Thursday, June 18, 2015

Soybean aphids on Minnesota soybean: They’re out there, but don’t panic

by Robert Koch, Extension Entomologist

Soybean aphids can now be found in soybean fields in southern Minnesota. There are also reports of soybean aphids from west central Minnesota. However, there is no need to panic. The percentage of plants infested and number of aphids per plant are still low (far below economic levels). Furthermore, aphid predators, such as lady beetles, have been observed feeding on soybean aphids in some fields.  As we get into late June, you may want to begin checking soybean fields for aphids.

Alfalfa Weevil Population Progress in WC and NW Minnesota

Alfalfa fields in west central (WC) and northwest (NW) Minnesota have been sampled for alfalfa weevil over the past 3 weeks. Though the spring started off warm and we anticipated early development of weevil populations, the cool wet conditions slowed development in the region. Currently, weevil populations are predominantly in the 2nd and 3rd larval stages in these areas (see maps). Very few 1st stage larvae are present (< 3% of the population). Larvae should be moving to the the 4th stage in these regions soon.