Sampling Methodology of a Key Pest: Technique and Sampling Unit for Evaluation of Leafhopper Dalbulus maidis Populations in Maize Crops

Abstract

Maize (Zea mays) is the most consumed food in the world. The leafhopper, Dalbulus maidis, (Hemiptera: Cicadellidae) is one of the most important maize pests, and due to its direct and indirect damage, it can cause losses of up to 100%. Sampling plans are essential components for integrated pest management programs. The first two components to be determined in these plans are the sampling unit and the sampling technique. The sampling unit consists of determining the plant organ to be evaluated in the sampling and the techniques are the devices used to sample populations of pests in crops. Thus, the objective of this work was to select the unit and technique to be used in the sampling of D. maidis in maize crops. For this purpose, pest populations in plants at stages V4, V6, V8, and V10 were monitored in 16 commercial crops in the Atlantic Forest and Cerrado biomes over two years. The sample units studied were the leaves at different positions in the canopy of the plants. The techniques studied were direct counting, shaking the apex of the plants in a plastic tray and using a beating cloth. In the process of selecting the unit and technique to be used in sampling populations of pests in crops, adequate criteria must be used. These criteria include precision, representativeness, sampling time and that the use of these components in the sampling plans should not cause damage to the plants. The most suitable sampling unit for evaluating these pest populations was the whorl leaves and the best technique was the direct counting. Therefore, the unit and technique selected in this work can be used in sampling plans for D. maidis in maize crops.