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Corn
Volume 60 Number 3 Date 05/07/2015 BLACK CUTWORM - Moths arrived in moderate numbers this week. The DATCP network of 42 pheromone traps registered 75 migrants during the reporting period ending May 6, for a cumulative total of 117 moths to date. This week's capture of moths in 58% of the survey traps is indicative of a larger and more substantial flight, and signals that egg deposition has intensified on winter annual weeds such as common chickweed, peppergrass and yellow rocket in no-tillage and reduced tillage fields. Larvae resulting from the spring flight could begin cutting corn seedlings by May 20. EUROPEAN CORN BORER - Emergence of the first spring moths may start next week in advanced southern locations. Most overwintered larvae are in the pupal stage, which requires 10 days to complete at average daily temperatures of 65°F. Degree day accumulations near Beloit and La Crosse, currently the warmest locations in the state, are expected to surpass the 374 units (modified base 50°F) required for moth emergence by May 10. WIREWORM - This soil pest has been noted during surveys in the last two weeks and, like the black cutworm, can injure seedling corn this month. Untreated corn planted into fields formerly in alfalfa or pasture is most vulnerable to infestation. Damage should become evident shortly after emergence. In severe situations, or if wireworms have been a serious problem in the past, treatment may be necessary. -- Krista Hamilton, DATCP Entomologist 
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