Vespula Germanica Research Articles

Non-native Vespula germanica yellowjackets dominate urban-to-rural gradient

Non-native Vespula germanica yellowjackets dominate urban-to-rural gradient

A call to further understand the role of carrion in food webs: a case study of the Australian Alps

ABSTRACT Carcasses are integral to the structure and function of ecosystems, providing a food source for a variety of scavenger species that recycle nutrients back into the biosphere. However, in many systems globally there is limited information on the extent of carcass use by scavengers and the length of carcass persistence. This prevents land managers from making well-informed decisions on whether carcasses should be removed if produced in excessive numbers following activities such as culling, or extreme weather and disease outbreaks, or when to undertake management operations that add to the overall carcass biomass in ecosystems. In this paper, we focus on the Australian Alps and highlight results from recent studies to show that carcasses persist in this bioregion for long periods in winter when insects are less active. We show that vertebrate scavenging rates are relatively low in the Australian Alps compared to other bioregions in Australia, and that carcasses in this system can become hotspots for introduced species like European wasps (Vespula germanica), red foxes (Vulpes vulpes), and feral pigs (Sus scrofa). We advocate that further carcass monitoring in the Australian Alps should focus on scavenger use and persistence rates for different carcasses species, including across different elevations, seasons, and following culling operations. This will ultimately help to guide understanding around when native scavenger guilds can effectively accelerate carcass biomass loss, which is a key indicator of a healthy, functioning ecosystem.

Spatial resolution and optical sensitivity in the compound eyes of two common European wasps, Vespula germanica and Vespula vulgaris.

Vespula germanica and Vespula vulgaris are two common European wasps that have ecological and economic importance as a result of their artificial introduction into many different countries and environments. Their success has undoubtedly been aided by their capacity for visually guided hunting, foraging, learning and using visual cues in the context of homing and navigation. However, the visual systems of V. germanica and V. vulgaris have not received any deep attention. We used electrophysiology, together with optical and anatomical techniques, to measure the spatial resolution and optical sensitivity of the compound eyes of both species. We found that both wasps have high anatomical spatial resolution with narrow interommatidial angles (Δϕ between 1.0 and 1.5deg) and a distinct acute zone in the fronto-ventral part of the eye. These narrow interommatidial angles are matched to photoreceptors having narrow angular sensitivities (acute zone acceptance angles Δρ below 1.3deg), indicating eyes of high spatial resolution that are well suited to their ecological needs. Additionally, we found that both species possess an optical sensitivity that is typical of other day-flying hymenopterans.

Stakeholder mapping to support invasive non-native species management in South America

Effective long-term management of invasive non-native species (INNS) in South America is a pressing yet complex task. Critically, the environmental, historical, cultural, and economic idiosyncrasies of the region call for the inclusion of a plurality of views from those sectors of society receiving the negative and positive impacts of INNS. This is a multifaceted, and often daunting, task that can be aided by an early identification of stakeholders – those affected by or with an interest in INNS and their management – accompanied by targeted stakeholder engagement. Here, we report the procedures and results of a stakeholder mapping activity aimed at identifying stakeholders and designing engagement strategies. Using expert knowledge procedures, we compiled comprehensive lists of stakeholders for six case-studies in South America: (i) invasive grasses (Urochloa spp.) in Brazil; (ii) glossy privet (Ligustrum lucidum) in Argentina; (iii) lodgepole and Monterey pines (Pinus contorta and P. radiata) in Argentina; (iv) American mink (Neogale vison) in Argentina and Chile; (v) lodgepole and Monterey pines in Chile; and (vi) German yellow-jacket (Vespula germanica) in Chile. Overall, we identified 250 stakeholders, which, based on their interest and influence, were classified into “context settlers” (2%), “key players” (47%), “crowd” (5%), and “subjects” (49%). We outlined strategies to engage with each of these four groups and for each of our six case-studies. Across case studies, communication with stakeholders was the most common engagement strategy proposed (27%; 19 of 70 strategies), followed by active involvement of stakeholders in INNS research and management (23%). Our results highlight the importance of considering power imbalances, as those stakeholders more likely to benefit from INNS were assessed to have more influence over INNS management relative to local and indigenous communities. Our work illustrates how to identify stakeholders in a rigorous and rapid manner, which should be complemented with the involvement of the stakeholders themselves.

Investigating the Influence of Varied Light-Emitting Diode (LED) Wavelengths on Phototactic Behavior and Opsin Genes in Vespinae.

