A full-grown, fifth-stage larva is nearly 1 1/2 times the length of a dime.
Tubercles
Setae (hairs) on the dorsal side of European corn borer larvae are encircled by a darker-colored “halo� or ring. This is a distinguishing characteristic with this insect in separating it from other corn attacking caterpillars.
First-stage larvae
Newly-hatched first stage larvae are very small-about the length of the letter "L" in Liberty on a dime.
Late-stage larva on Indian corn
A late-stage European corn borer larva on Indian corn.
Fifth-stage larva on Indian corn
The European corn borer also attacks ornamental varieties of corn. This fifth-stage larva is shown on Indian corn.
Fifth-stage larva (dark phase)
A fifth-stage larva on a commercial dent corn ear. Note that the head is completely black and the body is dark gray or brown in color.
Hatching first-stage larvae
First-stage larvae hatching from eggs. The black head of the unhatched larvae can be seen through the translucent egg shell.
Fifth-stage larva (light phase)
A fifth-stage larva on a commercial dent corn ear. Note that the head is not completely black, as is common in many individuals, but has reddish brown stripes.
Fifth-stage larva on Indian corn
A fifth-stage European corn borer on ornamental Indian corn. Note that this larva is a lighter color phase and shows a reddish brown head.
All five larval stages
European corn borers develop through five larval stages. A distinguishing feature is that the larva in each stage has a dark head, often black or reddish brown in color. The prothoracic shield (neck) may or may not be dark.