C.O.R.N. Newsletter

Additional authors: Marcus McCartney

By now, most of us are familiar with the brown marmorated stink bug, the new invasive stink bug that feeds on soybean, corn, fruits and vegetables.  As the cool weather returns over the next few weeks, we will see BMSB come into homes—and infestations can be large.  They will spend the winter as adults in homes, emerging once temperatures warm in the spring.

We have heard reports of growers spotting a few soybean aphids in their fields. Finding aphids at this time of year is consistent in the past—we have seen them arrive later and later. We do have a lot of late-planted soybean that are in R4 or R5 stage soybean. Remember that our economic threshold to treat soybean aphids is a rising population of 250 aphids per plant. But also remember that, at higher growth stages (>R6) the threshold increases dramatically. At this point it is important to note that none of the fields in Ohio have reached treatable levels.

We have been hearing reports of Japanese beetles in corn and soybean.  These beetles are large with a shiny copper and green color.  Foliage feeding in corn is almost never economic, though economic damage from silk clipping is possible (though rare).  Consider a rescue treatment when  silks are clipped to less than ½ inch and, fewer than 50% of the plants have been pollinated, and the beetles are still numerous and feeding in the field.