Johnson’s Hairstreak (Callophrys johnsoni): COSEWIC assessment and status report 2022

Official title: COSEWIC Assessment and Status Report on the Johnson’s Hairstreak (Callophrys johnsoni) in Canada

Committee on the Status of Endangered Wildlife in Canada (COSEWIC)
Special concern 2022

COSEWIC assessment summary

Assessment summary – May 2022

Common name

Johnson’s Hairstreak

Scientific name

Callophrys johnsoni

Status

Special Concern

Reason for designation

This butterfly is found in Canada only in southern British Columbia from Vancouver Island east to Hope. It lives in coastal old growth and late successional second growth coniferous forests with a large component of Western Hemlock. Caterpillars feed only on flowers of Hemlock Dwarf Mistletoe, a hemiparasite of Western Hemlock. Hemlock Dwarf Mistletoe reduces economic value of trees and therefore forest management practices that remove Western Hemlock to reduce mistletoe in older forests are an ongoing threat. This species could become Threatened if threats influencing its persistence are not managed.

Occurrence

British Columbia

Status history

Designated Special Concern in May 2022.

COSEWIC executive summary

Johnson’s Hairstreak

Callophrys johnsoni

Wildlife species description and significance

Johnson’s Hairstreak is a small (2.5-3.0 cm wingspan) chocolate-brown butterfly with white-tipped tails on the hindwings. Sexes differ slightly; females tend to be larger and paler brown than males.

Johnson’s Hairstreak is one of a group of butterflies that reach their northern distribution limit in western Canada. Caterpillars feed on Hemlock Dwarf Mistletoe that grows in Western Hemlock dominated forests. The mistletoe is considered a pest by the forest industry.

Distribution

In Canada, the species has a small range in southwestern British Columbia (BC), extreme southeastern mainland to Hope. There are ten extant and 5 historical subpopulations; however, there are likely additional subpopulations. The global range extends to coastal California, and east to Idaho. Less than 5% of the global range is in Canada.

Habitat

In BC, Johnson’s Hairstreak inhabits coastal old growth and late successional second growth (> 81 years) coniferous forests with a large (> 40%) component of Western Hemlock. Most records are under 625 m above sea level (asl); however, there is one subpopulation on Vancouver Island at 880-980 m asl.

Larvae feed on Hemlock Dwarf Mistletoe, a hemiparasitic plant dependent on Western Hemlock. As a forest stand ages, mistletoe abundance increases both on individual trees, and throughout the stand. Mistletoe forms dense brooms on different branches, produces seeds, and spreads throughout a tree. The caterpillar requires blooming shoots of Hemlock Dwarf Mistletoe upon which to feed. In BC, an estimated 15% of Western Hemlock stands host Hemlock Dwarf Mistletoe, concentrated in a north-south band about 150 km wide along the coast.

Adults spend time in the canopy and descend to open meadow where they feed on nectar from various flowers.

Biology

Johnson’s Hairstreak develops through complete metamorphosis (egg, caterpillar, pupa, adult). Adults fly and mate from late May through late June in BC. The eggs are laid singly on sprouting and blooming shoots of Hemlock Dwarf Mistletoe, presumably in the upper canopy. Eggs hatch within a few weeks and larvae grow through four instars, feeding on all parts of Hemlock Dwarf Mistletoe. Johnson’s Hairstreak overwinters as a pupa sheltered in a mistletoe broom. There is one generation per year in BC.

Population sizes and trends

Johnson’s Hairstreak surveys have focused on recording new subpopulations, natural history, and habitat information, resulting in observations from 1900 to 2021. The primary survey method has been wandering transects during the adult flight period, through potential areas where flowering plants are abundant, the surveyor targeting floral patches to observe resting and feeding butterflies. No information on the Canadian population size or trends are available. A decline in the overall Canadian population is inferred and projected based on the documented historical loss of older growth forest, projected future loss of Johnson’s Hairstreak habitat based on current logging practices, and long-term forest management practices that minimize mistletoe abundance to protect timber quality.

Threats and Limiting factors

The highest impact threat to Johnson’s Hairstreak and potential habitat is the removal of older growth and late successional second growth (> 81 years) forests throughout the Coastal Western Hemlock Biogeoclimatic Zone in southwestern BC. At present, approximately 1945 km² of old growth and late successional second growth (> 81 years) habitat remains within the potential range of Johnson’s Hairstreak.

Logging and forest management recommendations that limit the spread of Hemlock Dwarf Mistletoe are effectively reducing the potential future habitat for Johnson’s Hairstreak and can be used to infer and project a decline in future Johnson’s Hairstreak habitat. Forest management that results in reduced mistletoe include general or targeted removal of mistletoe-infected trees (e.g., clearcut harvesting, partial harvesting with selective removal of infected trees) and historical silvicultural practices that have resulted in stand conditions that are not conducive to mistletoe growth/establishment (e.g., clearcutting followed by even-aged planting).

Protection, status and ranks

Johnson’s Hairstreak has some protection under the provincial Forest and Range Practices Act, and Protected Areas Act. It is listed as Identified Wildlife and managed through provisions outlined in the Identified Wildlife Management Strategy. Johnson’s Hairstreak is not protected under the provincial Wildlife Act and there are no confirmed records in provincial parks or protected areas. The species is recorded from Stanley Park (a federal property owned by Parks Canada Agency and managed by the City of Vancouver) and Pacific Spirit Park (Metro Vancouver regional government).

Globally, Johnson’s Hairstreak is ranked apparently Vulnerable (G3), nationally it is Critically Imperilled/Imperilled (N1N2) and provincially it is S1 (Critically Imperilled). The host plant is not at risk. Most extant subpopulations of Johnson’s Hairstreak span multiple landowners including provincial crown forestland, municipal and regional parks, and private land.

Technical summary

Callophrys johnsoni
Johnson’s Hairstreak
Porte-queue de Johnson
Range of occurrence in Canada: British Columbia

Demographic information

Generation time

1 year

Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?

Inferred continuing decline in habitat quality and quantity due to logging of old growth and late successional second growth, and management of second growth that limits mistletoe development and therefore numbers of butterflies.

Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]

Unknown

[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].

Unknown

[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].

Unknown

[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.

Unknown

Are the causes of the decline a.) clearly reversible; b.) understood; c.) ceased?

1. No
2. Yes
3. No

Are there extreme fluctuations in number of mature individuals?

No

Extant and Occupancy Information

Estimated extent of occurrence (EOO)

17,385 km² (extant and historical records)

Index of area of occupancy (IAO)

48 km² (extant subpopulations)

68 km² (extant and historical subpopulations)

Is the population “severely fragmented” i.e., is > 50% of its total area of occupancy in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?

1. No
2. Yes

Number of “locations”^*

<20, but >10, based on logging

Is there an [observed, inferred, or projected] decline in extent of occurrence?

Yes. Inferred and projected for areas with forest management that minimizes the growth of host plant (mistletoe), including peripheral occurrences.

Is there an [observed, inferred, or projected] decline in index of area of occupancy?

Yes. Inferred and projected for areas with forest management that minimizes the growth of host plant.

Is there an [observed, inferred, or projected] decline in number of subpopulations?

Yes. Inferred and projected for areas with forest management that minimizes the growth of host plant.

Is there an [observed, inferred, or projected] decline in number of locations*?

Yes. Inferred and projected for areas with forest management that minimizes the growth of host plant.

Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?

Yes. Inferred and projected for areas with forest management that minimizes the growth of host plant.

Are there extreme fluctuations in number of subpopulations?

No

Are there extreme fluctuations in number of “locations”^*?

No

Are there extreme fluctuations in extent of occurrence?

No

Are there extreme fluctuations in index of area of occupancy?

No

* See Definitions and Abbreviations on COSEWIC website and IUCN for more information on this term.

Number of Mature Individuals (in each subpopulation)

Subpopulations (give plausible ranges): Few specimens collected and observed, insufficient information to calculate mature individuals

Unknown

N Mature Individuals : Total

Unknown

Quantitative analysis

Is the probability of extinction in the wild at least [20% within 20 years or 5 generations, or 10% within 100 years]?

Not applicable, insufficient data.

Threats (direct, from highest impact to least, as per IUCN Threats categories)

Was a threats calculator completed for this species?

Yes, threat impact High. Completed May 25, 2021:

• 5.3 Logging and wood harvesting – High impact
• 1.1 Housing and Urban Areas – Low impact
• 1.2 Commercial and Industrial areas – Low impact
• 9.3 Agricultural and forestry effluents – Low impact
• 7.1 Fire and fire suppression – Unknown impact
• 8.1 Invasive non-native/alien species/diseases – Unknown impact
• 11.2 Droughts – Unknown impact
• 11.3 Temperature extremes – Unknown impact

What additional limiting factors are relevant?

• Caterpillar host plant specificity and quality of host plant (i.e., exposed blooming shoots).
• Morphological attributes (e.g., length of tongue limits nectar availability).
• Small population size and genetic isolation.
• Vulnerability to weather patterns.
• Limited dispersal ability.

Rescue effect (immigration from outside Canada)

Status of outside population(s) most likely to provide immigrants to Canada.

Washington S2S3 (Imperilled/Vulnerable); closest population to BC is 60 km

Is immigration known or possible?

Not known, unlikely; generally short dispersal distances.

Would immigrants be adapted to survive in Canada?

Yes

Is there sufficient habitat for immigrants in Canada?

Yes, in small, isolated patches

Are conditions deteriorating in Canada?⁺

Yes, see Threats.

