Fenpyroximate for the control of Tetranychus ogmophallos and Mononychellus planki (Acari: Tetranychidae) in the peanut crop

Abstract

The mites Tetranychus ogmophallos and Mononychellus planki are emerging pests in the peanut crop and have been causing great economic damage. The objective of this work was to evaluate the acaricide fenpyroximate in the control of T. ogmophallos and M. planki mites in the peanut crop. The experiments were carried out under laboratory and field conditions. In the laboratory, experiments were performed using peanut leaf discs placed on Petri dishes containing 2% agar-water. Adult T. ogmophallos or M. planki mites were transferred to each experi­mental unit and exposed to different concentrations of fenpyroximate using a Potter tower. After defining the most efficient concentrations, a field experiment was carried out in a peanut cultivation area. In this area, infestation with T. ogmophallos mites was carried out at 30 days after emergence of the peanut plants, while M. planki occurred naturally in the area. Then, fenpyroximate applications were performed with a pressurized costal sprayer. In the laboratory, fenpyroximate was efficient in controlling T. ogmophallos and M. planki at concentra­tions above 2.5 g a.i. 100 L^-1. Under field conditions, fenpyroximate was effective against these mites at all con­centrations evaluated (10, 15, 20 and 30 g a.i. 100 L^-1).