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Oklahoma State University Stillwater, OK |
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Oklahoma Alfalfa |
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Oklahoma State University Stillwater, OK |
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Oklahoma Alfalfa |
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Potato Leafhopper |
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| Life Cycle and Damage. This small, wedge-shaped insect is
light-green in color and
about 1/8 inch long. This
species does not overwinter in Oklahoma, but migrates northward from coastal areas of the
Gulf of Mexico on storm fronts each spring, and is usually first collected in May. The
most characteristic symptom of damage by the leafhopper is chlorosis and eventual necrosis
of tissues at leaf tips called "hopperburn". In
addition, growth of alfalfa plants maybe severely stunted, resulting in both quality and
yield reductions.
Sampling and Control. The primary means for sampling to assess the need for control of leafhoppers is sweepnet sampling. At least 5 sets of 20 sweeps should be taken in each field up to 30-40 acres. More samples should be taken in larger fields. The greatest potential for losses due to potato leafhopper occurs with infestations on new growth after a harvest has been taken. Although sweeping is difficult in alfalfa stubble, the effort should be made because the economic threshold in 6-inch or shorter alfalfa is an average of 0.5 leafhoppers/sweep. When alfalfa is 12 inches or taller, the threshold is 2 leafhoppers/sweep. When growing conditions are optimal for alfalfa, applying insecticide when these thresholds are reached can be profitable. However, when exceedingly dry conditions prevail as often occurs in mid-summer in Oklahoma, the limited potential for alfalfa growth may not warrant the expenditure for insecticide. Leafhoppers survive from one flush of growth to the next by living stems that were missed by the harvester. Making sure that all standing alfalfa in a field is cut can help control this pest. Additional information relating to control of leafhoppers can be found in OSU Extension Facts No. 7150 and Oklahoma Alfalfa.
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| Richard Berberet,
Alfalfa Entomologist Department of Entomology and Plant Pathology Oklahoma State University |
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