How to Identify Caterpillars in Minnesota

Consider the host plant. Caterpillar species often prefer specific host plants, where they will feed and build their chrysalis to metamorphose into a butterflies. Consult a caterpillar and butterfly field guide to narrow down your options.

Note the caterpillar's coloring. The primary colors for caterpillars are black, brown, gray or blue, green, red or orange and yellow or white. The monarch caterpillar is as colorful as its butterfly form, but is yellow, white and black instead of orange and black.

Take note of the main pattern on the body. Caterpillars in Minnesota may be banded, camouflaged, slashed, striped, spotted or may have no discernible pattern. The monarch butterfly's caterpillar is striped vertically from head to tail.

Examine the characteristics of hair on the caterpillar. A Minnesota caterpillar species may have dense or sparse hair, tufts or no hair at all. The forest tent caterpillar, common in Minnesota, has tufts of hair along its length.

Note other distinct features of the caterpillar. Specific species may possess tails, split tails, horns on the head, lashes, knobs or spines. The thistle caterpillar has three-pronged spines along its length, for example.

Refer to a field guide with the details you have noted to narrow down your options. Most caterpillars are quite distinct from one another, so identification of Minnesota species should come fairly naturally once you are familiar with the species in the area.