Suppressive effect of prohydrojasmon on western flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) on greenhouse tomato plants

The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is an important pest that transmits tospoviruses such as Tomato spotted wilt virus. Jasmonate (JA) and its derivatives are phytohormones with essential roles in plant defense against herbivorous arthropods. In experiments conducted over 2 years, we evaluated how spraying with prohydrojasmon (PDJ), a JA derivative, affected F. occidentalis infestations of greenhouse-grown tomato plants. Single or consecutive sprayings of 400 nmol/mL PDJ in the early plant growth stage significantly suppressed thrips infestation and feeding damage as well as spinetoram. Although spraying with PDJ slightly inhibited initial plant growth, fruit yields and quality were not affected. These results suggest that PDJ could be practically used as a repellent to control F. occidentalis infestation and primary tospovirus infection in commercial tomato greenhouses.