'As far as we know, parasitoid wasps and flies don't attack adult butterflies - they don't generally live very long, so they're not a good food source. When a parasitized caterpillar hangs upside down in the pre-pupal “J”-shape, several tachinid fly larvae or maggots will come out of the monarch caterpillar.

The beautiful butterfly failed to emerge, and the wasp cut a neat circular hole through what would have been the wing pad of the pupa. When they're ready to pupate, the braconid wasp larvae chew their way out of their host, and spin silk cocoons on the caterpillar's exoskeleton.

Or so you would think.In reality, it's a hiding place that is vulnerable to attack.Wasps prey on caterpillars and butterfly eggs, using their nutrients before killing them © Katoosha/Shutterstock.comA butterfly is just one of the creatures that might end up emerging from a chrysalis or a pupa.Butterflies and caterpillars frequently host parasitoids, insects that attack and destroy their hosts, sometimes eating them alive. These protozoa multiply inside the caterpillar and can cause weakness, disfigurement, and … When a wasp larva finds itself nestled inside a butterfly egg, it has all the sustenance it needs in that hard-shelled, protective host environment. They lay eggs on the caterpillar, and their larvae eat the host caterpillar as the wasp larvae grow. Those wasps may eat the caterpillar directly, but are far more likely to use the caterpillar as a host for their own larvae.

Despite the fact that the caterpillars will live for a time after they’ve been parasitized, when they have been attacked by a parasitic wasp, they don’t have long.

The caterpillar, somehow controlled by the larvae, helps protect them by spinning its own silken blanket over the wasp cocoons to provide them with an extra layer of protection. 'For some of us, though, this is the starting point of an exploration of the amazing interactions between the two. When a parasitized caterpillar hangs upside down in the pre-pupal “J”-shape, several tachinid fly larvae or maggots will come out of the monarch. The parasitic wasp - cabbage white butterfly parasite (Cotesia glomerate) can smell the chewing of plants and follows the scent and then parasitises the caterpillars by laying multiple eggs on each caterpillar. Perhaps the ultimate parasitic strategy, adopted by several families of wasps, is to inject your egg into the egg of another animal. The fly maggots drop to the ground on long, gel-like threads. It eats the entire contents of the caterpillar's body and spins its own tough cocoon to pupate in, before emerging as another adult wasp.

After a newborn caterpillar hatches, its first meal will be the nutrition-laced egg shell.

Hosts may use behavioral evasion when they encounter an egg laying female parasitoid, like dropping off the plant they are on, twisting and thrashing so as to dislodge or kill the female and even regurgitating onto the wasp to entangle it. They may also get rid of their frass (body wastes) and avoid plants that they have chewed on as both can signal their presence to parasitoids hunting for hosts. Tachinid fly larvae feed from inside the caterpillar, but usually don’t kill the host until just before the caterpillar pupates. Many hosts try to hide from the parasitoids in inaccessible habitats. The female braconid wasp deposits her eggs inside the hornworm caterpillar's body. 'Parasitic wasps are common in Britain - there are at least 6,000 known species.They can have a huge impact on the population numbers of other insects.Museum scientists are studying the diversity of these wasps, researching what we can learn from them for use in pest control. Some insects secrete poisonous compounds that kill or drive away the parasitoid. Most ectoparasitoid wasps are idiobiont, as the host could damage or dislodge the external parasitoid if allowed to move or Many parasitoid wasps use larval Lepidoptera as hosts, but some groups parasitize different host life stages (egg, larva or nymph, pupa, adult) of nearly all other orders of insects, especially Host size is important for the development of the parasitoid, as the host is its entire food supply until it emerges as an adult; small hosts often produce smaller parasitoids.Some parasitoid wasps mark the host with chemical signals to show that an egg has been laid there. Thankfully, we will never have to endure what insects do.You would assume the caterpillar to be dead after having roughly 80 repugnant creatures eat through its body but no, it remains alive and does something very bizarre.

Most females have a long, sharp ovipositor at the tip of the abdomen, sometimes lacking Parasitoids can be classified in a variety of ways. Braconid wasps that kill hornworms are larval parasitoids.

Parasitoid wasps range from some of the smallest species of insects to wasps about an inch long. 'But every other stage - egg, caterpillar and pupa - can be attacked, as is the case with most insects. Most females have a long, sharp ovipositor at the tip of the abdomen, sometimes lacking venom glands, and almost never modified into a sting. Broad says, 'Thankfully, some of these wasps are in our collection. Well, once they find a caterpillar to take part in their sick experiment, this parasitic wasp will inject around 80 eggs into the host in one go. It eats the entire contents of the caterpillar's body and spins its own tough cocoon to pupate in, before emerging as another adult wasp.' It’s spread through microscopic spores coming off the wings and bodies of adult butterflies. Delve into the dark world of parasitic wasps and discover their grisly takeovers of living caterpillars.Becoming a butterfly is a dangerous game, and it's easy for caterpillars to fall victim to some very unsavoury characters along the way.As well as facing threats from hungry birds and insects, caterpillars can be devoured by parasitoids, chewed from the inside out.Dr Gavin Broad, Senior Curator of Hymenoptera, explains the gruesome phenomenon.The inside of a chrysalis: dark, sleepy, undisturbed. After the wasp larva hatches from its own egg, it proceeds to devour the developing embryo inside the host egg.