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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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Foliage-Feeding Caterpillars |
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Life Cycle and Damage. The larval stages, "caterpillars", of several species of butterflies and moths are common foliage feeders in alfalfa from May through October. The most important of these are the corn earworm, yellow-striped armyworm, fall armyworm, alfalfa caterpillar, green cloverworm, and forage looper. Each of these species completes several generations during summer and fall, with a generation time of 4-5 weeks. When present in large numbers, these caterpillars may completely defoliate alfalfa, consuming the leaves for their high nutrient content and leaving the stems, which have limited value as livestock feed. Sampling and Control. The most effective sampling approach for these caterpillars is sweeping with a standard 15-inch diameter net. A set of 20 sweeps should be made in each 5-10 acre field area. If numbers exceed 5-6 larvae/sweep, insecticide should be applied or, if the time for harvest is near, alfalfa may be cut to remove the habitat for the caterpillars. Additional information on control of foliage-feeding caterpillars 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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