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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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ALFALFA WEEVIL ADULT BEHAVIOR Most producers of alfalfa realize that the alfalfa weevil is the most troublesome alfalfa insect problem in the state. Other insect problems do occur and may require treatment but they frequently subside for a few years. Alfalfa weevil habits have been studied since the early 1970's and an array of control measures has been devised. After emerging from cocoons in spring (April, May), alfalfa weevil adults (beetles) feed for a period of time on foliage of alfalfa, then leave the fields for the summer. Several months are spent in a resting phase in areas with a lot of grass, weeds, and brush along field borders, roadsides, and streams. In fall, the weather cools, these adults become active again and return to alfalfa fields to start feeding and laying eggs. Their return normally occurs in October. Making a prediction about the numbers of weevil larvae (worms) that may occur in alfalfa each spring, based on adult populations in the fall, is often unreliable large numbers of adult weevils in the fall could translate into a busy season of mating and egg laying as the winter progresses. One of the most economical controls for the alfalfa weevil
is to discourage their egg laying. Grazing alfalfa during the winter accomplishes this
very well. Fields grazed in the winter generally have fewer larvae the next spring and
they begin damaging foliage later. |
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| Richard Berberet,
Alfalfa Entomologist Department of Entomology and Plant Pathology Oklahoma State University |
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