Atmospheric Diffusion of Grandlure Volatiles
| Problem: | Information is lacking about ambient concentrations of boll weevil pheromone produced in infested cotton fields and of grandlure dispensed from pheromone trap baits. Results of this study will contribute to universal improvements in the placement and density of pheromone traps and other monitoring and management technologies. |
| Objective: | Determine physical characteristics of plumes of volatile insect attractants for varying microclimatic conditions |
| Approach: | A point source of grandlure will be continuously emitted at high concentrations using a compressed-gas nebulizer. Vacuum air pumps with adsorbent columns and solid phase microextraction fibers (SPME) will be placed at fixed ranges downwind of the point source of grandlure to collect diurnal ambient air samples. Volatile compounds will be eluted from the columns and SPME fibers and analyzed by ion mobility spectrometer (IMS) or gas chromatograph (GC) to determine the constituent concentrations. Detailed microclimatic measurements will identify the influence of air temperature, temperature lapse rate, relative humidity, wind direction, wind speed, and turbulence on the diffusion of plumes of volatile compounds. This field research will be conducted in a level pasture at the Southern Plains Agricultural Research Center and in cotton in the Brazos Valley. |
|
Accomplishments: |
IMS technology was used in 2000 to identify chemical constituents of volatile insect attractants including grandlure in a laboratory environment. |
John K. Westbrook