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Tom Wenseleers - One of the best experts on this subject based on the ideXlab platform.
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Hydrocarbon Signatures of the Ectoparasitoid Sphecophaga vesparum Shows Wasp Host Dependency.
Insects, 2020Co-Authors: Robert L. Brown, Ian Stevens, Tom WenseleersAbstract:Sphecophaga vesparum often parasitizes nests of vespid wasps such as Vespula vulgaris and Vespula germanica. Inside the colonies, the ectoparasitic larvae feed on the immature forms of the wasps. There are two adult forms of S. vesparum. The large, winged adults emerge from either rigid yellow cocoons or the orange cocoons used for overwintering. The small, brachypterous females emerge from soft, white cocoons. The species is facultative deuterotokous, producing mostly parthenogenic females and infrequently producing males. Here, we describe the production of chemical compounds related to the different developmental forms of the parasitoid S. vesparum (larvae, pupae and adults). We also compare the chemical profiles of the parasitoid wasp adults to those of their two main host species, Vespula vulgaris and Vespula germanica. The results show differences in hydrocarbon composition of larvae, pupae and adults of S. vesparum. Our results also suggest a partial mimicry of each of the two host species, mostly relating to linear alkanes present in both parasitoids and the host vespid wasp species. This matching is likely due to the recycling of the prey’s hydrocarbons, as has been found in other species of parasitoids.
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Fitness and microbial networks of the common wasp, Vespula vulgaris (Hymenoptera: Vespidae), in its native and introduced ranges
Ecological Entomology, 2019Co-Authors: Monica A. M. Gruber, Tom Wenseleers, Oliver Quinn, James W. Baty, Jana Dobelmann, John Haywood, Philip J. LesterAbstract:1. Variation in microbial communities between populations is increasingly hypothesised to affect animal fitness and performance, including for invasive species. Pathogenic species may be lost during the introduction process, enhancing invader fitness and abundance. 2. This study assessed fitness, immune gene expression, and microbial network complexity of invasive common wasps, Vespula vulgaris. Microbial networks were assayed using 16S and 18S sequencing and gene expression arrays in the native (Belgium) and introduced range (New Zealand). The immune gene expression of the wasp Down syndrome cell adhesion molecule (Dscam) gene homologue was examined. Dscam expression can be induced by viruses, Gram‐positive and Gram‐negative bacteria, and parasites. 3. Individual nest fitness was higher in the native range of Belgium than in the introduced New Zealand range. Microbial communities of wasps in the introduced range were more diverse with more complex networks, although some microorganisms were range‐specific. Microbial networks in the introduced range showed higher clustering coefficients, number of connected paths, network centralisation, number of neighbours and network density. 4. Larvae, workers, virgin and foundress queens had higher expression of Dscam in the New Zealand samples. These immune gene expression patterns were associated with higher pathogen pressure and lower relative fitness. 5. Epidemiological theory predicts that a high density of pathogen and microbial hosts should result in a high rate of disease infection, prevalence, and highly connected microbial networks. The results of this study support these predictions. Wasps displayed lower relative fitness and more highly connected microbial networks in New Zealand than in Belgium.
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Intraspecific worker parasitism in the common wasp, Vespula vulgaris
Animal Behaviour, 2016Co-Authors: Ricardo Caliari Oliveira, Ayrton Vollet-neto, Tom WenseleersAbstract:Insect societies display a remarkable level of cooperation, but their colonies also represent a valuable resource that can be taken advantage of by genetically unrelated individuals. Indeed, several recent studies have documented cases of intraspecific reproductive parasitism, whereby workers penetrate and lay eggs in unrelated colonies in order to have their brood raised by the host workers. Previously, it has been predicted that queenless colonies should be a prime target of such intraspecific worker parasitism, as in such colonies the parasite workers would be able to reproduce without interference from either the queen or other workers. So far, this prediction has been supported with data from the honeybee, but evidence from other social insect groups is currently lacking. Here we present the first such test in the common wasp, Vespula vulgaris. In particular, workers from queenright colonies left the natal nest at a higher rate than those from queenless colonies. However, contrary to our predictions, drifter workers targeted queenless and queenright colonies equally. Chemical data suggest that this lack of discrimination may be linked to recognition constraints and the lack of volatile signals that reliably indicate the presence or absence of the queen. In addition, in queenright colonies, drifters activated their ovaries at a rate that was ca. five times higher than the natal workers. Overall, our results suggest that also in wasps, workers can gain inclusive fitness by drifting to unrelated nests, even if the chances of successfully reproducing there may be very slim.
