_IDEAS_ This idea must die
The question I’m always asked is, “What’s the point of wasps?” No one would deny that bees are great; as pollinators, they play a vital role in our ecosystems. But few people realise that bees are descended from wasps – so without wasps, there would be no bees.
As predators that eat other insects, wasps are nature’s pest controllers. And the hunting wasps are generalists, eating a range of insects, so they’re very useful in ecosystems: a Vespula (yellow jacket) wasp colony will eat spiders, earwigs, flies, ants and other wasps. It means they can keep the most abundant populations of insects in the area at a lower level – for example, you won’t get infestations of cabbage-white caterpillars or aphids because the wasps will be keeping the most abundant insects at bay. If you’ve got a wasp nest in your garden, you won’t need to use as many pesticides, because the wasps are providing that service.
Research into the value of wasps in agriculture has revealed that wasps predate on some of the main pests that plague our crops – especially caterpillars and flies. We think that they’re effective in keeping those pest populations down in the fields (or at least they’re contributing). In Brazil and Zambia, we’re looking at the potential effectiveness of social wasps as a biocontrol agent, something that would be especially useful for subsistence farmers in developing countries, where an uncontrolled pest outbreak on their crops would result in their families going hungry.
Governments have put a lot of money into researching pollination and pollinators, and it’s estimated that the pollinating services of bees are worth $350 billion. Pest control by hunting insects should be valued just as highly; a world without wasps would mean having to use a lot more pesticides. And as we realise the negative effects of these chemicals on the natural environment, it’s vital that we find alternative methods to live more sustainably, at one with nature – so embracing the natural biocontrol that’s provided by wasps is something that we must put more effort into. The value of hunting wasps as biocontrol agents is little studied, which is extraordinary given the clear importance of these insects as part of our natural capital.
“WE CAN’T BLAME THE PUBLIC FOR NOT SEEING THE VALUE OF WASPS IF THE SCIENTISTS AREN’T DOING THE RESEARCH”
Of course, we can’t blame the public for not seeing the value of wasps if the scientists aren’t doing the research. Bees have been studied for centuries, and we know about their direction-giving waggle dances, but how do wasps do it? At UCL, we’re studying live colonies of yellow jacket wasps to find out how they communicate. Recent research has shown that bees can count, and it occurs to me that since bees are descended from wasps, perhaps wasps might be even smarter. A foraging bee has visual cues to find its static flower target, but the carnivorous wasps are hunters that have to find and catch a moving insect. My guess is that wasps have much better visual systems than bees, and completely different kinds of cognitive processes.
In 2017, we launched the Big Wasp Survey. It was my first experience of a citizen science project and began life as a short slot on the BBC’s Countryfile, when I showed viewers how to make a beer trap and asked that they send me the wasps that they collected. After some initial bad press suggesting that we were advocating the killing of wasps (since corrected, as the wasps were nearing the end of their life cycle and all the traps catch are non-reproductive workers, who have little to contribute to the colony any more, as the brood no longer need feeding). The project got so much publicity that we were inundated with people’s wasps! The 2018 survey gathered 30,000 wasps, so this year we are being much more targeted, and going back to the 1,500 people who have done it for two years running. That’s valuable because it means we can track how wasp populations are changing in specific locations year after year. We’re also aiming to improve our sampling in more rural areas, as the survey is biased towards urban gardens right now. The questions we want to answer are where wasps like to be, how urban environments are affecting wasps and why certain species are resilient to those environments, disturbed habitats or agricultural land, while other species are only found in the more rural, natural locations.
The amazing thing about this project is that it’s totally unfunded. It runs on the goodwill of the public, who not only collect the samples for us but, via our workshops, are also learning how to identify wasps and then sort them for us. As well as creating distribution maps of the diversity of species across the UK, our Undergraduate and Master’s students who have managed to get DNA from these beer-trapped wasps are looking at the population genetics of these species across the UK.
Thanks to the public and volunteers, we’re sitting on a data gold mine – and maybe the public are warming to wasps.
Dr Seirian Sumner is Reader in Behavioural Ecology, Department of Genetics, Evolution and Environment at UCL. bigwaspsurvey.org