It was getting dark so I was on my way home… And there it was, a tiny longhorn beetle sitting on a leaf, waiting to have its photo taken! I’d spent about 5 hours looking for longhorns and here was one I’d never found before – very exciting!! The most obvious feature of this species is its thickened black femurs (“thighs”).
Coleoptera: Cerambycidae
Stenodryas clavigera
longhorn beetle = ameiro-kamikiri
Location: In orchards and bamboo/pine forest above Yokoyama Village (Google map)
so why such big thighs? do they benefit the insect in any way?
Good question!
Some beetles (called flea beetles) have big thighs to hold the muscles they use for jumping, but this longhorn beetle does not jump (I think). Or maybe it does jump when it takes off to fly.
I just found a scientific article suggesting that the enlarged femurs (thighs) in the males of some species of longhorn beetles hold flexor (bending) muscles rather than extensor (straightening) muscles, so the grip is stronger, which is probably related to mating…