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Chemical Strategies of the Beetle Metoecus Paradoxus, Social Parasite of the Wasp Vespula vulgaris
Journal of chemical ecology, 2015Co-Authors: Annette Van Oystaeyen, Jelle S. Van Zweden, Hilde Huyghe, Falko P. Drijfhout, Wim Bonckaert, Tom WenseleersAbstract:The parasitoid beetle Metoecus paradoxus frequently parasitizes colonies of the common wasp, Vespula vulgaris. It penetrates a host colony as a larva that attaches itself onto a foraging wasp's body and, once inside the nest, it feeds on a wasp larva inside a brood cell and then pupates. Avoiding detection by the wasp host is crucial when the beetle emerges. Here, we tested whether adult M. paradoxus beetles avoid detection by mimicking the cuticular hydrocarbon profile of their host. The beetles appear to be chemically adapted to their main host species, the common wasp, because they share more hydrocarbon compounds with it than they do with the related German wasp, V. germanica. In addition, aggression tests showed that adult beetles were attacked less by common wasp workers than by German wasp workers. Our results further indicated that the host-specific compounds were, at least partially, produced through recycling of the prey's hydrocarbons, and were not acquired through contact with the adult host. Moreover, the chemical profile of the beetles shows overproduction of the wasp queen pheromone, nonacosane (n-C29), suggesting that beetles might mimic the queen's pheromonal bouquet.
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A high recombination rate in eusocial Hymenoptera: evidence from the common wasp Vespula vulgaris
BMC genetics, 2011Co-Authors: Anu Sirviö, J. Spencer Johnston, Tom Wenseleers, Pekka PamiloAbstract:Background High recombination rates have previously been detected in two groups of eusocial insects; honeybees and ants. In this study we estimate recombination rate in a eusocial wasp Vespula vulgaris that represents a third phylogenetic lineage within eusocial hymenopterans.
Philip J. Lester - One of the best experts on this subject based on the ideXlab platform.
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Fitness and microbial networks of the common wasp, Vespula vulgaris (Hymenoptera: Vespidae), in its native and introduced ranges
Ecological Entomology, 2019Co-Authors: Monica A. M. Gruber, Tom Wenseleers, Oliver Quinn, James W. Baty, Jana Dobelmann, John Haywood, Philip J. LesterAbstract:1. Variation in microbial communities between populations is increasingly hypothesised to affect animal fitness and performance, including for invasive species. Pathogenic species may be lost during the introduction process, enhancing invader fitness and abundance. 2. This study assessed fitness, immune gene expression, and microbial network complexity of invasive common wasps, Vespula vulgaris. Microbial networks were assayed using 16S and 18S sequencing and gene expression arrays in the native (Belgium) and introduced range (New Zealand). The immune gene expression of the wasp Down syndrome cell adhesion molecule (Dscam) gene homologue was examined. Dscam expression can be induced by viruses, Gram‐positive and Gram‐negative bacteria, and parasites. 3. Individual nest fitness was higher in the native range of Belgium than in the introduced New Zealand range. Microbial communities of wasps in the introduced range were more diverse with more complex networks, although some microorganisms were range‐specific. Microbial networks in the introduced range showed higher clustering coefficients, number of connected paths, network centralisation, number of neighbours and network density. 4. Larvae, workers, virgin and foundress queens had higher expression of Dscam in the New Zealand samples. These immune gene expression patterns were associated with higher pathogen pressure and lower relative fitness. 5. Epidemiological theory predicts that a high density of pathogen and microbial hosts should result in a high rate of disease infection, prevalence, and highly connected microbial networks. The results of this study support these predictions. Wasps displayed lower relative fitness and more highly connected microbial networks in New Zealand than in Belgium.
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A metatranscriptomic analysis of diseased social wasps (Vespula vulgaris) for pathogens, with an experimental infection of larvae and nests.
