ABSTRACT

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