Scienceblogs.com has a great article about the bean weevil’s spikey penis. Two scientists have been investigating the evolutionary role these spikes play…
The genitals of different beetle populations are very varied and to study them under a microscope, Hotzy and Arnqvist first had to fluff their subjects. They anaesthetised the males with carbon dioxide, and erected their penises with an “artificial inflater” - a microscopic plastic tip connected to a pump.
Spikes are all very well but it’s the idea of an insect penis pump that I find most intriguing. Further research reveals that the phalloblaster which pumps pressurized alcohol into moth and beetle genitalia was invented several years ago by Australians.
We Aussies seem to spend a lot of time reading and writing about alcohol, wildlife and strange sexual habits. Lizards rate a mention at the ABC Science blog.
“When Lake Eyre lizards copulate the male bites the female’s neck, climbs on top of her, wraps his tail around hers and inserts one of his two penises. This can be hazardous to the health of the female because when the males bite them on the neck this can pierce the female’s spine and result in death.
Therefore once the female’s eggs have been fertilised, she will try to avoid mating. You get this runaway process where males evolve elaborate ways of trying to gain matings and females evolve elaborate ways of avoiding them.
f this doesn’t work, they throw themselves on their backs and reveal their bright orange underside. But what could be the evolutionary benefit to females of spending time on their back?
leave your theory in the comments section :-)