7 July, 2011

How to survive a black widow

Females eat the male after sex. This is the practice of the species of the dark black widow spider. But there is hope for the male victims. Their death can be prevented by walking and smelling the web of the female. This has been discovered by researchers of the U.S. Arizona State University.

Females eat their mating partner especially when they are hungry. This cannibalism is also the namesake of the species.

Cannibalism can thus be prevented. If the males walk on the web of the female, they are able to smell how hungry the potential bed partner is. When the male “smells” that the female has an empty stomach, he can escape.

By comparing two groups of female spiders, the researchers were able to see the difference. One group of spiders were fed a lot of crickets, the other group nothing. Thereafter, the males were put on the web with the ladies. It appeared that the men on the web of the fed-females made much more active ‘mating dances’. This usual goes on for about two hours before the actual mating commences. After mating, the male has to escape, before being caught and eating by the much larger female.

But because the males appeared to be able to smell whether a woman had recently eaten, they could reduce their risks. Black widows devour their prey because by wrapping them in their web. And additionally many odours are released that the males were able to pick up, so that their flirts become less life-threatening.

DNA, Nature, Neuroscience, Weblog