Evaluation of vegetable extracts from northeast flora in the control in the control of Sitotroga cerealella Olivier, 1819

Abstract

Zea mays L. maize is a rustic crop from the semi-arid, humid and sub-humid tropics, being grown mainly by small farmers in the northeastern and northern regions of the country where they consist of sources of protein and vegetable carbohydrates for the population, and social and economic costs of food supply and job creation, especially for rural populations. Among the limiting factors to its cultivation, pests stand out and, among these, the Sitotroga cerealella moth Olivier, 1819 (Lepidoptera, Gelechiidae). This work aims to evaluate the insecticidal activity of plant extracts obtained from plants of the Northeastern flora in the control of the cereal moth under laboratory conditions. Adults of Sitotroga cerealella were collected in grain stores with occurrence of the species. The tests were applied at the initial concentration 0% (control) to 100% ml of extracts. The extracts that present a mortality rate 50%, were conducted in bioassays with 4 replicates, each one being formed by a batch of 5 insects. The experimental design used was completely randomized. Aroeira, Mastruz, Melão de São Caetano and Pata de vaca obtained better performance in concentrations of 25%, 50%, 75% and 100% in the control of S. cerealella. For these species, we recommend the use of extracts in concentrations of 25% as they have maximum lethality and lower cost. The plants showed a high insecticidal power above 60% of the mortality rate of the cereal moth in low concentrations, except for lemongrass and black jurema. Thus, the selected plants can be used to obtain natural insecticides or to isolate the active ingredients that allow the synthesis of new phytosanitary products.