Callippe Silverspot Butterfly

Speyeria callippe callippe

Description

The callippe silverspot butterfly, Speyeria callippe callippe, a member of the brush-footed butterfly family (Nymphalidae), is a medium-sized butterfly with a wingspan of approximately 2.2 in (5.5 cm). The upper wings are brown with extensive black spots and lines, while the basal areas are extremely melanic (dark-colored). Wing undersides are brown, orange-brown, and tan with black lines and distinctive black and bright silver spots. Basal areas of the wings and body are densely pubescent (hairy). The discal area on the upper hind wings of the callippe silverspot butterfly is a darker, more extensive yellow than on the related Lilian's silverspot butterfly (S. c. liliana ). The callippe silverspot butterfly is larger and has a darker ground color with more melanic areas on the basal areas of the wings than the related Comstock's silverspot butterfly (S.c. comstocki ).

S. c. callippe was first described by J. A. Boisduval in 1852 from specimens collected by Pierre Lorquin in San Francisco during the month of June.Taxonomic studies were conducted in 1983 and 1985 on the subspecies of S. callippe using wing characters. He concluded that the species consisted of three subspecies rather than the widely recognized and accepted 16 subspecies; based on his studies, the range of S. c. callippe would extend from Oregon to southern California and east into the Great Basin. A comprehensive analysis of this species in 1986 found that the original classification remains more appropriate and that the subspecies callippe is restricted to the San Francisco Bay region. The U. S. Fish and Wildlife Service recognizes the conclusions of Hammond and the distribution of the callippe silverspot butterfly as described by Sterling Mattoon in 1992.

Behavior

Female callippe silverspot butterflies lay their eggs on the dry remains of the larvae food plant, Johnny jump-up (Viola pedunculata ), or on the surrounding debris. Within about one week of hatching the larvae eat their egg shells. The caterpillars wander a short distance and spin a silk pad upon which they pass the summer and winter. The larvae are dark-colored with many branching sharp spines on their backs. The caterpillars immediately seek out the food plant upon termination of their diapause in the spring. In May, after having gone through five instars, each larva forms a pupa within a chamber of leaves drawn together with silk. Adults emerge within about two weeks and live for approximately three weeks. Depending upon environmental conditions, the flight period of this single-brooded butterfly ranges from mid May to late July. The adults exhibit hill-topping behavior, a phenomenon in which males and virgin or multiple-mated females seek a topographic summit on which to mate.

Habitat

The callippe silverspot butterfly is found in native grassland and associated habitats.

Distribution

The callippe silverspot butterfly is known from 14 historic populations in the San Francisco bay region. The historic range of this butterfly includes the inner Coast Ranges on the eastern shore of San Francisco bay from northwestern Contra Costa County south to the Castro Valley area in Alameda County. On the west side of the bay, it ranged from San Francisco south to the vicinity of La Honda in San Mateo County. Five colonies, including the one located at Twin Peaks in San Francisco have been extirpated for a variety of reasons. Extant colonies are currently known only from private land on San Bruno Mountain in San Mateo County and a city park in Alameda County.

Threats

The callippe silverspot butterfly, once fairly widespread in the San Francisco Bay area, has lost at least five populations to urban development and other causes. Only two locations are still extant of the 14 known historical sites in San Mateo, Alameda, Sonoma, and Solano counties. One of the current populations of this butterfly is located in a city park in Alameda County. This colony is small and likely to be imperiled by anthropogenic and natural causes. The population at San Bruno Mountain in San Mateo County is largely protected against further loss of habitat, which will remain undeveloped in perpetuity by virtue of the San Bruno Mountain HCP. However, overcollection of specimens by lepidopterists at San Bruno Mountain and at sites where hybrids can be found in Solano County continues to pose a threat. An additional threat to this callippe silverspot butterfly population is the high level of dust from quarry operations in the vicinity. The adult and early stages of the taxon may be prone to injury and mortality from dust because their spiracles, the apparatus of respiration, are easily clogged.

Conservation and Recovery

One of the two known extant populations of the callippe silverspot butterfly is protected by the San Bruno Mountain Habitat Conservation Program (HCP). In 1982, an incidental take permit was issued to the cities of Brisbane, Daly City, South San Francisco, and the County of San Mateo, for the endangered mission blue butterfly, San Bruno elfin butterfly, and San Francisco garter snake. The permit allowed for the loss of animals and habitat through urban development of approximately 850 acres (340 hectares) of San Bruno Mountain. The HCP permanently protects about 2,752 acres (1,100.8 hectares) of natural habitat at this site. Ninety-two percent of the habitat for this silverspot is protected at the site through the mechanisms of landowner obligations for land dedications, open space set-asides, mitigation measures, and habitat enhancement; implement annual monitoring of its population; and adaptive management to conserve the species. No specific provisions are, however, included in the HCP to protect the callippe silverspot butterfly from poachers. Habitat for the other known population is partially protected in a city park in Alameda County.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
http://pacific.fws.gov/

Reference

U. S. Fish and Wildlife Service. 5 December 1997. "Determination of Endangered Status for the Callippe Silverspot Butterfly and the Behren's Silverspot Butterfly and Threatened Status for the Alameda Whipsnake." Federal Register 62 (234): 64306-64320.