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Looking Ahead
Volume 58 Number 2 Date 05/09/2013 BLACK CUTWORM - Migrants continued to arrive in low to moderate numbers. The first significant capture of nine moths per trap in two nights was registered in Dodge and Grant counties from May 6-7, signaling the start of oviposition in fields with winter annual weeds. Black cutworm larvae require 300 growing degree days (base 50°F) beyond a significant capture to develop from the egg to plant-cutting fourth instar stage. EUROPEAN CORN BORER - Pupation of overwintered larvae is expected to begin across southern Wisconsin in the next two weeks, as mountain ash flowers. According to the annual larval abundance survey last fall, populations are at an all-time low and the first flight of moths emerging in June will be extremely small again this year. Black light traps should be installed by May 15 to monitor the spring flight. POTATO LEAFHOPPER - One adult specimen was collected near Richland Center in Richland County on May 7, the first leafhopper of the season. Surveys in Grant, Iowa, Lafayette, Sauk and Vernon counties were negative. This finding indicates a few early migrants arrived on southerly winds in the last two weeks. GYPSY MOTH - Larvae began emerging from overwintered egg masses on May 6 in Rock County. Phenological indicators of gypsy moth egg hatch include beginning bloom of eastern redbud and saucer cup magnolia petal fall. Larval emergence is anticipated by May 15 in the central areas and about one week later in the north. PLUM CURCULIO - Migration to host trees is probable in the week ahead at orchard locations where mean daytime temperatures continue to exceed 60°F. Pyramid traps should be placed at this time and checked twice weekly during the six-week adult emergence period. -- Krista Hamilton, DATCP Entomologist 
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