Attraction Of Wasps Research Articles

Conspecific and Food Attraction in the Wasp <I>Vespula germanica</I> (Hymenoptera: Vespidae), and Their Possible Contributions to Control

We studied attraction of Vespula germanica (F.) by conspecifics and food. By confining different numbers of wasps in containers, we showed that wasp attraction is density-dependent. Attraction to the containers persisted when the wasps were removed, suggesting that wasps leave an odor trace. Moreover, we demonstrated that conspecific attraction is not seasonal and that thorax extracts are attractive. Conversely, cat food bait attractiveness varied during the season. Third, we studied the predatory behavior of V. germanica wasps to determine whether the attraction elicited by conspecific wasps is due to cannibalistic behavior. Finally, we showed that attraction to food varied seasonally, unlike conspecific attraction. We believe these experiments are useful for improving control methods of this pest that severely affects northwestern Patagonia by the utilization of specific and stable toxic baits.

Induced parasitoid attraction by Arabidopsis thaliana: involvement of the octadecanoid and the salicylic acid pathway.

Plants can use indirect defence mechanisms to protect themselves against herbivorous insects. An example of such an indirect defence mechanism is the emission of volatiles by plants induced by herbivore feeding. These volatiles can attract the natural enemies of these herbivores, for example, parasitoid wasps. Here, it is shown that the octadecanoid and the salicylic acid pathways are involved in the induced attraction of the parasitoid wasp Cotesia rubecula by Arabidopsis thaliana infested with the herbivore Pieris rapae. Besides exogenous application of jasmonic acid or salicylic acid, use is also made of transgenic Arabidopsis that do not show induced jasmonic acid levels after wounding (S-12) and transgenic Arabidopsis that do not accumulate salicylic acid (NahG). Treatment of Arabidopsis with jasmonic acid resulted in an increased attraction of parasitoid wasps compared with untreated plants, whereas treatment with salicylic acid did not. Transgenic plants impaired in the octadecanoid or the salicylic acid pathway were less attractive than wild-type plants.

Specific attraction of fig-pollinating wasps: role of volatile compounds released by tropical figs.

Floral scents often act as pollinator attractants. In the case of obligate and specific plant-pollinator relationships, the role of floral signals may be crucial in allowing the encounter of the partners. About 750 Ficus species (Moraceae) are involved in such interactions, each with a distinct species of pollinating wasp (Chalcidoidea, Agaonidae). Several species have been shown to release volatile compounds, but their role in pollinator attraction has rarely been simultaneously tested. We investigated the floral scents of four tropical fig species and combined chemical analysis with biological tests of stimulation of insects. Pollinators of three species were stimulated by the odor of their associated fig species and generally not by the odor of another species. The fourth actually comprised two distinct varieties. The main compound was often a different one in each species. Floral blends of different species always shared compounds, but ratios of these compounds varied among species.

Carbohydrate bait preferences of wasps (Vespula vulgarisandV. germanica) (Hymenoptera: Vespidae) in New Zealand

Abstract Carbohydrates are both a source of food and a potential bait for control of common and German wasps. Carbohydrate preferences of wasps were determined in a series of paired trials by counting the number of wasps caught in traps baited with carbohydrate‐based baits versus a standard protein‐based bait. Factors influencing wasp attraction to carbohydrate‐based baits included bait type, season, weather, and location. A 30% sucrose solution was more attractive than honey, jams, gels, or dry (solid) sugars. The sucrose solution was more attractive in spring and autumn than in summer, probably because rainfall washed away natural carbohydrate supplies. There was a significant relationship between rainfall in the previous week and the proportion of wasps caught in traps baited with sucrose solution versus sardine cat‐food. A higher proportion of German wasps than common wasps was caught in sucrose‐baited traps. This may have been related to seasonal differences in abundance and/or behavioural differences between the two species. In some locations, more wasps were caught in traps baited with sucrose solution than in those baited with sardine cat‐food. The proportion of wasps caught in sucrose‐baited traps was higher in locations without beech scale honeydew than with beech scale honey‐dew. Proportionally more non‐target species (mainly honey bees) and fewer wasps were caught in traps baited with sucrose solution than in those baited with sardine cat‐food. All five bee repellents tested also repelled wasps. These results indicate the importance of determining the bait preferences of wasps (carbohydrate or protein) and the presence of non‐target species before attempting a poison‐baiting operation. They also emphasise the need for a wasp‐specific carbohydrate‐based bait.

