A bug case

Dec 27, 2007 22:06 GMT  ·  By

We already knew this without science. But science now has just proven it: hot males can have more sex. Especially if they are from the ambush bug species.

These predatory bugs are famous for their color pattern that camouflage the insects against flowers. This way they can lie in wait to ambush insects stopping on the flower. The ambush bugs (Phymata americana) stand on their two hind pairs of legs, with their bodies raised in a very characteristic pose, while the front pair of legs are powerful and have claw-like tibiae employed for capturing and grasping prey, on the fashion of praying mantis.

The ambush bug has a pattern of mostly yellow with dark brown or black patches, but the males have darker heads and thoraxes (the mid-regions of insects to which legs and wings are attached) than females. A new research published online in the Proceedings of the Royal Society B has found why this difference in the color pattern between the two sexes exists: male ambush bugs could employ these dark patches to absorb light and warm up, an action that increases their mating chances.

The research team changed color pattern in male ambush bugs with thin coatings of yellow and black paint to see if darker colors meant hotter bugs.

Artificially light- and dark-colored male bugs were kept in chambers at either 64 o F (18o C) or 80o F (27o C), the average values for morning and midday summer temperatures in Ontario, Canada, the place where the insects had been collected. Both types of males had similar chances of mating with females at warmer temperatures, but darker males were more successful in the case of lower temperatures.

"A warmer body could help out the wing and leg muscles of the bugs, helping the males seek out females." wrote the authors.

"Sex differences in color pattern are very common in the animal kingdom," co-author David Punzalan, an evolutionary ecologist at the University of Ottawa, told LiveScience.

"The fact these colors actually have a physical effect on the males adds a different twist to an old story."