A tiny, very slender wasp - Gasteruption assectator

Gasteruption assectator wasp is a predator-inquiline that lay eggs inside the cells of solitary bees and wasps. Their alrvae are feeding on the food stores of the host and / or nest inhabitants. The ovipositor is not used for drilling into wood, but is used just to remotely place the eggs into an existing nest or burrow.