Soybean Aphid Watch 2006

Eileen Cullen, Extension Entomologist, UW Entomology Department

Low Average Plant Counts through June

Soybean aphids have been detected in low densities and patchy distribution for the month of June in Wisconsin and neighboring states. Comparing notes with field crop Extension entomologists in the region, summarizing our own Entomology Department research plots, phone call reports from consultants, reviewing agronomist and grower reports in the weekly Agri-View newspaper, and the WI DATCP pest survey bulletin … reports are consistent. Where found, June populations detected continue to average between 1 and 40 per plant. Averages at the end of June trend toward the low (less than 10 per plant) end of that range, and many UW-Extension county agents and other observers have yet to detect aphid.

Temperatures will play a role in aphid development, among other well known factors such as presence and level of predators and parasitoids. In a previous Wisconsin Crop Manager article I summarized the relationship between soybean aphid population growth potential and temperature (Soybean aphids and high temperatures, WCM Vol. 12, No. 16, June 23^rd, 2005 http://ipcm.wisc.edu/wcm/).  The situation can change quickly, and soybean aphids survive better and reproduce more quickly at relatively cool temperatures. Monitor soybean fields in the week ahead for presence of aphid, or lack thereof. Prepare for more intensive field scouting over the weeks ahead.

Two New Soybean Aphid Suction Traps in 2006 Bring WI Total to 7 Locations

More information will be included in WCM articles later this season on the North Central Region Soybean Aphid Suction Trap Network.  Please refer back to the introductory article on suction traps in Wisconsin (Soybean Aphid Expectations and Wisconsin Suction Traps, WCM, Vol. 12, No. 12, May 26, 2005 http://ipcm.wisc.edu/wcm/).

You can monitor Wisconsin and regional soybean aphid flights at the NCIPM Regional Soybean Aphid Suction Trap Network www.ncipmc.org/traps/.  New to the network in WI this year are a trap in Outagamie County (hosted and facilitated by crop consultant Bill Schaumburg and UW-Extension county agent Kevin Jarek) and a trap at Antigo, WI in Langlade County hosted by grower Andy Merry. The Wisconsin soybean aphid suction trap project installation was supported by the WI Soybean Marketing Board, and now continues through a University of Illinois USDA NCR IPM grant program.