Interesting Incidents with Sphex pensylvanicus Linnaeus, 1763 (Hymenoptera: Sphecidae) Wasps and Their Prey Items in Sioux City, Iowa, USA.

The behavior of Sphex pensylvanicus wasps was observed in the presence of live potential prey items (katydids) under artificial conditions in Sioux City, Iowa, USA. When a prey item was not attacked (17 out of 20 instances) wasps engaged in what looks like "displacement preening" of her antennae using her legs. In the three instances when stinging behavior was noted, the katydid appeared to have been stung ventrally behind the head. One of the three instances is suggestive of a prey item favored over another. [ABSTRACT FROM AUTHOR]