Variabilidade espacial dos níves de infestação e injúrias causadas pelo percevejo Dichelops melachantus (Hemiptera- pentatomidae) na cultura do milho

Abstract

Corn is one of the main cash crops in Brazil and is subject to attack by numerous species of insect pests. The objectives of this study was to evaluate the spatial variability of levels of infestation and injury caused to plants in maize (Zea mays) by belly-green stink bug (Dichelops melacanthus). Data were collected in the commercial area of the Experimental Farm of the Faculdade de Ciências Agrárias, Universidade Federal da Grande Dourados, in Dourados - MS. Sampling was carried out on a regular grid of 23 rows and 6 columns, with a spacing of 9 feet between points, totaling 138 points collection. The sample point consisted of a row of five plants, where the presence of insects was observed and assigned grades to the intensity of injury in the plant. Data were collected at 8, 15, 29 and 46 days after plant emergence and subjected to descriptive statistics and geostatistics. At 15 DAE on average yielded the apex of bedbug infestation. Is not got a fit semivariogram for the level of bedbug infestation seeing that in this case no spatial dependence between points, for injury caused by bedbugs adjustments were obtained in most seasons, resulting in medium and strong spatial dependencies between points . The level of infestation was significant for the control only two points of the maps 2 and 3 respectively, at 15 and 29 DAE. It is recommended to control only for that particular area. The injuries are easily distinguished with the development of the crop cycle, because the level of injury increases with the increase in the numbers of bedbugs. Keywords: green-belly, sampling and geostatistics.