Re: When are the females of the species deadlier than the male

Hi Mags:

The term for the behaviour you describe is "sexual cannibalism". A search under that term at Yahoo yields several hits that are worth checking out.

As near as I can tell, sexual cannibalism appears to be mostly limited to arthropods, occurring in insects (e.g. Mantids) and arachnids (e.g. some Scorpions and Spiders). Basically, I would expect that in any biological system where there is a carnivorous female that is larger than the male, there is a chance she'll try and take a bite out of him.

You also mentioned nuptual gifts- they are particularly common in insects of the order Orthoptera (e.g. Grasshoppers, Katydids and Crickets). I know of one cricket, those of the genus Cyphoderris, that has a very unique form of sexual cannibalism: During copulation, the female sits up on top of the male, nibbles on his wings, and drinks up the haemolymph ("insect blood") that seeps out. For more on this, along with a picture, check out this site. As far as I'm aware, other Orthopteran males generally give nuptual gifts in form of spermatophores. Spermatophores are packets of sperm that are passed to the female during copulation. In the case of many Orthopterans the spermatophore is very rich in protein and is eaten by the female (after the sperm have been inseminated, of course). I wouldn't really call that cannibalism though, because the male survives the courtship.

Hope that helps!
Rob Campbell, MAD Scientist