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Forages & Grains
Volume 60 Number 1 Date 04/23/2015 ALFALFA WEEVIL - Surveys in alfalfa indicate overwintered adult weevils have resumed activity and spring egg deposition is under way in far southern Wisconsin. The first appearance of larvae is anticipated by May 10. PEA APHID - Egg hatch was observed on April 17 in Grant and Richland counties, where nymphs were collected at the very low rate of 1-4 per 100 sweeps. Alfalfa sampled last week in Columbia, Dane, Dodge, Jefferson and Vernon counties contained no aphids. This insect is of primary concern in early spring as new alfalfa seedings are becoming established, with the critical aphid damage period about two weeks before harvest. TARNISHED PLANT BUG - Adults of this species are currently the most common insect in alfalfa sweep net collections, although counts are still very low at fewer than eight per 100 sweeps. Of greater importance than the populations in alfalfa at this time of year, is the fact that these overwintered adults and their nymphs will migrate into apple trees, strawberries and other fruit and vegetable hosts next month where their feeding damage is more significant. Plant bug abundance in alfalfa should be viewed as an indicator of damage potential for other more susceptible crops. -- Krista Hamilton, DATCP Entomologist 
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