Exclusion of Flying Insect Pests From a Plastic Hoop Greenhouse by a Bamboo Blind-Type Electric Field Screen

The present study describes an economically efficient method for controlling viruliferous whiteflies in a plastic hoop greenhouse, using a bamboo blind-type electric field screen (Bb-EFS) to create a pest-free space. The Bb-EFS had a layer of insulated round iron conductor bars (IBs) and two electrostatic direct current voltage generators that supplied negative or positive voltage to the IBs. The IBs were placed parallel at 4-mm intervals and were connected alternately to a negative or positive voltage generator. Adult test insects (whiteflies, western flower thrips, and tomato leaf miner flies) were blown at up to 5 m/s towards the IBs to identify the voltage range that would capture all the test insects. The results showed that a force ≥ 5.0 kV was strong enough for the IBs to capture all test insects, despite a wind speed of 5 m/s. The Bb-EFS was practical for a greenhouse that experienced frequent invasion by numerous viruliferous whiteflies. Seedlings grew normally inside the Bb-EFS-installed greenhouse. As a supplementary method, an electrostatic insect sweeper and electrostatic flying insect catcher were used to trap whiteflies that avoided the Bb-EFS. Both pieces of apparatus were convenient and easy to operate onsite in a greenhouse environment and were used to trap whiteflies residing on tomato plants or flying inside the greenhouse during daily plant care. These methods controlled the whitefly population to negligible levels, and nearly all tomato plants produced normal fruits.