Electroantennogram responses of a predator, Perillus bioculatus, and its prey, Leptinotarsa decemlineata, to plant volatiles

The two-spotted stinkbug, Perillus binculatus, is a predator of the Colorad o potato beetle (CPB), Leptinotarsa decemlineata. Behavioral tests revealed that P. bioculatus is attracted to potato plants, Solanum tuberosum L. (So lanaceae), infested by the CPB. Electroantennograms from the antennae of P. bioculatus were recorded in response to compounds present in the headspace of CPB-infested potato plants. (Z)-3-Hexen-1-ol and 2-phenylethanol elicit ed the highest EAG amplitudes. Linalool, 4,8-dimethyl-1,3 (E),7-nonatriene, nonanal, decanal, and (R)-(+)-limonene evoked lower EAG amplitudes. The ma jor headspace components beta-caryophyllene and beta-selinene produced only weak EAG responses. Antennal sensitivity of the CPB to (Z)-3-hexen-1-ol wa s higher than that of P. bioculatus, whereas the stinkburg was more sensiti ve to 2-phenylethanol, beta-caryophyllene, (R)-(+)-limonene, and decanal. A mong these compounds, 2-phenylethanol is of special interest since it was o bserved to be emitted by potato foliage only after being damaged by CPBs.