Species Report for Leona’s Little Blue Butterfly (Philotiella leona) Photo credit: Sarina Jepsen; The Xerces Society U.S. Fish and Wildlife Service May 20, 2015 Species Report for Leona’s Little Blue Butterfly (Philotiella leona) Purpose The purpose of this species report is to provide the best available scientific and commercial information about Leona’s little blue (Philotiella leona) and its habitat. The information within this report will be part of our biological basis for any potential listing, recovery, or consultation recommendations under the Endangered Species Act of 1973 as amended (Act), (16 U.S.C. 1531 et seq.). Executive Summary On May 12, 2010, the U.S. Fish and Wildlife (Service) received a petition from the Xerces Society for Invertebrate Conservation, Dr. David McCorkle of Western Oregon University, and Oregon Wild to list the Leona’s little blue butterfly under the Act. On August 17, 2011, the Service published in the Federal Register a positive 90-day finding stating that the petition presented substantial scientific or commercial information indicating that listing the Leona’s little blue butterfly may be warranted (76 FR 50971). As a result, we are initiating a status review of the species to determine if Leona’s little blue butterfly is warranted for listing under the Act. The Xerces Society for Invertebrate Conservation and Oregon Wild filed a notice of intent to sue on March 7, 2013, for failure to issue a 12-month finding on whether listing the Leona’s little blue butterfly is warranted under the Act. On July 31, 2014, the court ordered the Service to issue a 12-month finding for the Leona’s little blue butterfly by June 30, 2015. The Leona’s little blue butterfly is a member of the Polyommatini tribe of butterflies (a taxonomic group under family) within the Lycaenidae family, and is the largest species in the Philotiella genus (Hammond and McCorkle 1999, pp. 1, 82; Pyle 2002, p. 222). The species is found in volcanic ash and pumice fields and meadows consisting of non-forested bitterbrush/needlegrass-sedge vegetation community (Volland 1988, p. 29; Hammond and McCorkle 1999, p. 77; Pyle 2002, p. 236; Ross 2008, p. 1; Johnson 2010, p. 2). Information provided in the petition stated that Leona’s little blue butterfly was known from a single population (estimated at 1,000 to 2,000 individuals) and that its range was limited to a 6 square mile (sq mi) (15.5 square kilometer (sq km)) area of the Antelope Desert in Klamath County, Oregon. Based on a better understanding of habitat requirements, more focused survey efforts, and more rigorous sampling methods for the species between 2009 and 2013, the current known range of the species has doubled in size from 6 sq mi (15.5 sq km) to 12.8 sq mi (33.1 sq km) (see Figure 1). Similarly, the population size estimates have increased to approximately 20,000 individuals as a result of the additional survey efforts. Leona’s little blue butterfly is dependent upon the annual spurry buckwheat (Eriogonum spergulinum (A. Gray) var. reddingianum (M.E. Jones, J.T. Howell)) (Munz & Keck 1973, pp. 340–341) for the development of its larvae. A variety of nectar plants, including spurry buckwheat, are used by adult Leona’s little blue butterflies. The assemblage of plant species found within the range of the species appears to be unique and shows strong correlation with the presence of alluvial fans deposits formed after the eruption of Mt. Mazama 6,600 to 7,700 years 2 ago. The majority of land within the range of the species (93.7 percent) occurs on private lands (Mazama Forest, previously owned by Fidelity National Financial and now owned by Whitefish Cascade Forest Resources, LLC). A small percentage (1.5 percent) of land on which the Leona’s little blue butterfly occurs is in the Fremont-Winema National Forest, U.S. Forest Service (USFS). The USFS has designated the butterfly as a sensitive species, which similarly directs that USFS actions avoid or minimize effects to the butterfly and its habitat. The known stressors that potentially act on Leona’s little blue butterfly or its habitat include timber management, lodgepole pine encroachment, fire, fire suppression, invasive plants, and competition from other invertebrates (see Stressors Potentially Affecting Leona’s Little Blue Butterfly below for complete list of stressors). Of these known stressors, lodgepole pine encroachment and invasive plants may contribute to considerable loss of habitat and individuals. Timber management has the potential to alter or destroy habitat; however, the reduction of forested areas provides almost immediate benefits to Leona’s little blue butterfly that overcome negative impacts from timber management and the stressor of lodgepole pine encroachment. Abbreviations Used °C degrees Celsius °F degrees Fahrenheit