Pett Nature Notes: Wasps on Apples

It's the time of the year when apples are ripening and starting to fall off the trees. It is also the time when queen wasp grubs and male wasp grubs pupate and stop producing their sweet excrement. In a remarkable give and take process, adult wasps catch and kill (usually) smaller insect prey which they do not have the mouth-parts to ingest. They carry the prey back to the nest and feed it to their larvae which do have suitable mouth-parts. The larvae then digest the prey and produce sweet sugary excrement much like the honeydew produced by aphids. This is then eaten by the adult wasps so that they have enough energy to fly off and catch more prey. When the colony reaches the end of the cycle and the new queens and males emerge, there are no more larvae to feed the now redundant workers, so they go off to find other sources of sugar, such as the sweet soft drinks to be found in pub beer gardens or the jam in the Victoria sponge you took on your picnic.

They will also look for rotting fruit such as the windfall apples beneath your apple tree, and in many cases will start eating the apples before they fall off the tree if they are ripe enough. Despite their reputation, wasps are not generally aggressive and will not sting unless severely provoked, for example, by not cutting a slice of Victoria sponge for them. (Though when they do sting, they produce a pheromone that will cause other nearby wasps to go on the offensive.)

The pictures below are of Red Wasps on apples, a German Wasp chewing fence wood for nest-building, and another German wasp that got caught in the moth trap.

Fortunately wasps are not provoked by having a camera stuck in their face - even when they are drunk on fermenting apple juice.