Protein bait preferences of wasps (Vespula vulgarisandV. germanica) at Mt Thomas, Canterbury, New Zealand

Abstract Protein bait preferences of wasps (Vespula vulgaris and V. germanica) were determined by measuring the number of wasps attracted to different bait types, the amount of each bait type collected by wasps, and the proportion of wasps collecting bait. Fresh fish and meat baits attracted the largest number of wasps, but canned sardine cat‐food was collected in the greatest amounts. Factors influencing attraction of wasps to sardine cat‐food included wasp density, season, and weather. The number of wasps attracted to sardine cat‐food increased rapidly in January but lagged behind the number of wasps flying in and out of nests, peaked later, and declined earlier. The proportion of wasps that returned to nests carrying sardine cat‐food peaked in February‐March, when it was higher than the proportion collecting natural protein food. Sardine cat‐food is currently the best bait to use for wasp control because of its attractiveness, palatability, and acceptability to wasps. Future research should investigate...

Responses of fig wasps to host plant volatile cues

Fig wasps (Chalcidoidea; Agaonidae) are intimately associated with the 750 or so species of fig trees (Ficus, Moraceae). Each tree species is usually pollinated by a single species of wasp belonging to the subfamily Agaoninae, while other wasps of the family are parasitoids or seed predators. Previous experiments have shown that the wasps are attracted to the trees by volatiles emanating from the figs. Using fig-bearing trees and arrays of sticky traps baited with figs, we investigated the specificity of wasp attraction and its timing. The pollinators of two closely relatedFicus species were specifically attracted to figs of their host species and only at the time when figs were ready to be pollinated. Some nonpollinating fig wasps appear to respond to the same volatile cues.

Chemosensory attraction of fig wasps to substances produced by receptive figs

AbstractIn the mutualism between figs (Ficus spp., Moraceae) and their species‐specific fig wasp pollinators (Hymenoptera: Agaonidae), location of a receptive host tree by the adult insect is a critical step. The adult female wasp lives only a few days, and must usually fly to a different tree than her natal tree to locate receptive figs. Trees in receptive phase often occur at very low densities. Reproductive success of both fig and wasp depends on transmission of a very strong signal by the plant. Some evidence exists for the role of olfaction in location of receptive hosts by fig wasps, but very little work has been done on the chemical ecology of host location and host specificity. Here the first experimental evidence is presented for long‐distance olfactory attraction of wasps by volatile substances produced by receptive figs, and for short‐distance or contact chemostimulation by host volatiles that elicit entry of the wasp into the fig. In studies using Ficus carica L., pentane extracts of receptive‐phase figs attract the pollinator Blastophaga psenes L. from distances of at least 5 m in the field. Short‐distance chemostimulation was demonstrated in laboratory bioassays. Pentane extracts of receptive figs, when painted onto the ostiole of non‐receptive figs, elicit entry of pollinator wasps. Figs emit volatile compounds attractive to pollinating wasps only during the period of receptivity; pentane extracts of non‐receptive figs are not attractive. A simple reliable procedure is described to compare the attractivity of different types of extracts (total, internal, and external extracts) and of different fractions, in the first step towards identifying attractant substances.

Olfactory responses ofTrichogramma maidis Pint, et Voeg.: Effects of chemical cues and behavioral plasticity

Oriented responses of Trichogramma maidisPint, et Voeg. to airborne odors were observed in a four-armed olfactometer. Experiments were carried out with odors of host eggs, the sex pheromone of Ostrinia nubilalisHbn, and maize extract, offered singly or in combination, both to naive wasps and to wasps previously exposed to the tested odor during an oviposition experience. The exploratory behavior in the olfactometer was quantified by means of a computer program which performed a space-time analysis of the insect 's movements. Whereas the naive wasps did not respond to the odor of the eggs, the synthetic sex pheromone of O. nubilalis,or the maize extract presented singly, they did react to a mixture of these three volatile cues. Prior oviposition in the odor of maize extract or in the combination of odors induced an increased preference toward the conditioning scent. This phenomenon did not occur when the wasps were conditioned to egg odor or sex pheromone alone. These results suggest that females can learn to associate some olfactory cues with the presence of the host. Immediately following the presentation of the combination of odors, a strong attraction of experienced wasps occurred; it decreased as the experiment progressed and finally reached the level presented by naive insects. Adult conditioning to the combination of odors also resulted in reduced variability in the behavioral responses.

The Attractiveness to Bees of Synthetic Wasp Attractants

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.