Wasps – where do they come from and why are they so annoying?
As we move into the main holiday season, both children and adults will be working and playing outside in gardens, parks, on beaches. Barbecues will be going and picnics will be being enjoyed across the land only to be interrupted by one of the scariest of pests - the pest that is guaranteed to have children screaming and mothers frantically waving their arms around to get the invaders away from the cold meats.
The wasp is a social insect of the same order as ants, Hymenoptera (a name which refers to the types of wing that these insects have). There are over 7,000 types of wasp that inhabit our part of the world including many variants of parasitic wasps.
However, it is the big yellow and black species that strikes fear into us – this includes the common wasp and its various similar cousins, such as the hornet. There are eight social wasp species in the UK that look similar. Unlike honey bees, the common wasp has not evolved the ability to store food over winter and in temperate regions their nest colonies only last for one season.
In the early spring, a young queen will come out of her dormant winter state and build a small nest about the size of a walnut. It will contain 10 to 20 hexagonal cells and she will lay an egg into each one. As these hatch, the queen will busily feed the emerging larva. Towards the end of May, these workers will have pupated and turned into workers who will start growing the nest and feeding the emerging larva, leaving the queen to concentrate on laying eggs. By early September the nest will contain between 4,000 to 10,000 wasps.
The nest is made from wood pulp, in the same way that we make paper. You will often see wasps sitting on fence posts (and nowadays decking posts!) scraping off the top surface of the wood to take back to build either the combs inside the nest or the outside protection. In warmer countries you will often see just the combs with no outside protection. The nests will be in roof spaces, airbricks, tree stumps, hedges, rodent holes in gardens – in fact anywhere there is a little bit of protection. A full-grown nest will typically be up to 14” in width, but they can grow much larger – five square feet has been recorded in the past!
During the growth stage of the nest, the workers will be happily feeding their young on meat – such as insect larvae and flies – which they will kill with their sting - and carrion such as dead rodents. And, of course, the spare ribs and drumsticks that will be by the barbecue during the summer. They also have a liking for sweet things and, with their powerful jaws and short tongues, they can damage growing soft fruits and young apples on trees.
As summer nears its end, special large cells will be made and these will contain the next generation of queens and breeding males. Once these have reached adulthood, the workers have no more larvae to feed. They can now go out to play and enjoy different foods – jams and other sweet things that we may leave on the table. This is also when the wasps are at their most aggressive – often attacking anything moving too near to the nest (a very dangerous problem if the nest is in a hedgerow, and you are happily trimming the hedge with an electric hedge trimmer…carefully cutting the nest in two, releasing several thousand angry wasps).
It is the sting of the wasp that causes it to be on the hated pest list. The female wasp has a sting that she can use repeatedly, unlike a bee. The venom will, at the least, cause a very painful sting and at worst…..DEATH. No resistance is built up by being stung by a wasp – each sting, even over many years, can cause a worse reaction each time. A sting around the mouth or neck will cause other problems, besides anaphylactic shock, by causing the airways to close.
At the beginning of the season, when the nest is tiny, a quick squirt of the nest with a fly spray is all that is needed. As the nest grows – the treatment becomes more complicated – the wasps will have a direct flight path to and from the nest and, if you stand in the wrong place, they will attack you to get you out of their way. If the nest is in a loft, the first thing that many people do is turn the light on…or, even worse, climb into the loft holding a torch with no protection on their hands, face or other parts of the body. The wasps guarding the nest will immediately fly towards the light and the chances are that you will, whether this is in the loft or in the garden, try to bat the wasp away. The offending wasp will then emit a pheromone that will tell all of the other wasps in the nest and nearby that their nest is under attack and out they will come and attack the attacker which is YOU! If the wasps are flying around you or food – try to stay still and not move into a state of blind panic – and try to ensure that other adults around you and children remain calm. Now, how easy will that be?
A professional pest controller may well be able to treat and destroy an active nest in about 10 to 15 minutes using pesticides and equipment not available to the general public, providing that access is reasonably easy.
However, if you don’t want to spend the money, and if you know that you are not susceptible to wasp stings, and that you have all of the necessary personal protective equipment (covering ALL of your body), a ladder and somebody else to hold the ladder, and you have effective insecticides and application equipment - then by all means treat the nest yourself…and good luck!
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