Are conditions for the source (i.e., outside) population deteriorating?

Yes, see Rescue effect.

Is the Canadian population considered to be a sink?⁺

No

Is rescue from outside populations likely?

No

+ See Table 3 (Guidelines for modifying status assessment based on rescue effect).

Data sensitive species

Is this a data sensitive species? No

Status history

COSEWIC:

Designated Special Concern in May 2022.

Status and Reasons for Designation:

Status:

Special Concern

Alpha-numeric:

Not Applicable

Reasons for designation:

This butterfly is found in Canada only in southern British Columbia from Vancouver Island east to Hope. It lives in coastal old growth and late successional second growth coniferous forests with a large component of Western Hemlock. Caterpillars feed only on flowers of Hemlock Dwarf Mistletoe, a hemiparasite of Western Hemlock. Hemlock Dwarf Mistletoe reduces economic value of trees and therefore forest management practices that remove Western Hemlock to reduce mistletoe in older forests are an ongoing threat. This species could become Threatened if threats influencing its persistence are not managed.

Applicability of criteria

Criterion A (Decline in Total Number of Mature Individuals): Not applicable, insufficient data

Criterion B (Small Distribution Range and Decline or Fluctuation): EOO and IAO lower than thresholds for Threatened, and ongoing decline in habitat based on threats, but does not meet other criteria needed for Threatened as locations are at a minimum 10 but suspected to be greater, and the populations are not thought to be severely fragmented and do not undergo extreme fluctuations.

Criterion C (Small and Declining Number of Mature Individuals): Not applicable, unknown population size

Criterion D (Very Small or Restricted Population): Does not meet criteria

Criterion E (Quantitative Analysis): Insufficient data to conduct quantitative analysis.

COSEWIC History

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC Mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC Membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions (2022)

Wildlife Species

A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.

Extinct (X)

A wildlife species that no longer exists.

Extirpated (XT)

A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.

Endangered (E)

A wildlife species facing imminent extirpation or extinction.

Threatened (T)

A wildlife species likely to become endangered if limiting factors are not reversed.

Special Concern (SC)*

A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.

Not at Risk (NAR)**

A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.

Data Deficient (DD)***

A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.

* Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.

** Formerly described as “Not In Any Category”, or “No Designation Required.”

*** Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” (insufficient scientific information on which to base a designation) prior to 1994. Definition of the (DD) category revised in 2006.

The Canadian Wildlife Service, Environment and Climate Change Canada, provides full administrative and financial support to the COSEWIC Secretariat.

Wildlife species description and significance

Name and classification

Phylum Arthropoda – arthropods

Class Insecta - insects

Order Lepidoptera – butterflies and moths

Superfamily Papilionoidea – butterflies and skippers

Family Lycaenidae – blues, coppers, hairstreaks, harvesters

Subfamily Theclinae – hairstreaks

Tribe Eumaeini

Genus Callophrys

Species Callophrys johnsoni (Skinner 1904)

Synonyms:

• Thecla johnsoni Skinner 1904
• Mitoura johnsoni (see Ferris 1989)
• Loranthomitoura johnsoni (see Ballmer and Pratt 1992; Guppy and Shepard 2001)

Type locality: ‘British Columbia’ (Skinner 1904; Pelham 2008), lectotype (#7044) in Academy of Natural Sciences Philadelphia (Pelham 2008).

English common names:

• Johnson’s Hairstreak (NatureServe 2021)
• Mistletoe Hairstreak (Pyle 2002)
• Brown Mistletoe Hairstreak (Pyle 2002)

French common name: Porte-queue de Johnson (iNaturalist 2022)

Taxonomic background and similarities: Callophrys johnsoni is the accepted name and there are no subspecies (Pelham 2008; Pohl et al. 2018). The species was first described as Thecla johnsoni (Skinner 1904) and moved to Mitoura by Ferris (1989). Ballmer and Pratt (1992) used first instar caterpillar morphology to separate Loranthomitoura from Callophrys and Mitoura and named it based on the mistletoe host plants. Current authorities (e.g., Scott 1986; Layberry et al. 1998; Pelham 2008; Pohl et al. 2018) combine the three genera into Callophrys, based on morphological similarities.

Johnson’s Hairstreak is closely related to Thicket Hairstreak (C. spinetorum) (Layberry et al. 1998; Pyle 2002; Pelham 2008). In Canada the geographic ranges for these two species do not overlap (British Columbia Conservation Data Centre (BC CDC) 2021) (see Morphological description). In Oregon and California, there is evidence of limited hybridization between Thicket Hairstreak and Johnson’s Hairstreak (McCorkle pers. comm. 2007; Fallon and Black 2017). Thicket Hairstreak is abundant in the Oregon Cascades, and it is possible that this species is expanding into habitat previously only occupied by Johnson’s Hairstreak (Fallon and Black 2017).

Morphological description

Johnson’s Hairstreak develops through complete metamorphosis: egg, larva (four instars), pupa, and adult (see Biology).

Adults:

Johnson’s Hairstreak is a small (2.5–3.0 cm) butterfly with white-tipped tails on the hindwings (Guppy 1989) (front cover photograph and Figure 1). The dorsal wing surfaces of both sexes are dark brown (Guppy 1989). Females tend to be larger and paler than males. On the ventral wing surfaces, a white post-median stripe crosses the middle of the wings (Guppy 1989). Small blackish dots are evident on the ventral hindwing corner.

Figure 1. Comparison of Johnson’s Hairstreak (Callophrys johnsoni) (top row left ventral view; top row right dorsal view) and Thicket Hairstreak (C. spinetorum) (bottom row left ventral view; bottom row right dorsal view). Note the additional black spots on the Thicket Hairstreak’s ventral hindwing and blue tones on top. Photos by Raymond Davis (with permission).

Johnson’s Hairstreak is similar in appearance to Thicket Hairstreak which has a more pronounced W-shape in the post-median band on the ventral hindwings, and the dorsal wing surfaces are blue rather than dark brown (Layberry et al. 1998; Guppy and Shepard 2001) (Figure 1).

Eggs:

Johnson’s Hairstreak eggs are small (approx. 0.7 mm), compressed, round and white to pale green with numerous small divots (Figure 2) (Guppy 1989; James and Nunnallee 2011). The eggs look like gumdrops.

Figure 2. Johnson’s Hairstreak (Callophrys johnsoni) egg (1-2 mm) on Hemlock Dwarf Mistletoe (Arceuthobium tsugense ssp. tsugense). Photograph by Raymond Davis (with permission).

Caterpillars:

First instar Johnson’s Hairstreak caterpillars are 1-2 mm long (Figure 3A), yellow-green, and are covered with long hairs (Guppy 1989; James and Nunnallee 2011). There are four instars (Figure 3A-E), and as caterpillars pass through each instar, a pale green stripe with red, yellow, and white bars across each segment becomes more pronounced (Guppy 1989; James and Nunnallee 2011). These strongly raised chevrons create a sawtooth appearance (Figure 3E). Mature caterpillars are 8-15 mm in length.

Figure 3. Caterpillars of Johnson’s Hairstreak (Callophrys johnsoni). A. first instar (1-2 mm); B. second to third instar (2-6 mm); C. early fourth instar (6-12 mm); D. late fourth instar (12-19 mm); E. pre-pupa (8-15 mm); and F. pupa (10-12 mm). Photographs and captions by Raymond Davis (with permission).

Pupae:

Johnson’s Hairstreak pupae (10-12 mm long) are dark chocolate brown and oval shaped, covered in short setae and silk girdle threads (Figure 3F) (Scott 1986; Guppy 1989; James and Nunnallee 2011). The silk threads are used to anchor the overwintering pupa to its overwintering site. They have been found in or adjacent to Hemlock Dwarf Mistletoe (Arceuthobium tsugense ssp. tsugense) shoots, branches, or brooms, or within dense evergreen needles adjacent to exposed mistletoe (James and Nunnallee 2011).

Population spatial structure and variability

The population structure and variability of Johnson’s Hairstreak in Canada has not been studied. The species is somewhat mobile and although dispersal distance studies have not been completed on this species, they may be able to fly up to 1 km between habitat patches (see Dispersal and migration and Rescue effect). The host plant occurs patchily throughout the butterfly’s range in the southern portion of the Coastal Western Hemlock and Coastal Douglas-fir biogeoclimatic zones (see Habitat). However, extensive historical and present-day logging has and will continue to contribute to habitat fragmentation. Washington subpopulations are 10s of km from Canadian subpopulations, likely further than dispersal distance (see Rescue effect). It is unknown how this habitat fragmentation has affected the population spatial structure and variability.

Designatable units

Johnson’s Hairstreak is being assessed as one designatable unit. There is no information on discreteness or evolutionary significance among subpopulations in Canada. There are no described subspecies. The species occurs within the Pacific Maritime terrestrial ecozone of Canada (Canadian Council on Ecological Areas 2014).

Special significance

Hairstreak butterflies are of interest because of their tight associations with host plants, taxonomic and systematic complexity, and association with some of the most at-risk plant communities in the country. Johnson’s Hairstreak is tightly associated with its obligate mistletoe host plant. This species is difficult to observe because it spends most of its adult life in the tree canopy. The old growth and late successional second growth (> 81 years old) coniferous forests of southwestern British Columbia (BC) host numerous rare and at-risk invertebrates (BC CDC 2021). Johnson’s Hairstreak is part of Canadian ecosystems that are important to Indigenous people, who recognize the interconnectedness of all species within the ecosystem.

