Palaeagapetus nearcticus Banks 1936

Ito, Tomiko, Wisseman, Robert W., Morse, John C., Colbo, Murray H. & Weaver Iii, John S., 2014, The genus Palaeagapetus Ulmer (Trichoptera, Hydroptilidae, Ptilocolepinae) in North America, Zootaxa 3794 (2), pp. 201-221 : 202-211

Palaeagapetus nearcticus Banks 1936

( Figs. 1–6 , 8 , Table 1)

Palaeagapetus nearcticus Banks 1936 , 265, figs. 1 – 3, male; Frania & Wiggins, 1997, larva, 7, 13, 22, figs. 4, 7, 18; Schmid 1998, 31.

Palaeagapetus guppyi Schmid 1951 , 1 – 2, figs. 1 – 2, male; Djernaes, 2011, adult, 19, 35, 49, fig. 23; synonymized by Botosaneanu & Levanidova1987, 43.

Adult ( Fig. 1 ). Body black in life and dark brown in alcohol, 3.3 mm long in males (3.0– 3.8 mm, n=17) and 4.0 mm long in females (3.1–4.4 mm, n=4). Antennae 27- or 28-segmented (n=2), 2.7 mm long, 0.77 times as long as body in male (2.6–2.8 mm, n=2); scape (1A, B) slightly thicker and longer than other segments. Maxillary palpi (1A) each 5-segmented, segment I short and round, segments II to V cylindrical; labial palpi (1A) each 3- segmented, all segments cylindrical; both pairs of palpi covered with fine setae. Head (1A, B): large anteromesal setal wart (am) and pair of small anterior setal warts (a) often fused, pair of posterior setal warts (p) round, pair of posterolateral setal warts (pl) large; numerous setae scattered on anterior 1/3. Pronotum with two pairs of round warts, mesoscutum with pair of long oblique warts, and mesoscutellum with single subtriangular wart.

Wings (1C) broad, black, covered with short black hairs, with few small white spots in middle of each forewing. Length of each forewing and hind wing, respectively: 4.0 mm and 3.5 mm in males (3.8–4.3 mm and 3.1–3.9 mm, n=17), 4.2 mm and 3.6 mm in females (4.1–4.5 mm and 3.4–3.9 mm, n=4). Forewings each with apical forks 1–5 and hind wings lacking fork 4; discoidal cell present in male and absent in female. Venation variable individually and even on opposite sides of same specimen; cross veins r and s absent in forewings of some male and female specimens; apex of Sc joined to R 1 in hind wings of some female specimens. Spurs 2, 4, 4.

Lateral bulges (gland) of sternum V (1D, J) round. Acute ventral process developed on segment VII in male (1D) and segment VI of female (1J).

Male genitalia ( Figs. 1E–I ). Segment IX short, anterolateral margins long, projecting to middle of segment VIII. Lateral appendages of tergite IX (la ap) developed from mid-lateral region of genital capsule, slightly variable individually (1E, H, I); long, 1.2 times as long as capsule, directed caudad and tribranched at middle; dorsal branches (db) longest, with many fine spines at apical half and each with single seta apically; middle branches (mb) as long as 1/2 of dorsal branches, thickest, each completely covered with fine spines and with single seta apically; ventral branches (vb) shortest, 1/4–1/5 length of dorsal branches, each with single seta and several spines apically. Tergite X (tX) depressed dorsoventrally, curved dorsad apically in lateral view (1E), semicircular in dorsal view (1F). Inferior appendages (1E, G, ia) short, each divided into dorsal lobe (dl) and ventral lobe (vl); lobes subequal in length, subacute apically; dorsal lobe curved mesad, ventral lobe directed caudad. Phallus (1E, G, ph) short, broad, membranous with small sclerotized structure inside.

Female genitalia ( Figs. 1J, K ). Segments I–VII very setose, each with sclerotized tergite and sternite, tergite VIII unpigmented at anterior half and slightly pigmented at posterior half. Segments IX–X very short, each segment about 1/6th as long as segment VIII, with somewhat developed cerci. Vaginal apparatus (1K) slender, lateral projections undeveloped, lateral bands round.