PloS one, 2018Co-Authors: Oliver Quinn, Mariana Bulgarella, Robert L. Brown, Monica A. M. Gruber, James W. Baty, Philip J. LesterAbstract:Social wasps are a major pest in many countries around the world. Pathogens may influence wasp populations and could provide an option for population management via biological control. We investigated the pathology of nests of apparently healthy common wasps, Vespula vulgaris, with nests apparently suffering disease. First, next-generation sequencing and metatranscriptomic analysis were used to examine pathogen presence. The transcriptome of healthy and diseased V. vulgaris showed 27 known microbial phylotypes. Four of these were observed in diseased larvae alone (Aspergillus fumigatus, Moellerella wisconsensis, Moku virus, and the microsporidian Vavraia culicis). Kashmir Bee Virus (KBV) was found to be present in both healthy and diseased larvae. Moellerella wisconsensis is a human pathogen that was potentially misidentified in our wasps by the MEGAN analysis: it is more likely to be the related bacteria Hafnia alvei that is known to infect social insects. The closest identification to the putative pathogen identified as Vavraia culicis was likely to be another microsporidian Nosema vulgaris. PCR and subsequent Sanger sequencing using published or our own designed primers, confirmed the identity of Moellerella sp. (which may be Hafnia alvei), Aspergillus sp., KBV, Moku virus and Nosema. Secondly, we used an infection study by homogenising diseased wasp larvae and feeding them to entire nests of larvae in the laboratory. Three nests transinfected with diseased larvae all died within 19 days. No pathogen that we monitored, however, had a significantly higher prevalence in diseased than in healthy larvae. RT-qPCR analysis indicated that pathogen infections were significantly correlated, such as between KBV and Aspergillus sp. Social wasps clearly suffer from an array of pathogens, which may lead to the collapse of nests and larval death.
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The stinging response of the common wasp (Vespula vulgaris): plasticity and variation in individual aggressiveness
Insectes Sociaux, 2015Co-Authors: Davide Santoro, David M. Suckling, Stephen Hartley, Philip J. LesterAbstract:We studied the variability and plasticity of individual aggressiveness in a social insect, describing and quantifying the sting extension response (SER) of the common wasp Vespula vulgaris. As a proxy for individual aggressiveness we measured the SER of individual wasps, scoring the extent by which the sting was extruded in response to a mild electric shock (7.5 or 12 V for 2 s) on a scale from 0 to 1. We found that wasps vary greatly in their stinging propensity and aggression thresholds and that individuals change their SER during their life. Extremely aggressive or docile phenotypes, showing at first consistent mutual differences on different days, tended to converge over time and developed comparable SER responses later in their life. Older individuals tended to be more aggressive. Wasp size was not related to the stinging phenotype. Wasp foragers had a less pronounced sting extension than individuals previously involved in nest defense. For the same individual, the aggressive response was proportional to the intensity of the negative stimulus. We discuss the advantages of the SER bioassay as a tool to measure individual aggressiveness, plasticity and inter-individual variability in the Aculeata group, and its great potential in comparative and learning studies.
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No evidence of enemy release in pathogen and microbial communities of common wasps (Vespula vulgaris) in their native and introduced range.
PloS one, 2015Co-Authors: Philip J. Lester, Michael E. Archer, Monica A. M. Gruber, Evan C. Brenton-rule, Peter J. Bosch, Eugene A. Kapp, Lifeng Peng, Joe Buchanan, Wlodek L. Stanislawek, Juan C CorleyAbstract:When invasive species move to new environments they typically experience population bottlenecks that limit the probability that pathogens and parasites are also moved. The invasive species may thus be released from biotic interactions that can be a major source of density-dependent mortality, referred to as enemy release. We examined for evidence of enemy release in populations of the common wasp (Vespula vulgaris), which attains high densities and represents a major threat to biodiversity in its invaded range. Mass spectrometry proteomic methods were used to compare the microbial communities in wasp populations in the native (Belgium and England) and invaded range (Argentina and New Zealand). We found no evidence of enemy release, as the number of microbial taxa was similar in both the introduced and native range. However, some evidence of distinctiveness in the microbial communities was observed between countries. The pathogens observed were similar to a variety of taxa observed in honey bees. These taxa included Nosema, Paenibacillus, and Yersina spp. Genomic methods confirmed a diversity of Nosema spp., Actinobacteria, and the Deformed wing and Kashmir bee viruses. We also analysed published records of bacteria, viruses, nematodes and fungi from both V. vulgaris and the related invader V. germanica. Thirty-three different microorganism taxa have been associated with wasps including Kashmir bee virus and entomophagous fungi such as Aspergillus flavus. There was no evidence that the presence or absence of these microorganisms was dependent on region of wasp samples (i.e. their native or invaded range). Given the similarity of the wasp pathogen fauna to that from honey bees, the lack of enemy release in wasp populations is probably related to spill-over or spill-back from bees and other social insects. Social insects appear to form a reservoir of generalist parasites and pathogens, which makes the management of wasp and bee disease difficult.