The phototactic behavior of insects is commonly used to manage pest populations in practical production. However, this elusive behavior is not yet fully understood. Investigating whether the opsin genes play a crucial role in phototaxis is an intriguing topic. Vespinae (Hymenoptera: Vespidae) are a common group of social wasps that are closely associated with human activities. Efficiently controlling wasp populations while maintaining ecological balance is a pressing global challenge that still has to be resolved. This research aims to explore the phototactic behavior and key opsin genes associated with Vespinae. We found significant differences in the photophilic rates of Vespula germanica and Vespa analis under 14 different light conditions, indicating that their phototactic behavior is rhythmic. The results also showed that the two species exhibited varying photophilic rates under different wavelengths of light, suggesting that light wavelength significantly affects their phototactic behavior. Additionally, the opsin genes of the most aggressive hornet, Vespa basalis, have been sequenced. There are only two opsin genes, one for UV light and the other for blue light, and Vespa basalis lacks long-wavelength visual proteins. However, they exhibit peak phototaxis for long-wavelength light and instead have the lowest phototaxis for UV light. This suggests that the visual protein genes have a complex regulatory mechanism for phototactic behavior in Vespinae. Additionally, visual protein sequences have a high degree of homology among Hymenoptera. Despite the hypotheses put forward by some scholars regarding phototaxis, a clear and complete explanation of insect phototaxis is still lacking to date. Our findings provide a strong theoretical basis for further investigation of visual expression patterns and phototactic mechanisms in Vespinae.

Proposed vacuum sampling method for collecting foraging Vespula wasps at their nest entrance

AbstractSampling nests of yellow jackets, Vespula spp. (Hymenoptera: Vespidae), represent a particular challenge due to the danger involved in working with live colonies of a potentially aggressive venomous super‐organism. Here, we report on sampling methods using a petrol‐driven leaf blower/vacuum and a battery‐powered vacuum to sample returning Vespula germanica (Fabricius) foragers at their nest entrance. These methods make the sampling of returning foragers at the nest more efficient and convenient and represent a low‐risk approach to sampling. Applications include prey analysis and genetic sampling that can be done destructively or non‐destructively depending on the geographic location. We sampled 15 nests using the two‐stroke vacuum apparatus and collected on average (±SD) 454 ± 271 wasps per nest. We believe that the petrol‐driven vacuum collection apparatus we designed is a useful method for collecting a large number of social wasp foragers returning to a single‐nest entrance.

Neotropical songbird chick predation by an invasive wasp, the German yellowjacket (Vespula germanica)

AbstractSocial wasps (Family: Vespidae) are opportunistic and generalist feeders, which can occasionally feed on live vertebrates. The German yellowjacket (Vespula germanica) is native to Eurasia and Northern Africa, and has invaded many countries around the world, producing several environmental, economic and social impacts. Here we report the first video‐recorded evidence that this wasp species preys on chicks. Over six breeding seasons, we studied the parental care behaviour of the Chilean Elaenia (Elaenia chilensis), a long‐distance migratory bird that breeds in the Andean‐Patagonian Forest. We filmed 59 nests when chicks were 2–3 and 10–11 days old, and recorded in a nest containing two 10‐day‐old nestlings the predation of one of them by German yellowjackets. The other chick was found alive on the ground, indicating that it escaped from the wasps. Parents did not defend offspring against wasp attacks. The rarity of this observation may suggest either that this insect is not yet a significant nest predator or that it is difficult to obtain a record of predation by wasps, because birds may remove dead nestlings from the nests (i.e. nest sanitation). Although Chilean Elaenia is not threatened, 41% of bird species in the Andean‐Patagonian Forest are endemic, and this new nest predator may potentially become a threat to the conservation of any of those species, which deserves further research. Hence, to evaluate the German yellowjacket impact on bird populations, it is imperative to conduct videotaped nest monitoring in order to remove the masking effect of nest sanitation on predator identity, which will allow to determine how much this wasp contributes to nest failure in the invaded zone of the Neotropical region.

Worker trapping: a sustainable management tool for invasive social wasps?

The invasive social wasp Vespula germanica is a harmful pest, mainly in urban environments. Despite extensive research on ecology and control, there are currently no effective, sustainable strategies to manage populations in the invaded range. We evaluated the effects of worker trapping on V. germanica abundance and nest activity in Southern Argentina. During two consecutive years, a high-density trapping was deployed in four plots of one hectare each. The procedure consisted of placing 25 non-toxic meat-baited traps, creating a grid of 5 × 5 traps for 4 weeks. Worker wasp abundance and the traffic rate of all the nests in the plots were measured 1 week before and one after trapping. Our results showed that worker catches resulted in a 65% reduction in local wasp abundance and a 48% in traffic rate of nests within the treated area. Similarly, a decrease in wasp abundance was obtained one year after trapping. Employing worker trapping as a tool could prove useful and environmentally friendly in reducing local wasp abundance during peak activity.

