Calephelis muticum Mc Alpine 1937

The Swamp Metalmark (Calephelis muticum) is a small butterfly in the family Riodinidae. It has upper wings of a dull red-brown background color and two metallic rows outlining the outer margins. The underside is bright golden orange with black speckles. The wingspan is 0.9-1.2 inches (24-30 mm). Larvae are distinctive pale green caterpillars covered profusely with long white hairs and are found on the leaves of swamp thistle (Cirsium muticum), the larval host plant. The swamp metalmark inhabits bogs, marshes, swamps and wet meadows. Populations have been found in southern Michigan, southern Wisconsin, Ohio, Missouri, and northern Arkansas, with isolated populations in central Kentucky and eastern Iowa. Populations have also been reported in northern and southern parts of Indiana; populations in southern Indiana occur in barrens where larval food plants are Cirsium altissimum and possibly Cirsium carolinianum. It produces one to two broods per year, with the adults appearing in late spring (south) and again in late summer (north and south). Despite the production of multiple broods, the swamp metalmark is almost never common and most records consist of only one or a few individuals. The destruction of the nation's mesic grasslands and graminoid wetlands over the past 200 years has greatly reduced suitable habitat for this and many other species.

Swamp Metalmark, Calephelis muticum, is a small butterfly in the family Riodinidae that occurs from Michigan and Wisconsin south through Ohio and Indiana to Kentucky, west to Arkansas, Missouri and Iowa. Throughout its range the occurrence of this species is very irregular. Populations are generally widely scattered and rather small. Swamp Metalmark has a checkered pattern of brown and red spots above which is interspersed with a few lines of metallic or silvery spots. Below both wings are yellowish with some dark spots. The forewing is pointed in the male and rounded in the female. Despite claims to the contrary the ranges of the Northern Metalmark, Calephelis borealis, and Swamp Metalmark might overlap in parts of the range, especially in the upper Midwest. Northern Metalmark is generally darker above and the male has more rounded forewings than male Swamp Metalmark. Swamp Metalmark, as the name suggests, usually occurs in fens or other types of wetland where the larval foodplant, swamp thistle, Cirsium muticum, grows. However, in southern Indiana the species occurs in grassland habitats known as barrens and also in adjacent post oak savannas. At least two of the populations in Missouri are found in barrens also. The larval foodplants in barrens are tall thistle, Cirsium altissimum and carolina thistle, Cirsium carolianium. The latter species is less common than tall thistle. Nectar sources include black-eyed susan (Rudbeckia hirta), sunflowers (Helianthus spp.), wingstem (Actinomeris alternifolia) and mountain mints (Pycnanthemum spp.) Yellow colored flowers seem to be preferred. The caterpillars have long, white hairs and are well suited for life on the underside of the thistle leaves which have a white tomentum. Third instar caterpillars overwinter on the underside of the thistle rosette leaves. There are two broods in the south. Northern populations are single brooded. Potential threats to this species include drainage of wetlands, harvesting peat and invasion by non-native plant species. In barrens habitats fire could be a potential threat. It is recommended that not more than half of the available habitat be burned at any one time.