Studies were conducted in Uganda to evaluate the influence of distance, environmental factors, trap location and trap type on catches of Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) in pheromone-baited traps. Marked weevils were released at recorded locations within plots. Trap efficiency was low and decreased with distance from the pheromone trap. When weevils were released in close vicinity to the trap, significantly more weevils were recaptured from 0.5 m compared to those recaptured from 4 m within 30 days of trap placement. Relative humidity showed a significant positive relationship to C. sordidus catches, while wind speed, temperature and rainfall had no effect. Covering pheromone-baited traps with banana leaves increased capture rates. In one experiment, more weevils were captured in pheromone-baited traps placed in alleys than at the base of mats, while no differences were found in the second. This study provides information on how various factors influence the effectiveness of pheromone-baited traps that will assist in designing a pheromone-based mass trapping strategy for the control of C. sordidus.
- aggregation pheromone
- sampling range