Locomotor response of diamondback moth (Plutella xylostella) populations to a neurotoxic insecticide under laboratory conditions

Abstract

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 São Félix, PE (CSF); Sairé, PE (SR); and Lajedo, PE (LJ)] and two laboratory populations from Recife, PE (RCF), and Viçosa, MG (VÇS) 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.

Lethal and sublethal effects of insecticides used in the management of Plutella xylostella (Lepidoptera: Plutellidae) on the predator Cycloneda sanguinea L. (Coleoptera: Coccinellidae)

“…The diamondback moth (DBM), Plutella xylostella Linnaeus, 1758 (Lepidoptera: Plutellidae) is a major pest of Brassica crops on a global scale 1 . The females of this insect lay their eggs on the abaxial side of the leaves, which hatch after 3 or 4 days and the emerging larvae develop through four instars.…”

“…The diamondback moth (DBM), Plutella xylostella Linnaeus, 1758 (Lepidoptera: Plutellidae) is a major pest of Brassica crops on a global scale. 1 The females of this insect lay their eggs on the abaxial side of the leaves, which hatch after 3 or 4 days and the emerging larvae develop through four instars. The larvae feed on the parenchyma and epidermis of the leaves, forming holes, which makes commercialization impracticable, and these insects can cause losses in crop productivity of up to 100%.…”