Ediths checkerspot

Appearance

The Edith's checkerspot can be identified by its wings which are black with red and pale yellow or white bands. It also has a submarginal band that consists of yellow or white spots along with a wide postmedian band that is red. The undersides of the wings consists of alternating bands of yellow orange and cream. The wingspan is 3.2-5.1 cm. However, the subspecies of Edith's checkerspot vary slightly in appearance based on the areas they routinely inhabit. Coastal populations are black with red and cream spots; mountain populations are red or mottled with red, black, and cream spots. The higher-altitude populations are smaller and darker. The larvae of the butterfly are black, spotted with white or orange, or striped with white. The pupae are white or gray, with black blotches and streaks.

Naming

This species is often better known by the constituent subspecies listed at List of subspecies of ''Euphydryas editha'' and below. It is subject to change as the nomenclature is altered or new subspecies are found.
⤷ ''Euphydryas editha alebarki'' Ferris, 1971 – Klots' checkerspot
⤷ ''Euphydryas editha augusta'' – Augusta checkerspot
⤷ ''Euphydryas editha aurilacus'' Gunder, 1928 – Gold Lake checkerspot
⤷ ''Euphydryas editha baroni'' Edwards, 1879 – Baron's checkerspot
⤷ ''Euphydryas editha bayensis'' Sternitzky, 1937 – Bay checkerspot
⤷ ''Euphydryas editha beani'' Skinner, 1897 – Bean's checkerspot
⤷ ''Euphydryas editha bingi'' Baughman & Murphy, 1998 – Bing's checkerspot
⤷ ''Euphydryas editha colonia'' – Colonia checkerspot
⤷ ''Euphydryas editha edithana'' Strand, 1914 – Strand's checkerspot
⤷ ''Euphydryas editha ehrlichi'' Baughmon and Murphy, 1998 – Ehrlich's checkerspot
⤷ ''Euphydryas editha fridayi'' Gunder, 1931
⤷ ''Euphydryas editha hutchinsi'' McDunnough, 1928 – Hutchins' checkerspot
⤷ ''Euphydryas editha gunnisonensis'' Brown, 1971 – Gunnison checkerspot
⤷ ''Euphydryas editha insularis'' Emmel & Emmel, 1974 – island checkerspot
⤷ ''Euphydryas editha karinae'' Baughman & Murphy, 1998
⤷ ''Euphydryas editha koreti'' Murphy and Ehrlich, 1983 – Koret's checkerspot
⤷ ''Euphydryas editha lawrencei'' Gunder, 1931 – Lawrence's checkerspot
⤷ ''Euphydryas editha lehmani'' Gunder, 1929 – Lehman Caves checkerspot
⤷ ''Euphydryas editha luestherae'' Murphy & Ehrlich, 1981 – LuEsther's checkerspot
⤷ ''Euphydryas editha mattooni'' – Mattoon's checkerspot
⤷ ''Euphydryas editha monoensis'' Gunder, 1928 – Mono Lake checkerspot
⤷ ''Euphydryas editha nubigena'' Behr, 1863 – cloud-born checkerspot
⤷ ''Euphydryas editha owyheensis'' Austin & Murphy, 1998
⤷ ''Euphydryas editha quino'' – Quino checkerspot
⤷ ''Euphydryas editha remingtoni'' Burdick, 1959
⤷ ''Euphydryas editha rubicunda'' – ruddy checkerspot
⤷ ''Euphydryas editha taylori'' – Taylor's checkerspot
⤷ ''Euphydryas editha tahoensis'' Austin & Murphy, 1998 – Lake Tahoe checkerspot
⤷ ''Euphydryas editha wrighti'' Gunder, 1929 – Wright's checkerspot

Distribution

The Edith's checkerspot is found in North America, where it ranges from southern British Columbia and Alberta south to Baja California, Nevada, Utah, and Colorado. The species can be found in locations of the San Bernardino Mountains, Sierra Nevada, higher Cascade Mountains of Oregon to Washington, and in areas of the Great Basin, including central Oregon and the Rocky Mountains. It can also be found on several trails such as: Animas River Trail, Falls Creek Trail, Colorado Trail, Hermosa Creek Trail, Engineer Mountain Trail, and Spud Lake Trial.

