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Oklahoma State
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Oklahoma Alfalfa |
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Oklahoma State
University | |
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Oklahoma Alfalfa |
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Winter Grazing Alfalfa?
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| Egg lay by the alfalfa weevil typically begins in October of each year
after adults have returned to alfalfa from wooded or weedy areas along field borders and creeks where they spend the
summer in an inactive state called aestivation. Eggs are laid in the hollow stems of
alfalfa plants that have grown after the last harvest was taken. Numbers of eggs increase
throughout the winter until hatching begins in February and March. When stands are cleanly grazed with cattle at relatively high stocking rates (called "flash-grazing") during the period from December to February after foliar growth has been killed by freezing temperatures, 50-70% of eggs may be eaten along with foliar growth. The reduction in eggs often allows a delay of 2-3 weeks in spring before the economic threshold is reached and insecticide must be applied to control larvae. Thus, the numbers of sprays required for weevil control may be reduced, and at times, the need for spraying may be eliminated altogether.
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| Richard Berberet,
Alfalfa Entomologist Department of Entomology and Plant Pathology Oklahoma State University |
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