BEHAVIORAL-RESPONSES IN PREY LOCATION OF THE PREDATORY STINK BUG, EOCANTHECONA-FURCELLATA, TO CHEMICAL CUES IN THE LARVAE OF SPODOPTERA-LITURA

Behavioral responses of the predatory stink bug Eocanthecona furcellat a (Wolff) (Heteroptera: Pentatomidae) towards Spodoptera litura (Fabri cius) (Lepidoptera: Noctuidae) larvae were observed in olfactometers. In single-and dual-tube olfactometers, adult bugs were observed to app roach and stretch their proboscis toward the odor source. These types of behavior were also observed toward the control odor source in the d ual-tube olfactometer. However, the frequency of these phases toward t he control odor was significantly lower than that toward the odors fro m intact or dead larvae. The solvent extracts of larvae elicited these similar behavioral phases significantly more frequently and for signi ficantly longer duration than the control. In a linear track olfactome ter, E. furcellata nymphs were observed to be attracted to the fractio n eluted with hexane from silica gel chromatography but proboscis-prot ruding behavior was not observed. The other fraction, 15%-ether-in-hex ane from silica gel chromatography, elicited the proboscis-protruding behavior by a simple behavioral assay using a Pasteur pipette. These f indings therefore indicate the presence of at least two different chem ical cues in prey location.