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Credit: Keizo Takasuka

Newly discovered species of wasp controls web building in spiders

Spiders are usually creatures in people’s nightmares, but a new study shows that perhaps wasps should be. In particular the species Reclinervellus nielseni that can hijack a spiders body and turn it into a ‘zombie spider.’

R. nielseni is a newly discovered species of wasp that uses a host manipulation strategy on spiders. They lay their eggs on the back of a spider and when the larvae hatch, they hijack the body of the spider only to devour it when they’re done with it. When the larva takes over the spider, it feeds on its body fluids for several days. After about 10 days R. nielseni takes over the spider and controls it to build webs in order to keep the larvae safe until they are fully grown and can leave the spider. 

In order to understand how this process works, researchers studied the web building habits of a species of spider, the Cyclosa argenteoalba. Under normal conditions, this species of spider builds two different types of webs. First of all, there’s the orb web, which is used for catching insects, and then there’s the resting web, which the spider builds in preparation to molt.

The two webs build by C. argenteoalba. On the left is the Orb web. The resting web, on the left, has fewer radii and bright ornaments. Credit; Keizo Takasuka
The two webs build by C. argenteoalba. On the left is the Orb web. The resting web, on the left, has fewer radii and bright ornaments. Credit; Keizo Takasuka

When a spider has been taken over by a wasp, it is forced to build a cocoon web, which is similar to the resting web but is several times stronger on the outside, which gives the developing wasp protection. They team conducting the study also found the centre of web where the cocoon is, is about 30 times stronger than the centre of a normal resting web. These cocoon webs contain ornaments that are presumed to reflect light and give warning to other insects to prevent them from hitting the web and harming the wasp.

The cocoon web build after the spider has been taken over by the wasp. The cocoon that provides protection for the developing wasp larvae is in the centre. It has similar structure to the resting web.
The cocoon web build after the spider has been taken over by the wasp. The cocoon that provides protection for the developing wasp larvae is in the centre. It has similar structure to the resting web. Credit: Keizn Takasuka

After the cocoon web is increased, the wasp controls the spider to go to the centre of the web where it kills it. The wasps that take over these spiders are thought to have taken over the spider by manipulating the hormones involved in molting.

About Harry H

Harry H
Harry is currently studying biology and chemistry in University and hopes to go to grad school for evolutionary biology. He enjoys writing about sciences and sports and is a big fan of hockey and soccer. Some of his other interests are reading and rock climbing. Contact Harry: harry.h@youthindependent.com