Nevada Fish & Wildlife Office
Pacific Southwest Region

Spring Mountains acastus checkerspot butterfly

(Chlosyne acastus robusta)

Class: Insecta
Order: Lepidoptera
Family: Nymphalidae
Genus: Chlosyne
Species: acastus
Sub-species: robusta
Length: 1.1 - 1.65 in. wingspan
Feed: Nectar host plants
Habitat: washes and roadsides between 5900 and 8900 feet above sea level in the Spring Mountains
 

Life History:

The Spring Mountains acastus checkerspot butterfly (Chlosyne acastus robusta) is a subspecies of the sagebrush checkerspot butterfly (Chlosyne acastus) belonging to the Nymphalidae family (brush-footed butterflies). The subspecies is only known to occur in the Spring Mountains in Clark and Nye counties, Nevada at elevations from approximately 5,900 to 8,900 feet above sea level. The majority of observations and habitat of the butterfly are within the boundaries of the Spring Mountains National Recreation Area managed by the U.S. Forest Service.

The butterfly has been observed in 17 areas. Four of these areas (1-Trough Spring, 2-Kyle Canyon, 3-Griffith Peak Trail/Harris Spring Road/Harris Mountain Road, and 4-Potosi Mountain/Mt. Potosi/Boy Scout Camp) are currently the only locations where known colonies occur. A colony is “a local, isolated population.” The remaining 13 areas are referred to as incidental observations or sighting areas, where intermittent observations of a few butterflies were recorded at a location. Spring Mountains acastus checkerspot butterflies observed in a colony or sighting area represent the overall known population of the subspecies.

 

Distribution and Habitat:

 

The subspecies is only known to occur in the Spring Mountains in Clark and Nye counties, Nevada at elevations from approximately 5,900 to 8,900 feet above sea level.

 

Threats:

 

The available information indicates fuels reduction projects (prescribed burning and/or clearing of underbrush) may have a negative impact on Spring Mountains acastus checkerspot individuals and habitat. The possible declining trends at the Potosi Mountain/Mt. Potosi/Boy Scout Camp colony site indicate that fuels reduction projects may be a threat to the Spring Mountains acastus checkerspot at this site. Also, potential declining population trends at the Griffith Peak Trail/Harris Spring Road/Harris Mountain Road colony site and the Trough Spring colony site indicate that vehicle and hiking traffic disturbing the butterfly flight period may be a threat to the subspecies. Additionally, drought may be an added stressor to the Spring Mountains acastus checkerspot butterfly at some locations where additional threats occur.

 

Actions / Current Information:

 

09/26/2012
  • News Release: Endangered Species Act protection not warranted for Spring Mountains acastus checkerspot butterfly
     
  • Questions & Answers: Spring Mountains Acastus Checkerspot Butterfly 12-Month Finding
     
  • Notice of 12-month finding: Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to List Spring Mountains Acastus Checkerspot Butterfly as an Endangered or Threatened Species
         
    04/12/2011
  • News Release: Spring Mountains Acastus Checkerspot Butterfly to be Reviewed for Possible Protection under the Endangered Species Act
     
  • Questions & Answers: Spring Mountains Acastus Checkerspot Butterfly 90-Day Finding
     
  • Notice of 90-day petition finding: Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List Spring Mountains Acastus Checkerspot as Endangered
    Last updated: April 16, 2014