Landscape movement of tarnished plant bug

The impact of field corn on tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), populations infesting cotton fields in the Mississippi delta was investigated from June through August in 2008 and 2009. Adult tarnished plant bugs were collected weekly from four to five cotton fields adjacent to field corn and from four to five cotton fields distant (greater than 1 mile) from field corn. Wings from these adults were analyzed to determine whether individual tarnished plant bugs had developed as nymphs on a C3 or C4 host. Because the primary hosts (based on acreage) of tarnished plant bugs during the growing season are cultivated hosts (cotton, soybean, field corn), a C4 host signature was assumed to be indicative of nymphal development on field corn. During both years of the study, tarnished plant bug populations infesting cotton fields during late June through early July most likely originated from field corn. Generally 70-90% of the tarnished plant bugs infesting cotton during this period possessed a C4 host signature. In 2008, a higher proportion of tarnished plant bug adults infesting cotton fields adjacent to field corn during mid-July had a C4 host signature compared to those collected from cotton distant from field corn; however, this was not as evident in 2009. From mid-July through mid-August, the proportion of tarnished plant bugs in cotton with a C4 host signature declined rapidly. During both years of the study, August populations of tarnished plant bugs in cotton primarily developed as nymphs on C3 hosts, which would indicate reproduction in cotton. These results suggest that a significant portion of the tarnished plant bug population develops on field corn during June and July, and these populations eventually infest cotton. This information could lead to alternative control measures for tarnished plant bug populations in the future.