A pale green ambusher with sticky legs
Late July in Rhode Island, and this assassin bug was out in the summer greenery, the colour of a young leaf and almost too pretty to be a predator. It was exactly the colour of the leaves around it, which is the point. It sat perfectly still, which is exactly how its family makes a living.
This is Zelus luridus, an assassin bug of the family Reduviidae, order Hemiptera. The species name luridus means pale yellow-green in Latin, a fair description of the coloration. The genus Zelus has a hunting trick that borders on genius: the front legs carry rows of fine hairs coated with a sticky resin, so any small insect that brushes against them is glued in place on contact. The resin keeps its stickiness for the bug’s whole life, so the trap never needs resetting.
Once stuck, the victim is stabbed with the short rostrum, injected with saliva that liquefies the insides, and drunk dry. No web and no chase: the bug simply stations itself among the foliage and lets the forest deliver food to its doorstep. The sticky legs also solve the problem of holding struggling prey that may be larger than the hunter, and Zelus species are common in gardens across North America, where they are generally considered good neighbours for keeping plant pests in check.
I gave it a wide berth, because an ambusher with flypaper legs deserves respect. It never moved as I passed, and I suspect it was already watching something smaller than me.
