Behavioral Responses of the Potato Psyllid (Hemiptera: Triozidae) to Volatiles from Dimethyl Disulfide and Plant Essential Oils

The behavioral responses of the potato psyllid, Bactericera cockerelli (Sulc) to dimethyl disulfide (DMDS) and to 12 plant essential oils were examined in a glass Y-tube olfactometer. DMDS at doses of 0.5, 1, 2 and 5 g showed a significant repellent effect on the psyllids. Cedar wood, lime, savory, thyme and tea tree oils significantly repelled adults over a wide range of doses tested (1, 10, 100, 500, 1,000 and 2,000 mu l). The oils of clove and peppermint also had a significant repellent effect on adults at all doses except at the lowest dose (1 mu l). The residual effect of 1 g of DMDS persisted for 10 consecutive days whereas five oils (thyme, tea tree, peppermint, savory and clove) remained repellent for the 20-day longevity residual trial.