Distribuição espacial do percevejo-marrom Euschistus heros (F.) (Hemiptera: Pentatomidae) em algodoeiro (Gossypium hirsutum L.)

Abstract

The cotton crop is sown simultaneously with soybean in the Brazilian Cerrado. Pests are the main factor that negatively affects cotton productivity. In the recent years, there has been several evidences of the Neotropical Brown Stink Bug (NBSB) present in cotton fields. This specie moves to cotton crops due to a high population density at the time soybean is harvested in the field. The pest moves to cotton crops that are grown in surrounding areas. Several reliable resources can be found about spatial distribution of NBSB in soybean; however, few studies were conducted to identify the behavior of this pest in cotton crops in Brazil. The goal of this research was to understand the distribution pattern of NBSB in cotton using the aggregation indexes of variance/average, Morisita index and the exponent k, and the probabilities of Poisson Distribution and the Binomial Negative Distribution. Additionally, Inverse Distance Weight (IDW) interpolation maps were used torepresent the insect density. The experiment was conducted in a 1.1 hectare field of the Experimental Station of the Federal University of Grande Dourados. Weekly, 64 samples of stink bugs were collected. According to the data, the distribution was aggregated in only two samples when using the aggregation indexes, and the tests fit the Binomial Negative more than the Poisson Distribution. The use of maps showing the density of pests can be an important tool for sampling pests in crops. Controlling the pest at the beginning of infestations can be efficient.