ChileanJAR

The susceptibility level of Trialeurodes vaporariorum to methomyl was determined for three field populations collected from Lycopersicum esculentum Mill. in Quillota, Chile. Mean Lethal time (LT₅₀) was estimated by probit analysis, managing to detect minimum losses of susceptibility in field populations of 1.1, 1.2 and 1.6 times more than the susceptible population. Additionally, analysis of variance (ANOVA) permitted the rapid differentiation between a susceptible population and population with less susceptibility. Field experiments confirmed the loss of susceptibility to methomyl and in addition the efficacy of buprofezin control. The control failures may be caused by both loss of susceptibility to methomyl and inefficient spraying techniques. A strategy of resistance management is discussed, that includes the use of insecticides with different modes of action, cultural practices, and utilization of biological control via Encarsia formosa and Eretmocerus corni.