Colorado Large Marble
A subspecies of the large marble butterfly, the Colorado large marble has a kaleidoscope-like pattern of green and white markings on its wings.
About This Species
The Colorado large marble is one of seven subspecies of the large marble butterfly. The entire species has been petitioned for listing as threatened by the Xerces Society, but this subspecies is currently the most imperilled and is petitioned for listing as endangered. If you’d like to help this species’ conservation, plant plenty of flowers for the adults and plants in the mustard family for the caterpillars to feed on.
More Information:
Physical Characteristics
The large marble has a wingspan of 1.5-2 inches. The underside of the hindwing has a distinct marbled appearance of green swirls and white spots. The underside of the forewing is mostly white with some black.
Range
Large marbles, the species, can be found across the western United States and Canada; however, only the subspecies Colorado large marble can be found in Colorado.
Habitat
The large marble prefers grasslands and meadows, as well as riparian areas.
Diet
Caterpillars feed on a diversity of plants in the mustard family; adults are generalists, nectaring on a diversity of flowers depending on what is available. While adults have been observed feeding on flowers of many colors, they may prefer yellow and white flowers, like those of their host plants as caterpillars.
Reproduction
The large marble has a single annual generation, which means it is born, matures, reproduces and dies within one year. Adults emerge around May each year. Males typically patrol along streams, valley bottoms or berms in search of females. Females lay eggs singly on mustard plants, which the caterpillars use as hosts, feeding on the leaves, flowers and fruits. . Caterpillars go through multiple instar stages, phases in their growth before they develop into adults; The large marble has five instar stages separated by a molt, when the caterpillar sheds its exoskeleton. After the fifth instar, the caterpillar will leave its host plant to find a safe place to form a chrysalis, a hard out coating in which it develops into an adult.. The large marble overwinters in its chrysalis, emerging as an adult the following spring to start the cycle again.
Threats to Species
The major threats to the large marble are habitat loss, pesticide exposure and climate change.