Parasitic wasps are very often used to control populations of agricultural pests. Aphidius has very effective searching behaviour. Once the female has made contact with its host she stabs her ovipositor into the aphid to deposit an egg. All larval stages of Aphidius grow inside the aphid. An adult wasp will eventually leave the brown mummy of the aphid. Within three days Aphidius can parasitize hundreds of aphids.

More information about Aphidius colemani (APHIPAR):
https://www.koppert.com/pests/aphids/...