2005 Wrap-up

The 2005 growing season left many growers with very different experiences managing insect pests in soybeans. Aphids were feared to return to economic populations, and for nearly 2 million acres in Iowa, they did. However, many growers reported fields with 250 or more aphids per plant next to fields that had few if any aphids. I was a bit skeptical of this last observation, but such a situation occurred next to one of our research plots in Story County. Just as one would expect, the field that we had carefully marked and planted for research had a sub-economic population of soybean aphids

Soybean aphids on the go: Results from the suction trap network

Since the soybean aphids\u27 arrival in North America during 2000, there has been much speculation about how this new pest will establish and thrive. On-the-ground estimates have been helpful in measuring the range of this invasive species--currently, it is found in more than 22 states and three Canadian provinces

Mid-July soybean aphid update

Soybean aphid populations around Iowa continue to remain below the economic threshold in most areas reported by extension field agronomists on July 16. The one exception continues to be in northeastern Iowa where Brian Lang notes that the population in his research site near Decorah has gone from 30 per plant on June 28 to 405 per plant on July 5, to 1,137 per plant on July 12 (Table 1). Soybean fields in northeastern Iowa should be scouted now and an insecticide application should be considered when the population exceeds 250 aphids per plant on 80 percent or more of the plants. For more information, see ICM, July 9, pages 217-218