The host plant, Hemlock Dwarf Mistletoe (Arceuthobium tsugense ssp. tsugense) (Figure 4), is considered a pest by the forest industry and can have an economic impact on timber of Western Hemlock (Tsuga heterophyla). Infections reduce the growth of the tree, and reduce the wood quality. As the mistletoe spreads on a tree, cracks in the bark allow access by pests, such as fungi.

Figure 4. The tops of Western Hemlock (Tsuga heterophyla) trees with Hemlock Dwarf Mistletoe (Arceuthobium tsugense ssp. tsugense) brooms. Johnson’s Hairstreak (Callophrys johnsoni) observed at this site, Pacific Spirit Metro Vancouver Park (#13), May 28, 2007. Photo by Michelle Connolly.

Distribution

Global range

Globally, Johnson’s Hairstreak occurs in western North America from coastal south-western BC, south through western Washington, Oregon to central California, with a potentially disjunct subpopulation in Idaho (Figure 5; Shields 1965; Layberry et al. 1998; Guppy and Shepard 2001; Fallon and Black 2017; BC CDC 2021). Additional information on the range of the species in the United States is detailed in Pyle (2002), Miller and Hammond (2007), Fallon and Black (2017), Lotts and Naberhaus (2020), and NatureServe (2021). Less than 5% of the global range of Johnson’s Hairstreak is in Canada (based on a convex polygon around the global range).

Hemlock Dwarf Mistletoe, which grows on Western Hemlock in forests within a 150 km band along the coast in BC (Figure 6), is the host plant for Johnson’s Hairstreak (see Biology and Habitat). The global range of Hemlock Dwarf Mistletoe is from Haines, Alaska in the north, and extends southward through BC, Washington, and Oregon along the coast to northern California (Hennon et al. 2001). There are additional factors that limit the global range of the butterfly, which is smaller than the range of the host plant (see Habitat and Biology).

Figure 5. Global range of Johnson’s Hairstreak (Callophrys johnsoni). Map based on Pyle (2002), Hinchliff (1996), Fallon and Black (2017) and Lotts and Naberhaus (2020).

Figure 6. Hemlock Dwarf Mistletoe (Arceuthobium tsugense ssp. tsugense) distribution in British Columbia (118,329 km²). Map created by Greg Amos (ENV).

Canadian range

In Canada, Johnson’s Hairstreak occurs in southwestern BC, from Hope in the east to Powell River in the north, including the extreme southeastern mainland and southern Vancouver Island (Figure 7). On Vancouver Island, all records are from south of Port Alberni. There are fifteen known subpopulations^{Footnote 1} of Johnson’s Hairstreak; ten extant (#1, 2, 3, 4, 5, 11, 12, 13, 14, 15) and five historical (#6, 7, 8, 9, 10) (Figure 7). Subpopulations have been defined using a 10 km separation distance; all sites within a 10 km diameter linked by continuous habitat are considered one subpopulation. Subpopulations can be composed of multiple sites.

Figure 7. Canadian range of Johnson’s Hairstreak (Callophrys johnsoni) based on convex hull polygon around known records for the species (see Table 1). The extent of occurrence (EOO) is 17,385 km² based on a convex hull polygon around known subpopulations and removing the portion of the polygon within the United States. Map by Greg Amos (ENV).

There are four historical specimens that are labeled ‘Vancouver’, with no additional information, and these are not shown on Figure 7. A record from Spuzzum was in an early published list of records for BC (Jones 1951); however, this record was deemed a misidentification (Shields 1965).

The Canadian range of the host plant, Hemlock Dwarf Mistletoe, is restricted to coastal coniferous forests in BC; the mistletoe is not found east of the Cascade Mountains (Figure 6) (Muir et al. 2007; Rusch et al. 2019; thebeczone 2022). The absence of Johnson’s Hairstreak records north of the Campbell River area and where the host plants occur (e.g., further north in coastal BC) suggests there are other factors that limit the butterfly’s geographic range (see Limiting factors).

The range of the Thicket Hairstreak does not overlap with Johnson’s Hairstreak in Canada. Thicket Hairstreak ranges through the central and southern interior of BC (Guppy and Shepard 2001). The closest record is east of E.C. Manning Provincial Park (BC CDC 2021), approximately 100 km from the nearest Johnson’s Hairstreak subpopulation in Hope (#9) (Table 1).

Extent of occurrence and area of occupancy

The extent of occurrence (EOO) of Johnson’s Hairstreak in Canada is 17,385 km² using a minimum convex polygon encompassing extant and historical records (Figure 7). The index of area of occupancy (IAO) is 48 km² (2 km X 2 km grid) including only extant records and 68 km² including extant and historical records (Figures 8, 9). Even given an expectation of some new occurrences, IAO is expected to be less than 100 km².

Search effort

Johnson’s Hairstreak museum specimens, survey observations, and photographic records in Canada date from 1900 to 2021. The first records are labelled with the vague collection locality of ‘Vancouver’ in 1900 and 1904 and ‘West Vancouver’ in 1963. The three most recent records are observations from San Juan Ridge (#3; in 2016), North Vancouver (#1; in 2021) and Squamish (#15; in 2021). There has been a minimum of 47 sight and museum records in Canada since it was first recorded in 1900 (BC CDC 2021; Table 1).

Johnson’s Hairstreak searches target the adult life stage and are completed by searching for flowering plants in open habitats near Western Hemlock stands (Figure 8). Presumably, adult Johnson’s Hairstreak prefer the upper tree canopy (Scott 1986; Pyle 2002): males establish territories and patrol for mates, females seek mates and search for exposed mistletoe masses upon which to oviposit (lay) eggs; and both sexes may rest and seek shelter within these areas. However, adults need to maintain a constant nectar supply, and will travel down to the ground to feed upon flowering plants, where they are observed. Eggs, caterpillars, and pupae reside in mistletoe masses in the upper strata of old growth and late successional second growth Western Hemlock (see Life Cycle). The difficulty in access means surveys do not target these life stages.

Figure 8. Hemlock Dwarf Mistletoe range with occurrences of Johnson’s Hairstreak (Callophrys johnsoni) and sampling where no Johnson’s Hairstreak were found (see Search effort). Map created by Greg Amos (ENV).

Recent (in the past 25 years) surveys for Johnson’s Hairstreak (Table 2, Figure 8) have focused on potential habitat, recording the species’ presence and documenting habitat and natural history information. From 1997 to 2021 (including search effort completed during the preparation of this status report), butterfly search effort totals > 2248 survey hours and >12,023 km wandering transect surveys during the flight period, in suitable habitat (e.g., open areas adjacent to old growth or late successional second growth forests with mistletoe) and in the Canadian range of Johnson’s Hairstreak (Table 2).

Surveys completed in 2021 (during preparation of this status report) targeted seven areas with older records for Johnson’s Hairstreak in the lower mainland. Search effort totalled just more than 43 hours across six days and 96 km of linear surveys (Table 1 and 2). No Johnson’s Hairstreak were recorded during these surveys.

In BC, the range of Hemlock Dwarf Mistletoe (118,329 km²) is much larger than the known range of Johnson’s Hairstreak (17,385 km²) and extends through remote areas of coastal BC, where Lepidoptera surveys are limited. Data were compiled from iNaturalist and the Canadian Forest Service to partially compensate for this (see Figure 8).

iNaturalist is an effective online archive of butterfly observations (#1, 3, and 15 are from iNaturalist; see Table 1). This and other citizen science platforms (e.g., Victoria Natural History Invertebrate Alert, BugGuide, eButterfly) can show evidence of null search effort. Lepidoptera posted to iNaturalist within the BC range of Hemlock Dwarf Mistletoe and in the Johnson’s Hairstreak flight period include 3803 observations in May; 3681 observations in June and 4581 observations in July (as of March 1, 2022) (iNaturalist 2022)^{Footnote 2}. Of these 12,065 observations within the range of Hemlock Dwarf Mistletoe, only three (#1, 3, 15) are Johnson’s Hairstreak (Figure 7).

The study of forest insects and their impacts on Canada’s forests became a priority in the late 1940s, and for the past 80 years there have been ongoing surveys and programs led by the Canadian Forestry Service to monitor forest insects, colloquially known as FIDS (Forest Insect and Disease Survey) (van Sickle et al. 2001; Natural Resources Canada 2021). From the late 1940s until the mid-1990s, general Lepidoptera (and other insect) surveys on coastal BC collected and reared live larvae to adults for identification; the specimens were tallied and deposited in museums (i.e., the Pacific Forestry Centre, Victoria) (van Sickle et al. 2001). For example, two historical Johnson’s Hairstreak subpopulations are known from reared specimens collected during these studies (#7 in 1969, #8 in 1958). Few of these reports are available electronically, and the data are difficult to extract. However, two reports were used as exemplars: the 1964 (Canadian Forest Service 1965) report tallies 986 sites^{Footnote 3} within the range of Hemlock Dwarf Mistletoe were sampled for larvae and in 1976 (Canadian Forestry Service 1977), 2217sites were sampled. No Johnson’s Hairstreak were recorded during these years (Figure 8), but these are additional null data and demonstrate there has been extensive survey effort to the north of the known geographic range.

Habitat

Habitat requirements

Johnson’s Hairstreak occurs in the Coastal Western Hemlock (CWH) and Coastal Douglas-fir (CDF) biogeoclimatic zones (BGZ)^{Footnote 4}. The subzones for the host plants in the CWH are very dry maritime (CWHxm); dry maritime (CWHdm); moist maritime (CWHmm), and very wet maritime (CWHvm). The CDF subzone is the moist maritime (CDFmm) (Rusch et al. 2019).

