Evaluation of Pyridaben for Control of Twospotted Spider Mite on Rose Plants in the Greenhouse, 1994

Thirty 30-inch-tall roses were grown in 3 gal pots at the Pesticide Research Center, Michigan State University. In early Jun the plants were infested with twospotted spider mites, raised on bean plants in the laboratory, by placing infested leaves on the test plants. Precounts were made on 15 Jun by collecting 10 leaves from each rose plant and counting the no. of mites on the underside of each leaf with a dissecting microscope. The plants were blocked by the precounts. Plants were sprayed to runoff on 16 Jun with a R&D CO2 sprayer with an 8008 nozzle at 50 psi. Each treatment was replicated 6 times, each replicate being an individual plant. Postcounts were made on 21 Jun, 7 and 21 Jul in the same manner as the precounts.