United States Forest Blue Mountains Pest 1401 Gekeler Lane Department of Service Management Service Center La Grande, OR 97850-3456 Agriculture Wallowa-Whitman NF (541) 963-7122

File 2670, 3400 Date: April 16, 2008 Code: Route To:

Subject: Johnson’s Hairstreak and dwarf mistletoe backgrounder

To: Forest Supervisors, Wallowa-Whitman NF, Umatilla NF, Malheur NF through Natural Resource Staff Officers

Johnston’s Hairstreak ( johnsoni), is an uncommon butterfly in the Family (Gossamer-wing ) with a distribution limited to the Pacific northwest (Tilden and Smith 1986). In northeastern Oregon it is documented in or adjacent to the Baker City watershed, and the North Pine Creek and East Pine Creek areas in the southern Wallowa Mountains. It is also known as Mitoura johnsoni and has been called Loranthomitoura johnsoni (Black and Lauvray 2005). Johnson’s Hairstreak is also called the Mistletoe Hairstreak, or Brown Mistletoe Hairstreak because the larvae of this butterfly feed exclusively on the aerial shoots of dwarf mistletoes (Arceuthobium) (LaBonte et al. 2001). Dwarf mistletoes are highly specialized and adapted parasitic plants of a number of conifers. This may limit the butterflies’ occurrence and distribution to trees in stands that are infected with Arceuthobium. Adults are known to sip nectar at available flowers in several families in several genera (including Actostaphylos, Ceanothus, Cornus, dandelion, Fragaria, Rorippa and Spraguea) and nearby water and mud puddles (Shields 1965).

Johnson’s Hairstreak is included on the 2008 Interagency Special Status / Sensitive Species Program (ISSSSP) list for Oregon and Washington. It currently is on the Washington State Candidate list, and is not included on State of Oregon or State of Idaho lists. It does not currently have Federal Threatened or Endangered status. The Oregon Natural Heritage Information Center of the Institute for Natural Resources at Oregon State University (2004) includes it on their Threatened or Endangered throughout Range list.

There are several closely-related hairstreaks with overlapping ranges in the northwest that can be confused with C. johnsoni, making surveys difficult. This is especially true if identification is based on larvae. In particular, C. spinetorum, the Thicket Hairstreak butterfly, which also feeds exclusively on dwarf mistletoes, occurs throughout the western United States, including eastern Oregon and Washington (Shields 1965). The larvae of Johnson’s Hairstreak are indistinguishable from that of the Thicket Hairstreak (Scott 1986). Shields (1965) also states:

“However, it was necessary to see C. johnsoni specimens wherever possible or have someone familiar with C. johnsoni make the identification since there is definitely misunderstanding about what the name represents. C. nelsoni (another closely- related hairstreak) and C. spinetorum have occasionally been misidentified as C. johnsoni.”

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Color differences between the adults of C. Johnsoni and C. spinetorum is the primary way to differentiate these species, although Shields (1965) describes substantial variation between populations of both of these species.

Although Johnson’s hairstreak is documented from only three sites in northeastern Oregon it is likely to be more widespread. It is probable that surveys have not been numerous enough to reveal all locations of breeding populations. Species accounts describe it as not abundant and relatively few individuals have been found when compared to more abundant butterfly species (Dornfeld 1959, McCorkle 1962, Dornfeld 1980, Hinchliff 1994). This is likely due to several life history traits. First, although represent over a quarter of the number of species on earth, most are small, few in number or cryptic and thus little known. The Johnson’s hairstreak has the advantage of belonging to the , and thus receiving more attention than most insects. However, it is small and not common and thus has not been widely collected. Second, the larvae mimic the dwarf mistletoe plants and are thus not readily visible (Stevens and Hawksworth 1970). In addition, the plants and thus adult egg-laying occur in the crowns of trees, which are often not readily accessible or observable from the ground. Finally, northeastern Oregon butterfly fauna have not been as well surveyed as localities closer to urban areas..

