Scout now for armyworm and cutworm in southern and central Michigan
Farmers in southern Michigan should check wheat and corn for armyworms and cutworms.
Armyworm and cutworm
Farms should scout now for armyworms and cutworms in southern and central Michigan. There are caterpillars 0.5 to 1.25 inches long in southern counties in both wheat and corn. Some fields were destroyed “overnight,” which can easily happen this year with an unfortunate combination of big worms on small corn.
There is nothing that could have prevented this infestation other than (in corn) timely and effective weed control. Armyworm and cutworm moths moved up on the numerous weather fronts in May and rained out over fields, so it was simply luck of the draw to get a moth flight. Moths laid eggs on wheat, weeds in corn fields, or even in the tallest corn in an area, so there will be a patchwork of infestation across the region. The only way to confirm infestation is to scout for caterpillars or feeding. It is admittedly a challenge right now to fit scouting in with everything else going on.
There are many options for insecticides in wheat and corn such as Baythroid, Mustang, Warrior and generics. To save time and money, insecticides can be tank-mixed with Roundup applications on corn or with wheat fungicides, but be sure to check specific fungicide labels for compatibility.
Other insect pests
Soybean aphid. None found so far by my crew.
Bean leaf beetle. Bean leaf beetles are present in soybeans and chewing, but unless plants are being entirely chewed up and the stand lost, the holes in the leaves will not set the plants back. Beans will grow rapidly and yield will not be impacted.
Dr. DiFonzo’s work is funded in part by MSU’s AgBioResearch.