SAMPLING AND ACARICIDE EFFECTIVENESS ON THE CONTROL OF TWOSPOTTED SPIDER MITE Tetranychus urticae Koch (Acari: Tetranychidae) IN IRRIGATED COTTON CROP

The aim of this work went to evaluate mitcide effectiveness, as well as developing of evaluation methodology of twospotted spider mite Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) in reason of the offense symptoms of mite attack in the cotton crop. It was also evaluated, the correlation among, number of twospotted spider mite in cotton leaves, the size of the lesions and the number of leaves with lesions provocated by mite. The experiments were installed on randomized complete design blocks. In the Experiment #1, diafentiuron dosages were tested. In the Experiment #2, four application programs of chemical miticides (tolfenpyrad and diafentiuron) were evaluated. In the Experiment #3, two miticides on twospotted spider mite control were evaluated. The number of twospotted spider mite on ten leaves was counted. It was accomplished, also, the account of leaves attributing them intensity notes of attack injury of twospotted spider mite. Two or three applications with diafentiuron or tolfenpyrad were efficient in the twospotted spider mite control. Positive correlation was observed among the twospotted spider mite number in the leaves and the number of leaves with symptoms during the period evaluated, being significant between 10 and 15 days after the application. There is correlation, also, among the number of two-spotted spider mite and the note of the injury symptom provocated by the twospotted spider mite attack.