SPECIES FACT SHEETScientific Name: Ochlodes yuma (Edwards, 1873)Common Name(s): Yuma Skipper or Giant-Reed SkipperPhylum: ArthropodaClass: InsectaOrder: LepidopteraFamily: Hesperiidae(ITIS 2017)Conservation Status:

Global Status: G5 (last reviewed 18 Aug 2009)National Status (United States): N5 (01 Sept 1998)(NatureServe 2017)State Statuses: S1? (Oregon) (ORBIC 2016), S1 (Washington) (WNHP 2017) Federal Status (United States): None IUCN Red List: Not assessed (IUCN 2017)Candidate species in Washington (WNHP 2017)Taxonomic Note:

According to Pyle (2002), northwest colonies of the Yuma skipper are best referred to as O. y. lutea, although Warren (2005) has found significant variation between individuals from different sites.

Technical Description:

Adult: Ochlodes yuma is in the Hesperiinae subfamily also known as the monocot or folded-wing skippers. Ochlodes yuma is a large skipper, less than 1.75” in size and golden or tawny in color with few obvious markings (Pyle and LaBar 2018). Males have a narrow, indistinct black margin on the outer edge of both wings dorsally, a long, narrow stigma on the dorsal forewing, and a bright ventral hindwing (Pyle and LaBar 2018). Females are similar but lack the stigma and may have pale spotbands and black basal smudges on their ventral hindwing (Pyle 2002; Pyle 2009, pers. comm.; Pelham 2009, pers. comm.). In general, O. yuma is larger, brighter, and plainer than any other northwest Hesperiinae skipper.

Similar species: Ochlodes yuma may be confused with O. sylvanoides bonnevilla (woodland skipper), which is relatively plain on the ventral surface and can occupy some of the same habitat; however, O. yuma is 1.5 to 2 times larger than O. s. bonnevilla, is less heavily marked, has narrower

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stigmata, and typically has an earlier flying period (Pyle and LaBar 2018). Butterfly field guides (such as Pyle and LaBar 2018) are probably the best source of pictorial “keys” and it is best to refer to one of these when trying to identify this species.

Immature: Ochlodes yuma eggs are white to light green and the caterpillars vary in color from light green to tan (James and Nunnallee 2011). The caterpillar head is darker than the rest of the body and can vary from tan to dark brown; in later instars, it is bisected by a darker brown vertical stripe (James and Nunnallee 2011).

Life History:

Adults: In Oregon and Washington, O. yuma has one flight period from early July to early September, peaking in August (Pyle and LaBar 2018). Adults are often found near marsh edges nectaring on a variety of flowers including thistles (Cirsium sp.) and yellow composites (Asteraceae) (Pyle and LaBar 2018). Ochlodes yuma is closely associated with its single known host plant, Phragmites australis (giant or common reed). There are two strains of P. australis in the Pacific Northwest, one native and one non-native. It appears that O. yuma utilizes only the native genotypes of P. australis ssp. americanus, although ovipositing females have used the exotic subspecies in captivity (James and Nunnallee 2011). Males often perch on the host Phragmites, awaiting females. After mating, females deposit their eggs on or near the host plant.

Larvae: Ochlodes yuma eggs are laid on or near the host plant Phragmites australis ssp. americanus (Pyle and LaBar 2018); after hatching, caterpillars proceed to feed on P. australis. They also roll up leaves of their host plants to use as shelters (Allen et al. 2005; Pyle 2002; Opler et al. 2006; James and Nunnallee 2011). This species may be able to utilize alternative hosts; a colony in Washington was associated with Miscanthus (variegated eulalia grass) and was successfully reared on M. sinensis (Pyle and LaBar 2018). However, under natural conditions, O. yuma has only been documented to use P. australis ssp. americanus (James and Nunnallee 2011). This species overwinters as first-instar larvae (Pyle and LaBar 2018).

