A method for estimating sweep net collection efficiency for adult western tarnished plant bugs (Lygus hesperus) in cotton

Progress in boll weevil eradication efforts and the adoption of transgenic insecticidal varieties have combined to shift the emphasis of cotton pest management programs to sucking bugs, including Lygus spp. This shift has accentuated the need for improved sampling methods for Lygus. Although the sweep net is a standard sampling method for Lygus adults, factors influencing its collection efficiency are poorly understood. A system of evaluating sweep net collection efficiency using marked and released adult Lygus hesperus was devised and tested in early- to mid-season Pima cotton. Prior to extensive fruiting branch development, recovery of marked bugs by the sweep net was highly associated with previously established population levels. However, recovery of marked bugs was poorly associated with known population levels at more developed plant growth stages. These results demonstrate the utility of the mark-release-recapture technique, which provides the means for experimental evaluation of influential factors such as bug gender, age and physiological status, sampler bias, time of day, and plant canopy development or architecture. Such information should be of critical benefit to landscape-level studies of Lygus dispersal and population dynamics and in the construction of improved economic thresholds.