Ecosystem:

Johnson’s Hairstreak is considered an old growth forest obligate butterfly (Layberry et al. 1998; Guppy and Shepard 2001; Pyle 2002). The species inhabits old growth and late successional stage (> 81 years) coniferous forests dominated by Western Hemlock (Tsuga heterophylla) with the species’ host plant, Hemlock Dwarf Mistletoe. These forests can include areas that have not been logged (e.g., old-growth > 250 years); second or even third growth forests > 81 years, so long as the host plant is present and reproducing. Most records are below 625 m above sea level (asl) although records in the San Juan Ridge area (#3) are 880-980 m asl (BC CDC 2021). This higher-elevation record is likely a result of the south-facing aspect and nearness to the ocean that makes for a milder climate.

The primary host of Hemlock Dwarf Mistletoe is Western Hemlock. Secondary hosts can be parasitized when they grow near infected primary hosts (Rusch et al. 2019). These include Amabilis Fir (Abies amabilis), Subalpine Fir (Abies lasiocarpa), and occasionally Grand Fir (Abies grandis), and Shore Pine (Pinus contorta var. contorta) (Smith 1966; Mathiasen 1994; Rusch et al. 2019). Patterns of mistletoe growth are variable at the tree, stand and landscape level and depend on the tree structure, age, and the forest stand disturbance history. In BC, an estimated 15% of Western Hemlock stands host Hemlock Dwarf Mistletoe, mostly in a north-south band about 150 km wide along the coast (Alfaro 1985).

The extent of suitable habitat required to sustain a subpopulation of Johnson’s Hairstreak is unknown. Adult observations are often within floral meadows and roadsides, most with accurate geographic positioning system coordinates (#2, 3, 4, 11, 13, 14, 15) within 1 km of old growth or late successional stage forest cover (> 81 years, as determined using satellite imagery; Amos pers. comm. 2021). For the observations at Pacific Spirit Park (#13) (Connolly 2007), Stanley Park (#4) (Worchester and Johnson 2007), and Sechelt-Dakota Forest Service Road (#2) (Parkinson et al. 2009a) there is confirmed Hemlock Dwarf Mistletoe at these sites.

Adult habitat:

Johnson’s Hairstreak requires forest openings, likely within 1 km of Hemlock Dwarf Mistletoe in Western Hemlock stands, with an abundance and diversity of flowering plants to provide nectar through the flight period (May – June). See Table 3 for a list of Johnson’s Hairstreak nectar plants in BC (from Fallon and Black 2017).

Egg habitat:

Eggs are laid singly on an exposed mistletoe mass in the crowns of Western Hemlock (see Biology).

Caterpillar habitat:

Johnson’s Hairstreak caterpillars feed only on Hemlock Dwarf Mistletoe, which is a hemiparasitic (both photosynthetic and parasitic), perennial seed-bearing plant with the principal host Western Hemlock (Smith 1966; Hennon et al. 2001). Mistletoes contain chlorophyll and can make some of their own food but also need the host tree for water and nutrients. In BC there are two subspecies of Hemlock Dwarf Mistletoe that occur along the coast: Hemlock Dwarf Mistletoe and Mountain Hemlock Dwarf Mistletoe (A. t. mertensianae) (BC CDC 2021). Since Johnson’s Hairstreak has primarily been recorded at elevations less than 625 metres (Guppy and Shephard 2001; BC CDC 2021), it is assumed the species only feeds on Hemlock Dwarf Mistletoe (Layberry et al. 2001). There is one record of Johnson’s Hairstreak at 880-980 m asl (#3 San Juan Ridge) but as noted the higher elevation is likely because of a milder climate in coastal Vancouver Island. Confirmation of the mistletoe subspecies and nearby host trees is needed for this subpopulation. Figure 9 shows the known occurrences of Johnson’s Hairstreak and the stands of Western Hemlock presumed to be suitable to support Hemlock Dwarf Mistletoe.

Mistletoe life cycle is summarized from Rusch et al. (2019) and Hawksworth and Wiens (1996). Hemlock Dwarf Mistletoe seeds are surrounded by a fleshy berry, which swells with water pressure as the seed matures. When the inside water pressure becomes high enough, the berry explodes, and the seeds are discharged at speeds up to 24 m/s (Hinds and Hawksworth 1965). Seeds can travel horizontally (up to 10-15 m) and further laterally depending on their original height and position on the tree (Geils and Hawksworth 2002). The seeds are coated in a viscous, sticky substance (“viscin”) that allows them to attach to any host tree’s needles or branches they encounter during their flight. Rain softens the sticky viscin which enables the seed to slide down the branches or needles and become lodged at the base of a branch or needle. The viscin then hardens. The seed is protected through the winter months until germination in the spring. After germination it forms a rootlike structure that wedges its way through the bark of the host tree. These rootlike structures eventually spread under the bark and cause the host branch to swell, bloat, branch, become clumped, and sometimes develop brooms. Once the seed is rooted into the host tree, it takes 2 to 3 years to produce aerial mistletoe shoots which form minute flowers in July to August in the fourth year. These flowers contain nectar which attract insects that pollinate the female flowers in July, August, or September (Hennon et al. 2001). Fruits are formed in the fifth year with seed dispersal occurring in late September and October (Unger 1992). Fruit matures in 13 to 14 months (Mathiasen 1994) and seeds germinate in February to May (Smith 1966), the entire life cycle taking approximately 6 to 7 years to the seed germination stage. Hemlock Dwarf Mistletoe continues to live in the host tree if that tree is still alive; it will put out new aerial shoots if there is sufficient light for photosynthesis (Rusch et al. 2019). These shoots typically only live for 2 to 3 years (Baranyay and Smith 1972). Johnson’s Hairstreak caterpillars seem to prefer the terminal buds (see Physiology and adaptability) of Hemlock Dwarf Mistletoe (James and Nunnallee 2011).

Hemlock Dwarf Mistletoe spread is assisted by small-scale disturbance that occurs in older forests (> 81 years). Mistletoe seeds produced in older trees can colonize nearby younger trees growing in forest gaps where there is sufficient light (Hennon et al. 2001). Seed dispersal is through the explosive release of the seed (as described above) as well as likely spread by attaching to the fur of small mammals and feathers of birds (Rusch et al. 2019).

Figure 9. Johnson’s Hairstreak (Callophrys johnsoni) subpopulations (see Table 1) and polygons of present-day (2021) Western Hemlock (Tsuga heterophyla) forest stands > 81 years old. The spatial data from BC government data warehouse (VRI – 2020 – Forest Vegetation Composite) were used to filter habitat with the following parameters: Coastal Western Hemlock forests > 81 years old and dominated by Western Hemlock (host plant) and under 700 m elevation asl. Map completed by Greg Amos (ENV).

Pupa habitat:

Johnson’s Hairstreak overwinters as a pupa. Pupae have not been found in BC; however, pupae overwinter hidden between the needles of Western Hemlock or in dense mistletoe brooms. Keeping pupae alive is difficult (James and Nunnallee 2011).

Habitat trends

Johnson’s Hairstreak inhabits old growth or late successional second growth coniferous forests with a large component of Western Hemlock. Western Hemlock is not a tree of high commercial value; however, these same forests include Western Red-cedar (Thuja plicata) and Douglas-fir (Pseudotsuga menziesii). Both are extremely high value as timber and construction materials. The most efficient and economical method of timber extraction is clear-cut logging which cuts all standing forest, including those trees of little economic value (even when dominated by Western Hemlock). As a result, the old growth forests of coastal BC have been extensively logged over the past 150 years, including those forests with mostly Western Hemlock.

In the early 1990s the provincial government enacted the Forest Practices Code (Province of British Columbia 1996), which changed forestry in the province to include greater provisions for protecting old growth values (among many measures). This Code eventually became the Forest and Range Practices Act (Province of British Columbia 2002), which ensured forest management and silviculture was to certain standards (see Legal protection and status). However, most of the older growth (> 121 years) forest within the range of Johnson’s Hairstreak had been harvested, and what remained was in smaller pockets or late successional second growth forest (> 81 years).

Mapping was completed to determine the area of habitat potentially available for Johnson’s Hairstreak. All Johnson’s Hairstreak records were mapped, and a convex polygon created around these mapped records (Figure 7). The data from BC government data warehouse (VRI – 2020 – Forest Vegetation Composite) were used to filter habitat with the following parameters: Coastal Western Hemlock forests > 81 years old and dominated (or second most frequent tree) by Western Hemlock (host plant) and under 700 m elevation asl. Finally, a 100-km radius was extended around the convex polygon for Johnson’s Hairstreak (Figure 6, 7) to account for the possibility of undetected records for the species within this potential range (18,543.6 km², slightly more than the EOO).

The area of Western Hemlock dominated forests (both as leading and secondary species) within this potential range is 8228 km². Forests > 81 years = 4329 km² with high quality habitat, > 251 years = 2172 km² (Table 4). This analysis shows how little habitat is currently available for Johnson’s Hairstreak, about half of the Western Hemlock dominated forests.

Hw leading stands – Western Hemlock is the leading tree species in the stand.

Hw secondary stands – Western Hemlock is the second most abundant species in the stand (e.g., Douglas-fir or Western Red-cedar are primary).

Hemlock Dwarf Mistletoe is considered a tree disease in BC. When trees are parasitized, there is an increase in tree mortality, and a decrease in tree growth and wood quality mainly due to swellings on the stems (Muir et al. 2007).

