Effect of several reduced-risk insecticides on the population of Bemisia tabaci Genn. and incidence of pepper yellow leaf curl Indonesia virus (PepYLCIV) on chili plants

Abstract

Abstract Tobacco whitefly, Bemisia tabaci Genn. can directly, and indirectly damage chili plants by sucking the plant sap and transmitting Pepper yellow leaf curl Indonesia virus (PepYLCIV), respectively. Farmers control PepYLCIV by using synthetic insecticides with 2-3 applications a week to suppress the vector population. The intensive use of insecticide raises concern about potential detrimental effects on the environment and non-target organisms. An alternative control measure for B. tabaci is the use of reduced-risk insecticides that are effective but safer. Thus, the study aimed to determine the effectiveness of various reduced-risk insecticides in reducing the whitefly population and PepYLCIV incidence. This experiment consisted of 12 treatments using insecticides of abamectin, azadiractin, imidacloprid, deltamethrin, spinosad, and water (control), applied once and twice a week. The results showed that the low-risk insecticides had no significant effect on the numbers of adults and nymphs of B. tabaci and the PepYLCIV incidence. Imidacloprid had significantly lower egg number and PepYLCIV incidence than the control and the other insecticide treatments. Our results also showed that B. tabaci populations were low throughout the season but the incidences of PepYLCIV were relatively high. This indicated a possibility that PepYLCIV is seed-borne.