The larvae of this wasp species turns spiders into zombies for their service and then eats them

For years, scientists have documented the presence of parasites controlling the behavior of their hosts. They discovered a troubling relationship between the larvae of a parasitic wasp and a social spider.

Some organisms appropriate the brain of some carriers, usually for reproductive purposes. Mushrooms O. unilateralis consists, for example, in controlling the brain of carpenter ants. The parasite Diplostomum pseudospathaceum hides in the eye of the fish and leads to his death.

A team of scientists from the University of British Columbia discovered another interesting parasitic relationship, namely: the most unpleasant ones we have seen, both in its complexity and in its baseness. In the new study published today in Entological Ecological researcher Philippe Fernández-Fournier describes how the parasitic wasp species Zatypota uses and abuses it. social spider Anelosimus eximius using it first as a vehicle then forcing him to build an incubation chamber. Ah, finally we eat the spider.

Fernández-Fournier discovered this discovery in the Ecuadorian Amazon while he was studying several pests that live in the nests of A. eximius These arachnids are known as social spiders because they are the only ones in the world. they live in large colonies, work together to capture prey, share breeding tasks, and seldom venture beyond the boundaries of their basket-shaped common nests.

These spiders have a very predictable behavior. Fernandez-Fournier soon realized that some of them were infected with a parasitic larva, seeing that they were moving away from the colony. This observation was already quite rare in itself, but the scientist also observed how these same spiders started spinning dense silk buds and pieces of foliage.

"It was very strange because they usually do not do it, so I started taking notes," Fernandez-Fournier said in a statement.

Moved by curiosity, he brought the cocoon to the laboratory. When he opened it, to his surprise, he saw how a wasp was developing in him. Fernández-Fournier and his team have studied in more detail and discovered an undocumented interaction between these two species.

Here's how it works: a female wasp Zatypota lays an egg on the belly of a spider Anelosimus eximius . When the larva hatches, it becomes attached to the spider and begins to feed on its blood. The larva grows progressively and begins to absorb much of the spider's body.

Over time, the spider slowly turns into a "zombie" and no longer behaves normally. Under the influence of the larva, the spider leaves its colony and takes care of forming a network of cocoons. Once this construction task is completed as a slave, the spider remains motionless, allowing the larva to consume until it dies. Satisfied, the larva slides inside the cocoon that the spider has woven and uses as an incubator for its next stage of gestation. After a period of 9 to 11 days, a completely mature wasp emerges from the cocoon. The cycle then begins again, unfortunately for his next arachnid victim.

This strategy, say the researchers, is unique in that parasitic wasps have only been documented to attack solitary spiders.

"This modification The behavior is very serious," said Samantha Straus, co-author of the study, in a statement. "The wasp completely diverts the brain and behavior of the spider and forces it to do something that it would never do, like leaving its nest and creating a completely different structure." is a very dangerous thing for these tiny spiders. "

To which Straus added:" We think the wasps are targeting these social spiders as it is a large, stable host colony and one of the most common species in the world. A source of food We also discovered that the larger the spider colony, the more wasps were likely to target it. "

The fungus that turns ants into zombies is much more diabolical than we imagined

The carpenter ants of the Brazilian rainforest have been made. When one of …

Read More Read

Researchers believe that the wasp injects a hormone that modifies the brain of the spider to hypnotize it. This hormone causes the spider to think that she is at a different stage of her life or is acting as a signal that makes her run away from her colony. For the moment, they do not know exactly how the process that turns the spider into a zombie works. It's just a conjecture.

Fernández-Fournier and Straus now want to return to the forests of Ecuador to learn more about these devilish wasps and their hosts. In particular, they would like to know if the wasps still designate the same spider colonies and, if so, how to exploit them. [Ecological Entomology]