Optimizing air movement with pepper weevil exclusion screening

Abstract: The pepper weevil, Anthonomus eugenii, is an economically damaging pest of peppers and a concern for all pepper growing regions in North America. Management of pepper weevil is costly and labour intensive, through rigorous crop scouting, removal of infested fruit, proper disposal of plant material and chemical insecticides for suppression of adult populations. In greenhouse production systems, insect exclusion screening is an effective way to minimize external pest pressure. This method is commonly used in Mexico, though the screening used is small enough to also exclude whitefly and aphids. Mesh size this small restricts air flow and is a concern for internal environmental management. In this study, several sizes of mesh (0.8 × 0.8 mm, 1.0 × 1.0 mm, 1.0 × 1.5 mm, 1.0 × 2.5 mm) and a sieve (2.0 × 2.0 mm) used as a control, were evaluated for effective exclusion of pepper weevil. Ten adult weevils were separated from food and water by mesh and placed in a controlled environment chamber for a 24 hour period. Lateral depth and dorsal width of these adults were then measured. Mesh sizes of 0.8 × 0.8 mm, 1.0 × 1.0 mm, 1.0 × 1.5 mm, and 1.0 × 2.5 mm, excluded 100% of adults. The control (2.0 × 2.0 mm) condition did not exclude any adults with 100% of weevils reaching the food and water source. These results suggest that greenhouse pepper producers can maximize air flow by using 1.0 × 2.5 mm mesh and successfully exclude pepper weevil adults.