It's that time of year again, wasps and hornets are starting to fly around in sizable numbers, outside we will be spotting them all the time along with bees and other summer flying insects.
Worldwide there are 110,000 different wasp species, less than a third have developed the power to sting, so the majority are colourful flying harmless insects. Stinging species are predatory, whereas the remainder are parasitic and the vast majority are solitary, often living secretive lives. Some are tiny, as little as 0.14mm long, they are possibly the smallest insects. Their diversity is wonderful, spider-hunting wasps stock a burrow with paralysed but living spiders on which their larvae then feed. Potter wasps make nests of mud. Mason wasps burrow into loose mortar (like masonry and mining bees) and ichneumon wasps lay their eggs inside moth caterpillars.
Why is it then that wasps seem to get bad press and negative reviews all the time. They are made out to be the baddies of the insect world. However, I think we should put the record straight and sing their praises, like we do for bees. Celebrating their cooperative work ethic, glorious honey and commercially valuable pollination services. Bees have even been ranked higher than elephants and tigers in surveys of species people most wanted to save. So what about the bad guys?
Unwelcome picnic and bbq guests, wasps have been reviled for millennia. Once described as degenerate bees, wasps have always struggled to be loved. Even more feared are our largest wasp species the hornet. Headlines like "killer Asian hornets" Vespa velutina have hit the headlines in many a paper over recent years as this species continues to take a foothold on our shores. Also, persecution continues of our huge but docile European hornet, Vespa crabo, mostly fuelled by ignorance and fear, even though its numbers are declining, do any of us really care?
Time to reverse this negative stereotype, wasps make valuable contributions to ecosystems, the economy and our health. In ecosystems wasps and other insects pollinate most wild flowers, some plants rely exclusively on wasps to do this like 100 different species of orchids, without wasps some of these beautiful plants would become extinct. Wasps are also the third most important predators of insects after birds and spiders. They can use their powerful jaws to kill prey, snatched from plants or in mid-air. Their victims, wingless and dismembered bodies, are taken back to the wasp nest to feed the brood. In colonies of up to 10,000 wasps are reckoned to take between 3000 and 4000 prey a day at the height of the season. By one estimate wasps eat 14,000 tonnes of insects each summer. They target woodlice, spiders, flying beetles, butterflies, honeybees and moths. They will also eat crop insects like aphids, caterpillars and flies.
Wasp stings are thought to help relieve the pain of rheumatoid arthritis by stimulating our immune system and quelling inflammation. Wasp venom is more varied than bee venom and may therefore be even more useful as a source of medicines. Some venom has been seen to disrupt and kill cancer cells in mice, rupture cell membranes in targeted body tissue, either to destroy cells or to create routes for pharmaceuticals to get into them. Their venom also shows encouraging antibacterial and antiviral qualities. Further wasp venom constituents are being explored as treatments for neurological conditions, allergies and cardiovascular disease.
Wasps can play a role in conservation too. They are affected by climate change, intensified agricultural practices and the widespread use of pesticides. Surveying wasp numbers is a good way of checking for environmental stress. Keeping an eye on their diversity and location will help us understand them better along with other insect populations.
Time to look beyond our prejudices and stop demonising them, appreciate their individual beauty and the important role they play as part of our wonderful native insect population.