Volume 59 Number 2 Date 05/08/2014
SEEDCORN MAGGOT - Corn, soybean and vegetable crops planted next week may be at increased risk of seedling injury and stand establishment problems associated with this soil pest. Peak emergence of first generation flies is expected to occur from May 9-16 in locations where 360 degree days (sine base 39°F) are surpassed. This includes all of southern and portions of central Wisconsin as far north as Hancock in Waushara County. Sites with decaying organic matter near the soil surface, particularly recently plowed or disked cover crops or weeds, or heavily manured fields, will be preferentially selected for egg deposition.
BLACK CUTWORM - Migrants arrived this week in high numbers. The first significant capture was registered near Platteville in Grant County on the night of May 1, indicating the start of egg deposition in fields with heavy crop residues or early-season winter annual weed growth. The peak corn cutting window is projected to open by May 29 in Rock County, May 31 in Dane County, June 2 in Portage County, and June 6 in Brown County.
PLUM CURCULIO - Migration from hibernation sites into apple orchards could begin at advanced southern sites in the week ahead. A mean daily temperature of 55-60°F for three to four days induces the spring emergence and dispersal of this pome and stone fruit pest.
ALFALFA WEEVIL - Adults are appearing in alfalfa in very low numbers and oviposition has started. The first small larvae should be detectable by May 18.
EUROPEAN CORN BORER - Pupation is forecast to begin by May 13 in south-central and southwestern Wisconsin. As noted in last week's report, results of 2013 fall population survey suggest the overwintered generation of larvae remains historically low and will likely produce an extremely small flight of moths later this month. Black light traps should be installed by May 14 in anticipation of the spring flight.
-- Krista Hamilton, DATCP Entomologist