Forest management to reduce mistletoe includes 1) targeted removal of mistletoe-infected trees (e.g., clearcut harvesting, partial harvesting with selective removal of infected trees) and 2) clearcutting followed by even-aged planting. Historical forest management has led to the creation of dense, even aged, second growth stands with reduced abundance of Hemlock Dwarf Mistletoe (Muir et al. 2007). Hemlock Dwarf Mistletoe shoots and flowers require light while dense dark understory prevents the mistletoe shoots from growing. Hence, Johnson’s Hairstreak larvae cannot be sustained until pupation. Although most current forest management does not lead to these dense-even aged stands, what is present on the landscape is a legacy of regenerating stands from historical forest management.

Biology

Life cycle and reproduction

Johnson’s Hairstreak has a one-year life cycle (Guppy 1989; Layberry et al. 1998; Guppy and Shepard 2001; James and Nunnallee 2011).

The adult flight period for Johnson’s Hairstreak in BC is late May to late June (Guppy and Shepard 2001; BC CDC 2021). Hemlock Dwarf Mistletoe starts producing shoots in late May and flowers July through August. Adults come to the ground to nectar, bask and visit mud (Shields 1965), but also spend much time high in the trees where dwarf mistletoe grows (James and Nunnallee 2011). When disturbed, adults often fly up, high into the trees (James and Nunnallee 2011).

Eggs are laid singly, or sometimes multiple eggs are set close together, on sprouting and blooming shoots of Hemlock Dwarf Mistletoe, presumably in the upper canopy where there is the dappled light needed for the growth of mistletoe shoots and flowers (James and Nunnallee 2011). In captivity, eggs hatched in about seven days; caterpillars passed through four instars and reached the pupal stage in 31 days (James and Nunnallee 2011). Caterpillars use camouflage for protection. Caterpillars are difficult to detect and change pattern as they develop to closely match the host plant (James and Nunnallee 2011). In southern areas of the range, Johnson’s Hairstreak has been reported having two broods, yet in BC only a single brood is known, based on adult observations (Guppy and Shepard 2001; James and Nunnallee 2011; BC CDC 2021). Caterpillars feed on all exposed plant parts and secrete a sugary solution which may be used by ants that in turn protect the caterpillar from predators (see Interspecific interactions). Caterpillars can be found on host leaves from April to October (Allen et al. 2005). Johnson’s Hairstreak overwinters as pupa. Captive reared caterpillars pupated in dense evergreen needles adjacent to mistletoe (James and Nunnallee 2011).

Physiology and adaptability

Johnson’s Hairstreak caterpillars are dependent on Hemlock Dwarf Mistletoe to complete their life history. Caterpillars reside in the higher parts of large trees and are only occasionally observed on lower branches (James and Nunnallee 2011). While the caterpillars have been observed feeding on a variety of parts of Hemlock Dwarf Mistletoe, they prefer the pale-blue terminal buds while in captivity (James and Nunnallee 2011). While feeding, caterpillars of all instars chew small round holes into the sides of mistletoe buds, and then hollow them out from the inside (James and Nunnallee 2011). Caterpillar feeding has not been observed in BC but is expected to follow a similar pattern.

Johnson’s Hairstreak could feed on the mistletoe variety that parasitizes Mountain Hemlock (e.g., A. t. mertensiana). However, this has not been observed either in BC or other parts of its range.

Like other hairstreaks (e.g., Behr’s Hairstreak, Satyrium behrii columbia, and Half-moon Hairstreak, S. semiluna), the ability of Johnson’s Hairstreak to nectar on certain wildflowers is limited by the length of their proboscis (tongue); if the depth of the flower’s corolla is greater than the tongue length then the butterfly is unable to feed on that flower (St. John pers. comm. 2021). The adaptability of the species is unstudied.

Dispersal and migration

The dispersal distance of Johnson’s Hairstreak has not been measured. Adults can fly quickly when startled (James and Nunnallee 2011), indicating that they are relatively strong fliers. Johnson’s Hairstreak is non-migratory. Wind may play a role in dispersal; however, there is little information. The separation distance was set at 10 km through suitable habitat and 2 km across unsuitable habitat based on general knowledge from other hairstreaks (NatureServe 2020).

The subpopulations of Johnson’s Hairstreak in Canada on the mainland and Vancouver Island are naturally disjunct and are separated by the Strait of Georgia. The distance between known subpopulations is in Table 5. Johnson’s Hairstreak does not appear to be severely fragmented.

Interspecific interactions

Details regarding parasitoids, predators, diseases, or other factors influencing Johnson’s Hairstreak, either in BC or elsewhere, remain unknown (James and Nunnallee 2011). Evidence of wings with bite marks on museum specimens and photographs suggests Johnson’s Hairstreak is preyed upon by birds and small mammals. Caterpillars are dependent upon Hemlock Dwarf Mistletoe. Mistletoe is pollinated by wind and insects, potentially adult Johnson’s Hairstreak (Hawksworth and Wiens 1996).

Many lycaenid butterflies have mutualistic relationships with ants (Formicidae), where the caterpillars secrete liquid containing amino acids and carbohydrates, which the ants consume and in return the ants protect caterpillars from predators and parasitoids (Pierce 1987; Leimar and Axén 1993). While Andrews (2010) reported that Johnson’s Hairstreak caterpillars secrete a sugary solution that is used by ants that protect the caterpillars from predators, Fallon and Black (2017) found no documentation of this. Downey (1966) reported that Johnson’s Hairstreak pupae stridulate (i.e., make noise by rubbing). It has been hypothesized that stridulation is an auditory signal for symbiotic ants; experts consulted by Fallon and Black (2017) confirmed the “buzzing” of the pupae as well as the possibility of myrmecophily but were not aware of recorded myrmecophily in Johnson’s Hairstreak. Additional research is required to confirm the importance of ants in the life cycle of Johnson’s Hairstreak.

Population sizes and trends

Sampling effort and methods

Johnson’s Hairstreak surveys have focused on recording and confirming occurrences, and documenting natural history and habitat information. Surveys have been by transects through suitable habitat (Table 2) (see Search effort) where maximum abundance on any one date is tallied. Southern Vancouver Island is a butterfly diversity hotspot, and Johnson’s Hairstreak is a rarely observed species that attracts the attention of butterfly enthusiasts and naturalists. Numerous observations have been incidental (see Table 2).

Abundance

Johnson’s Hairstreak abundance estimates are not available. There are approximately 47 records of the species in Canada since it was first recorded in 1900. The few data available, including maximum counts, are of one or two individuals on a few dates and it is not possible to compare across time (Table 1).

Fluctuations and trends

There are insufficient data on abundance or distribution of Johnson’s Hairstreak to assess fluctuations or trends. The natural population fluctuations in butterflies are a result of factors such as parasites, predators, weather, and distribution and abundance of mistletoe and nectar plants. There is no evidence for extreme population fluctuations based on sites visited in multiple years (Table 2).

Rescue effect

The closest record in northern Washington (see Fallon and Black 2017) is approximately 60 km south of the closest known record in the lower Fraser Valley. At one time, before widespread logging and urbanization, natural re-establishment from Washington may have been possible. Currently there are few records for Johnson’s Hairstreak in northern Washington State. There may be some intervening old growth and late successional second growth (> 81-year-old) forest. Given the few documented sites in Canada, and the fragmentation of intervening older growth and late successional second growth forest habitat, rescue is unlikely.

Threats and limiting factors

Threats

Threats to Johnson’s Hairstreak were assessed based on the IUCN-CMP (International Union for Conservation of Nature–Conservation Measures Partnership) unified threats classification system (see Salafsky et al. 2008; Master et al. 2012; Open Standard 2016). A brief summary of threats that apply to each subpopulation (Table 6) and results of a threats assessment (Table 7) are discussed below under the IUCN-CMP unified threats classification system headings and numbering scheme. The overall threat impact was High.

Table 7. Johnson’s Hairstreak (Callophrys johnsoni) threats assessment in Canada. The classification below is based on the IUCN-CMP (International Union for Conservation of Nature–Conservation Measures Partnership) unified threats classification system. For a detailed description of the threat classification system, see Salafsky et al. 2008; Master et al. 2012; Open Standard 2016. Threats may be observed, inferred, or projected to occur in the near term. Threats are characterized here in terms of scope, severity, and timing. Threat “impact” is calculated from scope and severity. For information on how the values are assigned, see Master et al. (2009) and footnotes to this table.

Scientific name:
Johnson’s Hairstreak (Callophrys johnsoni)

Date:
May 25, 2021

Assessors:
Kristiina Ovaska (Facilitator), Brenda Costanzo (report writer), Dawn Marks (report writer), Jennifer Heron (report writer), David McCorquodale (Arthropods SSC Co-Chair), Jayme Lewthwaite (Arthropods SSC member), Jeremy deWaard (Arthropods SSC member), Sarah Semmler (Arthropods SSC member), Leah Ramsay (Arthropods SSC member), Robert Buchkowski (Arthropods SSC member), Greg Wilson (BC COSEWIC rep), Ian Cruikshank (Parks Canada Agency), Rosana Soares (COSEWIC Secretariat)

Assigned Overall threat impact:
B = High

Impact adjustment reasons:
No adjustment

Overall threat comments:
Scope based on potential range, rather than on just known subpopulations. Approximately 1944 km² for forests > 81 years and ~1011 km² for forests > 251 years. Some subpopulations in areas expected to be affected by forestry or development.