Nectar cardenolides and floral volatiles mediate a specialized wasp pollination system.

Specialization in plant pollination systems can arise from traits that function as filters of flower visitors. This may involve chemical traits such as floral volatiles that selectively attract favoured visitors and non-volatile nectar constituents that selectively deter disfavoured visitors through taste or longer-term toxic effects or both. We explored the functions of floral chemical traits in the African milkweed Gomphocarpus physocarpus, which is pollinated almost exclusively by vespid wasps, despite having nectar that is highly accessible to other insects such as honeybees. We demonstrated that the nectar of wasp-pollinated G. physocarpus contains cardenolides that had greater toxic effects on Apis mellifera honeybees than on Vespula germanica wasps, and also reduced feeding rates by honeybees. Behavioural experiments using natural compositions of nectar compounds showed that these interactions are mediated by non-volatile nectar chemistry. We also identified volatile compounds with acetic acid as a main component in the floral scent of G. physocarpus that elicited electrophysiological responses in wasp antennae. Mixtures of these compounds were behaviourally effective for attraction of V. germanica wasps. The results show the importance of both volatile and non-volatile chemical traits as filters that lead to specialization in plant pollination systems.

Scavenging with invasive species.

Carrion acts as a hotspot of animal activity within many ecosystems globally, attracting scavengers that rely on this food source. However, many scavengers are invasive species whose impacts on scavenging food webs and ecosystem processes linked to decomposition are poorly understood. Here, we use Australia as a case study to review the extent of scavenging by invasive species that have colonised the continent since European settlement, identify the factors that influence their use of carcasses, and highlight the lesser-known ecological effects of invasive scavengers. From 44 published studies we identified six invasive species from 48 vertebrates and four main groups of arthropods (beetles, flies, ants and wasps) that scavenge. Invasive red foxes (Vulpes vulpes), domestic dogs (Canis familiaris), feral pigs (Sus scrofa), black rats (Rattus rattus) and feral cats (Felis catus) were ranked as highly common vertebrate scavengers. Invasive European wasps (Vespula germanica) are also common scavengers where they occur. We found that the diversity of native vertebrate scavengers is lower when the proportion of invasive scavengers is higher. We highlight that the presence of large (apex) native vertebrate scavengers can decrease rates of scavenging by invasive species, but that invasive scavengers can monopolise carcass resources, outcompete native scavengers, predate other species around carcass resources and even facilitate invasion meltdowns that affect other species and ecological processes including altered decomposition rates and nutrient cycling. Such effects are likely to be widespread where invasive scavengers occur and suggest a need to determine whether excessive or readily available carcass loads are facilitating or exacerbating the impacts of invasive species on ecosystems globally.

Potential control of Vespula germanica and Polistes dominula (Hymenoptera: Vespidae) using entomopathogens

ABSTRACT The first recordings in South Africa of the invasive social wasps, Vespula germanica and Polistes dominula (Hymenoptera: Vespidae) were in 1974 and again in 2008. These wasps are known to represent a significant threat to the biodiversity of ecosystems and socio-economic activities in countries they invade. Here, the susceptibility of V. germanica and P. dominula larvae to indigenous species of entomopathogenic nematodes (EPNs), namely Heterorhabditis bacteriophora, H. noenieputensis and Steinernema yirgalemense, and entomopathogenic fungus (EPF) Beauveria bassiana was tested both in laboratory bioassays and in situ wasp nests application in the Western Cape province. The bioassay results indicate that both P. dominula and V. germanica larvae are susceptible to all biocontrol agents used. All larvae of both wasp species were dead and infected after exposure to 200 IJ/insect within four days after inoculation. Similar results were obtained seven days after inoculation with B. bassiana. To test in-field pathogenicity against P. dominula, wasp nests were treated with B. bassiana, H. bacteriophora, a mixture of the EPF and EPN species and a control of distilled water. The number of larvae and pupae infected 168 h after application were determined. In both cases, the mixture of EPF/EPN performed best, with a mean percentage of 31.39% ± 4.75% larvae infected, and only 3.42% ± 0.68% of pupae infected. The results obtained suggest that higher concentrations of selected biologicals can be used as inundative biological control agents within an integrated management programme for the control of P. dominula and V. germanica in South Africa. Highlights At 48 h after inoculation, 100% of the wasp larvae treated with EPN were infected After 168 h, 74–98% of EPF-treated larvae showed visual infection of Beauveria bassiana Heterorhabditis bacteriophora outperformed other biocontrol agents tested Combined EPN and EPF in situ nest application achieved larval infection of 31% ± 4.75%.