Pupa ( Fig. 2 ). Body (2A) slightly depressed dorsoventrally; length up to 4.0 mm. Antennae and wing pads reaching to abdominal segment V or VI (2A). Mandibles (2B) triangular, each with numerous minute teeth and large tooth on inner edge. Pair of hook plates (2A, C, D) present near anterior margins of each of segments III–VII and near posterior margins of segments III–V, 10–18 hooks on each plate. Anal process (2A) thick and round apically.

Instars of larva ( Fig. 3 ). Head widths of larvae reared from eggs in laboratory and collected on Mary’s Peak, Oregon, 1982–1983 (see ‘Habitat and specimens’), separating into 5 groups, suggesting 5 instars as follows: 1st instar 0.15–0.16 mm, 2nd instar 0.18–0.19 mm, 3rd instar 0.22–0.25 mm, 4th instar 0.28–0.32 mm, and 5th instar 0.36–0.39 mm, respectively.

Final (5 th) instar larva ( Fig. 4 ). Body (4A) suberuciform, length up to 5 mm, flattened dorsoventrally, widest at abdominal segments III–V, membranous portion whitish yellow and sclerites deep brown. Head (4B, C): Width subequal to length, black to deep brown except light eye spot, 18 primary setae present, secondary setae or spines absent; antennae (4C inset) situated just beneath anterior corner of eye spot; anterior ventral apotome subtriangular with concave anterior margin, posterior ventral apotome indistinct. Mandibles (4E, F) deep brown, stout, each with three teeth dorsally, mesal brush of left mandible with setae longer and more numerous than of right one, setae of brushes slightly serrate (4F inset). Labrum (4D) light brown, anterior margin deeply concave. Thorax (4A, G): Each segment dorsally covered by two, deep brown, square sclerites bearing about 55, 45 and 45 setae on each of pro-, meso- and metanotal plates; posterior margin of pronotum (4G) dark, posterior margins of meso- and metanota deep brown. Propleuron (4H, upper) rectangular with distinct pleural sutures separating it from foretrochantins; meso- and metapleura (4H, middle and lower) each crescentic with no distinct pleural sutures. Three thoracic legs (4H) brown, similar in structure, tarsi with two enlarged apical spurs, trochanter or femur with no ventral brush. Abdomen (4A): Segments I–VIII each with pair of truncate lateral tubercles, segment I with three small sclerites and about 40 setae, segments II–VIII each with 8–12 setae; dorsal tergite IX (4I) deep brown, semicircular with concave anterior margin and with about 30 long setae; lateral sclerites of anal prolegs (4J) rectangular, pale brown; anal claws (4J) strongly curved ventrad, deep brown without accessory hooks or denticles.

Early (1 st –4 th) instar larvae ( Figs. 5A–G ). Campodeiform (5A), sclerites brown in 4th instar larva and lighter in younger instar larvae, thorax and abdomen very setose.

Head (5A) length subequal to head width, with 18 primary setae; thoracic segments (5A) covered with two dorsal plates, each dorsal plate with 60–70 setae. Abdominal segments I–VIII (5A–D) each with rectangular dorsal sclerite, pair of lateral humps and lateral tubercles, lateral tubercles indistinct in earlier instar larvae, each segment with many setae and sensillae (5B–D). Dorsal sclerite IX (5E–G) with about 30 setae and several sensillae; anal legs (5A inset) extended caudad, without accessory hooks or denticles. Other characters as in final instar larva.

Egg ( Fig. 5H ). Eggs orange, spherical, about 0.2 mm in diameter, and separately deposited on leaves of liverworts.

Case ( Fig. 5I ). Case of final instar larva up to 7 mm long, depressed dorsoventrally and composed of two valves with slit-like openings at front and rear. Each valve consisting of roundish or oval pieces of liverwort.

Food and feeding behavior ( Fig. 5J ). Larvae eat leaves of the liverwort, Scapania uliginosa (Sw. ex Lindenb.) Dumort. (Jungermannidales, Scapaniaceae ). They pierce cell walls and swallow contents of cells one at a time.