In summary, forest management which aims to reduce Hemlock Dwarf Mistletoe, and ongoing reduction of older growth hemlock stands are the primary threats to Johnson’s Hairstreak. Additional threats include habitat conversion to urban and agricultural development and use of Bacillus thuringiensis var. kurstaki (Btk) to control Lepidoptera pests. Threats of unknown impact include alteration to fire regimes, invasive insects and impacts of climate change on host plant distribution and abundance.

5. Biological resource use (High threat impact)

5.3 Logging and wood harvesting (High threat impact)

The highest impact threat to Johnson’s Hairstreak and potential habitat is logging through the removal of older growth and late successional second growth (> 81 years) forests throughout the Coastal Western Hemlock BGZ in southwestern BC. At present, approximately 4329 km² of old growth and late successional second growth (> 81 years) habitat remains within the potential range of Johnson’s Hairstreak (Table 4; Figure 6; see Habitat trends).

Logging and forest management recommendations that limit the spread of Hemlock Dwarf Mistletoe (see Rusch et al. 2019) are effectively reducing the potential future habitat for Johnson’s Hairstreak and can be used to infer and project a decline in potential future Johnson’s Hairstreak habitat (see Habitat trends and management options in Rusch et al. 2019). Forest management approaches that result in reduced mistletoe include 1) general or targeted removal of mistletoe-infected trees (e.g., clearcut harvesting, partial harvesting with selective removal of infected trees) and 2) historical silvicultural practices that have resulted in stand conditions that are not conducive to mistletoe growth/establishment (e.g., clearcutting followed by even-aged planting).

Clearcut harvesting involves cutting most of the standing trees. Typically, larger old growth trees are left standing, with the purpose of future or ongoing nesting, denning and other wildlife habitat values. However, if these trees pose a safety concern during harvesting (e.g., they are overly rotten, leaning towards a work zone or at risk of blowdown during harvest operations), they may be cut regardless.

Partial harvesting removes only select trees (e.g., age class, species, or a mixture of objectives), to retain ecological values. This silvicultural practice allows for increased light, variable stand height, structure, and composition, and in the longer term enables the spread and establishment of Hemlock Dwarf Mistletoe seeds. However, when Hemlock Dwarf Mistletoe is present in a stand to be harvested, site prescriptions often call for removal of all Western Hemlock trees (e.g., rather than leaving scattered trees for wildlife values) such that post-harvest silviculture costs are minimized (Rusch et al. 2019). This management recommendation is considered the best way to reduce future loss of timber value due to mistletoes (Rusch et al. 2019).

Woodlots are also included in this threat category. In BC a woodlot is defined as a holding greater than 20 ha of forest. There are two types of woodlots in the province: privately owned, and a form of area-based tenure awarded by the Province of BC under a woodlot licence as a partnership between the province and the licence holder. Coastal licences (e.g., within the range of Johnson’s Hairstreak) have an 800-ha maximum amount of crown land.

There are 345 managed licence polygons (woodlot: 204, community forest: 82, First Nation woodlands: 59) within the potential range of Johnson’s hairstreak, totalling 22,863 ha of remaining potential habitat (> 81 years) (data extracted from Federation of BC Woodlot Associations 2020).

Woodlots are managed for timber production, and because Hemlock Dwarf Mistletoe parasitized trees are not of high economic value, management actions (e.g., removal of trees and/or limiting the spread of Hemlock Dwarf Mistletoe) would limit natural mistletoe spread and growth throughout the woodlot or adjacent areas. Deciduous pulp plantations are short-rotation (e.g., < 41 years) and are unlikely to have Western Hemlock. Areas with high mistletoe growth could potentially be cleared (logged) and then replanted with deciduous and/or non-host trees, thus reducing future habitat for the hairstreak.

Of the ten extant subpopulations, four are within forests with active logging (#2,3,5,14) and three are within areas with adjacent logging (#1,6,11). Four of the five historical subpopulations (#7,8,9,10) are on private land. Although the precise sites are unknown, two are from areas historically part of the forest insect and disease surveys (#7,8) and it is inferred these areas could still be within private forestland.

The Malcolm Knapp Research Forest (#11) is a privately managed forest with 5157 ha of private land belonging to the University of British Columbia and a 220 ha Woodlot Licence with the provincial government. Management of this woodlot includes biodiversity values (Lawson pers. comm. 2021) and logging is considered a negligible threat.

Two subpopulations are within active Tree Farm Licences (TFL) (#3 is within TFL61 and #5 is within TFL44). TFL61 occupies 20,240 ha of land, of which 14,477 hectares is within the timber harvesting land base. The allowable annual cut (AAC) is 121,000 cubic metres (Berg 2019). Typical coastal old growth sites can yield as much as 1,500 to 1,800 cubic metres per hectare; second growth forests yield approx. 500-600 cubic metres per hectare (second growth are > 81 years but typically < 121 years). Approximate spatial habitat loss = 67-242 ha/year = 0.5-2% of the land base. TFL44 occupies 141,566 ha of land, of which 80,409 ha are in the timber harvesting land base. The AAC is 645,000 m³/year (Nicholls 2020). Approximate spatial habitat loss = 358 - 1290 ha/year = 2-9% of the land base.

1. Residential and commercial development (Low threat impact)

1.1 Housing and urban areas (Low threat impact)

Approximately 15% of Johnson’s Hairstreak’s range lies within densely human-populated parts of the province (e.g., lower mainland). Most urban and rural development is historical and those pockets of habitat that remain within these urban areas are within protected areas (e.g., #1, 4, 11). Natural old growth and late successional stage coniferous forest habitats, large ravines, and riparian areas are habitat for Johnson’s Hairstreak in these areas. Some of these areas contain coniferous trees > 81 years old with mistletoe. Lower elevation (< 625 m) forests of the Sunshine Coast and southeastern Vancouver Island are largely privately owned by large land holding companies. There is ongoing pressure to develop this land into rural properties and new subdivisions, which would likely remove trees with Hemlock Dwarf Mistletoe. In addition, the southern west coast of Vancouver Island near Jordan River (near one locality for Johnson’s Hairstreak) and Port Renfrew are former forest lands that are currently being converted to residential developments. This threat applies to potential habitat, and portions of subpopulations #1, 6 and 10.

9. Pollution (Low threat impact)

9.3 Agricultural and forestry effluents (Low threat impact).

Aerial spray to control Spongy Moth

Spongy Moth, Lymantria dispar dispar (formerly known as European Gypsy Moth and LDD) is a non-native/invasive moth that has the potential to cause mass defoliation to over 100 different tree and shrub species in BC, including Western Hemlock. The moth is a threat to forests throughout much of eastern North America, although it has not established in western North America. The provincial Spongy Moth control program runs a network of detection traps. Small numbers of the moth are detected yearly (BC Ministry of Forests, Lands and Natural Resource Operations 2021) and Spongy Moth is often recorded within the range of Johnson’s Hairstreak.

A provincial Spongy Moth eradication program has been ongoing since 1997 and the species has not become established in BC (BC Ministry of Forests, Lands, Natural Resource Operations and Rural Development 2021). The species may be controlled through the aerial application of Btk. Spores of this naturally occurring bacteria are a component of commercial products to control defoliating caterpillars including Spongy Moth. Btk causes direct mortality to most caterpillars and is applied in early April to early May in BC, which coincides with the feeding period of Johnson’s Hairstreak caterpillars and therefore could cause direct mortality to this species. The Spongy Moth aerial spray program in BC is focused on areas where Spongy Moth has been detected for a minimum of two years and appears to be spreading. Therefore, spray programs have been targeted and mostly in urban areas. The subpopulations with the highest threat of Btk spray are those in urban areas, including Stanley Park (#4), Pacific Spirit Park (#13), North Vancouver (#1), and a historical subpopulation, West Vancouver (#6). The Spongy Moth spray eradication program of Btk in BC has not included subpopulations.

Aerial spray for Western Hemlock Looper (Lambdina fiscellaria lugubrosa)

Western Hemlock Looper is a defoliator of Western Hemlock forests. Documentation of outbreaks started in 1911, and data show outbreaks can occur every 11 to 20 or more years, lasting two to three years. Recent outbreaks have occurred within the past 20 years in the North Shore and Sunshine Coast. Aerial spray programs of Btk for long-term forestry management can be initiated by the Province of BC to decrease the defoliation of Western Hemlock (Province of British Columbia n.d.) and if Btk is sprayed it likely causes direct mortality to Johnson’s Hairstreak.

Roadside herbicide spray

Herbicide spray may be applied to control both native and non-native vegetation growing adjacent to and encroaching upon forest service roads. Herbicide spray would affect flowering nectar plants during the adult flight period (e.g., May – July). This threat is potentially applicable to subpopulations #2, 3, 5, 7, 9, 15 and surrounding habitats; these subpopulations are within areas managed for timber production and other subpopulations are within protected areas and/or are historical.

Chemical application to control Hemlock Dwarf Mistletoe

Chemical management to suppress Hemlock Dwarf Mistletoe may limit the abundance of Johnson’s Hairstreak (Pyle 1989; Washington Department of Fish and Wildlife 1995). Chemical control has been investigated in Canada (Unger 1992; Zeglen pers. comm. 2021); however, the chemical used is not registered for use in BC. The chemical application to the stems of the mistletoe causes the mistletoe aerial shoots to drop off the tree, but the chemical does not kill any of the material inside the branch (Zeglen pers. comm. 2021). Fungal biocontrol for Hemlock Dwarf Mistletoe has been investigated; however, the commercial application was not developed further (Zeglen pers. comm. 2021).

