Channel Seedsman Dustin Fouch, from Grand Junction, Iowa, explains how to scout for corn rootworm.
How do you scout for corn rootworm?
We go and scout these rootworm acres between July and August, unless we've had a really warm spring. It could be a little bit earlier, but tasseling is at it's most prominent during that July through August time frame. I like to take a spade out there, do an oval dig, and cut the plants about a foot and a half above the ground because you don't really need that. Then we soak these roots and some of the worm larvae will float to the top. But, you get those roots all washed off and then you can start scoring it on node damage. There's a zero-to-three index that we us. If it's just damage on the nodes, or full nodes missing, or clipped off 100%, then you can score that from zero to three and tell how bad the damage really is.