scissors game in which “paper” beats “rock,” “rock” beats “scissors,” and “scissors” beats “paper.” Additionally, this study compared the learning processes between chimpanzees and children. Seven chimpanzees were tested using a computer-controlled task. They were trained to choose the stronger of two options according to the game rules. The chimpanzees first engaged in the paper–rock sessions until they reached the learning criterion. Subsequently, they engaged in the rock–scissors and scissors–paper sessions, before progressing to sessions with all three pairs mixed. Five of the seven chimpanzees completed training after a mean of 307 sessions, which indicates that they learned the circular pattern. The chimpanzees required more scissors–paper sessions (14.29 ± 6.89), the third learnt pair, than paper–rock (1.71 ± 0.18) and rock–scissors (3.14 ± 0.70) sessions, suggesting they had difficulty finalizing the circularity. The chimpanzees then received generalization tests using new stimuli, which they learned quickly. A similar procedure was performed with children (35–71 months, n = 38) who needed the same number of trials for all three pairs during single-paired sessions. Their accuracy during the mixed-pair sessions improved with age and was better than chance from 50 months of age, which indicates that the ability to solve the transverse patterning problem might develop at around 4 years of age. The present findings show that chimpanzees were able to learn the task but had difficulties with circularity, whereas children learned the task more easily and developed the relevant ability at approximately 4 years of age. Furthermore, the chimpanzees’ performance during the mixed-pair sessions was similar to that of 4-year-old children during the corresponding stage of training.

Two methods of hole repair used by the paper wasp, Polistes fuscatus,were examined and compared, and the hypothesis that nest repair behavior may improve with experience was tested. Similarly sized holes were repeatedly made in the sides of nests and the repair behavior of the nest residents was recorded. The distance of the hole from the cell mouth determined which repair method was used. In addition, both the amount of time for hole repair completion and the number of pulp loads used in making the repair decreased significantly with experience.

This study focused on how a decrease in prey availability affected the development of aP. dominulus Christ colony. Nutritional oophagy and larval development were parameters found to be most directly affected. The more indirect effects on the growth of the nest and on offspring production were also analyzed.

The Dufour's gland of the paper wasp, Polistes fuscatus,is a source of the cues used by dominant females to recognize the eggs laid by subordinates or nonnestmates on pre (worker)-emergence nests. When dominant wasps were presented with an egg covered with either (1) the Dufour's gland extract of a subordinate cofoundress, (2) the extract of an egg from the same subordinate, or (3) the solvent alone, the dominant female destroyed and replaced the eggs covered with the Dufour's extract significantly more frequently than the other eggs. Eggs with the extract of a nonnestmate's Dufour's gland were also eaten significantly more frequently than those with the solvent. Given similar choices, subordinates did not destroy any eggs. The Dufour's gland appears to have little or no role in communicating dominance directly among aggressively interacting cofoundresses.

In temperate climates, female paper wasps typically initiate new colonies in the spring. Several nest-founding tactics have been documented in Polistes species, including solitary nest initiation, joining a cooperative association, usurping an existing nest, or adopting an abandoned nest. Occasionally, exceptionally large groups of females have also been found reusing nests from the previous season. Here we report this phenomenon in introduced populations of the Eurasian species Polistes dominulus. We describe in detail the demographic and genetic characteristics of one such spring colony from Los Angeles, California, USA, which was collected with 84 associated adults and all stages of developing brood in its 613 cells. Genetic and morphological data indicate the presence of multiple reproductively active females of varying relatedness, as well as many nonbreeding females, including probable early-produced offspring. Despite some evidence of chaotic social conditions, the colony appeared to have been highly productive. Additional observations of similar colonies are needed to determine how control is maintained within such a large breeding aggregation.

Experiments were performed to determine the effect of caterpillar feeding damage on wasp foraging behavior and to determine the relative importance of visual and olfactory plant cues for foraging wasps. In an experiment using caterpillar-damaged leaves, wasps took significantly more larvae from the previously damaged plants compared to the controls in the experiments with tobacco plants, but wasps did not distinguish between damaged and control plants in the experiments with tomato plants. Another experiment indicated that wasps use a combination of visual and olfactory cues of plant damage in their search for prey rather than just visual or olfactory cues alone. Furthermore, these results suggest that leaf shape may affect wasp detection of caterpillar feeding damage and thus detection of prey.

