Ohio State University extension entomologist Ron Hammond says near-record warmth across the Corn Belt this winter will cause some insects to appear earlier than normal, but spring weather will determine whether or not insects damage crops.
In addition to insects coming out earlier, many migrate from southern areas, such as black cutworm, true armyworm and potato leafhopper, said Hammond, noting that their development is affected by weather conditions farther south. Whether they migrate into the eastern Corn Belt earlier will depend on the weather conditions later this spring, he said, adding the impact these bugs can have on field crops depends more on the stage of crop development and growth.
"If insects arrive in fields early but no crop is even planted, this could lead to greater mortality if they cannot find alternative hosts," Hammond said. "However, if the insect arrives or begins feeding earlier when crops are smaller in size, a greater potential for injury exists."
In particular, Hammond says to be watching corn flea beetles, as their ability to vector Stewart's bacterial wilt, is of concern this year because of the warmer winter temperatures. In fact, more corn flea beetles are expected this year, significantly increasing the potential for Stewart's bacterial wilt, he said.
Farmers can mitigate the damage if they scout their fields earlier and with more tenacity, he said. "We recommend that growers scout, scout, scout," Hammond said. "Growers need to be out in their fields to be aware of the insects they're dealing with and pay more attention this year, especially in the crop rows, because more insects may be waiting for crops to come out of the ground."