Last year we had large numbers of our acorns afflicted by the knopper oak gall wasp, this year we seem to have done better. This tiny insect is one of those that make you wonder if Mother Nature was tinkering around with the idea of having three, or maybe even four, sexes.
At some point in its life cycle the wasp lays an egg in the acorn bud. This develops into a grub. The grub then uses the material, designed by the oak tree to form the acorn and cup, and chemically alters it to build itself a nice little hidey-hole. Naturally, nature doesn’t just leave it at that – there are also wasps that lay eggs that hatch into grubs that eat the knopper wasp grub and move into the, now vacant, property – but I digress.
At a completely different time of the year and in a completely different type of oak tree, eggs are laid that produce only female wasps. Later in the year both male and female wasps hatch out somewhere else in the forest. The mind boggles! Two different types of oak trees and the odds of clement weather in two different seasons in order to produce one generation of minute wasps – it’s a wonderful world.
Track and Hedge 