Moths: Sand-verbena Moth (Copablepharon fuscum)
Profile prepared by Nicole Rosmarino (WildEarth Guardians) and Julia Janicki (The Xerces Society for Invertebrate Conservation)
Sand-verbena Moth (Copablepharon fuscum) is a critically imperiled moth known to exist in only ten populations within a narrow range in the Strait of Georgia of British Columbia in Canada and the Puget Sound of Washington in the United States. Within its range, this moth depends on coastal habitat containing relatively large stands of its host plant, the yellow sand-verbena (Abronia latifolia). Yellow sand-verbena only grows near sea level, in sandy coastal areas that lack dense plant cover. Sand-verbena Moth depends on the yellow sand-verbena in all life stages except pupation. Adult moths feed on the nectar of the sand-verbena’s trumpet-shaped flower; adults lay eggs in its flowers; and larvae feed on its leaves and flowers.
Xerces Red List Status: Critically Imperiled
Canada – Species at Risk Act: Endangered
Canada – provincial status: S1
USA – Endangered Species Act: N/A
USA – state status: S1?; Species of Concern
NatureServe: Global Status G1G2; National Status N1N2
IUCN Red List: N/A
Sand-verbena Moth has a 35-40 mm (1.4-1.6 in) wingspan, is golden to dark brown, and has distinctive black and yellow lines parallel to the wing margins. Its wings have a predominantly gray underside. Overall coloring varies among individuals and southern populations may be darker than northern populations. Males and females have similar coloring, wing patterns, and size (Troubridge and Crabo 1995; COSEWIC 2003; British Columbia Invertebrates Recovery Team 2008).
Sand-verbena Moth was first described by J.T. Troubridge and L.G. Crabo in 1995, based on specimens collected near Sidney, British Columbia (BC), and on Whidbey Island, Washington (WA) (Troubridge and Crabo 1995).
Sand-verbena Moth is dependent on yellow sand-verbena, its only host plant. There is no evidence that it can use alternate host plants. Yellow sand-verbena grows exclusively in sandy coastal habitats along the Pacific Coast. Only large coastal sand features, such as dunes, beaches, and spits support this plant. Sand-verbena Moth requires the yellow sand-verbena in all life stages except pupation. Adult moths feed on the nectar of the sand-verbena, using their long proboscis to access the trumpet-shaped flowers. Adults lay eggs in the verbena’s flowers, which hatch within approximately 2 weeks. Larvae feed on the verbena’s leaves and flowers (COSEWIC 2003; British Columbia Invertebrates Recovery Team 2008;Raincoast Applied Ecology 2005).
Adult moths fly from mid-May to early July, with a lifespan of 7-21 days. The adults fly once per year, at dusk or early evening. The flight season and mating peaks in mid-June, which corresponds to the peak flowering period of the yellow sand-verbena. Adults deposit small groups of eggs or single eggs in the flowers of the yellow sand-verbena. Larvae feed nocturnally on sand-verbena’s flowers and leaves during the summer and subsequently enter dormancy (diapause) and overwinter from early fall to early spring. Diapause ends in early spring, at which time larvae continue feeding until they enter pupation in late April and May. Pupation takes place below ground in the sand, underneath verbena patches (COSEWIC 2003; British Columbia Invertebrates Recovery Team 2008). After a pupation period of approximately 10 days, adults emerge (SARA Registry 2009).
Sand-verbena Moth is limited to the Salish Sea (the Georgia Basin-Puget Sound watershed) of BC and WA (British Columbia Invertebrates Recovery Team 2008). Additional surveys have been conducted in suitable habitats on the Long Beach peninsula in Washington and have not uncovered new populations of this species (pers. comm. with Lars Crabo, 2 February 2010). The global range of this species is less than 220 km long and 45 km wide (137 mi by 28 mi) (British Columbia Invertebrates Recovery Team 2008).
Sand-verbena Moth is in a precarious situation, as it is a habitat specialist tied to a habitat specialist host plant in a highly threatened habitat type. This specialization on one food plant (monophagy) alone makes Sand-verbena Moth vulnerable to extinction. Primary anthropogenic threats include: inundation of its coastal habitat as a result of rising sea levels and increased storm surges due to climate change; habitat loss from stabilization of its shifting dune habitat; displacement of yellow sand-verbena due to non-native vegetation; recreation, development, and military activities within its habitat; use of pesticides that kill all Lepidoptera, including Sand-verbena Moth; and other threats.
The main threats identified to have caused the imperilment of Sand-verbena Moth include the present or threatened destruction, modification, or curtailment of habitat or range; disease or predation; the inadequacy of existing regulatory mechanisms; and other natural or man-made factors affecting its continued existence including climate change and the use of insecticides and herbicides.
Several factors reduce and degrade Sand-verbena Moth habitat. These include any activities altering the sand dune vegetation or other conditions at extant locations. Examples are: vegetation stabilization, habitat conversion, military and recreational activities, coastal erosion, and stochastic events, such as extreme weather (British Columbia Invertebrates Recovery Team 2008).
Collection is not known to constitute a threat to Sand-verbena Moth. However, the rarity of the species may make it more attractive to lepidoptera collectors. Lepidoptera populations that are small and easily accessible are especially vulnerable to over-collection. However, much information may be gained about the life history and conservation status of this species through collecting.
Predation and disease may cause annual changes in Lepidoptera numbers of an order of magnitude or more. The limited extent of Sand-verbena Moth populations increases their vulnerability to extirpation due to natural fluctuations that may occur as a result of disease or predation pressures. Adult and larval moths are likely subject to predation by bats, birds, and small mammals (British Columbia Invertebrates Recovery Team 2008).
Finally, Sand-verbena Moth is not adequately protected by federal or state laws or policies to prevent its endangerment or extinction in the US. It is designated as Endangered under the Canadian Species at Risk Act.
Necessary actions include protecting the habitat of known Sand-verbena Moth populations, with an emphasis on processes that influence the sand dune ecosystems and yellow sand-verbena populations; investigating the extent of collection and the potential consequences to the species during the course of a status review; further investigating disease as a threat in a status review for Sand-verbena Moth; and protecting the moth under federal or state laws by listing it as a threatened or endangered species.
Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 2003. COSEWIC assessment and status report on Sand-verbena Moth Copablepharon fuscum in Canada. Ottawa, ON. 39 pp. Online at: http://www.sararegistry.gc.ca/species/speciesDetails_e.cfm?sid=789
NatureServe. 2010. NatureServe Explorer: an online encyclopedia of life. Species Account for Abronia latifolia. Online at: http://www.natureserve.org/explorer/
Species At Risk Act (SARA) Registry. 2009. Species Account for Sand Verbena Moth. Online at: http://www.sararegistry.gc.ca/specie/speciesDetails_e.cfm?sid=789
Troubridge, J.T. and L.G. Crabo. 1995. A new species of Copablepharon (Lepidoptera: Noctuidae) from British Columbia and Washington. Journal of the Entomological Society of British Columbia 92: 87-90. Online at: http://www.biology.ualberta.ca/facilities/strickland/cop.pdf