When this large wasp flew past me, I thought it was a dragonfly! Then I saw her on the trunk of a tree and knew it was something entirely different. This wasp has long legs, a long abdomen and a long ovipositor (but no stinger). The ovipositor is used to insert eggs into the larvae of a Horntail Wasp, which live inside the wood. After the egg hatches, the young Ichneumon Wasp larva feeds on the horntail larva and then pupates in the wood. When it reaches maturity, it chews its way out and begins life as an adult.