Electrophysiologically and behaviorally active volatiles of buffalo gourd root powder for corn rootworm beetles

The dried, powdered roots of buffalo gourd, Cucurbita foetidissima, were te sted in a cornfield and shown to attract adult northern and southern corn r ootworm beetles. Coupled gas chromatography-electroantennography (GC-EAG) a nalyses of headspace samples of the root powder showed several GC-EAG-activ e compounds on the antennae of female northern, southern, and western corn rootworms. Among other techniques, solid-phase microextraction and CC-mass spectrometry identified the following GC-EAG-active compounds: hexanol, non anal, 1-octen-3-ol, benzaldehyde, benzyl alcohol, (E)-3-octen-2-one, (E,E)- 3,5-octadien-2-one, and (E,Z)-3,5-octadien-2-one. EAG dose-response studies of several of the identified root powder volatiles also were performed and compared with results from known attractants. Field tests of synthetic roo t powder volatiles in commercial cornfields showed that northern corn rootw orm adults were attracted to (E,E)-3,5-octadien-2-one. The antennae of the Diabrotica species and the field tests showed specificity for different geo metrical isomers of 3,5-octadien-2-one, with a behavioral preference for (E ,E)-3,5-octadien-2-one. In addition, we have shown that the efficacy of buf falo gourd root powder as a feeding stimulant and arrestant can be enhanced for northern and western corn rootworm adults by augmenting buffalo gourd root powder with additional (E,E)-3,5-octadien-2-one.