Swamp Metalmark

Our monthly pollinator spotlight shines brightly on the Swamp Metalmark (Calephelis muticum), an endangered butterfly known for its distinctive and visually appealing colors.

The upper side of its wings typically features a combination of metallic blue or green hues, giving it a striking and iridescent quality. The wingspan is usually small, ranging from 1 to 1.5 inches. On the underside, the wings of the Swamp Metalmark display a more subdued and earthy coloration, often with browns and grays. This serves as a form of camouflage when the butterfly rests on vegetation.

In the US, the Swamp Metalmark - along with all pollinators - face significant challenges, primarily stemming from habitat loss, degradation, and fragmentation. Urbanization, marked by replacing native vegetation with roadways, manicured lawns, and non-native gardens, threatens the essential food and nesting sites vital for the survival of these pollinators.

The life cycle of the Swamp Metalmark is intricately tied to its environment. The eggs are laid singly on the underside of the host plant. Fourth and fifth-stage caterpillars overwinter. In the Great Lakes region, there is only one brood between June and August, while in the southern regions, there are two broods between May and September. Given its weak flight and specific food plant requirements, the swamp metalmark rarely (if ever) leaves the streamside wetlands and grasslands where it occurs. Maximum individual dispersal distances are probably on the order of a few hundred yards, with the species generally regarded as rare and highly local in occurrence.

Typically found in wetland habitats like swamps and marshes, the Swamp Metalmark relies on areas where Swamp Thistle grows as their larval foods are usually Cirsium muticum and Cirsium altissimum. In the adult stage, sightings have been reported on the nectar flowers of Rudbeckia hirta, also known as brown-eyed susan or yellow ox-eye daisy.

Last year, the Wisconsin Department of Natural Resources (DNR) proposed to issue an authorization for the incidental taking of this rare butterfly, which is expected to affect roughly 7.5 acres of its habitat to be disturbed in Oconto County and Marinette County. More information about this notice along with updates can be found on WI DNR’s site.

As of December 2023, only ten observations of the Swamp Metalmark exist on iNaturalist for Wisconsin, predominantly in the southeastern regions between Fond du Lac and Sheboygan. Notably, there were no recorded sightings in 2023. Recognizing the importance of citizen science, this is WPW’s call to action to increase observations to enhance our understanding of the butterfly's location, population, and habits, ultimately contributing to improved conservation efforts! We will put out an additional “be on the lookout” notice in early June, along with a list of counties where the Metalmark has been reported in previous years.

References
"Wisconsin butterflies" Retrieved 2024-01-23 https://wisconsinbutterflies.org/butterfly/species/60-swamp-metalmark
Conservation Assessment for "The Swamp Metalmark" Retrieved 2024-01-23 https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsm91_054247.pdf
^ "Swamp Metalmark Calephelis muticum McAlpine, 1937 | Butterflies and Moths of North America". www.butterfliesandmoths.org. Retrieved 2022-01-25.
^ Illinois Endangered Species Protection Board (16 August 2019). "Summary of all ESPB preliminary listing decisions for the Illinois List review and revision ending in 2020" (PDF). Illinois Department of Natural Resources. pp. 1–15. Archived from the original (PDF) on 9 January 2020. Retrieved 9 January 2020.
^ "NatureServe Explorer 2.0". explorer.natureserve.org. Retrieved 2022-01-25.
"Swamp Metalmark". Butterflies and Moths of North America. Archived from the original on 2009-05-05. Retrieved 2008-10-11.
Photo Credit to: "https://alabama.butterflyatlas.usf.edu/species/details/27/swamp-metalmark"

Publicado el 23 de enero de 2024 por alyssal135