Insect netting is a physical exclusion tactic for insect control that provides growers with many benefits.Around the world, nets or screens are commonly used for reducing excessive solar radiation and weather effects on high-value crops such as vegetables. A net house is a sealed structure made of high-quality fabric designed to keep insects away from the host plants.
Depending on the mesh size, insects excluded can range from small insects like thrips to large moths like tomato hornworms. InAlabama, a large 50-mesh net house was found to exclude nearly 100% of hornworm moths and 80% of armyworms on tomatoes in an outbreak year. (Armyworms are very adaptive and will exploit any structural weakness.)
This reduced the need for insecticides to negligible levels. (Open tomato fields were treated weekly.) To be successful, however, a net house has to be carefully constructed and plants grown inside must be insect and disease free to reduce chances of carryover. Aphids, introduced via infested tomato transplants, caused a major problem on tomatoes and peppers grown in the net house evaluated inAlabama.
Keep Pests Out Of High Tunnels
In a large net house, the major expense is the cost of insect netting and support structures. Since 2010, research on various low-cost fabrics and integrated systems has continued inAlabama. Today, some producers are utilizing the concept of insect exclusion using readily available or existing materials.
One such possibility is the integration of insect exclusion with high tunnels. Greenhouse producers are already familiar with the use of insect netting, but the large-scale use with a high tunnel is relatively unknown. Insect netting can be put on the longitudinal sides to prevent entry of insects when the sides are rolled up. Producers may use black shade cloth on the sides to cut back on the cost of material.