An expert on bugs says Iowa farmers better be outstanding in their fields, literally, to hunt for invading insects. Agronomist Brenton Schwab blames the mild winter for growing spring populations of several sorts of pests that’ll gobble up corn and soybean crops.Schwab says bean leaf beetles are in good supply as are black cutworms, the European corn borer and corn rootworm beetles. He says farmers should get in their fields to frequently search for infestations. He recommends checking the crops as often as possible, at least every two days. In areas where infestations are still light, he suggests flagging it and returning in a few days. Schwab says the earlier farmers find the bugs, the sooner they can be wiped out.