Status

The Edith's checkerspot subspecies mirror the changes in climate over long periods of time. Global warming is expected to eliminate the butterflies in the south throughout the upcoming years, where the season is becoming shorter and shorter. In areas of the lowest latitude, about three-fourths of the populations have become extinct. This is in contrast to higher latitude areas in Canada where less than twenty percent have disappeared. It has been found that population extinctions were four times as high along the southern boundaries than along the northern boundaries . In addition, extinctions are nearly three times as high at lower elevations below 8,000 feet than at higher elevations from 8,000 to 12,500 feet . In agreement with global warming predictions, this extinction process has shifted the range of this butterfly both northward and upward in elevation since the 1800s.

In the case of ''Euphydryas editha quino'', habitat destruction is the major reason for its decline, although climate change problems also pose a threat. Quino checkerspot populations along the southernmost boundary are at the greatest risk from continuing warming and drying climate trends. Unfortunately, these are also the best remaining habitats with the lowest degree of threat from development. By contrast, most Quino habitat has been destroyed by development in the Los Angeles–San Diego corridor. The case of the Quino checkerspot has resulted in the first habitat recovery plan to list climate change not only as a current threat, but also as a factor that should be considered in reserve design and recovery management. Some sedentary checkerspots remain at their original habitats despite the continuation of human interference, and have evolved adaptations to deal with these changes.

In January 1997, the subspecies ''Euphydryas editha quino'' and ''Euphydryas editha bayensis'' received federal protection under the Endangered Species Act. ''Euphydryas editha bayensis'' has also been given the Nature Conservancy global rank of T1, which means that there are very few individuals remaining.

Behavior

Oviposition begins within a day of the female's emergence, with females depositing masses of up to hundreds of eggs at the base of host plants. Most populations are monophagous, with females normally ovipositing on only one of several potential host species. Such plants include ''Plantago erecta'' and ''Orthocarpus densiflorus''.

The eggs further develop into pre-diapause larvae whose goal is to enter diapause and reach the fourth instar before their annual host plants senesce. Thus, females try to enhance offspring survival by laying egg masses on cool moist slopes where host plant senescence is most delayed. Once the larvae reach the diapause stage and become post-diapause larvae , they must grow by basking in the sunlight to regulate their body temperature. Larval body temperature is about 10-12 °C above ambient temperature, and the fastest growth rate occurs at 30-35 °C . They must receive enough insolation to terminate the diapause stage and become a fully-grown butterfly. Thus, the paradox is that these larvae no longer prefer the cool slopes of host plants they grew up on, as it produces shade to restrict growth.

Habitat

Habitats are mountains, typically on ridgetops, from coastal chaparral and transition zone open woodland to alpine tundra. Edith's checkerspot butterflies prefer grasslands and rocky outcrops found in the mountains. They can be frequently found in areas of nutrient-poor, serpentinitic soils which sustain the native grasslands that they prefer.

Food

Populations of Edith's checkerspots use several different hosts to house and feed their pupae. Though they usually do not pollinate the flowers of the host, larvae have been known to eat the leaves, the flowers, and sometimes the entire host plant, and have starved trying to find another. Adult females and females feed on flower nectar. Caterpillars feed on leaves and flowers of the host plant and sometimes surrounding plants.

Evolution

This butterfly exhibits protandry. Males tend to emerge 4–8 days before females do and the average life span of both sexes is 10 days, though it can be as long as three weeks. Protandry may have an effect on the butterfly's mating success in a population. In many time constrained species such as the Edith's checkerspot, early season matings may have a higher probability of producing adults in the next generation than those later in the year. Pre-diapause larvae are under time pressure to mature to diapause size before host plants senesce in summer drought. Therefore, larvae hatching from eggs laid earlier in the season are more likely to have reached the intended size. This is why males mating at the beginning of the season are more likely to produce surviving offspring than males mating a few weeks later.