Parasitic Wasp Turns Spiders Into Web-Weaving Zombies
There is a species of parasitic wasp, named Reclinervellus nielseni, that can essentially turn its arachnid host into a zombie, forcing it to build a special web before the wasp kills it.
In nature's intricate web, a remarkable and eerie interaction occurs between certain spiders and parasitic wasps, showcasing the phenomenon of behavioral manipulation. This complicated dance of control is vividly demonstrated by Reclinervellus Nielseni, a species of parasitic wasp, and its host, the orb-weaver spider Cyclosa argenteoalba.
The Initial Attack
The cycle begins when a female Reclinervellus nielseni locates a suitable Cyclosa argenteoalba spider. In a precise and swift attack, the wasp stings the spider, temporarily paralyzing it. During this brief window of immobilization, the wasp deposits an egg onto the spider's abdomen. This seemingly straightforward act of laying an egg sets the stage for a complex interplay of neurochemical manipulation.
The Growing Parasite
As the wasp larva hatches, it remains attached to the spider, gradually growing while feeding off its body fluids. During this parasitic phase, the larva secretes toxins that profoundly alter the spider's behavior. The once self-sufficient spider now becomes an unwitting servant to its parasitic guest.
Altered Web Construction
Under the influence of these toxins, the spider abandons its typical web-building behavior. Instead of constructing intricate webs designed to catch prey, the infected spider begins to weave unusual 'cocoon' webs. These webs are characterized by stronger structural lines and a significant reduction in sticky catch threads. The purpose of these cocoon webs is not to trap insects but to provide a secure environment for the wasp larva as it prepares for its pupal stage.
The Final Act
Approximately ten days after the egg-laying, the larva reaches the point of pupation. At this critical juncture, the larva delivers one final injection of toxin, causing the spider to become more paralyzed. In a gruesome culmination of this parasitic relationship, the larva consumes the helpless spider entirely, leaving nothing but an empty exoskeleton. The larva then spins into a pupal case within the fortified cocoon web, completing its metamorphosis into an adult wasp.
Implications and Insights
This chilling example of behavioral manipulation highlights the extraordinary capabilities of parasitic wasps like Reclinervellus Nielseni. It underscores the complex interplay between physical and neurochemical influences in parasite-host relationships, revealing a sophisticated level of control beyond physical domination.
For those interested in delving deeper into this fascinating subject, a detailed study conducted by researchers at Japan's Kobe University offers profound insights. The study, titled "Mechanisms of Host Manipulation by a Parasitoid Wasp, Reclinervellus Nielseni," by Keizo Takasuka and colleagues, was published in The Journal of Arachnology (2015, Volume 43, Issue 1, pages 39–46). The study provides an in-depth analysis of the mechanisms behind this behavioral manipulation, offering a window into the dark yet captivating world of parasitic interactions. The full text can be accessed via DOI: 10.1636/K14-37.1.