Occurrence of Johnson’s Hairstreak has a well documented history in Oregon and Washington (Dornfeld 1980, Hinchliff 1994). West of the Cascade crest in low elevation “old” western hemlock forests larvae feed on dwarf mistletoe plants (Arceuthobium tsugense subsp. tsugense) on western hemlock and possibly A. tsugense subsp. mertensianae (McCorkle1962, Shields 1965, Dornfeld 1980, Hinchliff 1994, Hinchliff 1996, Washington Dept. of Fish and Wildlife 1995, Layberry et al. 1998, Pyle 2002), which rarely infects western hemlock (Hawksworth and Wiens 1996). It is documented in the Medford District and suspected in the Klamath Falls and Salem Districts of the Bureau of Land Management (ISSSSP 2008). It also is noted in high elevation stands in southwest Oregon and the Siskiyou Mountains on dwarf mistletoe-infected (A. abietinum) Brewer spruce and true fir (Miller and Hammond 2007).

While C. johnsoni is confirmed in northeastern Oregon (Dornfeld 1980, Hinchliff 1994), the dwarf mistletoe species that provide the larval food here are unknown. C. johnsoni has only been described feeding on the dwarf mistletoes that infect true firs, Brewer spruce and western hemlock and these dwarf mistletoes do not occur in northeastern Oregon. All western North American species of Arceuthobium are very similar and closely related. While not documented in the literature, Johnson’s Hairstreak is believed to feed generally on all dwarf mistletoe species throughout its range, and to perhaps specialize on locally available dwarf mistletoes in specific localities (Miller per.com. 2008).

The more common Thicket Hairstreak has been found feeding on ten different species of Arceuthobium. Each dwarf mistletoe species is closely tied to one or two host conifers, represented by ponderosa pine, lodgepole pine, western larch, white fir and six additional pines. Douglas-fir dwarf mistletoe (A. douglasii) however, is not included in the host list (Stevens and Hawksworth 1970, Shields 1965). This would represent three of the four dwarf mistletoes found in the Blue and Wallowa Mountains: A. laricis, A. campylopodum, and A. americanum. However, Hawksworth and Wiens (1996) state that they believe that Thicket Hairstreak can feed on all western north American species of Arceuthobium. This

2 would mean that the Thicket Hairstreak could use a wide range of conifer habitat where at least one of the species of Arceuthobium is found.

Dwarf mistletoe taxonomy dramatically changed in the 1970’s. Documentation of the host dwarf mistletoe species used by the Johnson’s Hairstreak appears to be based on observations from the 1960’s or earlier (Shields 1965) and pre-1972 Arceuthobium taxonomy literature. At one time there were five recognized species of dwarf mistletoe in North America, which included A. pusillum, A. americanum (on lodgepole pine), A. douglasii (Douglas-fir), A. vaginatum (three needle pines), and A. campylopodum (on other pines, spruce, true firs, hemlock, and larch), assigned based on their host (Gill 1935; Pierce 1960, Hawksworth and Wiens 1972). Of importance here is that the “host forms” of dwarf mistletoe, as they were then known, on Brewer spruce, true firs and western hemlock, were then considered within the Arceuthobium campylopodum complex. In 1972, Hawksworth and Wiens (1972) revised the Arceuthobium taxonomy and host forms were differentiated into separate species or subspecies. Dwarf mistletoe on Brewer spruce and white fir is now called A. abietinum f. sp. concoloris, and the principle species on western hemlock is now called A. tsugense subsp. tsugense (principle). Most importantly, the name A. campylopodum (western dwarf mistletoe) now is reserved for the single species that infects ponderosa pine and Jeffrey pine.

References of C. johnsoni in recent entomology literature to association with A. campylopodum (Pyle 2002, Opler 2006) are probably based on the old mistletoe taxonomy when campylopodum included true firs, hemlocks, spruces, and larch, rather than ponderosa pine. This is confusing because using the old taxonomy suggests that western dwarf mistletoe, which is only found on pines, has been documented as a foodplant for this . While Johnson’s hairstreak is documented in northeastern Oregon, there is no record as to what the larval host plant is here. Based on its use of several dwarf mistletoe species in west-side forests, it is probable that Johnson’s Hairstreak would likely use any of the available species of dwarf mistletoes, including A. campylopodum, in northeastern Oregon as well as elsewhere in its range.

