|Sant'ana, Josue - UNIV. RIO GRANDE DO SUL|
Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 2, 1998
Publication Date: N/A
Interpretive Summary: Beneficial insects such as predators are important because inundative releases of species such as the spined soldier bug, Podisus maculiventris, may be used to manage a number of insect pests including the Colorado potato beetle. A related but separate species of spined soldier bug, P. nigrispinus, occurs in South America. Pheromones and plant odors can manipulate these predators so their temporal and spatial activities correlate with those of their prey; thus increasing their effectiveness. We investigated how these related species detect components of their insect-produced attractant and plant odors present in their environment. Both species were sensitive to most of the odors tested indicating similarity in the chemical signals used by them. Chemicals comprising the odor of damaged green leaves were the most active odors indicating that these predators may use these signals to locate foliage-feeding prey. Receptors for these chemicals were localized to specific segments of the antennae. Knowledge of chemical communication in predaceous bugs will be used by entomologists interested in biological control to formulate improved control strategies and chemical ecologists as a guide to discovery of new chemical signals.
Technical Abstract: Electroantennograms (EAGs) were recorded from both sexes of spined soldier bug (SSB), and Brazilian SSB (BSSB), to determine antennal olfactory responsiveness for 23 compounds in SSB and 14 compounds in BSSB including the multicomponent male-produced aggregation pheromone and plant volatiles. (E)-2-Hexenol and (E)-2-hexenol elicited the greatest EAGs, followed by heptanal, nonanal, hexanal, and the pheromonal compounds, (+\-)-alpha-terpineol and benzyl alcohol. Both sexes of SSB and BSSB were more sensitive to components of the male-produced aggregation pheromone [(+\-)-alpha-terpineol, (+\-)-linalool and benzyl alcohol, and nonanal than either (E)-2-hexenol or (E)-2-hexenal (a component of the aggregation pheromone). However, BSSB were more sensitive to (+\-)-alpha- terpineol, (+\-)-linalool, benzyl alcohol, and nonanal than were SSB. EAGs to the plant volatile, 1-hexanol, and the pheromonal compounds (E)-2-hexenal and (+\-)-alpha-terpineol, decreased significantly with removal of antennal segments suggesting that receptors for these compounds are distributed over distal 3 segments of the five-segmented antennae. The striking similarity in EAG profiles of SSB and BSSB suggest similar chemical communication systems for both species.