How Do Wasps Kill Caterpillars?
WouterVarious species of wasps kill caterpillars by hunting them, parasitizing them, or using a variety of methods to control them. The most common methods are poison and insecticides. Another strategy is to build a nest in a suitable location where the caterpillars will feed.
Another strategy is to use a special parasitoid wasp to control the host. The parasitoid wasp will lay its eggs on the host caterpillar. These parasitoids will eventually kill the host. However, this strategy requires some support. One such strategy involves feeding the caterpillars a variety of different foods.
Another strategy is to use a chemical calling card. Parasitoid wasps have learned to use volatiles in order to find caterpillars. These volatiles are emitted from undamaged leaves, and the wasps use them to guide them to caterpillars.
One method of controlling caterpillars is by releasing a wasp-recruiting chemical called an aromatic. Some aromatics are toxins that were used by insect venomous species, but others may also function as antifungal agents. Turlings and colleagues reported on this strategy in the journal Proceedings of the National Academy of Sciences.
Turlings has been studying the relationship between plants and wasps for years. The most effective time to kill caterpillars is in the late spring and early summer.
Turlings and his colleagues also discovered that a parasitic wasp virus is an effective control against the caterpillars of cabbage butterflies. This wasp-and-virus combination will only work if the caterpillar infestation is severe enough. The package has to arrive at a time when there are a lot of caterpillars present. If the problem is large, multiple releases may be needed.
