10 Endangered Butterflies and Their Host Plants

There are more than 20 butterflies and moths listed as endangered by the U.S. Fish and Wildlife Service!

The main reason for these butterflies being placed under the Endangered Species Act is mainly due to loss of habitat (agriculture, commercial, residential). However, other reasons include: poor land management practices, excessive use of pesticides and herbicides, and loss of the butterfly's host plant that is necessary for it's growth and development.
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If faced with the risk of extinction, any species can be put under the protection of the Endangered Species Act (ESA). They are placed either as "threatened" and "endangered". To clarify those two terms: an “endangered” species is one that is in danger of extinction throughout all or a significant portion of its range. A “threatened” species is one that could become endangered in the near future.

The U.S. Fish and Wildlife Service received a petition to list the Monarch butterfly under the Endangered Species Act (ESA) on August 26, 2014. The status is currently under review and will be released by June 2019. 

Note: These butterflies are all listed as "Endangered" under the Endangered Species Act. The list is not exhaustive and the complete list can be found on the USFWS ECOS site here. 

Karner blue butterfly (Lycaeides melissa samuelis)

Federal Status: Endangered

Host plant: Wild lupine (Lupinus perennis)
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Historical Range: Illinois, Indiana, Massachusetts, Michigan, Minnesota, New Hampshire, New York, Ohio, Pennsylvania, Wisconsin. 

History and Description: The Karner blue butterfly was first described more than a century ago in Karner, New York. It is a small butterfly, with a wingspan of about one inch. The male's wings are distinctively marked with a silvery or dark blue color. The female is grayish brown, especially on the outer portions of the wings, to blue on the topside, with irregular bands of orange crescents inside the narrow black border. (ECOS- Environmental Conservation Online System)

While adult Karner blues feed on a variety of plants, wild lupine is the only known food plant for their larvae. Without wild lupine the cycle of life for this butterfly would be broken. Lupines are adapted to particular environmental conditions. The plants required by the larvae of the Karner blue, are found in savanna, barrens, and dune habitats which were once quite extensive. However, like many other places the habitats of the Karner blue have been subject to extensive development with a resulting decline in the butterfly. (USFWS Podcast Dave Harrelson)

Callippe silverspot butterfly (Speyeria callippe callippe)

Federal Status: Endangered

Host plant: Johnny-jump- up (Viola pedunculata)

Historical Range: California

History: "The callippe silverspot was historically found around the eastern, southern, and western sides of San Francisco Bay, but is now limited to just seven sites. It is found in native grassland and adjacent habitats, where females lay their eggs on the larval food plant, Johnny-jump-up. The causes of the callippe silverspot’s decline are fairly clear: The vast majority of potential butterfly habitat lies under the cities of San Francisco, Oakland, and Berkeley, and what open areas remain within this butterfly’s range are dominated by introduced plant species. Many of these areas are also grazed by cattle, mined, or subject to heavy recreational use." (Xerxes Society)

Bartram's hairstreak butterfly (Strymon acis bartrami)

Federal Status: Endangered

Host plant: Pineland croton (Croton linearis)

Range: Florida

History: The Bartram's Hairstreak is a small butterfly approximately 1 inch (in) (25 millimeters (mm)) in length with a forewing length of 0.4 to 0.5 in (10 to 12.5 mm) and has an appearance characteristic of the genus. Despite its rapid flight, this hairstreak is easily observed if present at any density as it alights often, and the brilliance of its grey underside marked with bold white postdiscal lines beneath both wings provides an instant flash of color against the foliage of its hostplant, pineland croton (Croton linearis). (ECOS- USFWS)

Saint Francis' Satyr (Neonympha mitchellii francisci)

Federal Status: Endangered

Host plant(s): Grasses, sedges, and rushes and are usually located in wet meadows

Range: North Carolina. 

History: "The Saint Francis’ satyr occurs in the sandhills of Cumberland and Hoke counties, North Carolina, (a single metapopulation) and has a single record in Virginia. Soon after its discovery in the 1980s, it was believed that this butterfly had been collected to extinction, but happily it was rediscovered in 1992. Its habitat is wet meadows, previously likely created by fire or beaver activity, although now mainly maintained by human activity. Despite its protected status, it is still in demand by collectors". (Xerxes Society)

San Bruno elfin butterfly (Callophrys mossii bayensis)

Federal Status: Endangered 

Host Plant: Sedum spathulifolium. Montara Mountain colonies are suspected to use Montara manzanita (Arctostaphylos montaraensis) and California huckleberry (Vaccinium ovatum). (Xerxes Society)

Range: California. 

