Hobby Farmer & others Whitefly traps can be made with boards plywood etc. Paint with Rustolium #659 yellow. Coat with criso, used bacon grease motor or chassis grease or There is a special spray that can also be used, found it a catalog but can't find it locally. When boards get loaded take them down wash, regrease and rehang There are several USDA whitefly monitoring stations, They use a 6 in square trap every 10 sq ft. For every whitefly trapped they figure there are 100 on the plants. Byron