Why wasps

Mating with males from other colonies, the gynes overwinter before starting a colony of their own the following spring. They may not make honey, but nonetheless wasps have just as fascinating social lives as the celebrated honeybee. Wasps are also just important in the environment. Social wasps are predators and as such they play a vital ecological role, controlling the numbers of potential pests like greenfly and many caterpillars.

Indeed, it has been estimated that the social wasps of the UK might account for 14 million kilograms of insect prey across the summer. A world without wasps would be a world with a very much larger number of insect pests on our crops and gardens. As well as being voracious and ecologically important predators, wasps are increasingly recognised as valuable pollinators, transferring pollen as they visit flowers to drink nectar.

It is actually their thirst for sweet liquids that helps to explain why they become so bothersome at this time of year. By late August, wasp nests have very large numbers of workers but they have stopped raising any larvae. All the time nests have larvae, the workers must collect protein, which accounts for all those invertebrates they hunt in our gardens.

The larvae are able to convert their protein-rich diet into carbohydrates that they secrete as a sugary droplet to feed the adults. With no larvae, all those adult wasps must find other sources of sugar - hence why they are so attracted to our sugar-rich foods and drinks. Wasps have a slender body with a narrow waist, slender, cylindrical legs, and appear smoothed-skinned and shiny. Yellowjackets, baldfaced hornets, and paper wasps are the most common types of aggressive pests encountered by people.

Wasps are predators, feeding insects to their young. What makes them beneficial is that they prey on many insects, including caterpillars, flies, crickets, and other pests. What makes them a pest is in late summer and fall they alter their tastes and go after sweets. Overall, if you are on the lookout for a nest, a homeowner can have an uneasy coexistence with these pests.

Because eliminating them most often requires toxic chemicals and poisons, it may best to let them live and avoid the nests, if possible. Yellowjackets commonly build nests below ground in old rodent burrows or other cavities. They can also build nests in trees, shrubs, under eaves, and inside attics or wall voids. But I did have a student who got stung times. He gave them a credit in his PhD thesis. This article is more than 6 months old.

Even the much-maligned common wasp provides important ecosystem services. Photograph: Alamy stock photo. Topics Insects Bees Biodiversity Wildlife news. Reuse this content. Environment Climate crisis Wildlife Energy Pollution. Surprisingly, only four species of solitary wasps are commercially available for biological control the most well-known is the Emerald jewel wasp, Ampulex compressa , which is famous for zombiefying cockroaches. Introductions of solitary wasps to non-native regions have not been very successful, possibly because their life histories are not understood well enough.

A more successful approach may be to exploit local species, and especially social species. Over years ago, colonists in the West Indies toyed with the idea of using social wasps on plantations, reporting anecdotally that crops appeared to be less plagued by pests and there was less need for pesticides when wasp populations were encouraged.

But apart from a handful of midth century studies and some encouraging opinion articles , the suggestive potential for using social wasps in biocontrol has largely been forgotten. Together with some enterprising Brazilians, we provided some tantalising evidence for the biocontrol promise of social wasps a couple of years ago. We showed that levels of crop damage and pest populations of the fall army worm a pest of maize, which causes billions of dollars in crop yield losses every year were significantly reduced when wasps were allowed to access them.

Although wasps hunt prey to feed to growing offspring, the adult hunters are herbivores, just like bees, who visit flowers for carbohydrates in the form of sugar. Much of the year adult social wasps are fed by their larvae, which provide the adults with a nutritious sugar solution in return for the meat they are fed.

Some plants are completely reliant on wasps for pollination; we counted plant species across six families. Most of these are orchids which have evolved to mimic female wasp pheromones — some even look like the back end of a female wasp.

Males of the Scoliidae and Thynnidae are duped into copulating with a sexy-looking orchid, during which pollen is attached to him and transferred to another flower as he flits from one sexy deceptor to the next. The vast majority of wasp-plant interactions are, however, non-specific.

We identified plant species across families that were visited by wasps. The social wasps in particular appear to be extremely unfussy about what flower they will visit, so long as they can reach the nectar. To date, there are no studies that allow even a rough estimate of the value of wasps as pollinators.

But, given the importance of natural pollinators to our food security and the apparent declines of well-recognised pollinators like bees and hover flies, now would be a good time to start taking wasp pollination a bit more seriously.

This is especially true given that some species of social wasp appear to be relatively resilient to anthropogenic change. In a recent analysis of museum and contemporary biological records, we showed that populations of social wasp species had changed very little over the last years. The yellowjacket wasps in particular appear to be resilient to anthropogenic challenges, like urbanisation and agriculture. Other species, like the hornet, may be more affected by pollutants and loss of habitat.

We need a better understanding of what life history traits make certain species resilient and others vulnerable to our changing planet in order to manage the potential pollinating power of wasps. When trying to put a value on insects, one rarely thinks beyond pollination and predation. In fact, these are only part of the services that insects, including wasps, might offer us.

Promoting entomophagy — insects as food for humans — is surely the solution to sustainable food security. Insects are high in protein and essential amino acids. They use less space and water, emit fewer greenhouse gases and ammonia than livestock. This means that farming them is very efficient. Over 2 billion people around the world consume insects as part of their diet, with species being eaten across 19 countries.

And wasps account for 4. The Japanese are especially appreciative of wasp larvae or pupae. When the queen wakes up in spring, the yeast hitch a ride to a nearby sugar source remember that wasps like flowers?