Corn Insects
Crops
During the growing season, SDSU Extension provides weekly production recommendations.
Aphid Populations Observed in South Dakota Corn Fields
During the last week, we have observed low level aphid populations in corn fields. Although aphid populations can reach high densities in corn, their presence doesn’t indicate guaranteed yield loss.
Monitor Your Corn for Corn Rootworm Adults to Inform Management for Next Year and to Avoid Substantial Silk Feeding
Corn rootworm adults are active across South Dakota, and as a reminder, it’s a good time to scout to determine if your fields have a rootworm issue.
Corn
Nearly one out of every three dollars generated by South Dakota agriculture starts in a corn field. Two of every three rows of corn become ethanol.
Large Grasshopper Nymph Populations Detected in Southeast South Dakota
This week we received several reports of large grasshopper populations originating from southeast South Dakota. The populations were well above threshold and actively defoliating crops.
European Corn Borer Caterpillars Are Active: Scout your conventional corn
European corn borer caterpillars have been observed in conventional corn at several locations. Indicators for presence of are a line of straight holes in the upper leaves that is often referred to as shot-hole injury.
Various Grasshopper Species Are Active Across South Dakota
While scouting, we have noticed increased grasshopper nymph activity and in some areas these populations are close to threshold levels. Crops in areas that have had high populations should be regularly scouted to ensure that extensive defoliation doesn’t go unnoticed.
Common Stalk Borer Identification and Management
Common stalk borer caterpillars typically only infest the first few rows of corn adjacent to a road-ditch or waterway. However, if weedy alternative hosts are removed early and the caterpillars are left unmanaged, they can reduce stands and leave the end rows looking rough.
South Dakota Grasshopper Prediction for 2026
Almost every year in South Dakota there is a risk that grasshopper populations will reach levels capable of causing issues for producers. Unfortunately, our prediction for the 2026 growing season won’t change the trend.
South Dakota Pest Management Guides
The South Dakota Pest Management guides are now available for free. The guides offer recommendations for controlling weeds, insects, and diseases in a variety of South Dakota crops.