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Transitioning from trials to pest control tool, the efficacy of controlling wasps Vespula vulgaris and V. germanica using Vespex® wasp bait was tested in 2015. Vespex® is a protein-based bait matri...

Morphological and physiological caste differences were compared from colonies of Dolichovespula maculata in middle and late phases of the colony cycle. The females showed three patterns of ovarian development and only females classified as queens were inseminated. In both phases, queens were larger than workers for most measures. Discriminant analyses showed high distinction of caste in both phases. We also found highly pronounced qualitative differences: workers had hairs covering the entire body whereas queens had no hair and also some colour differences in the gaster. These results indicate that D. maculata presents pre-imaginal differentiation as seen in other Vespinae, and that size variation occurs from colony to colony such that queens of one colony may be comparable to workers of a different colony although the castes are always distinguishable within colonies.

The nematode (Pheromermis spp.) is a potential biocontrol agent for wasps (Vespula spp.) in countries where invasive populations of wasps cause serious economic, social, and conservation problems. Using a simulation model previously developed for hornets, which belong to a genus with a similar biology to Vespula, we investigated the possibility of using nematodes as a biological control agent. The model wasp colony was exposed to different simulated levels of nematode infection during colony development, and the final number of wasp sexuals produced recorded. The model predicted that early and high levels of wasp infection had the greatest effect on reducing sexual production. However, even colonies with high (80%) levels of infection were still able to produce some sexuals, indicating that wasp colonies are resilient to infections. The model identified several key areas needing further research, including the effects of nematodes on the behaviour and physiology of wasps, of lengthening the infec...

A manageable, generalist, predatory insect has to date been considered to be unavailable anywhere for pest insect control. Polistes spp. wasps showed promise, but are limited by small numbers of wasps per nest and short nest life. Social Vespula spp. wasps appear to possess the necessary attributes which will allow their development as manageable, generalist predators of a wide range of pest insects. They have a large number of foragers per nest, a high demand for invertebrate protein, a very wide range of prey, an ability to tolerate low temperatures, a tolerance of nest manipulation, and a colony life cycle that can span at least two summers. High numbers per nest and high nest densities can lead to the consumption of many kilograms of prey per hectare per year. Successful development of characteristics desired of a manageable predator, such as the ability to increase colony numbers by dividing and re-queening, and enhancement of multi-year colony existence, could result in management procedures for Ves...

Sphecophaga vesparum burra (Cresson) (Hymenoptera: Ichneumonidae) has been released at seven sites in New Zealand as a biological control agent for wasps (Vespula spp.). Between 1996 and 1998, more than 35 000 overwintering cocoons were released nationwide, more than half of them at two South Island sites: Binser Track in Arthur's Pass National Park (13 200 cocoons) and Tennyson Inlet in the Marlborough Sounds (13 660 cocoons). Monitoring at these two climatically and altitudinally disparate sites revealed that over 5000 adult parasitoids emerged at each site over the 4 years. More than 300 wasp nests were dug and inspected for attack by S. v. burra, but there was no evidence of establishment.

Fipronil is a new insecticide being trialed in baits for control of introduced social wasps (Vespula spp.). The efficacy of fipronil was compared with sulfluramid (Finitron® wasp bait). In a laboratory bioassay, fipronil was faster acting and equally as toxic at concentrations over 1000 times lower than sulfluramid. Doses of 0.2 mg of fipronil active (0.2 g of bait when used at 0.1%) were sufficient to reduce colony activity by 90%. Trials in a 300‐ha site in beech forest used a single poison operation, without prefeeding, and bait stations in either a 50 × 50 m or 100 × 50 m grid. Use of fipronil reduced colony activity within the treated area by 99.7%, whereas sulfluramid had minimal effect on colony activity. Some foragers reinvaded the treated blocks after treatment with fipronil, but wasp densities remained below estimated ecological damage thresholds for vulnerable invertebrates in this habitat. Baiting in lines resulted in variable control of nearby colonies. Despite the low doses of fipro...

