Changes in the Biological Characteristics of Plutella xylostella Using Ethanolic Plant Extracts

The indiscriminate use of synthetic insecticides has led to the emergence of resistant populations of Plutella xylostella L. (Lepidoptera: Plutellidae), hindering its control and causing economic damage to brassica production. Thus, in order to seek control alternatives, this study aimed at assessing the bioactivity of the ethanolic extracts of Schinus terebinthifolius (Anacardiaceae), Annona coriacea (Annonaceae), Annona crassiflora (Annonaceae), and Serjania marginata (Sapindaceae) on the life cycle of P. xylostella. Cabbage leaf discs were immersed in the treatments at a concentration of 10 mg/mL and given daily to the larvae. Larval and pupal duration and survival, pupae weight, the longevity of males and females, number and survival of eggs, incubation period, and days of oviposition parameters were evaluated. All extracts differed significantly from the control in terms of larval and pupal duration, pupal survival, and pupae weight. All the extracts prolonged the larval and pupal period of P. xylostella. Only A. coriacea did not differ significantly from the control in terms of larval survival, and the highest larval mortality was observed in the treatment with S. marginata (50%). Pupal survival, pupae mass, oviposition period, and egg survival were reduced in all treatments with ethanolic extracts. The treatments with Annona and S. marginata species have reduced the number of eggs. Treatments with S. terebinthifolius and S. marginata have reduced the incubation time of eggs. Thus, the treatments with ethanolic plant extracts act on the life cycle of P. xylostella negatively impacting the biological parameters evaluated.