Harris' Checkerspot

Description: 1 1/4-1 3/4" (32-44 mm). Above, blackish-brown with orange bands (mostly orange in Manitoba and parts of Minnesota), row of black dots on HW. Below, orange on FW with rows of yellow crescents along red margin; HW has alternating bands of brick-red and pale yellow spots, and row of marginal yellow crescents.

Similar Species: Gorgone and Silvery crescentspots lack red below.

Life Cycle: Several hundred eggs laid in cluster on aster (Aster umbellatus) and sometimes crownbeard (Verbesina helianthoides). Young caterpillars feed together in silk nest; overwinter half grown. Mature caterpillar orange with black lines and black branching spines. Chrysalis white with black edge around orange, black-tipped tubercles on back.

Flight: 1 brood... read more; June-July.

Habitat: Moist meadows, edges of bogs and marshes, openings in forests, and old fields.

Range: SE. Saskatchewan east to Nova Scotia and south to North Dakota, Illinois, and West Virginia.

Discussion: Although hundreds of thousands of eggs may be laid in a field, most of the caterpillars die - they either starve as soon as the available food is depleted, or are killed by parasites or predators. If many survive and adults become abundant, some fly away to colonize new areas. The pattern is thus one of repeated local extinctions and recolonizations. Colonies are small, local, and relatively few, especially now as wetlands diminish.