Volatile constituents of fermented sugar baits and their attraction to lepidopteran species

The volatile compounds emanating from four fermented sugar baits, palm sugar, golden cane syrup, port wine, and molasses, were isolated by headspace sampling and analyzed by gas chromatography-mass spectrometry. Three classes of compounds including esters, alcohols, and aromatic compounds were identified in the headspace of the four fermented sugar baits. There was a high degree of qualitative similarity between the headspace contents of the four fermented sugar baits, although quantitatively they varied considerably. Ethyl acetate, 3-methylbutanol, ethyl hexanoate, 2-phenylethanol, ethyl octanoate, ethyl (E)-4-decenoate, ethyl decanoate, and ethyl dodecanoate were the major compounds identified in the headspace of the four fermented sugar baits. The efficacy of the four fermented sugar baits was investigated in field trapping experiments. Fermented palm sugar and golden cane syrup were superior in attracting significant numbers of moths as compared to port wine and molasses. Fermented molasses was the least attractive among the four baits. Over 90% of the insects caught were noctuids with Graphania mutans and Tmetolophota spp. being the main noctuids captured (over 55%) in the four fermented sugar baits. Male and female G. mutans were equally attracted to the four sugar baits. A number of tortricid species were also trapped.