European Corn Borer

European Corn Borer egg massEuropean corn borer egg masses will appear as a small white area of overlapping scales. These egg masses will be on the underside of leaflets and on stalks

The economic threshold for European corn borer egg masses: Average of 1 egg mass per 15 plants.

European Corn Borer Egg Masses

European corn borer egg masses will hatch in 3 to 7 days depending upon the weather. The warmer the weather, the more rapidly the eggs will hatch. The cooler the weather, the longer that it will take for the eggs to hatch.

When black dots can be seen in the egg mass, the egg mass is very near hatching.

European Corn Borer Entry SiteEuropean Corn Borer Entry Site

The entry site of a European corn borer larva into the potato stalk will be a small hole usually surrounded by frass. The frass is a sawdust-like material, which is waste from the insect.

European Corn Borer Larvae

European corn borer larvae can be found within the stalk. Once larvae are within the stalk, they are protected from intervention. Larvae will over-winter within the stalk.

European Corn Borer Larvae