Range, Distribution, and Abundance:

Type Locality: Sherman Island, Sacramento River Valley, Sacramento County California; 3m (Edwards 1873). However, Brown (1957) revisited the material

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for O. yuma and found that Owens Lake, Inyo County, California, is a more accurate type locality.

Range: At the species level, Ochlodes yuma is common in areas with its host plant in California, Nevada, Utah, Colorado, northern New Mexico, Arizona, Wyoming and in isolated areas in Oregon and Washington. Several subspecies of O. yuma occur, including O. yuma anasazi (New Mexico), O. yuma lutea (Nevada, Oregon, Washington), O. yuma scudderi (Wyoming, Colorado, Utah), O. yuma yuma (California, New Mexico, Arizona, Utah, Nevada), and O. yuma sacramentorum (California) (Pelham 2017). Oregon and Washington represent the northern extent of the Yuma skipper’s range. It was known no farther north than Nevada until 1984, when Jonathan Pelham discovered a colony at the Sun Lakes State Park in Grant County, Washington. In 1985, Ray Albright found another colony north of Imnaha in Wallowa County, Oregon, and then a third near Summer Lake, Oregon, in 1986 (Pyle 2002). The butterfly has also been found near the Deschutes River at I-84 in Wasco and Sherman County, Oregon (Shepard 2001, 2002). In 2002, the first record of O. yuma in Idaho was confirmed (Warren 2005).

Distribution: In Oregon, Ochlodes yuma is found in the Blue Mountains and Northern Basin and Range ecoregions (ORBIC 2016). Ochlodes yuma is known from three widely separated areas in the state. First, it is locally common near Summer Lake and Silver Lake in Lake County (Hammond 1994). Second, it is commonly found along the Imnaha River in Wallowa County (Oregon Natural Areas Program 2015). Third, it is found along the lower Columbia River in Wasco, Sherman, and Hood River counties (Pyle 2002; Warren 2005). Furthermore, it is suspected to occur in Harney, Malheur, Baker, Gilliam, Morrow, and Umatilla Counties (Warren 2005).

In Washington, O. yuma also has a highly disjunct distribution within the Columbia Basin ecoregion (WDFW 2015). It is known from Sun Lakes State Park below Dry Falls in Lower Grand Coulee in Grant County (Warren 2005; Pyle 2002). Ochlodes yuma records in Klickitat and Asotin Counties are likely outliers; a tiny colony at Maryhill Museum Gardens, on a cultivated ornamental grass, does not appear to be present after revisitation efforts (Pyle 2018, pers. comm.). Recent efforts to survey indigenous reedbeds in Klickitat County have not found this species (Pyle 2018, pers. comm.). The Asotin County record was a single worn female along the Snake River at Keller Bar, and not likely an established colony due to the lack of suitable habitat (Pyle 2018, pers. comm.). Surveys in Phragmites (spp. americanus)

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patches along the Columbia River, Klickitat County, are and are continuing to assess the current distribution of butterflies of conservation concern (Potter 2018, pers. comm.).

BLM/Forest Service Land:

Documented: In Oregon, Ochlodes yuma has been documented on the Wallowa-Whitman National Forest (in Wallowa County) and the Columbia River Gorge National Scenic Area (in Wasco and Hood River Counties).

Suspected: Due to the proximity of known records, this species is suspected on the Vale (Wallowa County), Lakeview (Lake County), and Prineville (Wasco and Sherman Counties) BLM Districts in Oregon. In Washington, the species is suspected by the Columbia River Gorge National Scenic Area and the Spokane BLM District (Grant County). Although within the general range of the species, both the Umatilla and Fremont-Winema National Forests do not consider the species suspected due to the lack of the larval host plant on these Forests.

