Newly Discovered Wasp Species Enslaves Spiders

Photo via Northrup

Spiders spend a lot of time crafting their webs in hopes of making a meal out of all manner of winged insect--but a recently discovered species of wasp is found to use the spider's engineering prowess to its own advantage. Through a not yet understood chemical process, the wasps are able to, quite literally, enslave the unsuspecting spiders to build a nest for their larva, and after all that hard work, become their first meal. Sure, it seems pretty dastardly, but researchers say it's evolution.According to a study published by a Brazilian team in the Journal of Natural History, and reported by Correio Braziliense, the newly discovered wasp species, a member of the Hymenoptera family, is able to control some spiders through a chemical process that remains a mystery.

How the Wasp Enslaves the Spider
A female wasp will target a spider and immobilize it with an unknown venom injected into its mouth--at which point the wasp lays its eggs on the spider's abdomen. When the spider revives, it seems to carry on unaffected as the wasp larvae develop.

Over the course of several days, as the larvae grow riding on the spider's body, they releases a chemical that changes the behavior of its host. Instead of its normally orderly web-pattern construction, the spider begins to build a special cocoon for the larvae--controlled by the mysterious substance they emit. According to researchers:

It may be a neurotransmitter or a potential neurotoxin that alters the behavior of the spider in building the web. This is because the spider is weaving a structure of three to four spokes and a central part of the cocoon where it will be.

A normal web, left, compared to one built by an enslaved spider, right.
Spiders Build Tough Wasp Homes
The cocoon is thought to be an ideal wasp nursery because "apparently, the structure is much more resistant to the weight of the cocoon and climatic factors such as rain."

As the wasps mature inside their custom-built home, they draw nutrients from the spider who constructed it--eventually devouring it completely when fully developed. So much for gratitude.

An Evolutionary Advantage?
While it seems like a pretty one-sided deal, scientists are hoping to better understand the evolutionary advantage of the wasp and spider relationship. According to researchers involved in the study, the behavioral change induced by the wasp may lead to new research into other species where similar influences have been observed.

Scientists also suspect that the chemicals used by the wasp may have some practical application.

The aim is to unravel this mystery in future experiments. We know it's possible to have medicinal properties in this substance, because the compound is shown to be very strong.

Let's hope that the wasp's special enslaving chemical doesn't fall into the wrong hands, however--one day they're terrorizing our picnics, the next we could be building their houses.

More on Crazy Parasites
9 Human Parasites You Don't Want Along for the Ride
Bizarre Tongue-Eating Parasite Discovered Off the Jersey Coast
Tropical Plant Uses 'Mind Control' Chemical to Make Ants Do Its Bidding

Tags: Biology | Brazil | Evolution | Insects

Best of TreeHugger