Fun fact: Illinois butterflies constitute less than ten percent of the total Illinois Lepidoptera population. Of the approximately 2000 butterfly and moth species in the state, about 150 of them are butterflies. One of the, the very popular Monarch Butterfly, pictured, is the state’s official state butterfly.
State wide action continues to be taken to reverse the downward pressures on local Monarch populations. Recent estimates suggest the populations have decreased as much as eighty percent over the past few decades. Public and private sector actors continue to promote the use of Milkweed in the garden to provide larval host plants.
In the Chicago areas, butterflies can be abundant in butterfly gardens. About twenty different species can live year to year in the metropolitian area because their caterpillars or pupa overwinter.
Populations of different species will differ slightly from area to area within the state. This one page review presents a list of Illinois butterflies divided by families. It is accompanied by some pictures of representative species.
Visitors interested in additional butterfly pictures and identification help can press the green butterfly button for more information.
Butterflies: Whites and Yellows
Pieridae is the formal name of the family that consists of the butterflies with white wings and yellow wings.
Yellow butterflies dominate the Illinois butterfly list. The Clouded Sulphur and Cloudless Sulphur are probably the most common yellow butterfly species in the north, including the Chicago region.
The picture shows a Barred Yellow butterfly.
It should come as no surprise to anyone that Cabbage White butterflies are the most common white butterflies in Illinois. Their caterpillars feed on plants from the cabbage family.
Olympia Marbles are small butterflies of prairies and open forests. Larvae feed on a few plants in the mustard family. They are early bird butterflies, flying for only one month in the year.
Blues, Hairtreaks and Coppers
The picture shows a Bronze Copper. They can most often be found near areas with water, including roadside ditches and ponds across the state.
The Eastern Tailed-blue and Azures are the most common of the Illinois blue butterflies. Mostly because their larvae have flexible diets of common plants such as peas.
The picture shows a Summer Azure. Both species are fairly easy to identify by the chevron markings on the wings.
Like most states, Illinois has a large number of hairstreak butterflies. They are the ones with the small extension or tail feature on the wings.
Most of the species are regional oriented. The Gray Hairstreak bucks that trend and is the most common hairstreak species in the United States.
The picture shows a Banded Hairstreak. They are very common in the eastern part of the United States. Their larvae consume leaves on a few common trees such as oak, walnut and hickory.
Great Purple Hairstreak
Eastern Pine Elfin
Brush Footed Butterflies
Illinois hosts a nice variety of Brush Footed butterflies, as shown in the following list. Visitors can often many of them in the larger metropolitan areas around areas with flowers.
Keep an eye out for the Painted Lady in the picture. It is one of the most common butterflies in the world, often refereed to as the Cosmopolitan butterfly. Its global range can be attributed to the fact that the caterpillars are not picky eaters and will feed from many host plants.
It’s also interesting to note that whether one visits Chicago in the North or the Shawnee National Forest in Southern Illinois, there will be a fairly decent wood-nymph presence.
Great Spangled Fritillary
astyanax Astyanax’ Red-spotted Purple
The picture shows an Eastern Tiger Swallowtail. They are very common because a variety of trees such as apple trees and cherry trees serve as larval hosts.
Since they are basically the only swallowtail species in Illinois with yellow wings, identification is fairly straight forward. There’s always a catch. Some females have a dark form. They can be identified by the absence of white spots on the abdomen.
Pipevine Swallowtails might be the least common in Illinois. Zebra Swallowtails can be found wherever the Pawpaw tree grows. It’s the larval host tree.
- Pipevine Swallowtail
- Zebra Swallowtail
- Black Swallowtail
- Eastern Tiger Swallowtail
- Spicebush Swallowtail
- Giant Swallowtail