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Forages & Grains
Volume 61 Number 1 Date 04/28/2016 ALFALFA WEEVIL - Surveys in alfalfa indicate overwintered adult weevils have resumed activity and spring egg deposition is under way in southern Wisconsin. The first larvae could appear in sweep net collections by May 7. PEA APHID - Egg hatch began by April 17 in Richland County. Alfalfa sampled this week in Columbia, Dane, Grant, Green, Iowa, Lafayette, and Rock counties had very low counts of 0-35 aphids per 100 sweeps, with an average of 14 per 100 sweeps. TARNISHED PLANT BUG - Adults can be found in most surveyed alfalfa fields. Although the average count from April 21-27 was extremely low at four per 100 sweeps, the appearance of plant bugs in alfalfa signals that strawberry growers and other fruit producers concerned about this pest should begin inspecting plants for tarnished plant bug next week. -- Krista Hamilton, DATCP Entomologist WHEAT DISEASES - Despite widespread reports of stripe rust across much of the country, survey observations in Dane, Green, and Jefferson County wheat fields on April 22 and April 25 found no evidence of stripe or leaf rust, no powdery mildew, and only traces of Septoria leaf blotch. The crop (most fields at Feekes 7) was remarkably healthy, perhaps due to dry conditions in recent weeks. These results are consistent with similar observations reported by UWEX Field Crops Pathology group on April 18. Survey efforts will continue, as weather conditions increase the chances of rust development. Nationally, stripe rust and leaf rust are being found across a wide swath of the wheat-growing region, with early-season stripe rust detections as far north as South Dakota and Minnesota, suggesting that stripe rust may have overwintered in those states. Information on the national development of rusts of cereals, along with current maps, is available through the USDA Cereal Rust Bulletin: http://www.ars.usda.gov/News/docs.htm?docid=9757 . -- Adrian Barta, DATCP Plant Pest & Disease Specialist 
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