A column by Frome Wild Bunch
Sometimes people wonder, ‘What is the point of a wasp?’ When we talk about wasps, most of us think of the black and yellow striped social wasps, disrupting picnics at the end of summer, homing in on that jam sandwich!
However, wasps are genuinely beneficial to our gardens: they have a role as pollinators, they are effective pest controllers and also scavengers of both fruit and carrion.
There are about 9,000 species of wasp in the UK: Buglife says that ‘these include the parasitic wasps, some of which are so tiny, they can barely be seen without a microscope. 250 of these are the larger wasps which have a stinger. Only nine of these are social wasps, which form large colonies.’
Only queen wasps (of social species) overwinter, seeking out shelter in sheds, trees and on one occasion, in my sock that was on the washing line! (Not a good outcome for either of us!) As the weather warms, she will emerge to feed and seek a suitable location in which to build her nest, often using outbuildings, roof spaces, animal burrows underground, or hollow trees.
She will build a small golf ball-sized structure using shredded wood and her saliva to make her papery nest, with hexagonal cells into which she will lay her eggs. She will care for her young, collecting invertebrates to feed them, until they are ready to become worker wasps.
At this point they take on hunting to feed the next grubs and they enlarge the nest. The queen will stay in the nest laying eggs and over the course of the summer, wasp nests can reach the size of a football, containing several thousand wasps. The workers feed on sweet secretions from the grubs and it is towards the end of summer, as the social structure of the nest starts to collapse with the emergence of new queens and the old queen failing to produce more eggs, that the workers start to seek sweet food elsewhere, often gathering around fallen fruit (and picnics!)
Solitary wasps are also useful garden pest predators. After mating, the female wasp will take her prey, usually paralysed but still alive, to her nest. Different species use different types of nest- a burrow in the soil, in a hollow stem, a hole in a wall or a mud cell built by the wasp. The prey is placed in the nest and a single egg is laid beside the immobilised victim. When the egg hatches, the larva feeds on its fresh prey, developing and then pupating in the safety of its nest until it emerges as an adult wasp.
Other type of wasps are parasitic, laying their eggs in aphids and caterpillars where they will hatch, feed then pupate leaving behind the husk of the organism that sustained them.
This is only a very brief introduction to the fascinating life of wasps. I hope that I have persuaded you (if you needed persuading) of the importance of wasps in our gardens as both pollinators and predators of garden pests.
The next Wild Bunch Gathering will be during the Big Green Week, Thursday 12th June, from 1.30pm to 4.30pm at Christ Church with advice and tips on wildlife gardening.
We look forward to meeting you!
