ORIENTATION OF A HEMIPTERAN PREDATOR TO VIBRATIONS PRODUCED BY FEEDING CATERPILLARS

Observations of search behavior in the predatory stinkbug Podisus macu liventris (Say) suggested that vibrations produced by prey as they che w on leaves may be an important cue used by this predator to locate pr ey. To test this hypothesis, studies were conducted to determine if P. maculiventris search and make directional choices in response to vibr ational stimuli produced by feeding green cloverworms, Plathypena scab ra (F.), and to recordings of chewing vibrations. Modified soybean pla nts [Glycine max (L.)] were used in Y-choice tests. Individuals expose d to vibrational signals-finished trials significantly more often on b ranches through which vibrations entered the plants than on no-stimulu s branches. Also, a significantly higher proportion of individuals tha t initially moved onto branches with no stimulus reversed course than did those moving up branches with vibrational stimuli. The response of P. maculiventris individuals to vibrational signals produced by a com mon prey species demonstrates that these predators are capable of usin g substrate-borne vibrations as cues for prey location.