Parasitoid wasps: Like the Alien movies, but real!

Our story starts here, in an allotment in England. Gardeners face many challenges when growing crops and one of them is this, the cabbage white butterfly, or rather their caterpillars. These insects have a voracious appetite and can easily strip entire plants of their leaves. But the smell of the caterpillar's saliva, when mixed with chewed up plant matter from a cabbage or radish, will attract visitors. This is Coetzea glomerata, a type of solitary wasp, and she's looking for somewhere to lay her eggs. Caterpillars like these do not make easy prey. They are much bigger and stronger than the wasps, as well as being incredibly aggressive. The first round goes to the caterpillar. The wasp is lucky to escape with her life. And yet, despite these dangers, the wasp presses on. She is determined, and rightly so. This is the single most important thing she will ever do in her short life. All she needs is a few uninterrupted seconds in which to lay, and that's exactly what she gets. And just like that, it's over. The wasp has taken a beating, but she has been successful. Outwardly, the caterpillar will appear completely normal. It will feed and grow as usual, but under the surface, the wasps are working. For two weeks now, they have been feeding on the caterpillar's non-essential tissues, and now they are ready for the next stage of their lives. It's time for them to emerge. The larvae release a chemical that paralyzes the caterpillar. Its skin is tough and thick, but the wasps have evolved sharp, chitinous teeth that allow them to bore through it. Once they're through to the surface, they begin wave-like contractions of their bodies from front to back. This helps the grubs to wriggle their way out, segment by segment. A female wasp can lay up to 50 eggs in a single caterpillar. Once they're most of the way out, the larvae will begin to produce a golden silk. They're spinning cocoons in which to pupate. As they extract themselves, the wasp grubs do not spill a single drop of blood. Incredible as it sounds, despite suffering such a horrific ordeal, the caterpillar is still alive. Only now, it is in the thrall of the wasp. Using its own silk, it will reinforce the wasp cocoons. It's important to note that under normal circumstances, this insect would not exhibit any maternal behavior whatsoever. Once the caterpillar has finished spinning, its watch begins. It will stand sentry over the wasps day and night, fiercely defending them against any intruders. It will continue to do this until it starves to death. A few days later, the new wasps emerge. Like many hymenopteran insects, the males emerge first. They will wait nearby with varying degrees of patience for the females. And thus, the cycle repeats itself. These wasps are so common that 70% of large white caterpillars will suffer this fate.