Shamelessly plugging some cool research going on in the Gilbert lab here at Cornell in the Department of Entomology and this nice write-up in Nat Geo. Not precisely mating related, although the article does mention that these tiger beetles also use their incredible speed to quickly chase down their mates. Can you imagine how terrifying THAT must be? I mean look at this thing!
In many animal species, males and females are different in some way – such as in their size or color – which is called sexual dimorphism. Might speed be a sexually dimorphic trait in this species? Not likely. If natural selection acts on these beetles to be able to catch their prey quickly, having only one sex do so would be quite an evolutionary dead end. Thus, I would predict that both are equally fast. But it’s often the case that males seek females. (Ever find spiders wandering around in your house? Chances are these are males out on the prowl.) This may be a situation where there is strong selection on males to be faster. Think about it. Faster males may be better at getting the girl, and thus spreading their genes (and the beetle love). Those in the slow lane, not so much. Assuming speed is a heritable trait, over time, males will become a tiny bit faster than females, and voila, suddenly you are a female tiger beetle being chased down by a speed demon. Better get away while he stops to unblur his image of you!