No practical methods are currently available for area‐wide, long‐term control of social wasps in New Zealand. Pathogens have received little attention as potential control agents. Records from wasps of the genera Vespula, Vespa, and Dolicho‐vespula and their associated nest material include 50 fungal, 12 bacterial, 5–7 nematode, 4 protozoan, and 2 viral species, although few have been confirmed through bioassay as pathogens of these wasp species. Despite few naturally‐occurring host‐specific pathogens and records of diseased colonies, wasps are susceptible to generalist insect diseases in bioassays. Fungi belonging to the genera Aspergillus, Paecilomyces, Metarhizium, and Beauveria have been confirmed through bioassay as Vespiniae pathogens, as have the bacteria Serratia marcescens and Bacillus thuringiensis, and nematodes Heterorhabditis bacteriophora, Steinernema (= Neoaplectana) sp., S. feltiae, S. carpocapsae and Pheromermis vesparum. Several of the pathogens listed here provide a resource fr...

The vespid wasp parasitoid Sphecophaga vesparum vesparum (Curtis) (Hymenoptera: Ichneumonidae) produces three types of cocoons, “white”, “weak‐walled yellow” and “yellow”. The adults that emerge from them represent a transition from wingless female morphs that emerge in a few weeks to alate females that remain dormant for 1–4 years. To determine the role of host age, nest temperature, and any intrinsic differences in the eggs on parasitoid cocoon type, newly emerged adult parasitoids were placed individually onto pieces of worker or queen comb containing Vespula vulgaris (L.) hosts of known age, and kept at different temperatures. Cocoon forms showed a continuous gradient in type rather than discrete morphs as was previously suggested. Cocoon type was principally determined by the age of the host on which the parasitoid oviposited; yellow cocoons resulted from eggs laid in early stages after the pupal cap was spun, and white cocoons from eggs laid on more developed pupae. Host age also influenced...

In Japan, the most popular edible insect is a grasshopper, Oxya yezoensis or O. japonica. It is consumed in large amount even at present. The grasshopper is rich in proteins. Mixtures of river‐living insect larvae are highly esteemed as favorite foods. The larvae and pupae of a wasp, Vespula lewisi, are consumed in considerable amounts. Pupae and female adults after oviposition of Bombyx mori are also consumed. The pupae are rich in nutrients. All of these insects are cooked with soy sauce and sugar, and are sold as canned foods. In addition to these insects, the larvae of cerambycid beetles are eaten by preference in countryside. Larvae of the dobsonfly, Protohermes grandis (Neuroptera) has been consumed as a traditional medicine.

Sphecophaga vesparum (Curtis), an ichneumonid parasitoid of vespid wasps, has been introduced into New Zealand for the biological control of Vespula species. S. vesparum is divided into two allopatric subspecies: S. v. vesparum (Curtis) from Europe, and S. v. burra (Cresson) from North America. S. v. vesparum has been released over most of New Zealand since 1987, and is established at two sites. S. v. burra was released in the field at one site in 1979 and failed to establish. It is now being held in quarantine pending re‐release. Establishment success and distribution patterns of the two subspecies will be studied in future, so a morphological study was carried out to determine whether they could be reliably distinguished. We examined 164 specimens of S. v. vesparum and 87 specimens of S. v. hurra, and scored 13 characters. Results showed that the two subspecies could not be reliably discriminated on any morphological characters, but that three colour characters gave >98% separation for females ...

The wasp parasitoid Sphecophaga vesparum vesparum has been released in many parts of New Zealand since 1987 as a biological control agent for German (Vespula germanica) and common ( V. vulgaris) wasps. We checked whether the parasitoid had established at 33 release sites. At 26 of these sites, we inspected enough nests (at least 20) to be more than 80% certain that we would have detected the parasitoid if at least 8.5% of the nests had been attacked. We suggest that the probability of 5. v. vesparum successfully invading a site is greatly increased when a large number of founders are released and there is a high density of wasp nests. The parasitoid has established in at least two sites, Pelorus Bridge (Marlborough) and Ashley Forest (Canterbury). S. v. vesparum has been established at Pelorus Bridge since 1988 and annually infests an average of 8.5% of nests within 2 km of the release site. The parasitism rate has increased since the parasitoid first established. Despite this increase, we did no...

