EFFECTS OF EARLY SEASON WILD HOST PLANTS AND HERBICIDESON TARNISHED PLANT BUG POPULATIONS

摘要

Tarnished plant bug (TPB), Lygus lineolaris, feeds and reproduces on a variety of early season wild host plants before thecotton cropping season begins. These host plants have been the focus of area-wide management programs that use burndownherbicides to reduce the hosts thus reducing crop infestation by TPB. Populations of TPB can be reduced by as muchas five times less than in untreated areas. Plot experiments were conducted to determine effects of plant species (broadleafhosts and non-host grasses) and burn-down herbicide applications (treated or untreated) on TPB populations. TPB numberswere significantly greater in broadleaves vs. grasses. Among broadleaf hosts, radish had the highest TPB numbers followedby crimson clover, vetch, and winter pea. Burn-down herbicide applications to vetch and vetch/ryegrass treatment plotsprevented TPB population increases, while untreated vetch and vetch/ryegrass plots had significant increases of TPB.Untreated plots had 5-fold more TPB than burn-down herbicide treated plots (which is similar to results from area-widemanagement studies). Remotely sensed imagery of plots revealed NDVI values and G-NDVI values of broadleaves that werelower than grasses. Remote sensing may be useful for early-season host detection, but more needs to be known about hostphenology, plant stand mixture, and texture.