Emergence ( Fig. 2E ). Emergence was observed in the laboratory (Corvallis, Oregon,) in late July, 2009. Teneral adults emerged on leaves of liverwort in the morning (5:30–9:30 AM). The newly emerged adults stretch their wings and abdomens in an upright position like mayflies, which takes ca. 3 minutes (n=2).

Annual life cycle ( Fig. 6 ). Occurrence of 5 development stages in British Columbia (B) ; Washington (W) ; Mary’s Peak , Benton County, Oregon (M) ; other sites of Oregon (O); and California (C) were summarized in 10- day periods based on the collecting data in “habitat and biology” and Table 1 in Fig. 6 . Collection records that did not specify early or final instar larvae were omitted from the figure.

Eggs and early instar larvae were found mainly in late July and September–early November, respectively. Final instar larvae were seen from September to the following July. Adults occurred mainly in June to September. Therefore, a univoltine life cycle with a summer emergence season was suggested as shown by the grey band in Fig. 6 . However, another annual cycle could be supposed for a few populations, because some adults and early instar larvae were collected in April–May and June, respectively.

Habitat and biology. The larvae live in springs, spring brooks and seepage areas of forested mountain streams, often just above the water surface and in hygropetric habitats, and they are exclusively associated with moss and liverwort.

Observation at Mary’s Peak, Benton County, Oregon. Many springs and seeps enter the stream around 1100–1200 m elevation where the channel is 1–2 m wide; moss and the liverwort Scapania ulinosa are abundant; cold year-round water regime. Many larvae and pupae of P. nearcticus were found in the liverwort and moss on cobbles and logs mainly just above water. Specimens were collected and deposited by RWW unless otherwise indicated: 21 August 1952, V. Roth, 1 male; 03 September 1982, many 5th and early instar larvae; 20 September 1981, 22 1 st –4 th instar larvae; 31 October 1981, 26 empty pupal cases, no larvae found; 30 May 1982, many 5 th - instar larvae; 03 November 1982, 1 st to 4 th- -instar larvae and many 5 th -instar larvae with newly constructed cases; 27 April 1983, 15 5 th -instar larvae; 09 August 1983, about 60 adults; 29 July 2009, 2 males, 2 females, 10 pupae, 2 5 th - instar larvae, 5 eggs, RWW & TI (TI); 07 July 2010, no larvae or adults; 01 August 2010, 4 males, many adults seen.

Observation at Flynn Creek, Lincoln County, Oregon. Oregon Coast Range, Flynn Creek, 44.53°N, 123.87°W, 150–300 m, 3 rd -order stream and tributaries, 0.3–3 base flow width, mean monthly water temperature varies from 7.5 to 12.5°C, mature second growth Douglas fir forest on slopes, red alder and big leaf maple overstory in riparian. Many larvae and pupae were found in moss and liverwort on logs and bedrocks. All specimens were collected and deposited by RWW: 09 December 1981, 3 4 th instar and 21 5 th -instar larvae; 09 December 1981, 2 old pupal cases; 29 January 1982, no larvae found; 05 March, 1982, 8 5 th -instar larvae; 07 April 1982, 4 5 th -instar larvae; 07 April 1982, 3 5 th -instar larvae; 26 April 1982, 9 5 th -instar larvae; 05 May 1982, 20 5 th -instar larvae; 05 May 1982, 4 5 th instar larvae; 22 May 1982, 20 5 th -instar larvae; 02 June 1982 ,7 5 th -instar larvae; 20 June 1982, 23 5 th -instar larvae; 20 June 1982, 1 male; 07 July 1982, no larvae or pupae found; 19 July 1982, 1 male; 05 August 1982, no larvae or pupae found; 04 October 1982, 2 probably 4 th -instar larvae without cases, 1 5 th -instar larva; 06 April 1983, 4 5 th -instar larvae .