Because the Johnson’s Hairstreak is documented in northeastern Oregon (Miller and Hammond 2007, Miller and Hammond per. com. 2008, Black and Lauvray 2005, Opler et al. 2006, Pyle 2002) the question of amount of existing larval food plant can be asked. Dwarf mistletoes are well-represented in many stand types in the Blue and Wallowa Mountains, and usually dwarf mistletoes will occur in two or more conifer species in the same community. The mistletoes that do occur in northeastern Oregon include A. laricis, A. campylopodum, A. americanum, and A. douglasii (Gast and others 1991). Their conifer hosts include western larch, ponderosa pine, lodgepole pine, and Douglas-fir. Table 1 displays incidence of dwarf mistletoes by proportion of trees infected and average Dwarf Mistletoe Rating from the Current Vegetation Survey (CVS) plot record (Schmitt 2002). There is no reason to believe that in northeastern Oregon, Johnson’s Hairstreak cannot use any of the four available species of dwarf mistletoes as foodplants (Miller per.com 2008). Range and distribution of the Butterfly would be limited by occurrence of dwarf mistletoe-infected conifers and other habitat requirements. These other dwarf mistletoe hosts, including all of the dwarf mistletoes found in northeastern Oregon, have not yet been reported as foodplants of Johnson’s Hairstreak in the published literature.

3 Table 1. Dwarf Mistletoe Occurrence and Severity in the CVS Plot Record for the Umatilla, Wallowa-Whitman National Forests (Schmitt 2002) Umatilla NF Wallowa- Malheur Whitman NF NF Lodgepole pine % Plot host trees infected 13.6% 6.6% 13.5% dwarf mistletoe Average DMR of infected trees 1.86 2.66 2.54 Western dwarf % Plot host trees infected 6.0% 8.3% 8.5% mistletoe Average DMR of infected trees 2.37 3.03 2.84 Douglas-fir % Plot host trees infected 13.6% 18.7% 17.1% dwarf mistletoe Average DMR of infected trees 2.73 3.45 2.78 Western larch % Plot host trees infected 10.5% 27.2% 17.7% dwarf mistletoe Average DMR of infected trees 3.0 3.53 2.39

In some areas of the western United States, dwarf mistletoe sanitation and control have substantially reduced the incidence of infected hosts. In northeastern Oregon changes in dwarf mistletoe incidence and severity associated with management have been low to moderate and dependent upon the species in question. Hessburg and others (1999) investigated changes in historical to current insect and disease vulnerabilities of selected subbasins within the Columbia River Basin, including subbasins in the Blue Mountains Ecological Reporting Unit, which covers the area reported to host Johnson’s Hairstreak. This is probably the best available data for approximating changes from historical to current insect and disease occurrence at the watershed level. For example, area and connectivity of patches vulnerable to Douglas-fir dwarf mistletoe disturbance increased. Percentage of area rose by 63 percent from 10.1 to 16.5 percent, with patch density more than doubling from 9.3 to 19.6 patches per 10,000 ha, and mean patch size increasing from 87.5 to 125.7 ha.

Area and connectivity of patches vulnerable to western (ponderosa pine) dwarf mistletoe disturbance declined. Percentage of area declined by 22 percent from 10.4 to 8.1 percent, with patch density increasing from 9.6 to 12.7 patches per 10,000 ha, and mean patch size decreasing from 83.8 to 59.8 ha.

Area and connectivity of patches vulnerable to western larch dwarf mistletoe disturbance declined. Percentage of area declined by 38 percent from 1.3 to 0.8 percent, with patch density increasing from 1.8 to 3.6 patches per 10,000 ha, and mean patch size decreasing from 16.0 to 9.8 ha.

Area and connectivity of patches vulnerable to lodgepole pine dwarf mistletoe disturbance increased. Percentage of area increased by 7 percent from 1.5 to 1.6 percent, with patch density increasing from 2.9 to 4.0 patches per 10,000 ha, and mean patch size increasing from 21.5 to 21.8 ha.

Reductions in dwarf mistletoe occurrence may occur in harvest units, especially where regeneration harvesting has been done. In some cases, harvesting will eventually increase dwarf mistletoe incidence and severity. Examples include seral larch or pine stands where shade tolerant true firs are removed to facilitate seral species regeneration. If serals are infected with dwarf mistletoe, infection will spread to the seral understory. On the landscape scale in the Blue and Wallowa Mountains, loss of dwarf mistletoe due to harvest or sanitation is minor.

