by: Andy Michel, Kelley Tilmon, OSU Extension
We have heard from a few extension educators and scouts that soybean aphids are starting to make their appearance. Right now, the number of infested plants is very low (around 5%) and the number of aphids on the plants is also low (average 5-10). With this level of infestation, it is highly doubtful that soybean aphids will reach threshold, especially in soybean that has already entered the late R stages (R5 and R6). However, there is a fair amount of late planted soybean that could still be at risk—in fact we were in a field last week that just reached R2. We recommend that growers continue to scout their fields to make sure that soybean aphid populations remain under the treatment threshold which is 250 aphids per plant.