Remarks. The male of this species is characterized by tri-branched lateral appendages of tergite IX, which are never seen in other congeneric species. On the other hand, the female, pupa, final instar larva, early instar larva, egg and case are very similar to those of other congeneric species, including Nearctic P. celsus ( Ulmer 1912; Ross 1938; Flint 1962; Ito & Hattori 1986; Botosaneanu & Levanidova 1987; Ito 1991a, 1991b, 1997, 1998, 2010; Ito et al. 1997).

The habitat, feeding behavior and emergence behavior of this species are also very similar to those of other species studied ( Ito 1998; Ito & Vshivkova 1999). The female pupal weights, used for an indicator of fecundity in the subfamily Ptilocolepinae ( Ito 1998) , were 1.43–2.00 mg (n=4, average 1.73 mg), suggesting P. nearcticus resembles P. parvus in terms of fecundity ( Ito 1998). The liverwort used for food and case materials by P. nearcticus is Scapania uliginosa (Sw. ex Lindenb.) Dumort. , which is the first report of this host for a Palaeagapetus species. Another congeneric liverwort host, Scapania undulata (L.) Dumort., was reported for a population of Japanese species, P. parvus ( Ito 1991a) .

Life cycles have been studied for five Far East Asian species; three of them, P. flexus , P. parvus and P. kyushuensis , are distinctly univoltine with a short summer emergence period ( Ito 1991b, 1998; Ito et al. 1997), and the fourth species, P. finisorientis , has 3–4 generations in 2 years with a long flight period from March–October ( Ito & Vshivkova 1999). For the fifth species, P. ovatus , two sorts of life cycles have been reported: 3–4 generations in 2 years with a long emergence period (from March to October) at many sites ( Ito 1988, 1998; Kuhara 2011), but univoltine with a short summer flight period in a very cool headwater stream at high elevation ( Kuhara 2011). According to the collecting data ( Fig. 6 ), the annual cycle of P. nearcticus may be 1 generation per year at many sites, but with a more complicated life cycle and long emergence period at a few sites (similar to P. ovatus ), and probably depending on local water temperature regimes.

Distribution and specimens ( Fig. 8 ). The species has been reported from the following states and provinces: CANADA: British Columbia ( Williams & Williams 1987; and as P. guppyi by Schmid 1951; Schmid & Guppy 1952; Blickle 1979), USA: Washington ( Banks 1936; Ross 1944; Blickle 1979; Ruiter et al. 2005), Oregon ( Anderson & Wold 1972; Anderson 1976; Blickle 1979; and as P. guppyi by Anderson 1976; Blickle 1979), and California ( Denning 1956; Blickle 1979).

The species is patchily distributed in mountain ranges along the western coast of North America from British Columbia (about 100–200 km north of the U.S. – Canadian border), southward in the Cascade and Sierra Nevada Mountains to Sequoia National Park in the southern Sierras ; and southward in the Olympic Mountains and coastal ranges of Oregon and California to Mendocino County ( Table 1). Most of the Cascade Mountain sites are on the wetter west slopes, though it has been found at several sites on the more xeric east slope of the Cascades. The majority of the springs and spring-streams where it occurs are in mature or old-growth coniferous forests. In the Cascade and Coastal Mountains in the northern part of its range, it is generally found at elevations <1200 m, below the alpine and subalpine zone. In The Sierra Nevada Mountains in the southern part of its range, it has been found in coniferous forests between 1265–2134 m elevation .

TABLE 1. Annotated collection data for Palaeagapetus nearcticus Banks 1936 .

British Columbia (BC): Mount Benson, 19 August 1949, R. Guppy, holotype male for Palaeagapetus guppyi Schmid, 1951 ; recorded as P. guppyi by Nimmo & Scudder (1978) and Schmid & Guppy (1952); but recorded as P. nearcticus by Scudder (1994) (Canadian National Collection). Mount Benson is in the maritime coastal ranges about 9.6 km west of Nanaimo, BC, on the southern end of Vancouver Island.

