Locomotor response of diamondback moth a inseticida neurotoxico em condicao de laboratorio

The present study aimed to evaluate changes in the locomotor activity of diamondback moth (Plutella xylostella) populations exposed to surfaces treated with the insecticide chlorantraniliprole under laboratory conditions. Diamondback moth populations from municipalities incorrectly using the insecticide [Camocim de Sao Felix, PE (CSF); Saire, PE (SR); and Lajedo, PE (LJ)] and two laboratory populations from Recife, PE (RCF), and Vigosa, MG (VCS) were exposed to dry insecticide residues in increasing concentrations. The following behavioral parameters of the populations were analyzed: walking time (WT), mean walking speed (MWS), and rest time (RT). Regarding RT, the SR and CSF populations demonstrated a behavior of irritability and increased WT with increased exposure concentration. The RCF population presented a contrasting response. The MWS values in the SR and CSF populations showed a decreasing trend with increased exposure concentration. The LJ and RCF populations showed no changes in terms of MWS. The RT values in the SR population decreased with increased insecticide concentration. In general, the SR and CSF populations presented a behavioral pattern different from that of laboratory populations. The changes in locomotor activity observed may result in lower control efficacy of the insecticide due to repellency or escape of insects. Regarding the effect of insecticide concentrations used in the populations, a defined pattern was not observed, and the effect alternated between an increase, a decrease, and an undefined pattern for the variables studied. Key words: control failure, sublethal dose, behavioral response, synthetic insecticide, chlorantraniliprole. O presente estudo teve por objetivo averiguar, em condiqoes de laboratorio, alteraqoes na atividade locomotora de populaqoes de traga-das-cruciferas, expostas a superficies tratadas com o inseticida clorantraniliprole. Populaqoes de Plutella xylostella provenientes dos municipios com uso inadequado de inseticida: Camocim de Sao Felix-PE (CSF), Saire-PE (SR), Lajedo-PE (LJ) e duas populaqoes de laboratorio: Recife-PE (RCF) e Viqosa-MG (VCS) foram expostas a residuos secos do inseticida, em concentraqoes crescentes. Estas populaqoes tiveram os seguintes parametros comportamentais analisados: Tempo de caminhamento (TC), Velocidade Media de caminhamento (VMC) e Tempo de Repouso (TR). Com relaqao ao TC, as populaqoes de SR e CSF demonstraram comportamento de irritabilidade, aumentando o tempo de camin