Megischus bicolor, a crown-of-thorns wasp in the family Stephanidae, photographed in Illinois, USA.

You might think an insect with an extra pointy derriere would pack a fearsome sting, but you'd be wrong. The extended rear appendage of the crown-of-thorns wasp is not a stinger but an egg-laying organ, the ovipositor, used to reach beetle grubs chewing through the wood below. Young wasps develop as ectoparasites of beetles in their burrows. Should this wasp take a stab at you, you'd feel as though tickled by a toothpick. Nothing more.

Why is this called a crown-of-thorns wasp? Have look at the head:

The function of the crown is not known, but it might help young wasps emerge from the beetle burrows.

Like the vast majority of wasps, Megischus is not aggressive. In fact, a challenge I faced photographing these delicate insects was their tendency to flee when the camera approached.

photo details (top):

Canon 100mm f2.8 macro lens on a Canon 6D

ISO 400, f/14, 1/160 sec

diffuse overhead speedlite

photo details (bottom):

Canon MP-E 65mm 1-5x lens on a Canon 6D

ISO 400, f/13, 1/160 sec

diffuse twin flash

More information about Stephanidae at the Tree of Life project.