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Nest-based information transfer and foraging activation in the common wasp (Vespula vulgaris)
Insectes Sociaux, 2015Co-Authors: Davide Santoro, David M. Suckling, Stephen Hartley, Philip J. LesterAbstract:The apparent absence of intra-nest signals and communication about food resources (recruitment) among social wasps does not rule out the possibility of information transfer and coordinated foraging among nestmates. In the present study, we tested the hypothesis that the common wasp (Vespula vulgaris) shows nest-based information transfer and foraging activation: an increase in the probability of an individual leaving the nest as a result of information about resources received from successful foragers. We controlled for the possibility of local enhancement, chemical trails at the food source and climatic variation. We found evidence that food choice and discovery of resources in the field by naive foragers were assisted by information previously or simultaneously provided by experienced nestmates. This information was related to chemical cues associated with the food and possibly to its location. Our observations suggest piloting between common wasp foragers. At the trained nest, there was a change in foraging effort at the colony level when known resources were available. Reactivated, experienced foragers were the main group responsible for the increase in foraging traffic rate observed at the colony level. To our knowledge, this is the first study clearly demonstrating nest-based information transfer about food resources in V. vulgaris and one of the few providing evidence of foraging activation in social wasps. Our data are consistent with the possibility of recruitment in this group of social insects.
Travis R. Glare - One of the best experts on this subject based on the ideXlab platform.
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Misidentification of Vespula alascensis as V. vulgaris in North America (Hymenoptera: Vespidae; Vespinae)
American Museum Novitates, 2010Co-Authors: James M Carpenter, Travis R. GlareAbstract:Morphological and molecular-based comparisons of the North American yellowjackets identified as Vespula vulgaris (Linnaeus, 1758) with samples from other parts of the world demonstrate they are not that species. The name Vespula alascensis (Packard, 1870) is applicable to the North American species, new status. Vespa communis de Saussure, 1857, non von Schrank, 1785, is a synonym of Vespula maculifrons (du Buysson, 1905), REVISED SYNONYMY.
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Susceptibility of Vespula vulgaris (Hymenoptera: vespidae) to generalist entomopathogenic fungi and their potential for wasp control.
Journal of invertebrate pathology, 2000Co-Authors: R. J. Harris, S. J. Harcourt, Travis R. Glare, E. A. F. Rose, T. J. NelsonAbstract:The pathogenicity of Vespula vulgaris wasp workers and larvae to a range of fungi was determined. All fungi were isolated in New Zealand and included isolates from Vespula, known generalist insect pathogens, and isolates generally nonpathogenic to insects. Workers and larvae were highly susceptible to pathogenic isolates at high spore concentrations (>1.75 x 10(5) cfu/individual). Eight isolates, two of Metarhizium anisopliae, five of Beauveria bassiana, and one of Aspergillus flavus were pathogenic while a single isolate of M. flavouiride var. novazealandicum, Cladosporium sp., and Paecilomyces sp. were not. The transfer of spores between workers, and between workers and larvae, was also investigated using several different application methods. Transfer of spores occurred between treated and untreated individuals, and for some of the application methods sufficient spores were transferred to cause mortality of the nontreated individuals. These findings are related to the potential of fungi for the control of wasps.
David M. Suckling - One of the best experts on this subject based on the ideXlab platform.
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The stinging response of the common wasp (Vespula vulgaris): plasticity and variation in individual aggressiveness
Insectes Sociaux, 2015Co-Authors: Davide Santoro, David M. Suckling, Stephen Hartley, Philip J. LesterAbstract:We studied the variability and plasticity of individual aggressiveness in a social insect, describing and quantifying the sting extension response (SER) of the common wasp Vespula vulgaris. As a proxy for individual aggressiveness we measured the SER of individual wasps, scoring the extent by which the sting was extruded in response to a mild electric shock (7.5 or 12 V for 2 s) on a scale from 0 to 1. We found that wasps vary greatly in their stinging propensity and aggression thresholds and that individuals change their SER during their life. Extremely aggressive or docile phenotypes, showing at first consistent mutual differences on different days, tended to converge over time and developed comparable SER responses later in their life. Older individuals tended to be more aggressive. Wasp size was not related to the stinging phenotype. Wasp foragers had a less pronounced sting extension than individuals previously involved in nest defense. For the same individual, the aggressive response was proportional to the intensity of the negative stimulus. We discuss the advantages of the SER bioassay as a tool to measure individual aggressiveness, plasticity and inter-individual variability in the Aculeata group, and its great potential in comparative and learning studies.
