Control of Western Flower Thrips in Roses, California, 1986

Three insecticides, Carzol 92SP, Monitor 4E, and Diazinon 4E (0.5 lb AI/100 gal H20) were evaluated for control of western flower thrips in commercially grown roses (Santa Barbara, CA). Each material was applied to 4 houses containing 6-130 ft beds. Four weekly applications of the materials were made using a 200 gal Bean sprayer with a hand wand equipped with Cornel) nozzles (300 psi), beginning 8 Apr. Ten samples were taken at random from each house on 7 Apr, 18 Apr, and 2 May. The samples consisted of 5 flowers placed in 50% ethanol (50 flowers/house, 200 flowers/treatment). All stages of thrips were extracted from the ethanol under suction and counted with the ait of a dissecting microscope. Data were analyzed using ANOVA and treatment mens were separated using Tukey's procedure.