Polistes versicolor (Olivier) (Hymenoptera: Vespidae) colonies are easily found in anthropic environments; however there is little information available on biological, ecological and behavioral interactions of this species under these environmental conditions. The objective of this work was to characterize the foundation pattern, the productivity, and the success of colonies of P. versicolor in anthropic environments. From August 2003 to December 2004, several colonies were studied in the municipal district of Juiz de Fora, Southeastern Brazil. It was possible to determine that before the beginning of nest construction the foundress accomplishes recognition flights in the selected area, and later begins the construction of the peduncle and the first cell. As soon as new cells are built, the hexagonal outlines appear and the peduncle is reinforced. Foundation of nests on gypsum plaster was significantly larger (p < 0.0001; χ2 test) in relation to the other types of substrate, revealing the synantropism of the species. On average, the P. versicolor nest presents 244.2 ± 89.5 (100–493) cells and a medium production of 171.67 ± 109.94 (37–660) adults. Cells that produced six individuals were verified. Usually, new colonies were founded by an association of females, responsible for the success of 51.5%. Although these results enlarge knowledge on the foundation pattern of P. versicolor in anthropic environments, other aspects of the foundation process require further investigation.

Intraspecific nest usurpation by foundresses was studied in 2 haplometrotic (solitary founding) species of different subgenera,Polistes (P.) riparius andP. (Polistella) snelleni, in areas where they cohabited. The overall probability for a nest to be usurped by a foreign foundress during the season was about twice as large inP. snelleni as inP. riparius. In both, however, probability of usurpation was largest on late pre-emergence nests, or in late June and early July. InP. riparius, all the usurpers of known origins were those foundresses that had lost their pre-emergence nests to destruction probably by some vertebrates; inP. snelleni, some usurpers had the same history as above, while the others had lost many of all larvae to predation by unknown agents before worker emergence. Usurpers of both species destroyed eggs and younger larvae to much greater extents than older larvae or pupae, and they produced fewer numbers of reproductives in comparison with non-usurping foundresses. We concluded that usurpation behavior has been maintained despite its relatively low productivity because renesting would lead to even lower or no reproductive production.

Worker reproduction and related behavior in 2 orphan colonies ofPolistes jadwigae, one of which had been maintained by a queen and 5 artificially introduced alien workers, were observed. After the queen loss, a dominance hierarchy was established among workers, and several workers laid eggs without physical interference from other workers. Only males emerged from worker-laid eggs, however, a few new queens were produced from queen-laid eggs. Investment sex ratio of queenright (=normal) colonies (0.27) fell between the 2 theoretical values, corresponding to worker control (0.20 or 0.18) and queen control (0.48 or 0.46) of the sex ratio, both being calculated by considering the excess of males produced in the orphan colonies.

The insectivorous tree swallow was chosen as an indicator species to investigate the uptake of pulp mill-related chlorinated hydrocarbons from emergent aquatic insects. Nest box populations were monitored for reproductive success at locations upstream and downstream of pulp mills on two river systems in British Columbia, Canada. Also, 16-day-old nestlings were collected and analysed for polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), pesticides, chlorophenols and chloroguaiacols. Most reproductive parameters were not different between populations at upstream and downstream locations, and were equivalent to or greater than those recorded for other tree swallow populations. Chlorinated hydrocarbon contamination of nestlings was low at all sites. The highest tissue concentrations were detected downstream of pulp mills on the Fraser River, where PCDD and PCDF patterns along with the presence of pentachlorophenol (PCP) suggested that the primary source of contaminants was past use of PCP for timber preservation. Although the absolute tissue concentration of contaminants was less, the toxic concentration (as estimated with I-TEQs) was greatest in nestlings downstream of a pulp mill on the Thompson River. The proportionately larger contributions from 2,3,7,8-TCDF and PCB-77 elevated these TEQs in comparison to other populations. Nest success was the one reproductive measure that showed substantial reductions in downstream populations on both rivers; however, there was little indication that nest failures were the direct result of contamination. Failures were largely due to parental abandonment, and, while poor parental attentiveness and nest abandonment have been associated with chlorinated hydrocarbon tissue concentrations in other studies, our 1-year assessment was insufficient to establish any link with pulp mill effluent exposure. Nestling growth models showed some subtle differences in growth patterns between nest box populations on the two rivers, but an association with pulp mill effects on aquatic insect prey availability was not established.