4 At the subwatershed scale, large stand replacement fires which have burned substantial areas in the last several decades, have probably caused a significant reduction in all dwarf mistletoes, and probably a longer term reduction with Douglas-fir dwarf mistletoe because of its shade tolerance. In stands with surviving large dwarf mistletoe-infected seral ponderosa pine and larch, long-term dwarf mistletoe infection may well increase, since these serals will readily regenerate in the understory. In especially hot fires with complete mortality including the old thick-barked pine and larch, dwarf mistletoe will have been effectively sanitized and many decades will elapse before dwarf mistletoe is reintroduced to significant levels by bird reintroduction and subsequent spread.

Black and Lauvray (2005) note that Johnson’s Hairstreak is called a late successional- associated Lepidoptera, “at least partially because of its dependence upon Arceuthobium”. While dwarf mistletoes can intensify and severely infest trees in old stands, especially shade-tolerant firs and hemocks, dwarf mistletoes are found in all age classes of conifers. Claims that dwarf mistletoes occur solely in oldgrowth or are dependent upon oldgrowth are erroneous. Dwarf mistletoes generally increase in incidence and intensity in older stands, although even young stands readily host dwarf mistletoes and maturing stands may be severely infected if they have been continually infected by a residual overstory.

Occurrence of Johnson’s Hairstreak in Brewer spruce, a small tree even when old, may dismiss the notion of dependence of the insect on large tree structure which may be equated with advanced age in most stand types. However, attributes other than tree size and dwarf mistletoe infection that are characteristic of late and old successional stands may be important to Johnson’s Hairstreak.

Conclusions Documentation of occurrence and distribution of Johnson’s Hairstreak in northeastern Oregon should continue. Confirmation of use by any or all of the different species of Arceuthobium, represented by larch, ponderosa pine, lodgepole pine and Douglas-fir, will allow better understanding of the needs of this insect and the habitats it is able to use. Four species of dwarf mistletoes occur in the Blue Mountains and all commonly occur in and adjacent to the Baker City watershed, East Pine Creek and North Pine Creek areas in managed and unmanaged stands. Dwarf mistletoe-infected conifers are common throughout northeastern Oregon. Current dwarf mistletoe levels are not believed substantially less than historic levels on a landscape scale, and with Douglas-fir dwarf mistletoe, are believed higher. This food source of the Johnson’s Hairstreak is unlikely to be a factor impacting its distribution or population. Because of the common occurrence of dwarf mistletoes in northeastern Oregon, Johnson’s Hairstreak is probably more common than the limited surveys and documentation that have been done to date would indicate. Populations within large fire areas are likely to be impacted until dwarf mistletoe levels return to historic levels.

In the absence of recent large scale disturbance, dwarf mistletoe infestation levels can occur in early, mid and late successional stands.

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Craig L. Schmitt Lia H. Spiegel Pathologist Entomologist cc: Bob Rock Don Scott Karen Haines Delanne Ferguson, Umatilla NF Rene Mabe, Malheur NF

Literature Cited

Black, S.H., and L.Lauvray. 2005. Fact sheet for the Johnson’s Hairstreak. Available at: www.fs.fed.us/r6/sfpnw/issssp/documents/planning-docs/20050906-fact-sheet- johnsons-hairstreak.doc 8p. Interagency Special Status / Sensitive Species Program (ISSSSP).

Dornfeld, E.J. 1980. The Butterflies of Oregon. Timber Press, Forest Grove, OR. 276p.

Gast, W.R., Jr.; D. Scott, C. Schmitt, D. Clemens, S. Howes, C. Johnson, R. mason, F. Mohr, and R. Clapp. 1991. Blue Mountains Forest Health Report, “New perspectives in forest health”. Baker City: OR; US Department of Agriculture, Forest Service, Pacific Northwest Region, Malheur, Umatilla, and Wallowa-Whitman National Forests.

Gill, L.S. 1935. Arceuthobium in the United States. Conn. Acad. Arts and Sci. Trans. 32:111-245.

