author(s)
Mitch M Legwaila, Motshwari Obopile and Bamphitlhi Tiroesele

abstract
The efficacy of chlorfenapyr was studied in the laboratory against the carmine spider mite on tomato. The acaricide was applied at five concentrations, including the label rate, separated on a log 10 scale. Each treatment was replicated three times. LC₅₀ and LC₉₀ values were determined by probit analysis during different periods after application and were used to determine the efficacy of the acaricide. LC₉₀ values were 0.52, 0.50, 0.44 and 0.38 ml/L when treatments were evaluated at 24, 48, 72 and 96 hours after treatment. This indicated that chlorfenapyr was highly effective against T. cinnabarinus adults. Probit line slopes were 8.15, 6.96, 5.50 and 2.96 at 24, 48, 72 and 96 hours after application. This indicates a fast change in spider mite mortality with increasing in acaricide concentrations. This study found that chlorfenapyr can be used to effectively control T. cinnabarinus under Botswana conditions, especially in combination with other control methods in integrated pest management programs.