Acrotaphus chedelae

Acrotaphus chedelae is a type of parasite wasp that uses the spider Argiope argentata (Gonzaga and Sobczak 2011). This species of spider is known for its intricate webs(Gonzaga and Sobczak 2011). The wasp injects the spider with eggs, and on the day the eggs are mature and ready to hatch, a chemical signal encourages the spider to make a web (Gonzaga and Sobczak 2011). The web is not constructed in its normal way however. The parasite causes the spider to construct a bare looking web with stronger silk (Gonzaga and Sobczak 2011). This is done so that when the eggs hatch and form a cocoon, they can do so on the special web (Gonzaga and Sobczak 2011).  The web is perfectly designed to help the cocoons successfully survive for eleven days; the threads of the web are perfectly spaced so that the web can withstand the most stress without breaking (Gonzaga and Sobczak 2011). The structures that make up the web can be compared to strats on a bridge, and offer optimal support.  It was even found that the individual threads lack stickiness which normally helps trap insects in the web so that the spider can eat them (Gonzaga and Sobczak 2011). Having insects caught and pulling on the web can cause the web to break and the cocoons to drop; therefore it is understandable that the parasite would manipulate to avoid this from happening (Gonzaga and Sobczak 2011).

Although many of the parasites I have wrote about on this blog use behavioral modification. None of them seemed to use it to this degree. Everything the parasite could control in the web construction to aid in offspring survival was taken into account and controlled. From the web design to the stronger less sticky silk.

Gonzaga M, Sobczak J. Behavioral manipulation of the orb-weaver spider Argiope argentata (Araneae: Araneidae) by Acrotaphus chedelae (Hymenoptera: Ichneumonidae). Entomological Science [serial online]. April 2011;14(2):220-223.