7. Natural system modifications (Unknown threat impact)

7.1 Fire and fire suppression (Unknown threat impact)

Johnson’s Hairstreak range is in the coastal temperate rainforests which have high rainfall (summarized in Alaback 1996). Large stand-replacing fires typically recur on average every 350-1000 years (Gavin et al. 2001; Daniels and Gray 2006), and average of 100-350 years in CDF zones (Parminter 2003). Historically, wildfire was not a threat; however, with fire suppression and climate change, wildfire is likely to increase.

Southern BC is expected to become warmer and drier (with climate change) and will experience more frequent, severe and extensive fires, leading to more area burned (Hawkes 2005; Spittlehouse 2008). Accidental fire by discarded cigarettes, unattended campfires, or vehicles in dry vegetation is a serious threat. Over the past 100 years, fire suppression programs have altered the natural fire regime in the CDF BGZ (Coastal Douglas Fir and associated Ecosystems Conservation Partnership Conservation Strategy 2015) within the range of Johnson’s Hairstreak.

Fires in Hemlock Dwarf Mistletoe-infected stands also play a role in the conservation of Johnson’s Hairstreak, as they can either limit the distribution of Hemlock Dwarf Mistletoe or favour the spread of the species, depending on the intensity and pattern of the fire (Shaw et al. 2004). Small-scale disturbance fires can assist in the spread of Hemlock Dwarf Mistletoe as small gaps can spread fruiting bodies to younger trees that grow in the new gaps. Large stand-replacing fires can remove Hemlock Dwarf Mistletoe (Hennon et al. 2001).

Fire suppression may have led to an increase in the distribution and abundance of Hemlock Dwarf Mistletoe in the United States (Fallon and Black 2017). Hemlock Dwarf Mistletoe brooms can act as fuel ladders and be a fire hazard. Forest managers recommend brooms be pruned to prevent the spread of fire as well as increase the quality of the wood (Rusch et al. 2019).

8. Invasive and other problematic species and genes (Unknown threat impact)

8.1 Invasive non-native/alien species (Unknown threat impact)

Compsilura concinnata (Diptera: Tachinidae) is a non-native parasitic fly introduced into eastern North America in the early 1900s as biological control agent for Spongy Moth. This fly now parasitizes more than 100 native moths and butterflies in North America and may parasitize Johnson’s Hairstreak (Boettner et al. 2000) in BC (GBIF Secretariat 2019).

11. Climate Change and severe weather (Unknown threat impact)

11.2 Droughts (Unknown threat impact)

Changes to the intensity, frequency, and longevity of droughts could impact the long-term survival and abundance of host plants. Reduced summer moisture due to climate change could increase fire frequency and severity (Hebda 1997) which could cause large stand-disturbance fires that would remove Hemlock Dwarf Mistletoe (Rusch et al. 2019).

11.3 Temperature extremes (Unknown threat impact)

Climate change is expected to change the range and reproductive success of Hemlock Dwarf Mistletoe (Rusch et al. 2019); warm temperatures are expected to increase the range and cold temperatures may reduce the reproductive success and geographic range of mistletoes (Smith and Wass 1986; Kliejunas et al. 2009). The latitudinal range and elevational range of Hemlock Dwarf Mistletoe is predicted to expand with increasing temperatures and reduced snowfall based on a model for southeast Alaska (Barrett et al. 2012).

Limiting factors

Limiting factors are generally not human-induced and include innate biological characteristics. The main limiting factors for Johnson’s Hairstreak are likely a combination of the following:

Caterpillar host plant specificity

Johnson’s Hairstreak is dependent on Hemlock Dwarf Mistletoe to complete its life cycle (see Habitat).

Morphological attributes

Adults forage for nectar opportunistically. Their short tongue length limits them to flowers with short corollas and may limit abundance.

Small population, host plant abundance and patch size

Johnson’s Hairstreak subpopulations are small, isolated, and limited to habitat patches. The average host plant patch size is unknown; however, the size of the host plant patch may limit the subpopulation within a given habitat (Spiegel 2014).

Vulnerability to weather patterns

The previous year’s weather affects the abundance of the next year’s generation of butterflies. Extremes in frost, temperature, humidity, and precipitation affect survival at all life stages. These factors also contribute to emergence of the next year’s generation. In old growth stands where Hemlock Dwarf Mistletoe has parasitized trees for decades, trees are weakened, and branches are susceptible to windthrow and breakage. Should the tree fall, or branches break, Hemlock Dwarf Mistletoe withers and dies. Overwintering pupae would likely survive and emerge as butterflies the following spring. However, if the tree blew over or branches broke during the caterpillar feeding period, the caterpillars would not survive.

Limited dispersal capability

Johnson’s Hairstreak is small and does not likely disperse long distances, especially through unsuitable habitats. Isolated subpopulations may lead to decreased genetic diversity, greater genetic differences, and inbreeding depression.

Number of locations

The highest threat to Johnson’s Hairstreak subpopulations and potential habitat is logging of old growth and late successional second growth (> 81 years) forests. Eleven of the 15 known Johnson’s Hairstreak subpopulations (extant and historical) are potentially at risk from logging (#1, 2, 3, 5, 6, 7, 8, 9, 11, 14, 15). Five of the ten extant subpopulations are within areas of ongoing logging (#1, 2, 3, 6, 14) and each represents a separate location (see Tables 6 and 7 for applicable threats). There are likely additional undocumented Johnson’s Hairstreak subpopulations in Canada, with the total likely around 15.

Protection, status and ranks

Legal protection and status

Federal protection

Johnson’s Hairstreak is known from Stanley Park (#4), which is owned by Parks Canada Agency and managed by the City of Vancouver. COSEWIC assessed the species as Special Concern in May 2022. It is not listed under the Species at Risk Act (SARA).

Provincial protection

In BC, there are several acts that protect species at risk in the province. The three main acts with provisions applicable to Johnson's Hairstreak are: the BC Protected Areas Act, the Forest and Range Practices Act, and the Oil and Gas Activities Act.

BC Protected Areas Act (Province of British Columbia 2000) protects invertebrate species at risk (provincially assessed as Red or Blue-listed by the BC CDC) in provincial parks and protected areas. When species at risk and the habitats they require are known to occur within a protected area, provisions for management are incorporated into the park master plan (if the park has a written and approved Master Plan). Provincial parks staff within the range of Johnson’s Hairstreak are aware of the species and its provincial at-risk status (see Non-legal Status and Ranks). Johnson’s Hairstreak is not recorded from any provincial protected areas (Table 1). However, the species has been recorded from Thormanby Island (#12) and there is potential habitat in the two provincial parks on the island: Buccaneer Provincial Park and Simson Provincial Park. When scientific research permits and other activities within parks and protected areas are proposed, parks staff consider adverse impacts from proposed activities on the butterfly and its habitat (Hirner pers. comm. 2021; McClaren pers. comm. 2021).

Forest and Range Practices Act and Oil and Gas Activities Act

The Identified Wildlife Management Strategy (IWMS) is an initiative from 1999 by the Ministry of Environment in partnership with the Ministry of Forests and Range (in consultation with other stakeholders) (see Province of British Columbia 2002). The IWMS goals are to ‘minimize the effects of forest and range practices on Identified Wildlife situated on Crown land’. Under the Forest and Range Practices Act, the Minister responsible for the Wildlife Act (e.g., Minister of Environment) is authorized to establish two categories of wildlife which require special management attention to address the impacts of forest and range activities on Crown land. The Category of Species at Risk includes ‘endangered, threatened, or vulnerable species of vertebrates and invertebrates, and endangered or threatened plants and plant communities that are negatively affected by forest or range management on Crown land and are not adequately protected by other mechanisms.’ This Category applies to Johnson’s Hairstreak butterfly (see Johnson’s Hairstreak species account in BC Ministry of Water, Land and Air Protection 2004). The second Category, Regionally Important Wildlife category, does not apply to Johnson’s Hairstreak. These same categories of Species at Risk and Identified Wildlife apply under the provincial Oil and Gas Activities Act (Province of British Columbia 2008).

Identified Wildlife are managed through the establishment of wildlife habitat areas (WHAs) and the implementation of general wildlife measures (GWMs) and wildlife habitat area objectives. Johnson’s Hairstreak is listed as Identified Wildlife (BC Ministry of Water, Land and Air Protection 2004); however, no Wildlife Habitat Areas have been created to protect the species (BC Ministry of Environment 2021).

In the United States, Johnson’s Hairstreak is classified as a Sensitive Species by Region 6 of the Forest Service and Oregon/Washington Bureaus of Land Management (Interagency Special Status/Sensitive Species Program 2015a, 2015b).

Non-legal status and ranks

The conservation status ranks for Johnson’s Hairstreak (NatureServe 2021):

• Global G3 (Vulnerable) (last reviewed Nov 2017)
• Canada N1N2 (Critically Imperilled/Imperilled)
• British Columbia S1S2 (Critically Imperilled/Imperilled) (BC CDC 2021)
• United States N3N4 (Vulnerable/Apparently Secure)
• Subnational state ranks California (SNR – status unranked), Oregon (S3), Washington (S2S3), Idaho (S1) (NatureServe 2021).

Johnson’s Hairstreak has not been assessed using IUCN Red-list criteria (IUCN 2016).

Habitat protection and ownership

Most Johnson’s Hairstreak subpopulations are on provincial land. The species is recorded from Stanley Park (Worcester and Johnstone 2007; Worcester and Titaro 2012), a municipal park managed by the City of Vancouver, on land owned by Parks Canada. Metro Vancouver regional district manages portions of subpopulations #1, 6, and 13. One subpopulation is likely within a provincial park (#12). Land ownership is listed in Table 1.

