Soybean Aphids Increasing
I have noticed a lot of sprayers in soybean fields the last week or so. Yes, the weather has been very conducive for aphids. In some fields populations have exploded to threshold levels. That is all soybean growers needed with low process, more expenses! However, you do not really have any options. When you get to economic threshold levels the increase in yields more than offset the cost of the insecticide application.
Soybean aphids can have an economic impact until the soybean growth stage R6. Depending on when the soybeans were planted, farmers will have to continue scouting for a week or two yet. Soybean aphids were native to China and were accidently introduced into the United States. Ironically, soybean aphids can overwinter on only one plant, buckthorn. Buckthorn is also native to China and it was intentionally brought to the United States to be planted as a shrub. Yes, the horticultural industry years ago brought the buckthorn plants to the United States.
While the buckthorn plant was a nice looking plant it turned out to be very aggressive. Birds ate the berries and spread them all over wooded areas. Now buckthorn has taken over many wooded areas and crowed out many native plant species! Plus, soybean farmers would not have to scout fields and apply insecticides if we did not have buckthorn in our area.