Frequency and abundance of selected early-season insect pests of cotton

Abstract

The use of insecticides at planting has been a common crop management practice in cotton for several decades. Historically, U.S. cotton growers relied on in-furrow applications of insecticides, such as aldicarb, to control earlyseason insect pests. In-furrow applications have largely been replaced with insecticide-treated seed. Since 2012, more than 60% of the U.S. cotton crop is planted with seed treated with insecticide, primarily the neonicotinoids imidacloprid or thiamethoxam. Several insects or insect groups are included on the labels of these neonicotinoids for use as seed treatments. An increased understanding of the risks associated with economically injurious populations of insect pests is needed to optimize use of early-season insecticides and reduce over-reliance on them in cotton, especially when initial decisions for insect control before planting have subsequent influence on future pest abundance. Existing literature pertaining to these early-season cotton insect pests was examined to identify factors favoring their distribution and abundance and the importance of insect control tactics used at planting. The relative importance of some of these pests is dependent on the cotton-growing region and impacted by local production practices. Thrips (predominantly Frankliniella spp.) (Thysanoptera: Thripidae) are the most prevalent early-season insect group in cotton across the United States and the primary target of initial insect control. Other targeted insects include the black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), aphids (predominantly Aphis gossypii Glover) (Hemiptera: Aphididae), plant bugs (Hemiptera: Miridae), and wireworms (Coleoptera: Elateridae).