Role of Semiochemicals in Prey-Locating Behavior of a Generalist Predatory Stink Bug, Eocanthecona Furcellata (Wolff) (Heteroptera: Pentatomidae)
Behavioral responses of a generalist predatory stink bug, Eocanthecona furcellata towards larvae of several lepidopteran species were observed in order to analyze the role of semiochemicals in cliciting a prey-locating behavior in this bug. Extracts of Spodoptera litura larvae elicited approaching behavior in E. furcellata. A hexane-eluted fraction from silica gel chromatography of the larval extracts was also attractive to the bugs. The hexane fraction contained n-tetradecane, n-pentadecane, n-haptadecane, n-heptacosane, n-nonacosane, n-hentriacontane and 2, 6, 10, 15, 19, 23-hexamethyl-2, 6, 10, 14, 18, 22-tetracosahexaene (squalene). Synthetic n-pentadecane was attractive to the bugs. On the other hand, a 15%-ether-in-hexane-eluted fraction from silica gel chromatography of the solvent extracts of S. litura stimulated bugs to display a proboscis-protruding behavior. (E) -3, 7, 11, 15- Teramethyl-2-hexadecen-1-ol [(E)-phytol] was identified in this fraction, and synthetic (E)-phytol showed the same effect on the bugs as the fraction. (E)-phytol content of larvae increased depending on the amount of chlorophyll in the diets. These results suggest that (E)-phytol in larvae, which is derived from chlorophyll in the prey diet, acts as an important cue in the prey-locating behavior of the generalist predatory stink bug, E. furcellata. In conclusion, the 2 different chemicals act as “kairomones” in the prey location for the predatory stink bug, E. furcellata.