Potato leafhoppers arrive each year following migration of the leafhoppers from southern states where they overwinter. Leafhoppers can be found in our alfalfa, soybeans and dry beans. Potato is another crop where their numbers often increase.

The small (1/8 in.), pale green, wedge-shaped winged adults (Figure 1) move rapidly by jumping. Sweep nets are useful for sampling Nymphs are paler green, lack wings, and characteristically walk sideways when disturbed on the leaf surface. They can be found on the undersides of the leaves.

Feeding injury is called "hopperburn". Leaves change from green to yellow to brown as they deteriorate. Leaf injury impairs plant growth. Controlling damaging populations should not be delayed to the point where damage symptoms are visible.

In alfalfa, potato leafhoppers that arrive early can cause problems with regrowth after the first cutting is complete. Monitoring regrowth with the use of 15 inch sweep nets to detect adults and/or nymphs is highly recommended. Treatment guidelines are based on plant height. Treatment thresholds are when 0.2 adults/sweep and alfalfa is 3 inches or less; 0.5 adults/sweep and alfalfa is 6 inches; 1adult or nymph/sweep and alfalfa is 8 -11 inches; and, 2 adults or nymphs/sweep and alfalfa is 12 -14 inches. Insecticides approved for use to control leafhoppers in alfalfa include: permethrin*, Baythroid*, carbaryl, dimethoate EC (Cygon, De-Fend), Furadan*, Lannate*, Lorsban, Malathion 57 EC, Mustang Max*, Proaxis* and Warrior*.

In dry beans, the treatment threshold is when an average of one leafhopper per trifoliate leaf is found. Insecticides approved for use to control leafhoppers in dry beans include: acephate (Address, Orthene), Asana XL*, Capture*, Dimethoate EC (Cygon, De-Fend), endosulfan (Thiodan, Phaser), Lannate*, Malathion 57 EC, Mustang*, Penncap-M*, and Proaxis*.