Mormon metalmark

Appearance

To date, two genetic studies have been done on "A. mormo", with analysis revealing that disjunct populations are genetically and phenotypically distinct. These studies support a potential need for refined taxonomies, although a larger body of data is required to make clear decisions.

Naming

There are at least twenty named subspecies of "A. mormo." Below is a partial list of recognized subspecies:
# "A. m. langei"
# "A. m. pueblo' "
# "A. m. mejicanus"
# "A. m. nigrescens"
# "A. m. arenaria"
# "A. m. pratti"

Populations of "A. mormo" are widely distributed throughout western North America, with peripheral colonies located in Canada and Mexico. The Canadian populations have historically lacked scientific study, prompting a series of investigations in the past decade. "A. mormo" is the only representative of the family "Riodinidae", a primarily Neotropic family consisting of roughly 1500 species, that lives in Canada.

Three populations of "A. mormo" have been given conservation statuses: the Saskatchewan population is listed as threatened, while both the British Columbia and Comstock Lange populations are classified as endangered. Conservation efforts are complicated by a dependency on human activity for habitat success. Soil disturbances, caused by human and railway traffic, are critical for the survival of host plants and subsequent "A. mormo" populations; however, overbearing human presence can lead to habitat destruction. Conservation statuses have been repeatedly defended by research, and recovery strategies developed in response.

Distribution

The proper taxonomic classifications for "Apodemia mormo" are still under debate. Because the species tends to occur in small, isolated populations, the relatedness between populations is frequently questioned. A population genetics study conducted by Proshek revealed that the British Columbia and Saskatchewan populations of "A. mormo" in Canada are genetically distinct; furthermore, they uncovered higher genetic diversity in eastern vs. western populations, emphasizing low diversity in the British Columbia population. A second genetic study using AFLPs supports low genetic diversity in the British Columbia population, and reports high spatial genetic structure and limited gene flow between populations. Furthermore, they found genetic similarities between the Saskatchewan population and more eastern populations. The combined results of these two studies indicate potentials for current migration activities, as well as high genetic drift. In addition to genetic evidence, morphological and behavioral data are required to make firm taxonomic distinctions; however, genetic investigation has begun to reveal some of the challenges of classification.

Status

Low genetic diversity, small, distinctive populations, semi-isolated geographic distribution, and habitat dependence all predispose "A. mormo" to risk of extinction and warrant conservation efforts. In particular, Canadian populations are perceived as especially vulnerable to stochastic events, such as natural disasters, climate change, and outbreaks of disease. Conservation efforts have been in effect for the Canadian populations since the early 2000s under COSEWIC, and for "A. m. langei" since 1976 under the US Federal Endangered Species Act.

Habitat

Populations of "Apodemia mormo" primarily occupy dry, arid habitats that support a high density of their larval host plant: various species of buckwheat. "Since "A. mormo" is singularly dependent on "Eriogonum" during the larval stage, its presence is the most stable predictor of habitat." "Dunes, sloping hillsides, grasslands and gravelly deserts have all been observed as viable environments for "A. mormo" habitats, indicating the species’ broad adaptability. Wick investigated microhabitat characteristics associated with "A. mormo" inhabitance, and found “host plant habitat[s] with lower elevation, a southerly to southwesterly aspect, lower available soil nitrogen, a steeper slope, higher % bare ground, and higher soil pH” were most often correlated with presence of "A. mormo".

The exact variety of buckwheat which functions as the larval host plant changes with the population being studied. "E. paucifllorum", commonly known as the branched umbrella plant, is closely associated with the Saskatchewan population. In British Columbia, "Eriogonum niveum" functions as the larval host plant, while in the population of "A. m. langei", "Eriogonum nudum" serves as the primary host and food source. "A. mormo" colonies have additionally been correlated with the presence of several other plants. In the Saskatchewan population, presence of "Ericamerica nauseosa" is a good predictor of "A. mormo" presence, and functions as a secondary nectar source. Furthermore, Wick investigated the possibility of complex dependencies with other observed habitat plants, including “creeping juniper, yellow umbrella plant, saltbush, prickly pear cactus, Colorado rubberweed, yellow sweet clover, wild rose and sage”.

Some level of human interaction with "A. mormo" habitats is thought to be crucial for their success. In the Canadian populations, specifically, human railway traffic through habitat corridors provides frequent disturbances to the soil, nurturing the growth of their larval host plant. To similar effect, steep and unstable slopes prone to frequent erosion provide appropriate conditions for host plant prosperity. "A. mormo" are rarely found on undisturbed flats.A key concern for conservationists is potential habitat loss. Urban development, agricultural expansion, ranching practices, and campground activities may be responsible for disturbing natural habitats and breaking them up into small patches. While efforts to prevent such fragmentation are encouraged, Crawford emphasizes a need to conserve even small habitat zones, which may function as bridges between sub-populations. Furthermore, habitat loss might result from invasive, competitive plant species. "A. mormo" populations would severely suffer if these intruders successfully outcompete local "Eriogonum" species, given their dependency on the host plant. Finally, "Eriogonum" plants go into senescence after 10–15 years. This poses a significant problem for habitat maintenance, and suggests a need for regular dispersal of new "Eriogonum" plants as part of conservation efforts.

Reproduction

Mating occurs approximately three days into the adult lifespan. Females seek out male partners, who wait on food plants for their arrival. It has been postulated that females of the subspecies "Langei" mate multiply, because of an observed ratio of 2.6 spermatophores per female.