Sycamore tussock moth larvae are known to drop in on anyone who’s spent a bit of time beneath a sycamore tree in July.

These hungry caterpillars then venture to skeletonize several of the tree’s leaves before becoming sycamore tussock moths (Halysidota harrissi).


That is, if they’re not devoured along the way.

Chances are, with her long, piercing ovipositor, a female braconid wasp could insert her eggs directly into a caterpillar.

The hatched wasp larvae will then feed on the caterpillar’s insides, break through its skin, and spin cocoons on the poor worm’s back.


This one survived barely longer than the wasp pupation.

Below, you can just about see the neatly cut and lifted lids where the wasps emerged, leaving their spent cocoons and desiccated host behind.


[Though they escaped observation, I inferred this general identification of braconid wasps based on a discussion at  You can read the discussion here.]