Variation in larval insect diet can influence later survival, adult size, and reproductive competitiveness, and has been proposed as a factor regulating the population dynamics of wasps (Vespula spp.). Larvae of V. vulgaris were starved to determine the influence of starvation on survival and adult size. Larvae pupated up to 16 days after starvation began. Those pupating after 6 days had lower survival rates than non‐starved larvae. As the length of time to pupation increased, the size of emerging adults decreased. Although apparently morphologically normal, newly emerged, starved adults were only 56% of the weight of non‐starved wasps. Variation in size caused by experimental starvation is similar in magnitude to that recorded in natural populations.

Density‐related variation in queen quality has been proposed as a possible mechanism regulating population fluctuations in Vespula species. We investigated annual variation in the quality (size, weight, and fat content) of adult V. vulgaris queens representing four stages of their life cycle (spring, founding, developing, and emerged) taken from six sites in beech forest, South Island, New Zealand. For each queen the dry weight, head width, and thorax length was measured. For a subsample of queens, the fat content was determined by ether extraction. The size of queen cells was measured from a subsample of nests. Size, weight, and fat content of queens varied between wasp colonies and sites. The smallest juvenile queens were under‐represented in the reproductive population. There was no direct link between body size and food supply. Size and weight of developing queens increased as the number of cells in the nest increased. The size of the queen cells varied significantly among layers in a nest an...

Crane flies (Tipulidae) are common in the diet of native insectivores and introduced Vespula wasps. The seasonality of adult crane fly species was determined by Malaise trapping so that species potentially vulnerable to an impact from high wasp numbers could be identified as possible indicator species for analyzing the wider impacts of wasps in beech forest (Nothofagus spp.) ecosystems. Four sites in beech forest at Lake Rotoroa, Nelson Lakes National Park, were sampled over 2.5 years. The seasonality of 20 species of larger Tipulidae were plotted against three broad seasonal levels of wasp abundance identified from Malaise trap catches. Eleven species shared at least 40% of their flight period with high wasp numbers, with three of these restricted almost entirely to the period of high wasp abundance. These species may be the most vulnerable to an impact from wasp predation.

Between 1977 and 1989 the social wasp Vespula germanicacolonised mainland Australia and became established in New South Wales, Victoria, and South Australia. Accidental transport between towns is the main mechanism of spread. In many towns wasp nests have not been detected until they became widespread; therefore, eradication is difficult Successful eradication has, however, been achieved in many other towns. Nesting places vary considerably among localities but relatively little among years at anyone locality. Peak wasp abundance occurs between January and April. Control of V. germanica nests costs Australia an estimated $600,000 (Aust. $) annually.

The number of Vespula wasp workers in a colony can be predicted from the mean of 1-minute counts of wasps entering or leaving the colony (traffic rate). The predictive equation (Adjusted R2 = 0.87) is: number of workers = 32.243 × traffic rate per minute and is independent of species, time of year, or location. However, we mainly measured mature colonies. The equation may overestimate the number of workers in spring colonies, because a greater proportion of workers forage then. Traffic rate can also predict the biomass of a V. vulgaris colony (Adjusted R2 = 0.90) by allowing for season. Colonies measured after mid May generally had a larger biomass for any given traffic rate than those measured earlier. There were too few data from V. germanica colonies to evaluate the relationship between traffic rate and biomass for this species.