Abundance: Abundance estimates are not available for this species. Ochlodes yuma colonies tend to be small and isolated; however, this species can be abundant (occurring in hundreds) within suitable habitat of Phragmites reedbeds (Hammond 1994; Pyle and LaBar 2018). This species is considered rare within the Columbia River Basin (Hammond 1994) and Washington populations appear to be in decline and highly disjunct with as few as 3-5 populations (WDFW 2015). Recent (2017) surveys at the Sun Lakes State Park location resulted in the detection of at least 30 skippers, confirming that this historical locale remains occupied by O. yuma (Potter 2018, pers. comm.).

Habitat Associations:

Ochlodes yuma is found in reedbeds and near edges of freshwater marshes, streams, oases, ponds, seeps, sloughs, springs, and canals (Scott 1986; Pyle and LaBar 2018). Adults are almost always found in close association with the primary larval hostplant Phragmites australis ssp. americanus, typically found in herbaceous wetland and riparian habitats, desert seeps, and along streams and canals (NatureServe 2017). Ochlodes yuma adults nectar near marsh edges on Cirsium spp. (thistles), yellow composites (Asteraceae), Eupatorium maculatum (Joe Pye weed), Centaurea spp. (knapweed), and Peritoma serrulata (bee plant) (Pyle and LaBar 2018). Additional nectar

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sources for O. yuma include Asclepias spp., Aster spp., Cirsium spp., Ericameria nauseosa, Grindelia spp., Helianthus spp., Heliotropium curassavicum, Solidago spectabilis, Arctium minus, Cirsium arvense, Cirsium vulgare, Medicago sativa, Melilotus officinalis, Polygonum pennsylvanica, Lamiaceae sp., and Aster chilensis (all species found in Oregon and/or Washington, species in bold are native; Scott 2014; Caldwell 2015).

Threats:

Any activities that alter wetland habitat, including water diversion and livestock disturbance, can potentially threaten O. yuma populations (Hammond 1994). The nominate species O. yuma is widely distributed and relatively secure (Opler et al. 2006). However, populations in Oregon and Washington are isolated and highly disjunct.

This species’ limited distribution in Oregon and Washington make it particularly vulnerable to recreation management, park development, and climate change (WDFW 2015). General and site specific threats include loss of wetland habitats to urban or agricultural uses, pesticide applications (especially the use of organophosphates and pyrethroids for mosquito control), grazing damage to wetland habitat, and recreation and development along Phragmites marshes. Modifications to hydrologic environments further fragment wetland and riparian habitats, threatening this species that relies on a single larval host (P. australis ssp. americanus), which is a riparian obligate species. Mining and mill tilling could change the water quality, quantity, and flow patterns of seeps and springs (Cary and Holland 1992).

Invasive Phragmites may pose a threat, as this species can overtake native Phragmites habitats and O. yuma does not appear to utilize stands of the non-native common reed in Oregon and Washington (WDFW 2015). However, O. y. sacramentorum is known to use the non-native strain of P. australis in California (Pelham 2007, pers. comm.). Plant identification skills are critical for ensuring native Phragmites stands are protected; state parks and other land managers have mistakenly treated native Phragmites with herbicides, thereby reducing the available hostplant for this species (WDFW 2015). Other invasive plants such as Fallopia japonica (Japanese knotweed), Lythrum salicaria (purple loosestrife), Lepidium latifolium (perennial

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pepperweed), and Phalaris arundinacea (reed canary grass) may threaten this species’ habitat by altering riparian zones.

Conservation Considerations:

Research: Observational studies are needed to gather information on suitable habitat, develop management recommendations, and assess this species’ potential to utilize invasive Phragmites (WDFW 2015). James and Nunnallee (2011) note that more research is needed on species dispersal and natural factors controlling abundance and distribution of this species.

Inventory: Surveys are needed to search for new sites with suitable habitat and determine distribution and population status at known sites (WDFW 2015). In particular, surveys for O. yuma are recommended in riparian corridors along the Snake River in Baker and Malheur counties, in the Owyhee River Canyon of Malheur County, along the John Day River, and along the Columbia River east of Sherman County (Warren 2005).