Coastal Mountains, tributary to Lillooet River at the Tenquilla Lake Trailhead ; 100–200 km NNE of Vancouver, 16 July 1988, R. W. Baumann, Wells & Whiting, 18 males, 7 females ( DER). This is the northern most record for P.nearcticus .

California ( CA): Sierra County, Rock Creek , 39.5986°N, 120.9972°W, watershed area 6.46 km 2, record extracted from US EPA national database and supplied by A. Herlihy, 24 June 2009, 6 larvae .

Del Norte County, California Coastal Ranges: Crescent City Fork of Blue Creek , 396 m, 41.532°N, 123.827°W, watershed area 26.98 km 2, record extracted from US EPA national database and supplied by A. Herlihy, 19 July 2000, 5 larvae; Clarks Creek , 58 m, watershed area 4.61 km 2, 41.8082°N, 124.1122°W, record extracted from US EPA national database and supplied by A. Herlihy, 30 July 2003, 4 larvae; Clarks Creek above Highway 199, 55 m, 41.8083°N, 124.1122°W, record extracted from the California SWAMP database and supplied by A. Rehn, 30 July 2003, larvae; South Fork Smith River Road , spring creek at mile 1.26, 27 September 2008, JL , 2 males ( JL); South Fork Smith River Road , spring creek at mile 12.69, 04 April 2009, JL , 1 larva ( JL) .

Humboldt County, Squaw Creek: 335 m, watershed area 2.47 km 2, 40.3167°N, 123.9976°W, for an EPA study, 08 August 2002, record supplied by A. Herlihy, 1 larva; about 1 km upstream from Grasshopper Creek, 341 m, 40.3167°N, 123.996°W, record extracted from the California SWAMP database and supplied by A. Rehn, 08 August 2002, larvae. California Coastal Ranges: North Fork Tectah Creek, north of Bald Hills Road, 27 June 2011, JL , 3 males ( JL); Godwood Creek , about 0.3 km above Prairie Creek, 49 m, 41.3679°N, 124.0243°W, record extracted from the California SWAMP database and supplied by A. Rehn , 15 September 2010, larvae; Arcata Community Forest, Jolly Giant Creek, about 200 m, 23 April to 14 June 1994, reared, JL , 2 males ( JL); 06 September , 2011, JL , 1 male, 1 female ( JL & RWW); Dragsaw Spring at Forest Service Road 13N01, tributary of Red Mountain Creek near Fish Lake, 10 July 2005, JL , 1 male ( JL); 30 September 2008, JL , 2 males ( JL & TI); Red Mountain Creek at Forest Service Road 10N12, near Fish Lake, 10 July 2005, JL , 4 males ( JL); 17 September 2009, JL , 8 males, 4 females ( JL); 30 September 2008, JL , 6 males, 4 females ( JL & TI); unnamed creek 1.6 km north of Trinidad, 03 June 1972 & 08 August 1973, adults (Burdick personal communication 1999, 2013); upper Willow Creek , below Berry Summit, 29 August 2012, JL , 4 males ( JL); Sixes Rivers National Forest , Slide Creek , Highway 13, south of Fish Lake Campground, 31 May 1991, R . Baumann and B. Stark, 1 female ( Brigham Young University ). Redwoods National Park : California Coastal Ranges , benthic biomonitoring samples collected by park personnel, Godwood Creek , 22 June 2012, larvae; Little Lost Man Creek , 05 July 2012, larvae. Madera County, Sierra Nevada Mountains , Nelder Creek , about 1.6 km above California Creek, 1535 m, 37.4249°N, 119.5957°W, record extracted from the California SWAMP database and supplied by A. Rehn : 05 May 2009, larvae; 15 June 2009, larvae; 15 October 2009, larvae .

Mariposa County, Sierra Nevada Mountains , 11.3 km ENE of Fish Camp, 2134 m, 11 July 1946, H.P. Chandler, 2 males ( CAS) .

Mendocino County, California Coastal Ranges, Wages Creek, Highway 1, 30 August 2009, JL, 2 males ( JL) .

