Side-effects caused by chlorpyrifos in the velvetbean caterpillar Anticarsia gemmatalis (Lepidoptera: Noctuidae)

Anticarsia gemmatalis is pest in soybean crops, which main control method is the use of insecticides. Toxicity, survival and side-effects (locomotor behavior, respiration, food consumption and histopathology of the midgut) of A. gemmatalis exposed to chlorpyrifos via ingestion were evaluated. Chlorpyrifos was toxic to A. gemmatalis (LC50 = 0.58 g L-1 and LC90 = 0.85 g L-1) and survival decrease from 99% in control to 30% in insects exposed to LC50 chlorpyrifos. The insecticide decreased the respiration rate, food consumption, altered behavioral responses with hyperactivity in A. gemmatalis. In addition the midgut had histopathological changes characterized by damages in the peritrophic matrix and striated border, high cytoplasm vacuolization, cell fragments released in the lumen and apocrine secretion, which can compromise the digestion of this insect. Chlorpyrifos is toxic to A. gemmatalis larvae, affecting survival, locomotion, respiration, food consumption and the midgut. (C) 2020 Elsevier Ltd. All rights reserved.