Mark Leach, the Society of Biology’s membership marketing manager, has been wondering what wasps are actually for.
As the summer (and hopefully the drier weather) approaches, this heralds the time of the year when wasps, ants and the children next door threaten the peace and tranquillity of British alfresco dining. But what are wasps actually for?
I’ve always been slightly wary of them ever since I managed (somewhat ridiculously) to get stung in the mouth, of all places, as a child, when one of them hitched a ride on a forkful of mashed potato. Unlike their much friendlier looking garden inhabitants the bees, they don’t make honey – and they seem to delight in looking scary, getting stuck into (and in) your drink if you take an eye off it for two minutes… and they sting. Which really hurts.
Wikipedia advises that wasps are typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant, which isn’t the most helpful of definitions. Unless you know a lot about bees and ants. However, the site goes on to offer the simpler definition – any member of the Vespidae family. I was somewhat mollified, however, to discover that almost every pest insect species is preyed upon by at least one wasp species. So while this suggests that wasps are important in natural biocontrol, they probably don’t get invited to too many insect parties.
I then made a visit to the website of the Royal Entomological Society which explains that wasps can be further divided into social and solitary categories. As you might expect, social wasps live in colonies, which not unlike the honeybee, have a dominant queen, reproductive males (drones) and non-reproductive worker females. It seems that they have a really good system – the workers feed the foraged insects I mentioned earlier to wasp larvae, which in return exude a sweet substance that feeds the workers. However, the system falls down in the autumn, when the queen stops producing eggs, forcing the workers to dive bomb our picnic tables in search of sweet sustenance. In contrast, adult solitary wasps are all fertile, living and operating alone, and most of them do not construct nests.
And what about the dreaded sting? It appears that while honeybees have barbs on their stings, which prevent them from removing the sting once they’ve stung (so presumably make them a little more reluctant to use them), in general terms wasp stings are smooth, so they can be withdrawn and used again. And again. And again.
While the sting of the common wasp should wear off within 24 hours, a small number of people can react badly to this. So it makes sense not to antagonise them. Even more so when they are near their colleagues, as according to Rentokil, the venom in wasps contains a pheromone that causes other wasps to become more aggressive.
So while there’s an awful lot to learn about wasps, and they certainly play a vital role in biocontrol, there doesn’t appear to be a lot to love.