Though Polistes wasps are important predators of silver-spotted skipper larvae, we have found that naïve foragers do not open the leaf shelters to extract the caterpillars within, even after extended periods of exposure. We have determined (in collaboration with Ignacio Castellanos at the University of Maryland) that the wasps must learn to remove E. clarus larvae from their shelters. In a dramatic change of behavior, wasps that have had the opportunity to kill and process a caterpillar exposed on an opened shelter are subsequently able to extract caterpillars from closed shelters. We are also investigating the relative importance of visual and olfactory cues in location of skipper larvae by wasp foragers.

As Polistes fuscatus, the common paper wasp, is a generalist predator, we wondered whether these wasps, having learned to access sheltered caterpillars on kudzu, could generalize and subsequently open sheltered larvae on another host plant. More on generalization studies.

These wasps are not learning how to open the shelters, but seem to instead learn to associate shelter cues with the presence of a tasty prey item. We are investigating the volatiles and olfactory cues associated with leaf shelters and whether wasps require these cues for learning. More on the role of volatiles in wasp learning.