ROOTWORM: The Penn State Extension offered some planting and bug tips as the growing season locally winds down.

With rootworm adults emerging from corn fields, this is the time of year to notice large populations of rootworm beetles or their damage to corn plants.

Western corn rootworm is the most damaging pest of corn production in the U.S. In Pennsylvania and surrounding states, western corn rootworm is easily controlled with rotation. Rootworm larvae cannot survive on roots of soybeans, alfalfa, sorghum, and sorghum sudangrass, among other crops species; therefore, rotating from corn to these crop species can effectively eliminate populations of rootworm in fields.

For dairies and other farming operations that grow continuous corn, however, western corn rootworm presents a challenge.

Those encountering really high beetle populations or goosenecked corn at this time of the year should examine the root systems, as that will indicate whether rootworms have been feeding heavily. Keep in mind however that there is little to do now to manage the problem; treating populations of adult beetles is ineffective, so solutions will have to be implemented next spring. The easiest way to fix this problem, or to prevent it from developing, is to regularly rotate fields from corn to soybeans, alfalfa, sorghum, etc. for the next growing season.

If rotation out of corn is not possible, growers need to know which proteins they have been using and should switch to different proteins, particularly hybrids with two genes active against rootworms, but the number of options and combinations is limited.

For those who encounter unexpected damage from rootworms, the first step is to report the problem to the seed company. Next, reach out to the local Extension for help and an advocate.