They discover a wasp that converts their araas into zombie drones

A recently discovered wasp species in the Ecuadorian Amazon transforms a "social" spider into a zombie drone that he leaves his colony to execute the wasp's orders.

It's the terrible discovery of real life made by researchers from the University of British Columbia, detailing the first example of a manipulative relationship between a new wasp species Zatypota and a social spider Anelosimus eximius in a study recently published in Ecological Entomology.

"The wasps that manipulate the behavior of spiders have already been observed, but not at such a complex level," said Philippe Fernández-Fournier, lead author of the study and former master's student in the department of zoology. # 39; UBC. "Not only does this wasp target a species of social spider, but it makes her abandon her colony, which she rarely does."

Fernández-Fournier was in Ecuador to study different types of pests that live in spider nests Anelosimus eximius, one of the 25 species of "social" spiders around the world. They are distinguished by their cohabitation in large colonies, their cooperation in capturing prey, sharing the duties of parents and abandoning their nests in the form of a basket.

When Fernandez-Fournier noticed that some of the spiders were infected by a parasitic larva and saw them moving away from their colonies to spin closed nets of densely spun silk and bits of foliage, he was perplexed. "It was very strange because they do not usually do that, so I started taking notes," he said.

Intrigued, he cautiously picked up some of the structures, called "canvases of cocoons", to see what would emerge from the depths. To his surprise, it was a wasp.

"These wasps have an elegant appearance," said Samantha Straus, co-author of the study and a student in the Department of Zoology at the University of British Columbia. "But then, they become more brutal."

Using data collected in Ecuador for different projects between 2012 and 2017, researchers began to reconstruct the life cycle of the wasp and its parasitic relationship with the spider.

What they found was equally fascinating and horrifying: after an adult female wasp has laid an egg in the abdomen of a spider, the larva hatches and attaches to its unfortunate host, the arachnid. Then, probably, he feeds on the hemolymph, similar to the blood of the spider, which grows up and takes the body slowly. The spider now "zombified" is leaving the colony and spinning a cocoon through the larva before patiently waiting to be killed and eaten. After being regaled with the spider, the larva enters its protected cocoon and comes out completely formed nine to eleven days later.

In other similar cases of parasitism, it is known that wasps target solitary spider species such as orb weavers and manipulate them to adopt behaviors that fall within their normal repertoire.

"But this change in behavior is serious"Straus said." The wasp completely diverts the behavior and brain of the spider and makes it do something that it would never do, like leaving its nest and creating a completely different structure. This is very dangerous for these little spiders. "

It's unclear how the wasps do this, but scientists believe that this can be caused by an injection of hormones that make the spider think that it is at a different stage of life or that it is dispersed from the colony.

"We think the wasps are targeting these social spiders because they provide a large colony of stable hosts and a source of food," Straus said. "We also discovered that the larger the spider colony, the more likely it is that these wasps will target it."

Straus, who is now wearing a wasp tattoo, will return to Ecuador to research whether the wasps are returning to the same generation-to-generation spider colonies and what evolutionary benefits might present. Meanwhile, wasps will likely continue to play their main role in the worst nightmares of spiders.