Use of Neonicotinoid Insecticides Applied to Soil and Seed for Green Peach Aphid Management on Spinach

Abstract

The green peach aphid, Myzus persicae Sulzer, a common pest of spinach produced in the Arkansas River Valley of western Arkansas and eastern Oklahoma, is currently managed with foliar applications of neonicotinoid insecticides. Data reported herein indicate that the neonicotinoid insecticdes, imidacloprid and thiamethoxam, can also be applied to spinach seed and into the soil for effective aphid management. In greenhouse studies both imidacloprid (Gaucho) and thiamethoxam (Cruiser) seed treatments were effective against adults and prevented the establishment of juvenile aphids for a period of 12 weeks after planting. Similar results were obtained in field studies. Regardless of rate, each of the neonicotinoid seed treatments significantly reduced the number of aphids when compared to aphid population levels on non-treated spinach. In addition to the seed treatments, in-furrow applications also resulted in significantly lower aphid numbers than on plants in plots not receiving the applications. Tests also demonstrated that imidacloprid (Admire) effectively managed aphid populations after being injected into the soil. Of the seed and soil applications evaluated, the only application method currently available is use of imidacloprid applied into the soil. This method currently offers the spinach producer an alternative management tool for green peach aphid control on spinach. As the labels of imidacloprid and other neonicotinoid insecticides are expanded to include additional use patterns such as seed treatments, effective alternatives to foliar sprays should prove effective for aphid management on spinach. Accepted for publication 10 November 2007. Published 8 February 2008.