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Nest-based information transfer and foraging activation in the common wasp (Vespula vulgaris)
Insectes Sociaux, 2015Co-Authors: Davide Santoro, David M. Suckling, Stephen Hartley, Philip J. LesterAbstract:The apparent absence of intra-nest signals and communication about food resources (recruitment) among social wasps does not rule out the possibility of information transfer and coordinated foraging among nestmates. In the present study, we tested the hypothesis that the common wasp (Vespula vulgaris) shows nest-based information transfer and foraging activation: an increase in the probability of an individual leaving the nest as a result of information about resources received from successful foragers. We controlled for the possibility of local enhancement, chemical trails at the food source and climatic variation. We found evidence that food choice and discovery of resources in the field by naive foragers were assisted by information previously or simultaneously provided by experienced nestmates. This information was related to chemical cues associated with the food and possibly to its location. Our observations suggest piloting between common wasp foragers. At the trained nest, there was a change in foraging effort at the colony level when known resources were available. Reactivated, experienced foragers were the main group responsible for the increase in foraging traffic rate observed at the colony level. To our knowledge, this is the first study clearly demonstrating nest-based information transfer about food resources in V. vulgaris and one of the few providing evidence of foraging activation in social wasps. Our data are consistent with the possibility of recruitment in this group of social insects.
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Attraction of the invasive social wasp, Vespula vulgaris, by volatiles from fermented brown sugar
Entomologia Experimentalis et Applicata, 2014Co-Authors: Robert L. Brown, Ashraf M. El-sayed, C. Rikard Unelius, David M. SucklingAbstract:The introduction of invasive social wasp species of the genus Vespula (Hymenoptera: Vespidae) to New Zealand has caused a major ecological problem, particularly in the beech forests (Nothofagus spp.) of the South Island, where they have destabilized the native bird and invertebrate biodiversity. New attractants are under investigation as part of a search for pest management solutions. Fermenting brown sugar has been previously reported as a social wasp attractant. This work was undertaken to identify compounds from fermented brown sugar attractive to social wasps. Raw fermented brown sugar was confirmed to be attractive in a field trial and 10 chemical compounds present in the headspace were positively identified by coupled gas chromatography-mass spectrometry and synthetic references. During electroantennogram experiments, 3-methyl-1-butanol, 3-methylbutyl acetate, and ethyl hexanoate elicited high electrophysiological responses from Vespula vulgaris (L.) antennae. These compounds mediated attraction of V. vulgaris wasps in forest margins by trapping. A blend of these compounds could be used as a lure in a monitoring tool, or even a local suppression method if combined with a toxin.
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Attraction and antennal response of the common wasp, Vespula vulgaris (L.), to selected synthetic chemicals in New Zealand beech forests.
Pest management science, 2009Co-Authors: Ashraf M. El-sayed, L. M. Manning, C. Rikard Unelius, Kye Chung Park, Lloyd D. Stringer, Nicola White, Barry J. Bunn, Andrew M. Twidle, David M. SucklingAbstract:BACKGROUND: The common wasp, Vespula vulgaris (L.), and the German wasp, Vespula germanica (F.), are significant problems in New Zealand beech forests (Nothofagus spp.), adversely affecting native ...
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New attractants for Vespula vulgaris from honeydew
New Zealand Plant Protection, 2008Co-Authors: N.j. White, L. M. Manning, Lloyd D. Stringer, David M. Suckling, A. R. Gibb, C. R. Unelius, K.c. Park, Ashraf M. El-sayedAbstract:The common wasp (Vespula vulgaris) is a major pest species in New Zealands forests and urban areas Attractants for wasps could enable new environmentallyfriendly management techniques against this invasive species Beech forest honeydew known to be attractive to vespid wasps was analysed using Solid Phase Micro Extraction Several volatile compounds were identified and two compounds (I and II) were tested for attraction in a Canterbury beech forest Four different lures (manuka honey; compound I; compound II; and a blend of compounds I and II) were placed in delta traps and the number of V vulgaris trapped recorded Compound II trapped significantly more V vulgaris than manuka honey and compound I and had significantly less honey bee (Apis mellifera) bycatch than the other three lures A controlled release experiment was carried out by placing 05 ml of compound II in vials with a 2 4 or 6 mm diameter hole or no hole in the lid The 4 mm treatment caught significantly more V vulgaris than the control no hole and 2 mm treatments A gravimetric release rate experiment on compound II in the laboratory showed a significant difference in weight loss between treatments These results suggest that compound II deserves further research as a wasp attractant
Jacqueline R Beggs - One of the best experts on this subject based on the ideXlab platform.