Management: Protect significant areas of suitable habitat (WDFW 2005). Avoid disturbing established beds of the native P. australis ssp. americanus at known sites of O. yuma. Train land managers to differentiate between native and non-native Phragmites in order to prevent aggressive weed management where native Phragmites exists (WDFW 2015). Discourage application of pesticides for mosquito control on or near occupied habitat; if spraying is unavoidable, take precautions to limit inadvertent spray onto individual adults or larvae (Larsen et al. 1995). Restrict the use of Bacillus thuringiensis israelensis (Bti) and Bacillus sphaericus (H-5a-5b) in mosquito control activities in areas where this species is found (see WSDE 2004 for WA guidance).

Version 2: Prepared by: Katie Hietala-HenschellThe Xerces Society for Invertebrate ConservationDate: April 2018

Reviewed by: Candace FallonThe Xerces Society for Invertebrate ConservationDate: May 2018

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Version 1: Prepared by: Scott Hoffman Black, Logan Lauvray, and Sarina JepsenThe Xerces Society for Invertebrate ConservationDate: December 2007

ATTACHMENTS:

(1)References (2)List of pertinent or knowledgeable contacts (3)Map of known records in Oregon and Washington(4)Photographs of this species(5)Survey protocol, including specifics for this species

ATTACHMENT 1: References

Allen, T.J., J.P. Brock, J. Glassberg. 2005. Caterpillars in the Field and Garden: A Field Guide to the Butterfly Caterpillars of North America. Oxford University Press, Oxford, NY. 232 pp.

Austin, G.T. 1985. Lowland riparian butterflies of the Great Basin and associated areas.

Brock, J.P. and K. Kaufman. 2003. Butterflies of North America. Houghton Mifflin Company, New York, NY. 384 pp.

Brown, F.M. 1957. The type locality for Ochlodes yuma. The Lepidopterists’ News 11(4-5):153-154.

Caldwell, J.A. 2015. California plants as resources for Lepidoptera: a guide for gardeners, restorationists and naturalists. 458 pp.

Cary, S.J. and R. Holland. 1992. New Mexico butterflies: checklist, distribution and conservation. Journal of Research on Lepidoptera 31(1-2):57-82.

Hammond, P.C. 1994. Rare butterfly assessment for the Columbia River Basin in the Pacific Northwest. Eastside Ecosystems Management Strategy Project. 15 pp.

[ITIS] Integrated Taxonomic Information System. 2017. Ochlodes yuma. [web application]. Available at: https://www.itis.gov (Accessed: 30 March 2018).

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[IUCN] International Union for Conservation of Nature. 2017. The IUCN red list of threatened species. Version 2017-3. Accessed April 2018. Available at: http://www.iucnredlist.org

James, D. and D. Nunnallee. 2011. Life Histories of Cascadia Butterflies. OSU Press, Corvallis, Oregon. 448 pp. NatureServe. 2017. Ochlodes yuma (Edwards, 1873). Version 7.1 (2 February 2009). Data last updated: November 2016. Accessed March 2018. Available at: http://explorer.natureserve.org/index.htm

Opler, P.A., H. Pavulaan, R.E. Stanford, M. Pogue, coordinators. 2006. Butterflies and Moths of North America. Bozeman, MT: Mountain Prairie Information Node. http://www.butterfliesandmoths.org/ (Version 08292007)

Opler, P.A. and A.B. Wright. 1999. A Field Guide to the Western Butterflies. Second Edition. Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA. 540 pp.

[ORBIC] Oregon Biodiversity Information Center. 2016. Rare, threatened and endangered species of Oregon. Institute for Natural Resources, Portland State University, Portland, Oregon. 130 pp. Available at http://inr.oregonstate.edu/sites/inr.oregonstate.edu/files/2016-rte-book.pdf

Oregon Natural Areas Program. 2015. Oregon Natural Areas Plan. Oregon Parks and Recreation Department and the Oregon Biodiversity Information Center, Institute for Natural Resources – Portland, Portland State University, Portland, OR. 189 pp.

