Preliminary study of cotton yield response to Lygus hesperus infestation

Lygus spp. (Lygus hesperus and L. lineolaris) constitute the most important pest complex in U.S. cotton. Despite the perceived importance of Lygus in cotton, relationships between infestation levels and plant injury or yields are not well understood. We infested small plots of both Acala (Upland) and Pima cottons with known numbers of L. hesperus adults at key plant phenological stages and evaluated subsequent lint yields. Patterns of cotton yield in relation to timing of Lygus infestation appeared different between the two cotton types. Numbers of green bolls remaining at harvest suggested the different patterns in yields may have reflected differences in crop maturity of the varieties we evaluated. These observations, combined with other related research at the Shafter, CA ARS laboratory, suggest specific changes to the experimental approach may be necessary to more effectively quantify the relationship between Lygus infestation and cotton yield.