Many parasitoid wasps use larval Lepidoptera as hosts. Still, some groups parasitize different host life stages (egg, larva or nymph, pupa, adult) of nearly all other orders of insects, especially Coleoptera, Diptera, Hemiptera and other Hymenoptera. ParasiticWaspEggs. All female parasiticwasps possess an organ called an ovipositor, located at the tip of the abdomen.Most eggs contain a single larva, but some species produce multiple parasiticwasplarvae within a single egg. The young wasplarvae then eats the weevil larva. How wasps track down and find the hidden weevils remains unclear. They may find the pests by tapping their antennae on the kernels and feeling vibrations, by “smelling” the weevils, or by hearing the weevils chewing. The parasiticwasp Hymenoepimecis argyraphaga, for example, lays its eggs in the spider Plesiometa argyra. The larvae then eat their way out of their host. Nor is mind control very extraordinary for parasites. In their larval stage (as caterpillars), these critters can be delicious hosts for parasiticwasps. Adult wasps lay their eggs inside the bodies of caterpillars, and once the eggs hatch, the wasplarvae eat their way out. It’s a larvae-eat-larvae world out there. When a wasplarva finds itself nestled inside a butterfly egg, it has all the sustenance it needs in that hard-shelled, protective host environment. One wasp, Hyposoter horticola, employs a sinister tactic to get inside its host, the egg of the Glanville Fritillary butterfly. The parasitelarvae were able to attract more attention from the workers than the host larvae - including being fed more often - which would appear to offer an explanation for the faster larval development and shorter larval/pupal stages. Wasplarva emerging from fruit fly. (Matthew Ballinger / FOX Weather). The insect world is filled with examples of parasitic species, with most parasiticwasps targeting juvenile insects. Thus, the discovery with S. perlmani is notable. They lay eggs in caterpillars due to higher survival rates and the development of larvae into wasps. Mortality rates are a few times higher in larvae not hosted by a caterpillar, so some wasps use caterpillars as a source of food. Some parasiticwasps are “hyperparasitoids” that target... The parasitic ichneumon wasp (Rhyssa persuasoria) lays its eggs on the larvae of the sirex wasp, deep inside a pine tree. It was introduced as a means of controlling the sirex epidemic. Pepsis wasps (also known as tarantula hawks ), on the other hand, will lay each egg inside a single paralyzed tarantula. The emerging larva will then proceed to eat the imprisoned spider from the inside out. A parasiticwasp (Leptopilina boulardi) lays its eggs into larvae of the vinegar fly Drosophila melanogaster. In nature, many Drosophila larvae are killed this way. However, both larvae and adult flies are able to sense and actively avoid the wasps' odor. Typically, a species of parasiticwasp will attack a host during one particular stage of the host’s development. Some specialize in attacking a host in the egg (Fig. 1) while others may seek out larvae in cocoons; still others parasitize adults. Surviving waspparasitism is dependent on the ability of the Drosophila larva to reroute basal hematopoiesis and produce, in a timely manner, lamellocytes to neutralize waspeggs before they hatch in the fly larva.
