Olfactory reception of 23 odorants, including plant volatiles and male-prod
uced aggregation pheromone, by third and fifth instars of the spined soldie
r bug (SSB) Podisus,maculiventris was investigated by using electroantennog
rams (EAGs). Both nymphal stages were sensitive to male-produced aggregatio
n pheromone components (E)-2-hexenal, benzyl alcohol, and alpha-terpineol.
The plant volatile, (E)-2-hexen-1-ol (a chemical known to be released by pl
ants in response to prey feeding over the short-term), elicited the largest
EAGs of all volatiles tested. While third instars were sensitive to nonana
l, only fifth instars responded to both nonanal and (+/-)-linalool, both co
mpounds released systemically by plants in response to feeding by potential
prey. Antennal extirpation experiments showed that sensilla responsive to
hexan-1-ol, (E)-2-hexenal, and cu-terpineol are situated mainly on the term
inal antennal segment. The results support the hypothesis that P. maculiven
tris nymphs use both plant volatiles and pheromone components in locating p
otential prey and other behaviors.