Researchers in Japan have found that a wasp that lays eggs on the back of a spider can also attain control of its behavior as well, enslaving the spider.
The wasps are able to “demand” the spiders to create cocoons for their offspring, and when they then die, their blood and guts are drained its body by the growing larvae. Hence the nickname, zombie spiders, according to Sydney Morning Herald.
“It’s like the Alien movies but on a miniature scale,” said Andy Austin from Adelaide University’s Australian Centre for Evolutionary Biology and Biodiversity.
Professor Austin is an expert in parasitic lifestyles of insects. He remarked that the Kobe University research was a “really cool study” that accurately showed what is known in biology as host manipulation, a common behavior of the parasitic wasp. The research was published this week in The Journal of Experimental Biology.
“This is their modus operandi, this is what they do,” Professor Austin said.
He added that the study really added a layer of insight to the field. It showed that the web and cocoon the zombie spider was making is similar to the type of web it made when moulting.
“The spider normally builds a retreat for itself to hide in when it is moulting and vulnerable but here the spider is building the retreat when the wasp wants it, not when the spider is moulting and needs it,” he said.
The wasp, called the Reclinervellus nielseni wasp, exists in Australia. It injects the spider, in this study, the Cyclosa argenteoalba spider, with venom before laying an egg on its back. After the larvae hatch, they use their teeth-like structures to puncture its host’s body and suck the insides out as it grows. In other words, it takes control of its mind and body to make a nursery with a food pantry for the little ones.
“The big unknown is whether it is the larvae injecting something into the spider, the female wasp injecting the venom or a combination of the two which allows the wasp to manipulate the spider,” Professor Austin said.
“It’s probably happening in backyards all around us,” Professor Austin said. “It’s just that it’s happening on a microscopic scale and you wouldn’t see it.”