abstract_textpA 3-yr study was conducted from 1990 through 1992 to determine the phenology of the alfalfa weevil, Hypera postica (Gyllenhal), in relation to alfalfa growth at four Iowa field locations along a latitudinal gradient. Strong phenological differences were observed between central and southern Iowa alfalfa fields. At the northernmost sites, the majority of eggs was deposited in the spring, whereas there was greater fall oviposition and survival of overwintering eggs at the two southernmost sites. These phenological differences led to greater densities of larvae present earlier in the growing season, when plants were smaller, at the southernmost sites relative to the northernmost sites. Therefore, alfalfa fields located in the southern part of Iowa have a greater potential for incurring economically damaging densities of alfalfa weevil. New management recommendations are proposed for Iowa using our current understanding of alfalfa weevil phenology./p/abstract_text
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