Difficult to Predict Soybean Aphid for 2009

Ron Hammond, OSU Extension Entomologist, recently discussed predictions for 2009 soybean aphid infestations. Spoiler alert: there is no prediction. Read on if you want the details.

The soybean aphid in 2008 held true with its trend of every other year infestations. Since we first found aphid in Ohio several years ago, soybean aphid has been predictable in a way that led us to classify it as a threat every other year. With the exception of a few areas in northern Indiana, the soybean aphid has behaved as predicted in Ohio for 2008 with very few infestations and not much justification to spray an insecticide.

The question is now what can we expect for soybean aphids in 2009? If the soybean aphid is true to its infestation pattern, then 2009 should be a year with heavy soybean aphid infestations and need for soybean insecticide applications. But OSU researchers such as Dr. Hammond are suggesting that the soybean aphid may not be a problem again in 2009. The data on predicting soybean aphid is contradictory right now.

On one hand, aphid numbers went up in the fall months as expected. These higher fall collections are the initial sign of something brewing for the following summer. However, there was almost a total lack of aphid colonies on buckthorn (the plant that aphids overwinter) in Ohio during September and October, and we have yet to find our first egg. In past years, OSU Entomologists have always found aphid colonies and eggs in the fall after a low-aphid summer, and preceding a high year. Thus, it is difficult to offer a prediction of what will happen in 2009.

At this time, I recommend reading the C.O.R.N. newsletter closely next spring and summer to see what is, or is not, happening. In fact, I recommend you subscribe to the C.O.R.N. newsletter so that you can receive weekly email updates. By following aphid development to our north, we hope to be able to give growers at least a few weeks notice if something might occur. This notice will be announced immediately through the C.O.R.N. newsletter. It is important to stay abreast of soybean aphid populations during the summer. During the summer, the soybean aphid can reportedly complete 15 generations a season, with populations doubling in just a few days. Subscribe to the C.O.R.N. newsletter here. If you prefer not to subscribe, you can visit the website weekly at http://corn.osu.edu/

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