The outlook for control of New Zealand’s most abundant, widespread and damaging invertebrate pests: social wasps

Invasive social wasps (Vespula germanica and V. vulgaris) are probably the most damaging, widespread invertebrate pests in New Zealand. In large areas of beech forests they can attain a biomass as great as, or greater than, the combined biomasses of birds, rodents and stoats. Wasps are effective and voracious predators and pose a significant risk to human health. Here, we highlight the scale and diversity of wasp impacts and the opportunities to develop cost effective landscape-scale tools for wasp control. Toxic baits can be extremely effective for wasp control, though the most effective pesticide (fipronil) is currently not commercially available for wasp control within New Zealand. Significant progress has been made to enhance lures for toxin delivery, including the use of synthetic lures. Biological control could offer the possibility of controlling wasps over huge areas at reasonable cost, though previous releases of biocontrol agents have not been successful. Avenues for further biological control work, such as the use of pathogens or parasitoids, are encouraged. We believe it is necessary and strategic to develop a suite of control tools. We urge government and the public to take action to control the wasp problem and to designate one agency as having the prime responsibility for doing this. Given that wasps are harming our natural heritage and inhibiting or adversely affecting people’s enjoyment of natural areas, we look to the natural resource sector to drive research and implement solutions. This includes Department of Conservation, Ministry of Primary Industry and Councils.

Flight capabilities of invasive yellowjacket Vespula germanica drones: the effect of kinship and nutrition

AbstractDispersal is a multifactorial process which may influence, among several others, population dynamics, inbreeding likelihood, and mate competition. For species that disperse by flight, many studies have suggested that life‐history traits, such as body size or nutritional condition, could promote variation in flight capabilities and, consequently, on dispersal behavior. Eusocial hymenopterans are likely to experience high densities of related reproductive individuals near their nests, thus increasing probabilities of inbred matings and kin competition. Spatial segregation resulting from differences in flight capabilities of Vespula germanica (Fabricius) (Hymenoptera: Vespidae) nestmate drones could reduce interactions with kin, thus decrease inbreeding and kin competition. Our aim was to characterize, in the laboratory, flight capabilities of sibling drones and elucidate traits that could affect it, focusing on the relevance of carbohydrate intake (diets with different sugar concentration) during early adulthood. Our results indicate that in tethered flight mill assays, V. germanica drones have highly variable flight capabilities within and between nests, with most drones likely to remain relatively close to their nest of origin. The observed flight capabilities are affected by nutrition, with those individuals better nurtured (i.e., with higher nutritional index), flying farther distances. Additionally, diets with variable carbohydrate concentration provided during early adulthood did not affect flight capabilities (only those exposed to a carbohydrate‐free diet had reduced flight distances and speeds), suggesting that nutrition during larval stages is determinant for flight. Our findings contribute to the understanding of the mechanisms underlying V. germanica drone dispersal behavior which, in turn, might influence inbreeding likelihood in the species.

Aggression between invasive hymenopterans in Southern California: scutellata-hybrids versus German yellowjackets

Honey bee defensive behaviors are crucial for countering new predators such as invasive German yellowjackets (Vespula germanica). We provide the first data on the ability of scutellata-hybrids (Africanized bees) to defend their colonies against V. germanica wasps, as compared to European honey bees. The scutellata-hybrid colonies recruited twice as many defender bees in defense, and killed yellowjackets three times more often than managed European honey bee colonies. The defensive ability of such hybrids against new threats is intriguing and suggests that more research should be conducted into how defensive traits in the wide variety of honey bee subspecies may help against threats such as invasive wasps and hornets.

