Residual and Contact Sprays, 1988

Abstract

Abstract Two laboratory tests were conducted to evaluate the effectiveness of PP-321 (cyhalothrin), Demon, Dursban, and Ficam for brown recluse spider control. Test 1 consisted of a residual study, and Test 2 involved spraying the spiders directly with the above chemicals. The surfaces or spiders were treated with a modified B & G sprayer, model 104-S. The sprayer was mounted on a motorized track. A spraying system MulTee-Jet fan nozzle 800067 was attached to the nozzle stand and transported by the motorized track. The nozzle was set at a height of 12 inches over the target area. The nozzle delivered 2.2 oz of finished spray/100 ft2 at 20 psi. The application speed was 2.5 ft/s. The sprayer design, speed of delivery, and amount of liquid applied was set to duplicate field application. Each treatment was replicated 10 times in a complete randomized block design. In Test 1, after spraying, treated plywood panels (4 by 4 by one-quarter inch) were allowed to dry for 24 h before spiders were placed on the treated surface. One spider was placed under a 1 oz plastic cup (1.1 inch2) and confined to the treated surface for 48 h. Mortality counts were made at 1, 4, 8, 24, and 48 h. Tests were conducted at 1, 7, and 14 DAT. In Test 2 spiders were placed in 10 oz plastic cups and sprayed directly with one of the candidate materials. They were removed immediately and transferred to the same type of untreated container. This was done so that the residual surface would not be a factor in control. Spider mortality was recorded at 1 h, 90 min, 4 h, 24 h, and 48 h after treatment. All mortality figures in both tests are cumulative from the first observation for that particular date to conclusion of the test on that date.