In New Zealand the nematode Sphaerularia bombi Dufour is currently confined to an area of about 30–40 km around Christchurch, where bumble bees were originally released. The spread of this nematode has been much slower than that of its bumble bee hosts during the 100 years since their introduction. Levels of apparent parasitism of up to 56% in B. terrestris (L.) and 7% in B. hortorum (L.) were detected. The incidence of S. bombi queens foraging in spring rises sharply as healthy queens become unavailable when they start their nests. Estimated mortality levels caused by S. bombi are between 3–10% in both B. terrestris and B. hortorum. These levels are lower than in Europe. Infected B. terrestris averaged 5.0 nematode uteri per host and B. hortorum 1.7 uteri per host, which is similar to records from Europe. The status of S. bombi as a parasite of Vespula queens remains uncertain.

Three groups of Conservation Corps workers in 3 different years recorded the number of times they were stung by. Vespula wasps while surveying wasp nests in the Nelson/Marlborough area. On average, males were stung 3 times more often than females. There was little difference in the median number of stings received by each work group, but in years when wasp density was higher the workers tended to receive more stings. We suggest that human behavioural differences are largely responsible for the differences in the prevalence of stings between the sexes, but it is possible that other factors such as odours also influence the likelihood of being stung.

SummaryTwelve synthetic attractants for wasps, Vespula spp., were only marginally attractive to honeybees (Apis mellifera,) alfalfa leafcutter bees (Megachile pacifica Panzer, = M. rotundata Fabr.), and alkali bees ((Nomia melanderi.) Traps baited with these wasp attractants can therefore provide a useful control measure against wasps without harming bees.

Variation in the production of beech honeydew by the scale insect (Ultracoelostoma assimile), and in the density and abundance of insects feeding on it, was studied in a mixed beech (Nothofagus) forest near Nelson, New Zealand. Nearly all anal tubes were connected to a feeding instar of the scale insect and so were able to deliver drops of honeydew to feeding insects and birds. The number of anal tubes and drops was high in winter and spring and declined to a trough in late summer and autumn. Drop quality (size and sugar concentration) also reached a low in the late summer and autumn. It is suggested that consumption of drops by wasps (mainly common wasps, Vespula vulgaris, but also German wasps, V. germanica) caused the paucity of honeydew in late summer and autumn. Wasps probably also prevented feral honey bees (Apis mellifera) from gathering honeydew then. Wasps were by far the most abundant insect feeding on honeydew, peaking at an average of 58 wasps per m2 of trunk of honeydew-infested tree...

Isotachophoresis, with its inherent high resolving power is a rapid and powerful technique for characterization of Hymenoptera insect venoms. By applying a combination of isotachophoresis for the first dimension separation step, and enzyme based assays, electrophoresis or immunological assays for the second dimension identification, it has been possible to identify the most important peptide/protein components in “Yellow Jacket” (Vespula species) venom. The combined two dimensional procedure is rapid, reproducible and well suited for determination of the antigenic/allergenic composition of various Hymenoptera venoms.

A bait of canned fish poisoned with 0.5 % or 1 % mirex substantially reduced populations of the European wasp, Paravespula germanica (Fab.), in a part‐cleared, part‐forested resort area in the Marlborough Sounds. In separate baiting regimes, bait was taken for as long as 9 weeks when 0.5% formulation was offered from 5 stations, but when 1 % formulation was offered from 10 and from 15 stations the time was reduced to 5 weeks and 4 weeks respectively. Synthetic and extracted materials tested as baits were unattractive to wasps, but fish baits attractive when fresh could be freeze‐dried without loss of acceptability. Marked wasps were caught up to 1200 m from their nests, and in the control programme 64 ppm mirex was recovered from dry brood comb of a defunct nest 700 m from the nearest bait source. The importance to bait control programmes of data on flight distance and foraging habits, and of the winter survival of colonies with prolonged queen production, is discussed. Some observations on reproductive b...

This paper records the capture of a live queen of the American bald-faced hornet in Dunedin.

The design of an entrance trap to enable collection of food from foragers returning to common and German wasps (Vespula vulgaris and V. germanica) nests is presented.