Hawksworth, F.G., and D.Wiens. 1972. Biology and classification of dwarf mistletoes (Arceuthobium). Agriculture Handbook No. 401. Washington D.C: US Department of Agriculture, Forest Service. 234p.

Hawksworth, F.G., and D.Wiens. 1996. Dwarf mistletoes: biology, pathology, and systematics . Giels, B.W. technical ed. And Nisley, R.G. managing ed. Agriculture Handbook No. 709. Washington D.C: US Department of Agriculture, Forest Service. 410p.

Hessburg, P.F., B.G. Smith, S.D. Kreiter, C.A. Miller, R.B. Salter, C.H. McNicoll, and W.J. Hann. 1999. Historical and current forest and range landscapes in the Interior Columbia Basin and portions of the Klamath and Great Basins. Pages 186, 188, 337, 338. Part 1: Linking vegetation patterns and landscape vulnerability to potential insect and pathogen disturbances. General Technical Report PNW-GTR-458. Portland OR: US Department of Agriculture, Forest Service, Pacific Northwest Research Station. 357p.

Hinchliff, J. 1994. An atlas of Washington butterflies. The Evergreen Aurelians. The Oregon State University Bookstore, Inc, Corvallis, OR. 162p.

6 Hinchliff, J. 1996. An atlas of Oregon butterflies. The Evergreen Aurelians. The Oregon State University Bookstore, Inc. Corvallis, OR. 176p.

LaBonte, J.R., D.W. Scott, J.D. McIver, J.L. Hayes. 2001. Threatened, endangered, and sensitive insects in eastern Oregon and Washington forests and adjacent lands. Northwest Science 75, Special Issue: 185-198.

Layberry, R.A., P.W. Hall, and J.D. Lafontaine. 1998. The butterflies of Canada. Univ. Toronto Press, Toronto, Ont. 280 p. (http://www.cbif.gc.ca/spp_pages/butterflies/species/Johnson'sHairstreak_e.php)

McCorkle, D.V. 1962. Notes on the life history of Callophrys (Mitoura) johnsoni Skinner (Lepidoptera, Lycaenidae). Proc. Wash. State Ent. Soc. 14: 103-105.

Miller, J.C., and P.C. Hammond. 2007. Butterflies and moths of the Pacific Northwest forests and woodlands: Rare, endangered, and management-sensitive species. Report FHTET-2006-07. US Department of Agriculture, Forest Service, Forest Health Technology Enterprise Team. 234p.

Miller, J.C., and P.C. Hammond. 2008. Personal communication

Oregon Natural Heritage Information Center. 2004. Rare, Threatened and Endangered Species of Oregon. Oregon Natural Heritage Information Center, Oregon State University, Portland, Oregon. 105 pp. (http://oregonstate.edu/ornhic/2004_t&e_book.pdf).

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

Pierce, W.R. 1960. Dwarf mistletoe and its effect upon the larch and Douglas-fir of western Montana. Bulletin No. 10, School of Forestry, Montana State University. Missoula, MT 38p.

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 WA. 419p.

Schmitt, C.L. 2002. Incidence and severity of selected conifer diseases identified in the Current Vegetation Survey (CVS) for the Umatilla, Wallowa-Whitman, and Malheur National Forests. Report BMPMSC 02-05. US Department of Agriculture, Forest Service, Pacific Northwest Region, Wallowa-Whitman National Forest.

Scott, J.A. 1986. The butterflies of North America: a natural history and field guide. Stanford Univ. Press. Stanford: CA

Shields, O. 1965. Callophrys (Mitoura) spinetorum and C. (M.) johnsoni Their known range, habits, variation, and history. Journal of Research on the Lepidoptera 4(4):233- 250.

7 Stevens, R.E., and F.G. Hawksworth. 1970. Insects and mites associated with dwarf mistletoes. US Department of Agriculture, Forest Service, Rocky Mountain Research Station. Research Paper RM-59. 12p.

Tilden, J.W., and A.C. Smith. 1986. Peterson Field Guides: A Field Guide to Western Butterflies. Houghton Mifflin Co. Boston: MA.

Washington Department of Fish and Wildlife. 1995. Johnson’s (mistletoe) hairstreak. Volume 1: Invertebrates: (7). 3p.

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