Whats the best way to scout for potato leafhoppers?
Invest in a sweep net. The purchase of a 15-inch (diameter) sweep net is a valuable insect sampling tool for alfalfa producers. Static treatment thresholds are based on the number of leafhoppers per sweep of the net. The threshold increases as alfalfa grows and becomes more tolerant to leafhopper feeding: 0.2 per sweep on stubble (up to 3 inches), 0.5 per sweep on 3- to 6-inch alfalfa, 1.0 sweep on 6- to 12-inch alfalfa, and 2.0 or more per sweep on plants 12 inches or taller. The sweep net should be swung like a broom through the top 4 to 6 inches of growth. Each thrust with the net is a sweep. Take 20 sweeps per location in 5 to 10 sites within the field if the alfalfa is taller than 4 inches. If the alfalfa is shorter than 4 inches, more sweeps are required for a precise sample estimate. Count the number of leafhoppers caught in the net and divide by the number of sweeps taken. If the number exceeds suggested treatment thresholds, an insecticide application may be warranted.
