Wasps! What are they good for?

Wasps, black and yellow pest, or useful insects with a public relations problem?

“I hate wasps,” said the innocuous looking old lady in the corner shop. I’d popped into to buy a couple of ice lollies and was stood in the queue, listening to the conversation.

The sales assistant readily agreed, adding that if a wasp shows it’s around his shop, he kills it. The old lady added her own murderous confession.

“Bees are OK, I love to see them on my flowers, but of I see a wasp, I kill it on sight. They will just go for you. Nasty things!”

We all know them. The one friend who, when a wasp appears they become a whirling dervish of fear, thrashing their arms, making chimpanzee noises and often running twenty yards away from the picnic table. There’s something in our culture that has demonised wasps. Maybe it’s because they’re not a fluffy and cute as Bees, something about the angular sharpness of their features and the vivid contrast of their yellow and black colours.

Maybe it’s a cultural fear that’s been ingrained from childhood by those people who are inclined to nervous panic when confronted by them. Or maybe it’s the “shark effect” in the media, that continues to demonise the species; it’s about that time when the less-intelligent tabloid newspapers will be running lurid tales of “killers” wasps, come to ruin our summer. And this cultural blacklisting it goes a long way back; Plutarch, back in the days of the ancient Greeks referred to wasps as degenerate bees, as if they were perfectly upstanding citizens who went on to develop bad habits! Whatever it is, it’s not healthy and not fair on the wasps.

In the corner shop, I commented to the lady’s husband that wasps have a bit of a PR problem. We agreed that they must be useful for something, and agreed that that something was pest control, but the message didn’t really carry. Later, reflecting on the conversation, I decided to do a bit of research and find our what wasps are really good for.

First of all, there are over 9000 species of wasps in the UK, with around 100,000 species worldwide, most of them are tiny or parasites and don’t bother us, but as with so many things in life, there’s a small minority that are more noticeable and have become the common image of wasps in the public imagination.

The ones that we pay attention to are the Social Wasps. These inhabit colonies around a queen and create their nests from wood fibre harvested from dead wood. If you’re sitting outside and can hear a faint scratching noise, take a look at your picnic table or some other wooden object and you’ll often see a wasp gnawing at the wood, collecting the raw materials that, mixed with wasp saliva, creates a papery building material. In spring, the queen finds a suitable place for a nest, perhaps in a shed, in the eaves of a house or a nook in a tree and builds the first small embryonic layers of her nest, hatching out a first generation of offspring to continue the building; it’s like the queen bootstraps the colony.

So far, so interesting, but what are wasps for?

Well, they are voracious predators, consuming vast amounts of insects that would otherwise plague our summers, consume our crops, and ravage our gardens. Wasps eat aphids and caterpillars that can decimate the plants we cultivate. As predators, hunting wasps are more important to humans than we acknowledge, dealing with significant pests. Research in Brazil showed that Paper Wasps, a common hunting species could control Fall Army Worms that can destroy Maize crops and can protect Sugarcane from Sugarcane Borer Moth larvae. The research showed that wasps formed a viable form of pest control that was less damaging to crops and more environmentally friendly than agricultural pesticides.

In evolutionary terms, wasps were around before bees, hunting insects for their survival before bees moved into gathering nectar as their source of nutrition. I suppose we can think of bees as vegetarian wasps.

This next bit is going to get a bit gruesome but stick with it.

Wasp venom has remarkable properties. Solitary wasps, those that live alone, bury their larvae in the ground. Being good parents, they ensure that the larvae have a ready supply of fresh food, burying paralysed insects with them to act as a living food source. This might make it hard to love wasps, but this behaviour is only possible because wasps have evolved venom that contains both paralytic and antibiotic properties. Because of these properties wasps have been used in some indigenous cultures for medicinal purposes, and modern research is beginning to back this up.

As well as the obviously useful ability to bury paralysed insects and feed baby wasps, researchers at the São Paulo State University have identified that a native wasp’s venom contains a toxin that can target cancerous tumour cells, leaving healthy cells alone. More research is needed, but surely we could rehabilitate wasps in the public imagination if they helped us cure cancer!

Wasps have also been overlooked as pollinators. Bees are visible pollinators, moving from flower to flower, but perhaps because we’re so busy trying to swat them, similar behaviours in wasps have been overlooked. Wasps have hairs that, like the bees, pick up pollen as they go about their business, drinking sweet liquid from flowers. We don’t often see wasps as hairy as their hair is much thinner than that of bees, but it’s there.

Figs are a keystone species (that is a species that forms the foundations of an ecosystem) and rely on wasps for pollination. Neither the Fig or the Fig Wasp can survive without the other and, without this symbiotic relationship, 1,274 other species would lose one of their main sources of food. But there are many other instances of particular flowers, such as hyacinths and some orchids that benefit from wasp pollination. But why are wasps bothered with flowers when we’ve already discussed their voracious insect consumption? Well, it turns out that wasps can’t survive on insect meat alone, they need sugary substances as well and this is where they turn pollinator, eating fruits, such as Blackberries and Raspberries.

And here is where they come into conflict with humans. Imagine for a moment that it’s then end of the summer and you’re a wasp in need of some sugary food. You spot a rich spot with abundant sugar and think, “this is perfect” and descend to enjoy the feast; at which point the shrieking starts and you’re lucky if you get away alive! That’s right, that can of coke, pint of cider or ice cream is the perfect food for wasps and that overflowing rubbish bin is like an “all you can eat” buffet. It’s no wonder that the wasps begin to gather, but there’s a simple way around to help the wasps and hopefully divert their attention. Simply put an alternate rich food source away from where you’re sitting, perhaps a saucer of coke at the other end of the garden and feel good that you’ve help our wasp benefactors.

So next time you hear someone denouncing wasps and all their kind, perhaps put in a good word for them and stop the cycle of persecution. As a minimum, spare a thought for the good they do and don’t persecute these wonderful creatures anymore.