Allee effects in an invasive social wasp: an experimental study in colonies of Vespula germanica

Allee effects rely on the existence of mutually beneficial intraspecific interactions that increase individual fitness and per capita growth rate, as the number of individuals in a population or group increases. When the number of individuals falls below a given number, the success of a group or population drops. Social insects heavily rely on cooperation between individuals for various tasks such as foraging and breeding. In this study, we experimentally explored component Allee effects and the underlying mechanisms in colonies of the social wasp Vespula germanica. After the removal of workers, we counted the number of gynes produced, estimated the body mass index as a proxy of their quality, and registered the protein-food collected by foragers in colonies. Our research revealed a correlation between the decrease in worker population and a subsequent decrease in the production of gynes. However, the removal of workers did not impact the quality of the produced gynes or the quantity of protein-food collected by the colonies. These findings highlight the crucial role of the worker caste in the success of eusocial species and suggested an ability of workers to perform multiple tasks that enable colonies to respond to disturbances. Additionally, our study provides the first evidence of Allee effects at the colony level of V. germanica, with potential practical implications for managing this invasive species.

Image background assessment as a novel technique for insect microhabitat identification

Habitat fragmentation under increased urbanisation, industrial agriculture and land clearing, are changing the way insects occupy habitat. Some species are highly adaptable and may occupy urbanised areas, utilising anthropogenic microhabitat-scale features. Other species are dependent on natural elements of their habitats, having to locate small regions of natural microhabitat within increasingly hostile landscapes. Consequently, humans are encountering insects in new settings. Identifying and analysing insects’ use of natural and anthropogenic microhabitats is therefore important to assess their responses to a changing environment, for instance to improve pollination or manage invasive pests. But such studies are labour-intensive.Traditional studies of insect microhabitat use can now be supplemented by machine learning-based insect image analysis. Typically, research has focused on automatic insect classification, but valuable data appearing in image backgrounds has been ignored. In this research, we analysed the backgrounds of insect images available in the Atlas of Living Australia database to determine the microhabitats in which they were commonly photographed. We analysed the image backgrounds of three globally distributed insect species that are common across Australia: Drone flies (Eristalis tenax), European honey bees (Apis mellifera), and European wasps (Vespula germanica). Image backgrounds were classified broadly as either natural or anthropogenic using computer vision and machine learning tools benchmarked against a manual classification algorithm.Our automated image background classification achieved 97.4% accuracy when compared against manual classification. Mis-classifications were scarce, usually less than 1%, and primarily for backgrounds of wood and soil or bare ground. Our results indicate that drone flies and European honey bees were predominantly photographed against natural backgrounds (flies manual classifier 95±3%, automated classifier 94%, bees 89±2%,87%), implying frequent observations by humans in natural microhabitat. European wasps were less frequently photographed against natural backgrounds (70±6%,63%). Within this data set, observations of the wasps in anthropogenic microhabitats were more common than for flies and bees.Our results are aligned with the expectation that the wasps are relatively well-suited to urban environments, and that European honey bees and drone flies utilise natural features of their environment. In general, although biases in data collected without formal protocols limits their application, our new automated approach for image background analysis can provide valuable data about insects’ interactions with humans, our artefacts, and natural features of their environments.

Aversive reinforcement improves visual discrimination learning in free-flying wasps (Vespula vulgaris)

Understanding and assessing the capacity for learning, memory, and cognition in non-model organisms is a growing field. In invertebrate cognition, eusocial hymenopteran species such as honeybees, bumblebees, and ants are well-studied for their learning and memory abilities due to decades of research providing well-tested methods of training and assessing cognition. In the current study, we assess the use of different conditioning methods on visual learning in a non-model hymenopteran species which is becoming increasingly used in learning and memory tasks, the European wasp (Vespula vulgaris). We trained individual wasps to learn to discriminate between perceptually similar colours using absolute conditioning (reward on target stimulus in the absence of distractors), appetitive differential conditioning (reward on target stimulus and no outcome for incorrect stimulus), or appetitive-aversive differential conditioning (reward on target stimulus and aversive outcome for incorrect stimulus). When trained with absolute conditioning, wasps were unable to learn to discriminate between perceptually similar colours. However, when trained with appetitive differential conditioning or appetitive-aversive differential conditioning, wasps were able to learn to discriminate between two similar colours, although they performed best when an aversive reinforcement was provided during training. Our results show similarities to learning behaviour in honeybees and bumblebees, and provide insight into the learning and cognition of a non-model invertebrate. Our findings provide important comparative data to aid in understanding the evolution of learning and memory in hymenopterans.Significance statementForaging insects such as bees, ants, and wasps visit a variety of food sources such as flowers, insect prey, and rotting fruit. Many of these insects must learn and recall resource traits such as location, scent, shape, colour, and size. To understand the process of learning in insects which are comparatively less studied than those such as honeybees and bumblebees, we trained wasps to discriminate between two similar colours using three different types of conditioning methods. Wasps were best able to learn to discriminate between the similar colours when trained with appetitive-aversive differential conditioning, where a reward is provided for a correct choice and an aversive outcome was providing for an incorrect choice. Our results show that similar to popular invertebrate cognition models, wasp learning is improved when an aversive outcome is introduced for incorrect choices.

