Daphnia magna is proposed as a bioindicator to establish the minimum concentration capable of controlling pests before performing toxicity tests. This study uses the proposed pest control extracts of two Peruvian species, Clibadium peruvianum Poepp. (seeds) and Petiveria alliacea L. (leaves). The toxicological effects of the plant extracts were evaluated with D. magna, using five neonates over a period of 24–48 h. A lack of mobility or the absence of heart rhythm for 15 s under a stereomicroscope was considered to indicate mortality. Organic extracts were discarded due to their higher toxicity when compared with the aqueous extracts of C. peruvianum and P. alliacea, which had LC50 = 460.74 mg/L and LC50 = 711.18 mg L−1 at a concentration of 10 mg L−1, respectively. Using this Daphnia-safe concentration, toxicity tests were performed on the third instar larvae of Musca domestica (ho...

Chemical insecticides are commonly used to control insect pests in stored wheat. However, the presence of insecticide residues in food may endanger consumers. We studied the degradation and persistence of two insecticides, fenitrothion and esfenvalerate, in wheat grain, bran, and flour. The application system was calibrated to treat grain at theoretical concentrations of 10 and 0.5 mg kg−1 of fenitrothion and esfenvalerate, respectively. Samples treated with the insecticide mixture were collected at 0, 15, 30, 60, 90, 120, 180, 240, and 360 days after treatment. Samples were analyzed quantitatively by gas chromatography with an electron capture detector (ECD, Ni63). The experimental design was completely randomized with three replicates. Esfenvalerate was more persistent than fenitrothion, with the residues of both insecticides concentrated mainly in the bran, and with least amounts ...