ac acres Act Federal Endangered Species Act of 1973, as amended APHIS Animal and Plant Health Inspection Service BPA Bonneville Power Administration C Celsius cm centimeter F Fahrenheit FR Federal Register ft feet GHG greenhouse gas ha hectare in inch IPCC Intergovernmental Panel on Climate Change km kilometer m meter mm millimeter NRCS Natural Resources Conservation Service NWR National Wildlife Refuge ODOT Oregon Department of Transportation Service U.S. Fish and Wildlife Service sq km square kilometer sq mi square mile USFS U.S. Forest Service USGS U.S. Geological Survey Whitefish Whitefish Cascade Forest Resources, LLC 3 Introduction Harold and Leona Rice discovered the Leona’s little blue butterfly (Philotiella leona) in 1995. Hammond and McCorkle (1999, p. 77) formally described Leona’s little blue butterfly as a new species in 1999. The Leona’s little blue butterfly occupies volcanic ash and pumice fields that form non-forested meadows in the vicinity of Sand and Scott Creeks in Klamath County, Oregon (Hammond and McCorkle 1999, pp. 77, 80; Pyle 2002, p. 236; James et al. 2014, p. 264). The species is known from a single location measuring approximately 12.8 sq mi (33.1 sq km) in size and is believed to be a local endemic species. Land ownership within the range of Leona’s little blue butterfly consists of Fremont-Winema National Forest (1.5 percent), multiple small privately owned parcels (4.8 percent) , and Whitefish Cascade Forest Resources, LLC (Whitefish; previously owned by Fidelity National Financial, Inc.; 93.7 percent). Figure 1 provides an overview of the location of the Leona’s little blue butterfly range, land ownership, and species detections. The points are representative of a single survey effort in which one or more Leona’s little blue butterfly were detected. On May 12, 2010, the Service received a petition from the Xerces Society for Invertebrate Conservation, Dr. David McCorkle of Western Oregon University, and Oregon Wild to list the Leona’s little blue butterfly under the Endangered Species Act, as amended (Matheson et al. 2010, entire). The Service determined that an emergency listing of the Leona’s little blue butterfly was not warranted on September 10, 2010 (Service 2010a, pp. 1–2). On August 17, 2011, the Service published in the Federal Register a positive 90-day finding stating that the petition presented substantial scientific or commercial information indicating that listing the Leona’s little blue butterfly may be warranted (76 FR 50971). As a result, we are initiating a status review of the species to determine if Leona’s little blue butterfly is warranted for listing under the Act. The Xerces Society for Invertebrate Conservation and Oregon Wild filed a notice of intent to sue on March 7, 2013, for failure to issue a 12-month finding on whether listing the Leona’s little blue butterfly is warranted under the Act. On July 31, 2014, the court ordered the Service to issue a 12-month finding for the Leona’s little blue butterfly by June 30, 2015. Species Description The Leona’s little blue butterfly (Figure 2) is a member of the butterfly family Lycaenidae (gossamer winged-butterflies) and the tribe Polyommatini (Pyle 2002, p. 222). The wingspan of Leona’s little blue butterfly measures less than 0.75 to 1 inches (in) (1.9 to 2.5 centimeters (cm)) (Pyle 2002, p. 236). Male dorsal wing color is dark, dusky blue with black submargins while female dorsal wing color is brown (Hammond and McCorkle 1999, p. 77). Ventral wing color for both sexes is white with black spots on fore- and hind-wings (Hammond and McCorkle 1999, p. 77) (see Figure 2). Leona’s little blue butterfly may be confused with other co-occurring species of little blue butterflies such as the glaucon blue (Euphilotes glaucon) and the lupine blue (Plebejus lupini) (Ross 2010, pp. 10–12), especially when in flight or observed at a distance (Ross 2008, p. 1) (see Figure 3). 4 Figure 1: Map of Leona’s little blue butterfly range and observation locations. 5 Figure 2: Leona’s little blue butterfly roosting on dead twig. Photo credit: Will Hatcher Figure 3: Similar Species: Glaucon blue (Euphilotes glaucon) (left) and Lupine blue (Plebejus lupini) (right) Photo credit: Kim Davis and Mike Stangeland Life History, Species Needs, and Habitat Features Life History The life-cycle of the Leona’s little blue butterfly takes approximately one year to complete, beginning with an egg and ending with an adult butterfly. Very little information is present on the exact timing of the life cycle from the wild population; however, James (2012, pp. 94–95) describes the Leona’s little blue butterfly life cycle as observed in a captive setting. 6 Oviposition, or egg laying, by Leona’s little blue butterfly under natural conditions may occur as early as June 30 (James 2011, p.