ELECTROANTENNOGRAM-ACTIVE COMPONENTS IN BUFFALO GOURD ROOT POWDER FORWESTERN CORN-ROOTWORM ADULTS (COLEOPTERA, CHRYSOMELIDAE)

Buffalo gourd, Cucurbita foetidissima Kunth, root powder contains pote nt, nonvolatile arrestant and feeding stimulants for adults of Diabrot ica virgifera virgifera LeConte, the western corn rootworm. and baits containing this powder mixed with insecticide have become a viable alt ernative to granular insecticide. Anecdotal evidence has indicated tha t these baits may also contain volatile attractants. Solvent extracts of buffalo gourd root powder were evaluated for electroantennogram act ivity to western corn rootworm adults, and a sequential fractionation scheme was conducted to isolate and identify the primary EAG-active co mponents in the extract. A probability-based computer mass spectral li brary search indicated that the best matches for compounds in the most EAG-active fractions to be (E,E)-3,5-octadien-2-one, (E,Z)-2,6-nonadi enal, (E)-2-nonenal, 2-phenylethanol, benzyl alcohol, (E,E)-2,4-decadi enal, and 6,10-dimethyl-5,9-undecadien-2-one. Retention time, mass spe ctrum, and EAG activity of the synthetic compounds were consistent wit h those of compounds in the purified EAG-active fractions (synthetic m aterial was unavailable for 6,10-dimethyl-5,9-undecadien-2-one). Previ ous work indicated that several of these same compounds were in the mo st EAG-active fractions from corn, Zea mays L., silk. EAG data are dis cussed in terms of possible evolutionary considerations.