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primer registro de Vespula vulgaris hymenoptera vespidae en la argentina
Revista de la Sociedad Entomológica Argentina, 2010Co-Authors: Maite Masciocchi, Jacqueline R Beggs, James M Carpenter, Juan C CorleyAbstract: Abstract. Vespula vulgaris (Linnaeus) is a social vespid native to the Holarctic region. The first detection of this species in Argentina is here reported. Workers were captured close to San Carlos de Bariloche (Argentina) during February 2010, while sampling for another successful invader, the German wasp or Yellowjacket, Vespula germanica (Fabricius). Both these wasp species are very similar morphologically and share a number of common habits. Also, some identification features and biological characters are here explained.
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the difficulty of reducing introduced wasp Vespula vulgaris populations for conservation gains
1998Co-Authors: Jacqueline R Beggs, Henrik Moller, P AlspachAbstract:Summary: Introduced common wasps (Vespula vulgaris) are widespread, abundant pests in New Zealand. They compete for food with native birds and feed on native invertebrates. We poisoned wasps annually over 4 years to see if it was possible to reduce their abundance in two 30-ha beech forest sites. Two different poisons (sodium monofluoroacetate and sulfluramid) were used, mixed with sardine catfood. There was no evidence that one poison was more effective than the other. Between 82 and 100% of the colonies were killed in the poisoned sites, but reinvasion by foraging workers meant that cumulative wasp biomass (measured using Malaise traps) was reduced by only 55 - 70%. Individual wasps were about 16% heavier in the poisoned sites at the peak of the wasp season (March) than in the non-poisoned sites, although this had a minimal effect on cumulative biomass over the entire season. Conservation gains need to be quantified in order to assess whether the expense of such poisoning operations is warranted.
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Impacts of introduced common wasps (Vespula vulgaris) on experimentally placed mealworms in a New Zealand beech forest
Oecologia, 1996Co-Authors: Kirsty Barr, Henrik Moller, Emma Christmas, Philip Lyver, Jacqueline R BeggsAbstract:An introduced social wasp Vespula vulgaris may compete with native birds for honeydew and invertebrates in New Zealand forests. Experimentally hidden mealworms (Tenebrio molitor) persisted longer at two sites following wasp poisoning that at two sites where wasps were not poisoned. Mealworms persisted longer in the morning than in the afternoon within all study sites. An unusually low mealworm removal rate during a morning trial before wasp poisoning heavily influences the results of this experiment but we have no ecological reason to ignore it. Wasps may therefore be having a heavy impact on invertebrate abundance on very short time scales (within a day following dawn emergence). They may also remove cached food items that would otherwise be retrieved by the South Island robin (Petroica australis australis) during cold or dark feeding conditions.
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Altitudinal variation in abundance of common wasps (Vespula vulgaris)
New Zealand Journal of Zoology, 1991Co-Authors: Jacqueline R BeggsAbstract:AbstractCommon wasps (Vespula vulgaris) were caught in traps set along a 2 km altitudinal transect (455–1590 m a.s.l.) through New Zealand beech (Nothofagus) forest and adjacent alpine tussock in 1990. No German wasps (V. germanica) were caught Very few wasps were caught in the tussock above the bushline (1425 m a.s.l.), compared with the red (N. fusca)/silver beech (N. menziesii) forest from 550 m to 1020 m a.s.l. The highest density of wasps was found in this mid-altitude red/silver beech zone. Wasp density within vegetation zones decreased as altitude increased, but honeydew abundance also varied with altitude. Nevertheless, there is evidence that altitude itself affected wasp abundance. Bird counts before the arrival of common wasps indicated that the mid- altitude zone, where wasps and honeydew were most abundant, was also the main habitat of some native bird species. Therefore, wasps may affect those bird species that are largely confined to this zone.