Pelham, J. 2007. Personal communication with Scott Hoffman Black, Logan Lauvray, and Sarina Jepsen, the Xerces Society. Lepidopterist, Seattle, WA.

Potter, A. 2018. Personal communication with Katie Hietala-Henschell, the Xerces Society. Wildlife Biologist, Washington Department of Fish and Wildlife, WA. April 18, 20.

Pyle, R.M. 2002. The Butterflies of Cascadia: A Field Guide to All the Species of Washington, Oregon, and Surrounding Territories. Seattle Audubon Society, Seattle, Washington. 420 pp.

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Pyle, R.M. 2007. Personal communication with Scott Hoffman Black, Logan Lauvray, and Sarina Jepsen, the Xerces Society. Lepidopterist, Gray’s River, WA.

Pyle, R.M. 2018. Personal communication with Katie Hietala-Henschell, the Xerces Society. Lepidopterist, Gray’s River, WA. April 18.

Pyle, R.M. and C. LaBar. 2018. Butterflies of the Pacific Northwest. Timber Press Field Guide, Timber Press, Portland, OR. 461 pp.

Ross, D. 2007. Personal communication with Scott Hoffman Black, Logan Lauvray, and Sarina Jepsen, the Xerces Society. Lepidopterist, Corvallis, OR.

Scott, J.A. 1986. The Butterflies of North America. Stanford University Press, Stanford, California, USA, 583 pp.

Scott, J.A. 2014. Lepidoptera of North America. 13. Flower visitation of Colorado butterflies with a review of the literature on pollination of Colorado plants and butterfly attraction (Lepidoptera: Hesperioidea and Papilionoidea). Contributions of the C.P. Gillette Museum of Arthropod Diversity Colorado State University. 190 pp.

Warren, A.D. 2005. Lepidoptera of North America 6, Butterflies of Oregon: Their Taxonomy, Distribution, and Biology. Department of Zoology, Oregon State University, Corvallis, Oregon.

[WDFW] Washington Department of Fish and Wildlife. 2005. Washington’s comprehensive wildlife conservation strategy. Washington Department of Fish and Wildlife. 62 pp.

[WDFW] Washington Department of Fish and Wildlife. 2015. State Wildlife Action Plan Update. Washington Department of Fish and Wildlife, Appendix A-5, Species of Greatest Conservation Need, Fact Sheets, Invertebrates. 123 pp.

[WNHP] Washington Natural Heritage Program. 2017. List of animal species with ranks. Accessed 21 March 2018. Available at: https://www.dnr.wa.gov/publications/amp_nh_animals_ranks.pdf?3p5c8.

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[WSDE] Washington Department of Ecology. 2004. Best management practices for mosquito control. Washington State Department of Ecology Water Quality Program, Olympia, WA. 59 pp.

Map references:

Hinchliff, J. 1994. Eric Scheuering, ORNHIC, shared records used in the atlas of butterfly records with Scott Hoffman Black, the Xerces Society. July 2011.

Potter, A. and D. James. 2018. Ann Potter, WDFW, and David James, WSU, shared Washington species occurrence records with Katie Hietala-Henschell, the Xerces Society. April 2018.

Shepard, J.H. 2001. Zone 2, Pacific Northwest: Idaho, Oregon, Washington, British Columbia, pp. 4-7. In: Tuttle, J. P., editor. 2000 Season Summary. News of the Lepidopterists’ Society 43(supplement S1):1-76.

Shepard, J.H. 2002. Zone 2, Pacific Northwest: Idaho, Oregon, Washington, British Columbia, pp. 5-8. In: Tuttle, J. P., editor. 2001 Season Summary. News of the Lepidopterists’ Society 44(supplement S1):1-76.ATTACHMENT 2: List of pertinent, knowledgeable contacts

Jonathan P. Pelham, Lepidopterist, Washington State Burke Memorial Museum, University of Washington, Seattle, WA.

