As I was walking by the hydrangea bush, an insect pollinator caught my eye. It caught my attention because it was remarkably large, an inch and a half long or more, and dark. What IS that? I grabbed my camera, which I usually keep handy for just such moments, and snapped a few shots.
Then I got out my insect guide, the Kaufman Field Guide to Insects of North America, by Eric Eaton, to see what I could find out about the visitor. It seems to be a Great Black Wasp (Sphex pensylvanicus), certainly an appropriate name.
Great Blacks are solitary wasps. Females are specialized predators of katydids, and these wasps are sometimes called ‘Katydid Hunters’. The female excavates nest cells in which she lays her eggs, provisioning each with katydids. The katydids are paralyzed by her sting, rather than killed, and thus the bodies don’t decompose before the eggs hatch. The cell is then sealed, and when the larva hatches, it has a food supply waiting. The young overwinter in the burrow and emerge as adults the following summer.
The wasp doesn’t eat her prey herself. Katydids are baby food. She herself feeds on the nectar of flowers…which explains why I saw her on my hydrangea bush!