Although they differ from predators and parasites, parasitoids are important in pest suppression.
Unlike predators, parasitoids do not kill their host immediately, and unlike parasites, they do eventually kill their host.
Parasitoid wasps and flies have been keystone agents in biological control, in part, because of their specialization on certain pest families and species.
Their life histories inspire science fiction. They are cryptic insects, but upon close observation, they can be found everywhere.
Mass production of parasitoids has expanded their use against several pests.
Many sci-fi movies have utilized (either on purpose or by accident) the intriguing development of parasitoids as a proxy for alien development.
Parasitoids lay eggs in or on their host and the parasitoid larva hatches and survives on or within the host. Eventually the host dies when the parasitoid has completed development.
The temporary relationship between the parasitoid and its host can be quite dynamic and is geared toward the survival of the parasitoid.
In an extreme case, Glyptapanteles parasitoid wasp pupae are protected from other predators by the actual host caterpillar from which they fed upon.
You don’t have to look far to find parasitoids.
Having a keen eye for a healthy versus parasitized insect is key.
Identifying features include parasitoid exit holes or exposed parasitoid larvae and pupae.
Continued next month
See this article in Tree Fruit July 2014