Dr. Robert Michael Pyle, Lepidopterist, Biologist, Writer, and independent scholar, Grays River, WA.

Dana Ross, Lepidopterist, Corvallis, OR.

Dr. Andrew Warren, McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, FL.

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ATTACHMENT 3: Map of known Ochlodes yuma records in Oregon and Washington

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Known records of Ochlodes yuma in Oregon and Washington, relative to Forest Service and BLM land.

ATTACHMENT 4: Photographs of this species

Ochlodes yuma lutea male (left) and female (right) taken August 13th, 2010, from Ana Reservoir near Summer Lake, Lake County, Oregon. By Kim Davis and Mike Stangeland, used with permission.

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Ochlodes yuma habitat near Summer Lake, Lake County, Oregon. By Kim Davis and Mike Stangeland, used with permission.

ATTACHMENT 5: Survey Protocol

By Candace Fallon and Sarah Foltz Jordan, last updated May 2018

Taxonomic group:

Lepidoptera

Where: Lepidopterans utilize a diversity of terrestrial habitats. When surveying new areas, seek out places with adequate larval food plants, nectar sources, and habitat to sustain a population. Many species have highly specific larval feeding preferences (e.g. limited to one or a few related plant species whose defenses they have evolved to overcome), while other species exhibit more general feeding patterns, including representatives from multiple plant families in their diet. For species-specific dietary preferences and habitat information, see the section at the end of this protocol.

When: Adults are surveyed in the spring, summer, and fall, within the window of the species’ documented flight period. Although some butterfly species overwinter as adults and live in the adult stage for several months to a year, the adult life spans of the species considered here are short and adults are available for only a brief period each year (see species-specific details, below). Larvae are surveyed during the time of year when the larvae are actively foraging on their host plants.

How to Survey:

Adults: If possible, all sites should be surveyed for this butterfly during the following environmental conditions:

Minimum temperature: Above 60° F (15.5° C).

Cloud cover: Partly sunny or better. On cooler days, the sun can play a very important role in getting butterflies to take to the air. On warmer days (above 60° F), direct sunlight is less important, but a significant amount of the sun’s energy should be coming through the clouds to help elevate the temperature of basking butterflies.

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Wind: Less than 10 MPH (4.5 m/s). On windy days, butterflies will drop out of the air if they cannot maintain their direction and/or speed of flight.

Time of day: Between 10AM and 4PM. Success is most likely during the warmest parts of the day.

Time of year: Varies by region (see notes on flight period, below). If known, currently occupied sites should be checked before the start of the planned survey period, as flight times may vary due to weather conditions in the spring and early summer.

Upon arriving at each potential site, the following survey protocol should be used:

Approach the site and scan for any butterfly activity, as well as suitable habitat. Butterflies are predominantly encountered nectaring at flowers, in flight, basking on a warm rock or the ground, visiting host plants, or puddling (sipping water rich in mineral salts from a puddle, moist ground, or dung). Walk through the site slowly (about 100 meters per 5 minutes), looking back and forth on either side, approximately 20 to 30 feet out. Try to walk in a path such that you cover the entire site with this visual field, or at least all of the areas of suitable habitat. If you must leave the transect path (e.g., to look at a particular butterfly), do your best to return to the specific place where you left your path when you resume walking/searching through the site.

When a suspected target species is encountered, net the butterfly to confirm its identification. Adults are collected using a long-handled aerial sweep net with mesh light enough to see the specimen through the net. When stalking perched individuals, approach slowly from behind. When chasing, swing from behind and be prepared to pursue the insect. A good method is to stand to the side of a butterfly’s flight path and swing out as it passes. After capture, quickly flip the top of the net bag over to close the mouth and prevent the butterfly from escaping. Once netted, most insects tend to fly upward, so hold the mouth of the net downward and reach in from below when retrieving the butterfly.

