Antibiose de extrato aquoso e etanólico de Duguetia furfuracea (A. St.-Hil.) Benth. & Hook (Annonacea) sobre Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae)

Abstract

Diamondback moth (Linnaeus, 1758) (Lepidoptera: Plutellidae) is one of the Lepidoptera that cause damage to brassica crops worldwide, accounting for annual expenditures for its control. Chemical control is still the most widely used due to its practicality, but successive inadequate applications have selected populations resistant to different insecticides present in the market, and requires the use of alternative control strategies, which stresses the application of botanical insecticides. In this study, the effects of aqueous extracts (EA) and ethanol extracts (EE) of Duguetia furfuracea on the biological cycle of P. xylostella. For this, cabbage disks were dipped in the different treatments at concentrations of 10 and 20% (EA) and 1 and 3% (EE), being provided daily to the tracked until they reach the pupal stage. We evaluated the duration parameters and larval and pupal viability, pupae weight, sex ratio, number and viability of the eggs. The extracts from the leaves of D. furfuracea at a concentration of 3%, was the most efficient in the larval stage reducing its duration by 1.55 days when compared to the control. The larval viability was reduced by 20% aqueous extract. When analyzed pupal duration parameter, it was observed that treatment with 10% EA does not differ from the treatments, the treatments 20, 1 and 3% showed prolonged duration pupae, compared to the control. The lower pupal weight was found in bioassays 20% EA, differing from the control. The number of eggs did not differ between treatments, however the lowest viability index of eggs, was obtained by the extract of 1 and 3% EE when compared to control, can be inferred that existing bioactive substances in the extract are causing this reduction.