Pale yellow dune moth (Copablepharon grandis) COSEWIC assessment and status report: chapter 2

• Previous page
• Table of contents
• Next page

Executive Summary

Species information

Copablepharon grandis (Strecker 1878) Pale Yellow Dune Mothis a medium-sized moth with evenly coloured pale yellow forewings and white hindwings.

Distribution

Copablepharon grandis is widely distributed in western North America. It has been found from southern California in the southwest tocentral Texas in the southeast, and as far north as Lloydminster, Alberta. It has been found at approximately 84 localities in North America since it was described in 1878. Its range is 4,345,223 km² globally and 184,590 km² in Canada. Since 1902, C. grandis has been captured 36 times representing ten localities in Canada: four in Alberta, five in Saskatchewan, and one in Manitoba. Three of the ten localities were found during the 2004–2005 sampling program.

Habitat

Copablepharon grandis occurs in sparsely vegetated sandy habitats. Sampling records from 2004–2005, supplemented with inferences about habitat conditions in previous sampling locations, suggest it most often occurs in semi-stable dunes with sparse grass and forb cover. Several factors affect habitats in which C. grandis has been found: 1) cattle grazing; 2) land development; 3) recreational disturbance; 4) sand dune stabilization; 5) reduced fire frequency.

Biology

Little is known about the biology of C. grandis. It is a nocturnal moth with a short summer flight season and is difficult to observe in the field. Indeed, other than light-trap captures, it was not observed in the field in 2004–2005.

The moth has one flight season per year; in Canada it is from early July to late August. Eggs are fully formed in newly emerged adults, but mating and egg laying have not been observed. Eggs are believed to be deposited in shallow sand. Larvae emerge from the eggs approximately three weeks later. Larvae likely feed nocturnally on the above-ground parts of plants and bury themselves in the sand during the day; they may also feed below ground. Larvae likely undergo a below-ground diapause between the fall and early spring, although the location and depth of burial are unknown. Spring or early summer feeding may also occur prior to pupation. Pupation occurs in an earthen cell in the soil. Copablepharon grandis does not appear to be limited to a single host-plant for adult feeding, reproduction, or larval feeding.

Dispersal abilities of C. grandis have not been measured. Given that dune habitats are often patchily distributed, it is likely that short-distance dispersal occurs. However, dispersal between regionally isolated dunes systems (>10 km) is considered unlikely or is very infrequent.

Population sizes and trends

A total of 18 C. grandis specimens were captured in 2004–2005 ranging from 1 per trap to 12 per trap (mean of 3 per trap where present). Because of the low number of moths captured and the inherent uncertainties in measuring capture success, suitable habitat, and other factors, a reliable population estimate cannot be calculated for C. grandis. There is no quantitative information on population fluctuations and trends for C. grandis. The population of C. grandis near Turtle Mountain, North Dakota, USA, is approximately 250 km south of the closest Canadian population at Spruce Woods Provincial Park in Manitoba. Recolonization is unlikely over this distance.

Limiting factors and threats

Copablepharon grandis is most threatened by the progressive stabilization of sand dunes caused by natural vegetation colonization.

Grazing is a possible threat to C. grandis. Grazing may maintain sparsely vegetated sandy habitats; however, it may cause soil compaction and browsing of vegetation that is used for larval feeding, and may destroy eggs, larvae, or pupae.

The spatial isolation of C. grandis habitats may make the species susceptible to demographic collapse, particularly with development of the landscape between suitable habitats. Demographic collapse is considered a possible threat.

Development activities, such as road building and petroleum infrastructure construction that result in direct loss or disturbance to natural habitats or mortality of moths are considered a possible threat to C. grandis.

Recreation may be intensive in some sandy habitats and result in loss of vegetation, disturbance to sand substrates, and destruction of eggs, larvae, and pupae. Recreation may also maintain or create open sand habitats. It is considered a possible threat.

Special significance of the species

Copablepharon grandis is associated with sand dunes, a regionally rare habitat in the southern Canadian prairies. Copablepharon moths are of interest to entomologists and taxonomists because of their association with spatially isolated dune habitats. There is no information to suggest that C. grandis has an important cultural or economic role for First Nations.

Existing protection or other status designations

Copablepharon grandis is not protected in any jurisdiction in North America. Portions of the populations at Wainwright (Wainwright Dunes Ecological Reserve), Suffern Lake Regional Park, and Spirit Dunes (Spruce Woods Provincial Park) are found in protected areas.

COSEWIC History

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC Mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC Membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions (2007)

Wildlife Species

A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.

Extinct (X)

A wildlife species that no longer exists.

Extirpated (XT)

A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.

Endangered (E)

A wildlife species facing imminent extirpation or extinction.

Threatened (T)

A wildlife species likely to become endangered if limiting factors are not reversed.

Special Concern (SC)^Footnotea

A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.

Not at Risk (NAR)^Footnoteb

A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.

Data Deficient (DD)^Footnotec

A category that applies when the available information is insufficient (a) to resolve a species' eligibility for assessment or (b) to permit an assessment of the species' risk of extinction.