Parasitic Wasp Turns Spiders Into Cocoon Building Zombies

Posted on August 16, 2015

A parasitic wasp larva on the back of zombie spider

A parasitic wasp can take total control of its host spider and turn it into a zombie. The wasp paralyzes the spider and then lays an egg on or near it. When the egg hatches the wasp larva takes control of the zombie spider's nervous sysem and forces it to build it a stronger web with a cocoon at the center. The photograph above shows the larva on the spider's back.

The wasp, Reclinervellus nielseni, was observed by Keizo Takasuka from Kobe University, Japan. He observed the spiders (Cyclosa argenteoalba) building cocoon webs for their masters in the lab. Over a ten hour period the zombie spiders would build a new web with a cocoon at the center for the larva. The researchers found that the center of the new web was 30 times stronger than the spider's normal orb web. When the web was completed the larva directed the spider to return to the center of the web. The larva would then drain the spider of its fluids.

This timelapse video below shows a zombie spider building a web for its larval master. The video was sped up by 50 times and scenes during which the spider is inactive were removed. Take a look:

A research paper on the zombie spider can be found here in the Journal of Experimental Biology.

Photo: Dr. Keizo Takasuka/Kobe University

More from Science Space & Robots