Wasps

We’ve been fortunate enough to have a good summer this year, and we’ve enjoyed the outdoors: children and dogs playing in paddling pools, a little sunbathing, washing billowing on the line, and the inevitable barbeque, all accompanied by a few friends and often, a few unwanted guests. A little bit of sun not only summons fluffy bees and beautiful butterflies, gracing our days with hard work and elegance, it rouses another winged insect, one that’s rather less popular or romantic than the former – aggressive, even – and has the ability to turn a dreamy afternoon into a frenzied uncoordinated dance if it decides to attack. It’d be hard to find anyone that would welcome a wasp or two to the party, and maybe that’s why they just turn up and start throwing their miniscule weight around!

No matter how we feel about them, wasps are essential to the biodiversity of our gardens, and you may be surprised – nay, scared! – to learn there are at least 200,000 species of this mini beast around the world, with a potential 100,000 still undiscovered. That’s the bad news; the good news is there are only around 9,000 species in the UK… maybe 8,999 more than we’d hoped for! In fact, after spiders, wasps are the most disliked bug in the UK, and given the fact they’re more hostile and painful than the average British arachnid, that’s surprising. The majority of wasps here, however, are solitary creatures that live alone and pose no threat to the family barbeque.

Like bees and butterflies, wasps are pollinators; unlike their contemporaries, however, they’re not fussy about which plants they frequent, ensuring many otherwise unvisited plants continue to exist. They consume nectar for energy, but they prey on other insects to provide food for their young, and they’re not fussy about those either, they’ll feed on whatever’s most abundant. Whilst that may enhance their violent reputation, like their fellow hated mini-beasts, they’re ridding our outdoor spaces of pests – aphids, caterpillars, flies – which might otherwise damage our beloved plants. We may be involuntarily familiar with the most common UK wasp – the Vespula vulgaris or yellowjacket – but there is a species of wasp, no bigger than 0.14mm in length that’s purported to the smallest insect in the world, a parasitoid wasp that lays its eggs in the bodies of pest insects that feed on crops, negating the need for chemical pesticides. But is it enough for us to forgive them for their belligerent behaviour? We’re not always the most welcoming species ourselves, but then we’re not generally in the habit of injecting our adversaries with poison if they get in our way!

Aside from the obvious brutality, the lifestyle of a social UK wasp is rather similar to that of social bees, living in colonies of up to 10,000. When queen wasps emerge from hibernation, they search for suitable sites and start building nests in which to lay their eggs; that initial construction will be large enough – approximately the size of a golf ball – to house the first brood of larvae, which will pupate in their hexagonal cells from white maggots to mostly infertile female workers. As more become available, they will assume responsibility for building the nest to increase its size to that of a football and gathering food, whilst the queen remains in the nest to lay more eggs; later broods contain male and fertile female wasps, and those females will become the next generation of queens. The nest is made from collected wood fibres that are mixed with saliva to form both the hexagonal cells for the larvae and the outer casing, and they’re generally found in dark places, which can include lofts and sheds. Despite the work involved in creating nests, they’re only ever used once, and if there’s a nest in the local insect neighbourhood, queens will search for another location to build theirs.

Worker wasps are also responsible for forging for food for the young, and that can either be carrion or insects that are partially digested and regurgitated. After feeding these delights to the offspring, their generosity is reciprocated with a sugary saliva-infused drink produced by the youngsters.

Life in a wasp nest can be just as colourful as ours, with all the social complications and concerns we experience as humans: ant-social behaviour, leaderships contests and those that drain the colony with little or no contribution, and there are wasps that ‘specialise’ in the areas, assuming the roles of police officers and undertakers! Move over Eastenders!

And if you thought the queen always ruled the roost think again: sometimes it’s the queen inadvertently causing the problems… During the mating season, some queens mate with several males, diluting the gene pool, and that upsets the happy household. Female worker wasps (some bees too) can also lay eggs, but as they’ll be unfertilised they will only produce male bees; those male bees, however, will be of the same bloodline, and that is preferrable for some. Many workers loyal to the queen and untroubled by the diversity of the nest will take action if they discover eggs from their peers, eating them before they have a chance to hatch.

The most common wasps in the UK are Vespula vulgaris and Vespula germanica, and whilst almost identical, you can tell them apart by the markings on their faces and thorax, if you really want to get that close! Alternatively, the more aggressive wasps tend to be the latter of the two, so maybe leave it at that and move on!

Of course, hornets come under the same umbrella, including the Asian hornet, which should be reported via the Asian Hornet Watch app or by emailing alertnonnative@ceh.ac.uk. It differs from the Asian giant hornet – the largest wasp in the world – which is not found in the UK, thankfully!

Whilst it may be difficult living with wasps, for the most part, they’re doing their own thing, regurgitating wood pulp to enlarge their nest, killing insects to feed their young, the everyday household tasks one would expect, and they’re unlikely to cause any real problems unless they or their nest is threatened; if that happens, it’s all-out war, and the result could be serious with enough stings or if you’re allergic to their venom – up to 3.3%of the population is allergic, and though not all will experience anaphylaxis, wasp stings cause twice as many fatalities as bee stings, mostly because wasps can and often do sting multiple times. Adults seem to be more prone to severe reactions than children, but even the most insensitive amongst us will still experience a great deal of pain. On a more positive note, unless a nest is disturbed, wasps will generally leave us alone for most of the summer…

Once all broods have been reared, there’s nothing left for the workers to do, and that’s when they become a nuisance. Aside from new queens that mate and hibernate for the winter, wasp nests generally die out in autumn, and before that happens, they like to party! Searching for a few last sugar fixes before they die, wasps are not fussy; they’ll consume nectar from flowers, but they’re just as happy with your Eton mess, fruit salad, glass of wine or apple juice, and swatting them away is an act of war that could result in a sting or two. The solution? Offering a sugary treat away from you activities to distract them from the delights you want to enjoy. Wasp traps work by doing just that, drawing the hunters towards a reward, keeping them contained until we’re ready to release them; other traps are not so forgiving, much like the jam jars of yore, filled with water and a taster of jam, just remember you could be attracting more wasps to the party than you may otherwise.

Wasps can also cause damage to fruit, particularly apples, and although their jaws are not strong enough to pierce the skins, they’re opportunists that will capitalise on damage caused by birds. Wasp traps will help, as will enclosing the fruit in bags made from suitably strong fabrics.

Surprisingly, wasps are not here just to irritate us. Not only are they indiscriminate pollinators, they’re vital predators, keeping other garden pests in check whilst, despite their cautionary appearance, being predated on themselves by larger insects, birds and mammals – badgers enjoy wasp larvae, as, it would seem, do many humans! Wasps are the most popular insect eaten in China, and Japan has a history of collecting wasp larvae for consumption, cooking them in a variety of ways. Now, research has found an active ingredient in wasp venom that attacks cancer cells, and continues in the hope of finding a treatment.

So should we continue to attack these little warriors? They’re said to have invented paper, in a roundabout way, when a Chinese man watched a wasp constructing its nest around 2000 year ago, and where would we be without paper?

This year’s weather has been particularly good for wasps, so there’s likely to be an abundance of them in the coming weeks. In a world that’s losing insects at an alarming rate, wasps are holding their own, with very little change in their overall numbers over the last 100 years. So, given the work they do and the brevity of each nest’s existence, should we, maybe, cut them a little slack and let them be?