Binoculars and cameras may also be used to view wing patterns of perched butterflies. Since most butterflies can be identified by macroscopic characters, high quality photographs will likely provide sufficient evidence of species occurrences at a site, and those of lesser quality may at least be

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valuable in directing further study to an area. Use a camera with good zoom or macro lens and focus on the aspects of the body that are the most critical to species determination (i.e. dorsal and ventral patterns of the wings) (Pyle 2002). When possible, take several photographs of potential target species showing a clear view of the underside and upperside of the wings at each survey area where they are observed.

If needed, the collection of voucher specimens should limited to males from large populations. The captured butterfly should be placed into a glassine envelope. To remove the specimen from the net by hand, grasp it carefully through the net by the thorax with fingers or a pair of flat-nosed forceps, making sure the butterfly has its wings folded back. Place the specimen in an envelope and then into a small plastic container. Place the container in a cooler with ice, buffering the specimen from the ice with a towel. Transfer the container to a freezer to kill the animal.

Fill out all of the site information on datasheet, including site name, survey date and time, elevation, aspect, legal location, latitude and longitude coordinates of site, weather conditions, and a thorough description of habitat, including vegetation types, vegetation canopy cover, suspected or documented host plant species, landscape contours (including direction and angle of slopes), degree of human impact, and insect behavior (e.g. “puddling”). Record the number of target species observed, as well as butterfly behavior, plant species used for nectaring or egg-laying, and survey notes. Photographs of habitat are also a good supplement for collected specimens and, if taken, should be cataloged and referred to on the insect labels. Collection labels should include the following information: date, time of day, collector, and detailed locality (including geographical coordinates, mileage from named location, elevation). Complete determination labels include the species name, sex (if known), determiner name, and date determined. Mating pairs should be indicated as such and stored together, if possible. Record data for sites whether butterflies are seen or not. In this way, overall search effort is documented, in addition to new sites.

Relative abundance surveys can be achieved using either the Pollard walk method, in which the recorder walks only along a precisely marked transect, or the checklist method, in which the recorder is free to wander at will in active search of productive habitats and nectar sites (Royer et al. 2008). A test of differences in effectiveness between these two methods at seven sites found that checklist searching produced significantly more butterfly

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detections per hour than Pollard walks at all sites, but the overall number of species detected per hour did not differ significantly between methods (Royer et al. 2008). The study concluded that checklist surveys are a more efficient means for initial surveys and generating species lists at a site, whereas the Pollard walk is more practical and statistically manageable for long-term monitoring. Recorded information should include start and end times, weather, species, sex, and behavior (e.g. “female nectaring on flowers of Lathyrus nevadensis”).

Immature: Lepidoptera larvae are generally found on vegetation or soil, often creeping slowly along the substrate or feeding on foliage. Pupae occur in soil or adhering to twigs, bark, or vegetation. Since the larvae usually travel away from the host plant and pupate in the duff or soil, pupae of most species are almost impossible to find.

James and Nunnallee’s Life Histories of Cascadia Butterflies (2011) includes descriptions of many Lepidoptera species, providing important diagnostic information for identification of larval stages. For species or subspecies not covered in this book, rearing can be critical in both (1) enabling identification and (2) providing novel associations of larvae with adults (Miller 1995). Moreover, high quality (undamaged) adult specimens, particularly of the large-bodied species, are often best obtained by rearing.