In BC, non-government conservation organizations, such as The Nature Trust of BC (McNaughton pers. comm. 2021), the South Coast Conservation Program, Salt Spring Conservancy, Garry Oak Ecosystems Recovery Team, and Stanley Park Ecological Society work with lands managers and/or private landowners to protect butterfly species at risk. Should additional information become available on Johnson’s Hairstreak, these organizations may initiate stewardship actions.

Acknowledgements

Thank you to the BC Ministry of Environment and Climate Change Strategy (ENV) for providing time and resources to complete this report. The following people provided scientific information and advice: Denis Knopp, Dennis St. John, Katie Calon, Claudia Copley, Lea Gelling, Leah Ramsay, Cris Guppy, Norbert Kondla, Jeremy Gatten, Mike Yip, James Miskelly, Jeremy Tatum, Pascale Archibald, Shelley Pruss, Markus Merkens, Adam Braz, Jasmine Carlin, Sean Nightingale, Purnima Govindarajulu, and Manjit Kerr-Upal. Pascale Archibald completed 2021 surveys during preparation of this status report.

Claudia Copley (Royal BC Museum, Victoria) and Karen Needham (Spencer Entomological Collection, Beaty Biodiversity Museum at the University of British Columbia) provided access to museum specimens. Greg Amos (ENV) completed habitat mapping/modelling and habitat statistics for the species.

Members of the Arthropods Specialist Subcommittee (Robert Buchkowski, Syd Cannings, Jeremy deWaard, Allan Harris, Colin Jones, John Klymko, Jayme Lewthwaite, Jessica Linton, Jeff Ogden, Leah Ramsay, John Richardson, Michel Saint-Germain, Sarah Semmler, Brian Starzomski, Myrle Ballard [ATK subcommittee], Dan Benoit [ATK subcommittee] and individuals from the range jurisdictions reviewed early drafts of this report and provided numerous comments. David McCorquodale (Arthropods SSC Co-chair), Rosana Nobre Soares (COSEWIC Secretariat) and Joanna James (COSEWIC Secretariat) edited and oversaw the report.

Cover photograph of Johnson’s Hairstreak (Callophrys johnsoni), Pacific Rim Regional Park, Vancouver, BC, May 29, 2007, by Michelle Connolly. Thank you to David McCorkle and Raymond Davis for permission to use their respective photographs in this report.

Authorities contacted

Anderson, Robert. Curator. Canadian Museum of Nature, Ottawa, Ontario.

Archibald, Pascale. Entomologist. British Columbia Conservation Foundation, Victoria, British Columbia.

Cannings, Syd. Canadian Wildlife Service, Environment and Climate Change Canada, Whitehorse, Yukon Territory.

Copley, Claudia. Entomology Collections Manager, Royal British Columbia Museum, Victoria, British Columbia.

Davis, Raymond. Monitoring Lead – Older Forests and Spotted Owls, Forest Service Region 6 – Pacific Northwest Region, Corvallis, Oregon.

Fraser, David (retired). Ecosystems Branch, BC Ministry of Environment and Climate Change Strategy, Victoria, British Columbia.

Fyson, Andrew. Lepidopterist, Denman Island, British Columbia.

Gatten, Jeremy. Lepidopterist, Victoria, British Columbia.

Gelling, Lea. Program Zoologist, BC CDC, Victoria, British Columbia.

Goulet, Gloria. Co-chair Aboriginal Traditional Knowledge COSEWIC Subcommittee, Manitoba.

Govindarajulu, Purnima. Unit Head, Species at Risk Conservation Unit, Ecosystems Branch, BC Ministry of Environment and Climate Change Strategy, Victoria, British Columbia.

Guppy, Crispin. Lepidopterist, Whitehorse, Yukon Territory.

Hirner, Joanna. Conservation Specialist, Parks and Protected Areas, North Vancouver, British Columbia.

Holden, David. Western Area Survey Biologist, Canadian Food Inspection Agency, Burnaby, British Columbia.

Esme, John. Research Biologist. Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, Victoria, British Columbia.

Knopp, Denis. BC’s Wild Heritage Consulting, Sardis, British Columbia.

Kondla, Norbert. Lepidopterist, Calgary, Alberta.

Lilley, Patrick. Biologist, North Vancouver, British Columbia.

McClaren, Erica. Conservation Specialist, Parks and Protected Areas, Black Creek, British Columbia.

Miskelly, James. Independent entomologist, Victoria, British Columbia.

Needham, Karen. Spencer Entomological Collection, Beaty Biodiversity Museum at the University of British Columbia, Vancouver, British Columbia.

Neilson, Joanne. Executive Director, Fraser Valley Conservancy, Mission, British Columbia.

Page, Nick. Biologist, Raincoast Applied Ecology, Courtenay, British Columbia.

Penny, Jenifer. Program Botanist, BC CDC, Victoria, British Columbia.

Pohl, Greg. Insect/Disease Identification Officer, Northern Forestry Centre, Northwest Edmonton, Alberta.

Ramsay, Leah (retired). Program Zoologist, BC Conservation Data Centre, Ecosystems Branch, BC Ministry of Environment and Climate Change Strategy, Victoria, British Columbia.

Richardson, John. Professor. Faculty of Forestry, University of British Columbia, Vancouver, British Columbia.

St. John, Dennis. Private Entomologist, Agassiz, British Columbia.

Swan, John. Curator. University of Calgary, Alberta.

Tatum, Jeremy. Private Lepidopterist, Victoria, British Columbia.

Yip, Mike. Nature photographer, Nanoose Bay, British Columbia.

Zack, Richard. Department of Entomology, Washington State University, Pullman, Washington USA.

Zeglen, Stefan. Forest Pathologist, BC Ministry of Forests, Lands, Resource Operations and Rural Development, Nanaimo, British Columbia.

Zevit, Pamela. Biodiversity Conservation Planner, Surrey Parks-Urban Forestry, Surrey, British Columbia.

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Biographical summary of report writers

Brenda Costanzo is the Senior Vegetation Specialist with the Conservation Science Section, BC Ministry of Environment and Climate Change Strategy. For the past 18 years Brenda has been involved in leading recovery teams and/or writing numerous recovery plans for plants at risk in BC. Her background includes an M.Sc. from the University of Victoria in biology on the seed germination of two native shrubs from BC. She has written several status reports on rare vascular plants from BC.

Jennifer M. Heron is the provincial Invertebrate Conservation Specialist with the Conservation Science Section, BC Ministry of Environment and Climate Change Strategy. She directs and manages the provincial approach to invertebrate conservation, including the development and implementation of provincial legislation, policy, procedures, and standards for Conservation, and recovery of invertebrate species at risk, their habitats and ecosystems, and to keep these species from becoming at risk. Her background includes an M.Sc. from the University of BC. Her interests include the native bees of western Canada and thermal spring’s invertebrates.

Dawn Marks is the Invertebrate Conservation Environmental Biologist with the Conservation Science Section, BC Ministry of Environment and Climate Change Strategy. Over the past ten years she has conducted inventories, mapping, report writing, invertebrate policy and recovery plan development that has centred on invertebrate species at risk in BC. She has also worked with the BC CDC on species mapping.

Online data sources and collections examined

British Columbia Conservation Data Centre (BC CDC). BC Species and Ecosystems Explorer: Johnson’s Hairstreak. (online database, see Table 1, February 2021)

BugGuide^® (online database, no records for BC, February 2021)

Butterflies and Moths of North America (online database, no records for BC, February 2021)

Canadian National Collection of Insects, Arachnids and Nematodes, Agriculture and Agri-Food Canada, Ottawa, ON (online database, see Table 1, February 2021)

Crispin Guppy Lepidoptera Collection, Whitehorse Yukon Territory (no BC records, Guppy pers. comm. 2021)

Cortes Island Museum and Archives, Cortes Island, British Columbia. (online database) https://cortesmuseum.com/museum/butterfly-sightings/ (no records, Trzesicka pers. comm. 2021)

eButterfly: a citizen-based butterfly database in the biological sciences. http://www.e-butterfly.org (one BC record, February 2021)

iNaturalist^® www.inaturalist.ca (three BC records, February 2022)

Invertebrate Zoology, Royal Alberta Museum, Edmonton, Alberta. (no BC records, Buck pers. comm. 2021)

Northern Forestry Centre, Canadian Forest Service, Natural Resources Canada, Edmonton, Alberta. (no BC records, Greg Pohl pers. comm. 2021)

Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, Victoria, British Columbia. (see Table 1, Esme pers. comm. 2022)

Royal British Columbia Museum, Victoria, British Columbia. (see Table 1, Copley pers. comm. 2021)

Royal Saskatchewan Museum, Regina, Saskatchewan. (no BC records, Sheffield pers. comm. 2021)

Spencer Entomological Collection, Beaty Biodiversity Museum, University of British Columbia, Vancouver, British Columbia. (see Table 1, Needham pers. comm. 2020)

Strickland Entomological Museum, Department of Biology, University of Alberta, Edmonton, Alberta. (no BC records, Danny Shpeley pers. comm. 2020)

University of Calgary, Insects and Invertebrate Zoology Museum, Department of Biological Sciences, Calgary, Alberta. (no BC records, Swann pers. comm. 2020)

Victoria Natural History Society Invertebrate Alert (online database, https://www.vicnhs.bc.ca/?cat=8) (see Table 1, Tatum pers. comm. 2021)