Repellency of selected biorational insecticides to potato psyllid, Bactericera cockerelli (Hemiptera: Psyllidae)

Bactericera cockerelli has recently become a major concern because of its direct feeding and vectoring of bacterial diseases in many solanaceous crops. The repellency of four biorational insecticides, MOI-201 (a Chinese medicine plant extract), Requiem (a plant extract of Chenopodium ambrosioides), BugOil (a mixture of four plant essential oils), and SunSpray oil (a mineral oil), to B. cockerelli adults was tested on tomato. In a no-choice test, all insecticides had significant repellency to adults and deterrence to oviposition as compared with untreated control. Of the four insecticides, the two oils showed a stronger repellency to adults and oviposition deterrence than Requiem and MOI-201. In the choice test, all insecticides had significant repellency to adults and deterrence to oviposition as compared with untreated control. Of the four tested insecticides, <1 adults and no eggs were found on the leaves treated with SunSpray Oil, BugOil and Requiem 3 d after treatment. The repellency rates of these three insecticides were 77.2-95.4%. MOI-201 also had significant repellency to adults and deterrent effect on oviposition as compared with untreated control even though it was the least effective insecticide among the four. In conclusion, all four insecticides tested showed significant repellency to B. cockerelli adults and oviposition deterrence, especially the two oils. The overall repellency to potato psyllid adults can be arranged in a descending order of SunSpray oil > BugOil > Requiem > MOI-201. These insecticides could be used in integrated pest management programs targeted against the potato psyllid on solanaceous crops.