Effects of elicitors on plant host selection by adult Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

The Colorado Potato Beetle, Leptinotarsa decemlineata Say, is the principal defoliator of potato crops globally. It is well known for its propensity to rapidly develop resistance. Thus, new control options which are resilient to the pest's resistance capabilities are a critical need. The use of chemical ecology in integrated pest management (IPM) programs has been proposed as a means to delay resistance. Elicitors are chemical growth regulators that activate plant defenses. These plant defenses provide numerous opportunities to integrate chemical ecology into IPM programs, including changes to a plants volatile profile. In this laboratory study, we provide evidence that elicitors which mimic jasmonic acid (JA) and salicylic acid (SA) can be used to attract or repel L. decemlineata respectively. Adult beetles are highly attracted to potato plants sprayed with the JA mimicking elicitor Blush 2X, while plants sprayed with SA mimicking elicitor, Actigard 50WG, appear to be repellent. Additionally, residency time on plants sprayed with Actigard 50WG was significantly shorter than with control plants. The potential use of elicitors within IPM program is discussed.