ANALYSIS OF VOLATILES EMITTED BY POTATO PLANTS BY MEANS OF A COLORADOBEETLE ELECTROANTENNOGRAPHIC DETECTOR

An electroantennographic detector based on the antenna of the Colorado potato beetle (Leptinotarsa decemlineata Say, 1824) was used to inves tigate volatile organic compounds emitted by injured potato plants (So lanum tuberosum L., 1753). Samples were collected on charcoal traps us ing the CLSA method. Analyses were performed with a GC-EAD-FID setup a s well as a CC-MS system. The experiments revealed that several groups of compounds are perceptible to the Colorado potato beetle. The abili ty of the Colorado potato beetle to detect green leaf odours (e.g. (Z) -3-hexen-1-ol and (E)-2-hexenal), linalool and some terpenes has been noticed before [Visser et al., J. Chem. Ecol. 5 (1979) 13]. In this wo rk the presence of(Z)-3-hexen-1-ol, (E)-2-hexenal and linalool in the potato odour could be confirmed. Moreover, beta-myrcene, benzeneethano l, and several sesquiterpenes (e.g. caryophyllene and germacrene-D) we re identified. The GC-EAD experiments reveal that apart from the green leaf odours and linalool prominent reactions of the Colorado bettle a ntenna are induced by benzeneethanol and the sesquiterpene fraction. ( C) 1997 Elsevier Science B.V.