Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2005
Publication Date: 12/1/2005
Citation: Bancroft, J.S. 2005. Dispersal and abundance of Lygus hesperus in three field crops. Environmental Entomology. Vol. 34, No. 6, pp. 1517-1523. Interpretive Summary: Lygus hesperus, western tarnished plant bug (WTPB), is a major pest of cotton and other seed crops in the Western U.S. In order to predict WTPB population dynamics in the field, a quantitative understanding of dispersal is needed. We performed dispersal experiments that measured movement and abundance in cotton, black-eyed bean and alfalfa fields. WTPB males moved farther than females, and movement was greater in the east-west axis than the north-south axis. Dispersal distances declined from cotton, alfalfa and bean. Results predict that 98% of WTPB move less than 12.5 meters day. Estimates of L. hesperus abundance in alfalfa were five times those in cotton during the August population peak.
Technical Abstract: We performed mark recapture experiments that measured movement and abundance of Lygus hesperus Knight in cotton (Gossypium hirsutum L), alfalfa (Medicago sativa L), and blackeye bean (Vigna sinensis L). L. hesperus males moved farther than females, 3.6 v. 4.6 meters per day. Movement was greater in the east-west axis than the north-south axis, 7.0 v. 2.4 meters per day. Calculations based on mark-recapture data suggest that a random walk model describes L. hesperus dispersal well. Diffusion estimates predict 98% movement radiuses in cotton, alfalfa and bean as 15.6, 14.4, and 7.3, respectively. Estimates of absolute L. hesperus abundance were 112,000 per acre in alfalfa during the August peak, approximately five times those in cotton.