When a parasitic wasp skewers an orb spider and glues an egg to its back, she sets off a chain of events that soon alters the behavior and destiny of the spider. A new study from the host-parasite pair's Japanese homeland shows that, some time after the egg hatches, the spider abruptly abandons its former lifestyle and follows a precisely choreographed sequence of actions that modify its normal web-building activities to produce the best possible home for a developing wasp.
Zombie Web Design
Transformed by the ichneumonid wasp Reclinervellus nielseni's sting into an obedient zombie, the orb-weaving spider Cyclosa argenteoalba does more than nourish the wasp's larva with its own inward parts. The zombie spider serves its new master by modifying its web design to make a stronger-than-normal web devoted to the protection of the wasp's pupal cocoon. No longer concerned with catching prey for itself, the spider reworks its web to build a hammock of extra-strong non-sticky silks that will ultimately cradle the cocoon.
Kobe University's Keizo Takasuka and colleagues, who published their work in The Journal of Experimental Biology, painstakingly searched for spiders already parasitized by the wasp and then observed how the spiders' behavior was affected. They also collected and observed the behavior of normal spiders.