Gustatory responsiveness in Vespula germanica workers: exploring the interplay between sensory perception and task specialization.

Workers' task specialization and division of labor are critical features of social insects' ecological success. It has been proposed that the division of labor relies on response threshold models: individuals varying their sensitivity (and responsiveness) to biologically relevant stimuli and performing a specific task when a stimulus exceeds an internal threshold. In this work, we study carbohydrate and protein responsiveness and their relation to worker task specialization in Vespula germanica, an invasive social wasp. The sucrose and peptone responsiveness of two different subcastes, preforagers and foragers, was determined by stimulating the antenna of the wasps with increasing concentrations of the solution and quantifying whether each concentration elicited a licking response. We studied responsiveness in five different ways: (1) response threshold, (2) concentration 50 (concentration to which at least 50% of wasps responded), (3) maximum response, (4) mean scores and (5) median scores. Our results suggest that V. germanica foragers are more sensitive to sucrose (lower thresholds) than preforager workers. However, we found no differences for peptone thresholds (i.e., a protein resource). Nonetheless, this is the first study to investigate response thresholds for protein resources. The intercaste variation in sucrose responsiveness shown in our work contributes to the existing knowledge about response threshold theory as a mechanism for task specialization observed in V. germanica.

Nest visitors of Vespula wasps and their potential use for biological control in an invaded range

The common and the German wasp, Vespula vulgaris and V. germanica, have proved to be prolific invasive species capable of degrading local ecosystems and costing invaded countries millions of dollars annually. Despite clear incentive, control strategies are yet to have any significant deleterious impact on invasive populations. Several species of arthropods are known to inhabit Vespula nests and feed upon developing larvae as either parasitoids or predators. Recent control strategies propose the use of such parasitoids as agents of biocontrol against invasive wasps (Volucella inanis in particular). Despite a general understanding of parasitoid ecology, some aspects such as prevalence, distribution, and behaviour remain limited. Here, we surveyed natural enemy prevalence in wasp nests over the period of three years and we tested larvae prey preference of two Volucella species, V. inanis and V. zonaria towards Vespula wasps. We find V. inanis to be the most prevalent of four prominent candidates for Vespid biocontrol—V. inanis, V. zonaria, Sphecophaga vesparum, and Metoecus paradoxus. Using two-choice assays, we find larvae of V. inanis to have slight yet significant prey preference for V. vulgaris larvae over V. germanica larvae, whilst V. zonaria display no preference. Furthermore, V. inanis were not averse to still predating upon V. germanica, doing so in 41% of trials. Prior exposure has no effect on the prey-preference. Our work provides experimental evidence that V. inanis is a promising candidate for biocontrol of invasive Vespula wasps, as the larvae predate on both target species of Vespula and display no exclusive preference among them.

Chemical signatures of egg maternity and Dufour’s gland in Vespine wasps

Cuticular hydrocarbons (CHCs) are often used in the chemical communication among social insects. CHCs can be used in nestmate recognition and as queen pheromones, the latter allows the regulation of the reproductive division of labor. In the common wasp Vespula vulgaris, CHCs and egg-marking hydrocarbons are caste-specific, being hydrocarbon queen pheromones and egg maternity signals. Whether these compounds are conserved among other Vespinae wasps remains unknown. Queens, virgin queens, reproductive workers, and workers belonging to four different wasp species, Dolichovespula media, Dolichovespula saxonica, Vespa crabro, and Vespula germanica, were collected and studied. The cuticular hydrocarbons, egg surface, and Dufour's gland composition were characterized and it was found that chemical compounds are caste-specific in the four species. Quantitative and qualitative differences were detected in the cuticle, eggs, and Dufour's gland. Some specific hydrocarbons that were shown to be overproduced in the cuticle of queens were also present in higher quantities in queen-laid eggs and in their Dufour's gland. These hydrocarbons can be indicated as putative fertility signals that regulate the division of reproductive labor in these Vespine societies. Our results are in line with the literature for V. vulgaris and D. saxonica, in which hydrocarbons were shown to be conserved queen signals. This work presents correlative evidence that queen chemical compounds are found not only over the body surface of females but also in other sources, such as the Dufour's gland and eggs.