|KRUTZ, JASON - Mississippi State Extension Service|
|GORE, JEFF - Mississippi State Extension Service|
Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/27/2014
Publication Date: 9/1/2014
Citation: Jackson, R.E., Allen, K.C., Snodgrass, G.L., Krutz, J.L., Gore, J., Perera, O.P., Price, L.D., Mullen, R.M. 2014. Influence of maize and pigweed on tarnished plant bug (Hemiptera: Miridae) populations infesting cotton. Southwestern Entomologist. 39(3):391-400.
Interpretive Summary: Tarnished plant bug is the number one insect pest of cotton in the mid-South. Because of wide-spread insecticide resistance within this species, population management within the colton crop is difficult. Stable carbon and nitrogen isotope analyses were used to identify on what type of host that tarnished plant bug adults collected within cotton fields developed as immatures. This study demonstrated that field corn and pigweed were the primary hosts contributing to tarnished plant bug populations in cotton during late June and early July. This knowledge will allow for more timely insecticide management decisions in cotton and potentially offer an avenue for population reduction in non-cotton hosts.
Technical Abstract: The influence of maize, lea mays L., and pigweed, Amaranthus spp., on populations of tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), adults infesting cotton, Gossypium hirsucum L., in the Mississippi Delta was studied using stable isotope analyses. Cotton fields adjacent to maize and those greater than 1 mile from maize were identified in four MS Delta counties. Tarnished plant bug adults were collected on a weekly basis from these colton fields throughout the growing season and subjected to stable carbon and nitrogen isotope analyses for natal host determina tion. The proportion of tarnished plant bug adults collected from cotton that developed as nymphs on plants that utilized the C4 photosynthetic pathway, primarily maize and pigweed, peaked anywhere from 79-91% during 2008-2009. Distance of cotton fields from maize did not influence the peak proportion of tarnished plant bug adults collected with a C4 signature from cotton fields, the peak timing, or the peak duration. The timing of these (~peaks occurred from 28 June to 8 July, and the duration was between 13 and 19 days. Stable nitrogen isotope analyses of tarnished plant bug adults indicated that maize was the major contributor of C4 individuals infesting cotton compared to pigweed. Nevertheless, pigweed produced a significant proportion of tarnished plant bug adults infesting cotton, and improved control of these weed species could potentially reduce tarnished plant bug infestations in cotton. Because maize makes up a significant portion of the cropping acreage in the MS Delta, this information can be used to estimate the timing of mass movements of tarnished plant bugs into cotton fields, thus allowing for more efficient use of insecticides for tarnished plant bug control within cotton. It may also allow for future targeting of tarnished plant bug populations in field corn prior to movement to cotton.