Most species of butterflies can be easily reared from collected eggs, larvae, or pupae, or from eggs laid by gravid females in captivity. Large, muslin-covered jars may be used as breeding cages, or a larger cage can be made from boards and a fine-meshed wire screen (Dornfeld 1980). When collecting caterpillars for rearing indoors, collect only as many individuals as can be successfully raised and supported without harm to the insect population or to local host plants (Miller 1995). A fresh supply of larval foodplant will be needed, and sprigs should be replenished regularly and placed in wet sand rather than water (into which the larvae could drown) (Dornfeld 1980). The presence of slightly moistened peat moss can help maintain appropriate moisture conditions and provide a retreat for the caterpillar at the time of pupation (Miller 1995). Depending on the species, soil or small sticks should also be provided as the caterpillars approach pupation. Although rearing indoors enables faster growth due to warmer temperatures, this method requires that appropriate food be consistently provided and problems with temperature, dehydration, fungal growth, starvation, cannibalism, and overcrowding are not uncommon (Miller 1995). Rearing caterpillars in cages

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in the field alleviates the need to provide food and appropriate environmental conditions, but may result in slower growth or missing specimens. Field rearing is usually conducted in “rearing sleeves,” which are bags of mesh material that are open at both ends and can be slipped over a branch or plant and secured at both ends. Upon emergence, all non-voucher specimens should be released back into the environment from which the larvae, eggs, or gravid female were obtained (Miller 1995).

According to Miller (1995), the simplest method for preserving caterpillar voucher specimens is as follows: Heat water to about 180°C. Without a thermometer, an appropriate temperature can be obtained by bringing the water to a boil and then letting it sit off the burner for a couple of minutes before putting the caterpillar in the water. Extremely hot water may cause the caterpillar to burst. After it has been in the hot water for three seconds, transfer the caterpillar to 70% ethyl alcohol (isopropyl alcohol is less desirable) for permanent storage. Note that since this preservation method will result in the caterpillar losing most or all of its color, photographic documentation of the caterpillar prior to preservation is important. See Peterson (1962) and Stehr (1987) for additional caterpillar preservation methods.

Species-specific Survey Details:

Ochlodes yuma

Ochlodes yuma occurs in low-elevation marshes, seeps, canals, rivers, and ponds and is restricted to stands of its host plant American common reed (Phragmites australis ssp. americanus) (Pyle and LaBar 2018). This butterfly is found in Hood River, Lake, Wasco, Sherman, and Wallowa Counties in Oregon and Grant, Klickitat, and Asotin Counties in Washington.

To more accurately identify its range, surveys for O. yuma and its host plant are recommended in riparian corridors along the Snake River (Baker and Malheur counties), Owyhee River canyon (Malheur County), John Day River, and Columbia River.

Surveys to detect O. yuma in the Northwest should be conducted during the peak flight period in August; additional surveys to document flight seasonality could occur between July and September. Ochlodes yuma nectars near marsh edges on Cirsium spp. (thistles), yellow composites

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(Asteraceae), Eupatorium maculatum (Joe Pye weed), Centaurea spp. (knapweed), and Peritoma serrulata (Bee Plant) (Pyle and LaBar 2018).

References (Survey Protocol only):

Dornfeld, J. 1980. The Butterflies of Oregon. Timber Press, Forest Grove, Oregon. 276 pp.

James, D. and D. Nunnallee. 2011. Life Histories of Cascadia Butterflies. OSU Press, Corvallis, Oregon. 448 pp.

Miller, J.C. 1995. Caterpillars of Pacific Northwest Forests and Woodlands. U.S. Department of Agriculture, Forest Service, National Center of Forest Health Management, Morgantown, West Virginia. FHM-NC-06-95. 80 pp.Peterson, A. 1962. Larvae of insects. Part 1: Lepidoptera and Hymenoptera. Ann Arbor, MI: Printed by Edwards Bros. 315 pp.

Pyle, R. 2002. The Butterflies of Cascadia: A Field Guide to all the Species of Washington, Oregon, and Surrounding Territories. Seattle Audubon Society, Seattle. 420 pp.

Pyle, R. and C. LaBar. 2018. Butterflies of the Pacific Northwest. Timber Press Field Guide, Portland, OR.

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