The Corpus Callosum

Deceptive Genitals

Sorry, no bizarre sex organ photos this time.  But
the story is interesting from an evolutionary standpoint.

href="http://news.nationalgeographic.com/news/2007/09/070925-bat-bugs.html">Bat
Bugs Evolved Fake Genitals to Avoid Sex Injuries
   
Anne Minard
for National Geographic News
September 25, 2007

For African bat bugs, the battle of the sexes is quite literally a
violent struggle—and now it appears that the bugs are using
gender-bending tactics to defend themselves.

Bat bugs are small, reddish-brown parasites related to bed bugs that
suck the blood of bats and sometimes bite humans.

Researchers have long known that male bat bugs ignore females’
conventional parts and instead use their sharp penises to stab the
females’ abdomens, injecting sperm directly into the bloodstream.

So the females evolved a defense: structures called paragenitals that
guide a male’s needle-like member into a spongy reservoir of immune
cells.

But the females aren’t the only ones in need of protection. Observers
documented males performing the same injurious sexual acts on other
males.

Now evolutionary biologist Klaus Reinhardt of the University of
Sheffield in England has discovered that male bat bugs have developed
their own versions of female paragenitals to avoid the assaults…


Bat bugs (Cimex adjunctus) are small, about 6mm
long, so the anatomy is not easy to study.  I gather nobody
thought it was worth looking all that closely, before now.

Wikipedia has more on the topic of href="http://en.wikipedia.org/wiki/Traumatic_insemination">traumatic
insemination
.