Twenty-two cycloalkane and two aryl esters of mandelic acid (α-hydroxybenzeneacetic acid) were tested for repellency against adult confused flour beetles, Tribolium confusum Jacquelin du Val. High levels of repellency were found only with the cycloalkane esters. Among these esters, repellency increased as size of the ring increased to the cyclooctyl analog. When the cycloalkyl moiety also contained a straight-chain alkyl group, repellency generally increased over that of the parent cycloalkyl ester. When the alkyl group contained branching at the 1-position, the level of repellency was markedly below that of their straight-chain isomers. The 2-cyclohexylethyl and 3-cyclohexylpropyl mandelates were the most effective repellents in this study with average repellencies of 83.8 and 82.6%, respectively.
Contributor Notes
1 Coleoptera: Tenebrionidae.
2 Mention of a chemical does not constitute an endorsement or recommendation for its use by the U. S. Dept. of Agriculture nor does it imply registration under FIFRA as amended.
3 Stored-Product Insects Research and Development Laboratory, Savannah, GA 31403.
4 Insect Chemical Ecology Laboratory, Agricultural Environmental Quality Institute, Beltsville, MD 20705.
5 Retired.