Christina DiFonzo
Entomology
Michigan State University

Editor’s note: MSU Entomologist Christina DiFonzo sent this message recently to MSUE educators. We are sharing it here for your information.

On Sunday/Monday (October 1-2), there was a huge flight of soybean aphid gynoparae (winged females) from soybeans to buckthorn. On Monday (October 2), I found females with tiny newly-deposited nymphs on every buckthorn shrub I examined around MSU. Many of these were ant-tended (i.e. being protected), and I didn't see any ladybugs or other predators. These nymphs will mature into oviparae and lay eggs in October.  Suction trap catches throughout Michigan in September have been "0", but I expect that the trap catch from this week will have soybean aphids.  Heavy aphid numbers were also reported this week in Ontario and Ohio (apparently from the same flight), and last week from Indiana, Illinois and Minnesota.

Thus early indications point to higher soybean aphid populations in 2007.