History: Its habitat has been diminished by quarrying, off- road recreation, and urban development. Development pressures on the San Francisco peninsula continue to grow, and the major threats to the butterfly— increased urbanization in the area, and loss of habitat by road construction and rock and sand quarrying—reflect this. Grazing may have encouraged the growth of exotic plants in the area. In the early 1980s, a habitat conservation plan was developed to allow development on San Bruno Mountain while minimizing the adverse effects on the San Bruno elfin butterfly and other rare species in the area. This plan is currently being amended, which may result in further urban development. (Xerxes Society) 

Miami Blue  (Cyclargus thomasi bethunebakeri)

Status: Endangered

Host plant:

Range:  Florida Keyes

History: This butterfly is one of the most endangered insects in the world. After Hurricane Andrew in 1992, there were no sightings of this species again until 1999 in Bahia Honda State Park. All known individuals were thought to be gone as of 2010. This leaves only a few scattered individuals in another population in the Marquesas Keys in Key West National Wildlife Refuge. (ECOS- USFWS)

Schaus swallowtail  (Heraclides aristodemus ponceanus)

Status: Endangered

Host plant(s): Torchwood and Wild lime

Range: Florida. 

History:  Listed on April 28th, 1976 as threatened, the Schaus swallowtail was the first butterfly to be protected under the Endangered Species Act, or ESA as the law is often referred to. This butterfly was originally described by William Schaus in 1911 from specimens collected in the south Miami area in 1898. The butterfly was originally distributed in southern Florida’s tropical hardwood hammocks from south Miami to Lower Matacumbe Key. Hardwood hammocks are a type of forest that is on ground that is slightly elevated above the surrounding landscape. These forests are essential for the survival of the butterfly. The ongoing loss of habitat and food plants was pushing the Schaus swallowtail even farther toward the brink of extinction. This resulted in the Fish and Wildlife Service reclassifying the butterfly to the more imperiled status of endangered in 1984. (Xerxes Society)

​Palos verdes blue butterfly (Glaucopsyche lygdamus palosverdesensis)

Federal Status: Endangered

Host Plant(s): Milkvetch and deerweed

Range: Palos Verdes Peninsula (Los Angeles County), California
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History:  The Palos Verdes Blue butterfly was listed as endangered in 1980 and was feared extinct until it was rediscovered in 1994. This butterfly's habitat is under constant threat of development. The population is also threatened by weed control, off-road vehicle use, non-native invasive plants, and fire suppression. Conservation initiatives include control of human use of the habitat, replanting of the host species, and a captive breeding program. (Xerxes society) 

Florida leafwing butterfly (Anaea troglodyta floridalis)

Federal Status: Endangered

​Range: Florida

Host plant: Pineland Croton

Description and History: The Florida leafwing is a medium-sized butterfly approximately 2.75 to 3 inches (in) (76 to 78 millimeters (mm)) in length. The upper-wing (or open wing) surface color is red to red-brown, the underside (closed wings) is gray to tan, with a tapered outline, cryptically looking like a dead leaf when the butterfly is at rest. The Florida leafwing exhibits sexual dimorphism, with females being slightly larger and with darker coloring along the wing margins than the males. The Florida leafwing occurs only within pine rocklands that retain its hostplant, pineland croton. 

Uncompahgre fritillary butterfly (Boloria acrocnema)

Federal Status: Endangered

Host plant: Snow willows (Salix nivalis)

Historical range: Colorado. 

Description and History: The Uncompahgre fritillary is a small butterfly with a 2-3 cm (1 inch) wingspan. Males have rusty brown wings criss-crossed with black bars; females’ wings are somewhat lighter. Underneath, the forewing is light ocher and the hindwing has a bold, white jagged bar dividing the crimson brown inner half from the purple-grey scaling on the outer wing surface. The body has a rusty brown thorax and a brownish black abdomen. The Uncompahgre fritillary butterfly was discovered on Uncompahgre Peak, Hinsdale County, Colorado on July 30, 1978. It was subsequently described as a new species. (ECOS- USFWS)

References

Xerxes Red List of Butterflies and Moths: https://xerces.org/red-list-of-butterflies-and-moths/

U.S. Fish and Wildlife Service. ECOS Environmental Conservation Online System
https://ecos.fws.gov/ecp0/reports/ad-hoc-species-report?kingdom=V&kingdom=I&status=E&status=T&status=EmE&status=EmT&status=EXPE&status=EXPN&status=SAE&status=SAT&fcrithab=on&fstatus=on&fspecrule=on&finvpop=on&fgroup=on&header=Listed+Animals

Butterflies and Moths of North America. 
​https://www.butterfliesandmoths.org/search/google/

Endangered Butterflies and Plants - USFS Podcast with Dave Harrelson
https://www.fws.gov/pollinators/audio/EndangeredPollinators_Dave.mp3