The monarch is the state insect of Illinois. This butterﬂy has a wingspan of three and one-fourth to four and seven-eighths inches. The male has bright orange wings with black veins and black edging. The black border contains two rows of white spots. The female is dull orange with scales along the black veins. The body and antennae are black. The front legs are small and not used for walking. The caterpillar has rings of yellow, black and ivory on each segment and black and white stripes on the head. It has three pairs of tubercles (projections) on the back of segments two, ﬁve and 11. The pupa is green with a line of gold and black and scattered gold spots.
The monarch may be found statewide in Illinois. It can be seen in open weedy areas, roadsides, ﬁelds, pastures and marshes. One to three broods are raised during the warm part of the year. This migratory insect overwinters in central Mexico or rarely in the United States along the coasts of the southern Atlantic Ocean or the Gulf of Mexico. The monarchs that return in the spring are not the ones that migrated south but are their offspring. The larva eats milkweeds. Some of these plants contain toxins that build up in the larva’s body and remain in the adult. If the toxins are present, they make the adult and larva distasteful to predators. If the toxins are absent, the monarch may still gain some protection by looking like the unpalatable viceroy butterfly. Adults visit flowers for nectar.