A team of researchers from Kobe University inv Hyōgo, Japan made the discovery after they collected spiders belonging to the Cyclosa argenteoalba species from Tamba and Sasayama in Japan. They monitored the spiders in the laboratory and soon realized that some of them had been parasitized by a wasp from the species Reclinervellus Nielseni.
Impossible as it may seem, the wasp managed to complete this task by laying eggs inside the spider. After having been infected, the spiders worked without interruption for about 10 hours to create a very strong web that even had decorations and was completed with a cocoon. These webs were reported to be enormously strong, even compared to the spider’s usual web. The researchers said it was 2 to 40 times stronger than normal.
This usually occurred just before the wasp’s larvae were about to pass to the pupal stage. This larvae would then move into the cocoon. The spider would afterwards be called to the hub of the web by the larvae, which have the ability to lure the defenseless enslaved insect.
One the spider is in the cocoon, the larvae would ruthlessly dig their teeth into the insect’s back and suck on its blood and guts until it dies. Thus, it is safe to say that the infected spider will not only serve as a home builder but also as food to the wasp’s offspring.
Even if the lab conditions did not allow some of them to behave as they would in a natural environment, 10 spiders were able to give a demonstration, after all.
Keizo Takasuka, the lead researcher of the study, said that the wasp larvae most likely injects an”unusual concentration of a manipulative substance”, that he believes is a hormone which might be similar to another one that the spider’s body naturally produces.
“The manipulative substance may react with the spider’s endocrine system,” said the authors of the paper published in the Journal of Experimental Biology.
This wasp can be found in certain parts of Australia and it is not the only one that can prompt behavioral changes. In humans, there are parasites that can develop inside the brain and lead to memory loss or dramatic change in the individual’s behavior.
Image Source: nationalgeographic