All parasite wasps are specialised in targeting a single host species, typically at a certain point in the host species’ life cycle. An immense variety of parasitosis has developed as a result of this specialization. Many parasitic species have not yet been found, and estimates of their number vary greatly. Some parasitic wasps have an odd life history that allows them to significantly alter their host’s behaviour for their gain. In addition to laying eggs, parasitic wasps from the groups Ichneumonidae and Braconidae introduce a polydnavirus into the host. The virus alters the host’s immune system by infecting host cells, preventing the host from encasing the wasp larvae and putting them to death before they hatch.
Similar to certain other wasps, parasitic wasps have such a narrowing that gives the impression that they have a “waist” between their thorax and abdomen. The majority of parasitic wasps are under 1/4 inch long and often measure less than an inch in length. Their size typically depends on the size of their host, for example. Parasitic wasps are indeed the size of the letter at the end of the sentence due to the length of the insect larvae that they attack, whereas Caterpillar killer wasps are enormous. They are thin, hairless flying insects that can range in length from small to very long. They have two pairs of transparent to smoky membrane wings and antennae that can be short to rather long.
The majority are black or brown, but some have vivid yellow or orange markings, while some are metallic bluish-green or blue. The ovipositor, an egg-laying apparatus near the tip of the female parasitic wasp’s abdomen, is used to lay eggs on or inside the host. Some ovipositors are lengthy enough to touch insects that are sheltered places like cocoons, trees, and other places where they can’t be seen. Only a very small number of species of parasitic wasps have a proboscis that may pierce human skin, even though it may be significantly huge.
Eggs, larvae, pupas, and adults are the normal stages of a parasitic wasp’s life cycle. The parasitic wasps have a variety of life cycles, some of which are among the most complex life histories yet discovered by science. Since eggs are frequently implanted into the body or eggs of the host insect, eggs are rarely seen. On or near parasitized insects, certain parasitic wasp pupae appear as little, rice-like cocoons that are whitish or yellowish. In some species, the males may not even exist, and the females reproduce exclusively through sexual reproduction. Normally, each parasitic egg produces a single larva. Several generations of parasitic wasps can be produced in a single season, but some may take a year or longer to reach maturity.
When parasitic wasps sting, they frequently also inject venom and a virus into the host along with the eggs. The unknowing host is frequently killed when their larvae mature and eventually exit from it. They grow up and fly away as adults to carry on the cycle.