Acaricidal efficacy of neem against Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae).

摘要

The broad mite, Polyphagotarsonemus latus, is one of the most serious pests attacking chilli pepper in Brazil. Aiming to offer an additional tool to be used for its control, we tested the acaricidal effect of neem, Azadirachta indica, on P. latus. Chilli pepper seedlings were sprayed with neem seed extract (NeemAzal T/S, 1% of azadiractin) at concentrations of 0.05, 0.10, 0.15 and 0.20 g a.i./l, with abamectin 1.8% (Vertimec 18 CE) and with water. Adult females of P. latus were transferred to each treated plant and after 6 d, the instantaneous rate of increase (r_i) was calculated. All mites on plants treated with abamectin died without ovipositing before the end of the experiment. The r_i for P. latus decreased linearly with increasing neem concentration, with the population growth rate becoming negative when mites were exposed to plants treated with neem at concentrations higher than 0.13 g a.i/l.