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dogface
dogface (Zerene cesonia)
Illinois Status: locally encountered migrant
Photo © Michael Jeffords/Susan Post
Features and Behaviors
FEATURES
The dogface belongs within a large group of butterflies known as sulfurs and whites. They are small, black-bodied, yellow butterflies with a brown pattern resembling the profile of a “dog’s head” on the upper, open forewing. Females are whiter in color and the patterning is present, but less clearly defined edges. The summer form is yellow, while the winter form has reddish-pink color on the margins and undersides of the wings. The caterpillar is green and covered with black tubercles (small, rounded knobs). Caterpillars vary greatly in their markings and may or may not have black and yellow horizontal stripes in addition to the black tubercles.
BEHAVIORS
The dogface is found throughout the Southern USA, Central America, to Argentina. It cannot survive freezing winter temperatures, but regularly flies as far north as Manitoba, and breeds most summers in the Midwest. Males patrol for females during most daylight hours, flying quickly and pausing only briefly for sips of nectar. Mating pairs are found from mid-morning to late afternoon, and flower visitation occurs both before and after mating hours. There are three generations of these butterflies each year, the third of which doesn’t become reproductive until spring (reproductive arrest), spending most of the winter resting on vegetation in warmer climates than Illinois. They migrate to Southern United States to South America in the winter. The yellow-green spindle-shaped eggs are laid on young host leaves of indigo bush, false indigo, soybeans, and clovers. Adults feed on the nectar of alfalfa, verbena, coreopsis, and houstonia bush.
Illinois Range
Taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Pieridae
Habitats
The dogface is found in open, dry spaces like open woodlands and shortgrass prairie.