The first years of this century have seen significant advances in integrating the many perspectives on what it will take to achieve a healthy and sustainable future. Intense activity among agencies worldwide has produced a stream of reviews of the global condition. These include the combined United States Research Council (1999); a consortium of the United Nations Development Programme, United Nations Environment Programme (UNEP), World Bank, and World Resources Institute (2000); the Millennium Development Goals (2000). United Nations Environment Program (2003); the Global Reporting Initiative (2006); and Millennium Ecosystem Assessment (2005). Each review has deplored a lack of adequate follow-up action on the implications of previous reports. Continuing concern about the state of the planet and the associated risks to health (Millennium Ecosystem Assessment, 2005; Corvalen et al., 2005) has increased the challenge to deliver an effective response. That success is possible has been demonstrated in the Montreal protocols, in which United Nations members continually monitor and control their use of chlorofluorocarbons and so slow the disintegration of the planet s ozone layer (United Nations Environment Programme, 1999). Local government authorities agreement to reduce their carbon emissions in the face of global warming is beginning to show results (ICLEI, 2002). Such effective responses are still far from established practice. There is an inability, first, to agree on, and then to implement, protocols controlling global environmental hazards; for instance, the Kyoto protocols for reducing national carbon dioxide emissions have only just established a framework (United Nations Environment Program, 2006). At the local scale, the management of ecosystem resources tends not to take sufficient account of the needs for long-term sustainability (Corvalen et al., 2005). These precedents confirm that there is much yet to be learned on taking action in response to scientific reports on the state of the world. In this essay, we report on a workshop on that theme held at the EcoHealth ONE meeting, in Madison, Wisconsin in October 2006. The workshop reviewed the three initiatives below with the aim of determining how EcoHealth actions can best be guided in the future. One, a master plan has been provided by the suite of eight United Nations Millennium Development Goals, formed from the synthesis of national commitments made separately at conferences and summits during the 1990s Published online: February 7, 2007 Correspondence to: Valerie A. Brown, e-mail: val.brown@anu.edu.au EcoHealth 4, 95–98, 2007 DOI: 10.1007/s10393-007-0082-8

The role of nest paper hydrocarbons in nest and nestmate recognition for the social waspPolistes metricus was examined. Newly emergedP. metricus workers maintained in the laboratory spent four days alone on a fragment of nest paper that was subjected to one of the following tretments: untreated, extracted with hexane to remove surface hydrocarbons, or extracted with extract reapplied. Test wasps were returned to their natal nest with nestmates and observed for 1 h. Time spent on nest by test wasp and its behaviors were recorded. Wasps exposed to untreated and reapplied nest fragments spent an average of 34.13 and 31.75 min on their nests, respectively, while wasps from extracted fragments averaged 17.19 min. Behavior of wasps exposed to extracted paper differed significantly from wasps exposed to paper with hydrocarbons. These results suggest that exposure to nest paper hydrocarbons is important for both nest and nestmate recognition.

Social insect colonies often have one or a few queens. How these queens maintain their reproductive monopoly, when other colony members could gain by sharing in the reproduction, is not generally known. DNA microsatellite genotyping is used to determine reproductive interests of various classes of colony members in the paper wasp, Polistes annularis. The relatedness estimates show that the best outcome for most individuals is to be the reproductive egg-layer. For workers, this depends on the sex of offspring: they should prefer to lay their own male eggs, but are indifferent if the queen lays the female eggs. The next-best choice is usually to support the current queen. As a rule, subordinates and workers should prefer the current queen to reproduce over other candidates (though subordinates have no strong preference for the queen over other subordinates, and workers may prefer other workers as a source of male eggs). This result supports the theory that reproductive monopoly stems from the collective preferences of non-reproductives, who suppress each other in favor of the queen. However, we reject the general hypothesis of collective worker control in this species because its predictions about who should succeed after the death of the present queen are not upheld. The first successor is a subordinate foundress even though workers should generally prefer a worker successor. If all foundresses have died, an older worker succeeds as queen, in spite of a collective worker preference for a young worker. The results support the previous suggestion that age serves as a conventional cue serving to reduce conflict over queen succession.