Screening organic pesticides for control of Asian citrus psyllid (Diaphorina citri) in California
We evaluated the efficacy of several organic insecticides with different modes of action on the control of Asian citrus psyllid (ACP). All trials were conducted under greenhouse conditions at the Chula Vista Insectary, in San Diego California, with infested plants of Volkameriana lemon.
Products evaluated included botanical, biological and horticultural oils, used for organic plant production (i.e., pyrethrins, azadirachtin, diatomaceous earth, kaolin), and several adjuvants.All trials included a water treated control and Danitol, a pyrethroid conventional insecticide, which was used as a positive control to ensure mortality.
Forty-eight hours after treatment, the conventional insecticide, Danitol, always caused 100% mortality. Most of the organic products and adjuvants tested were also effective on contact, causing from 80 to 90% nymph and adult mortality 48 hours after application. However, Danitol had a greater residual effect. The efficacy of organic compounds fell rapidly over time, and most of these products caused less than 60% mortality fourteen days after treatment.
Our results suggested that repeated applications of organic pesticides would be necessary to sustain a high level of control.