Biologia comparada de spodoptera frugiperda (lepdoptera: noctuidae) com folhas de algodão, mamona, milho e dieta artificial

Abstract

Cotton (Gossypium hirsutum L.), corn (Zea mays L.) and castor bean (Ricinus communis L.) crops are important plant species cultivated in Brazil. The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is considered one of the main pests of corn and cotton in several countries in South America, including Brazil. The control of this polyphagous pest is challenging because the possible host plants have different phenologies and are cultivated during different seasons of the year, although close to each other, which can facilitate the movement of this pest between crops. The aim of this research was to study the comparative biology of S. frugiperda with cotton leaves, castor bean, corn and artificial diet. Specimens of S. frugiperda were obtained from the stock rearing of the Embrapa Algodão Entomology Laboratory, kept fed with artificial diet, in a climatized chamber, at 25 °C, 70 ± 10% relative humidity and a photoperiod of 12 hours until the end of the observations. The experimental design was completely randomized, with four treatments and 48 repetitions. Treatments consisted of S. frugiperda larvae fed with (1) an artificial diet, (2) pieces of cotton leaves; (3) pieces of castor bean leaves and (4) pieces of corn leaves. Duration and survival of the egg, larva, pre-pupa, pupa and egg-adult stages and reproductive characteristics were determined. The results obtained in this research indicate that the survival, development and reproduction of S. frugiperda originated created with cotton and castor bean were negatively affected by these diets, but the high number of non-viable eggs deposited by females of this insect originating from populations of caterpillars fed with castor bean leaves is of fundamental importance for its management, which may contribute to reduce population outbreaks of this pest in cotton and corn crops in the main producing regions of Brazil.