Plumas County, Sierra Nevada Mountains, Rice Creek , north arm, 1814 m, 40.4002°N, 121.4390°W, record extracted from the California SWAMP database and supplied by A. Rehn, 16 June 2009, larvae .

Sierra County, Sierra Nevada Mountains, Rock Creek , 1.9 km upstream of Little Rock Creek , 1265 m, 39.5986°N, 120.9978°W, record extracted from the California SWAMP database and supplied by A. Rehn, 24 June 2009, larvae .

Siskiyou County, Klamath-Siskiyou Mountains , Big Springs , Mount Shasta , City of Mount Shasta, Mount Shasta Park, about 1000 m, 25 May 2007, B. Kondratieff and R . Baumann, 2 males ( CSU) .

Tulare County, Sierra Nevada Mountains, Sequoia National Park , 1829 m ,, 20 July 1946, D.G. Denning, adults ( CAS) (Burdick personal communication 1999, 2013) .

Oregon (OR): Benton County, Oregon Coast Range, unnamed perennial tributary to Crooked Creek, tributary of the Alsea River, Oregon Coast Range, 348 m, 44.4374°N, 123.4900°W, early August, year unknown, J. Banks, 1 adult (OSAC-F); Oak Creek, tributary of the Mary’s and Willamette River near Corvallis, 213 m, densely forested, cobble/ gravel substrates, emergence trap, 5–9 June 1969, J. Wold, 1 male ( Anderson & Wold 1972, Anderson 1976).

Clackamas County, Western Cascade Mountains : Dinger Creek near mouth at Timothy Lake, 1484 m, old-growth conifer watershed, snow-melt and spring-fed stream, 4–5 m wide channel, cold year-round temperature regime, moderate gradient, cobble substrates, 5–10% coverage with moss and liverwort, 04 June 2000, RWW , 2 5 th -instar larvae ( TI); Mount Hood , Hidden Lake outlet stream, 1219 m, 23 July 1953, collector unknown, 1 male ( INHS); Mount Hood , Still Creek Forest Camp , 10 August 1955, S.G. Jewett, 1 male, 1 female ( NMNH); Mount Hood , Still Creek near Swim, midelevation, 20 July 1947, S. Jewett, males, females (1 male, OSAC-E; others INHS); Last Creek, 1219 m, 45.0009°N, 121.8152°W, watershed area 3.76 km 2, record extracted from US EPA national database and supplied by A. Herlihy, 1997, larvae.

Douglas County, Western Cascade Mountains : tributary to Emile Creek at river mile 0, 1274 m, 43.2454°N, 122.7943°W, watershed area 2.67 km 2, record extracted from US EPA national database and supplied by A. Herlihy, 1999 larvae; upper Emile Creek , Umpqua National Forest biomonitoring site, 1189 m, 2–4 m wide channel, relatively open canopy, moderate gradient, meadow/wetland above site, cold year-round water temperature, spring-fed with low seasonal discharge amplitude, 50–60% coverage of substrates with moss and liverwort, mostly sand and gravel substrates, 21 October 1997, RWW, 13 larvae ( RWW); Umpqua National Forest , headwater tributaries of Bulldog Creek , tributary to Big Bend Creek , Steamboat Creek , & North Umpqua River, Western Cascades, 1183–1561 m, 43.40°N, 122.50°W, Forest Service road 3850 and spur roads, Site 1, 1561– 1573 m, 1 st -order stream and ponds in subalpine meadow, 18–19 June 1998, RWW , 10 5 th -and two -early instar larvae ( TI); headwaters of Little River , tributary to the South Umpqua River, about 1000 m, 18 April 1998, RWW, 1 male ( RWW) .

Jackson County, Klamath / Siskiyou Mountains , East Fork Ashland Creek , Rogue River National Forest, 914 m, 100–200 m above Reeder Reservoir, City of Ashland water supply, mature 2 nd growth conifer/hardwood forest, 2–4 mwide channel, moderate gradient, cobble/boulder substrate with abundant decomposed granitic sand, primarily springfed, cold year-round water temperature, 2 November 1999, RWW , 3 5 th -instar larvae ( RWW). Western Cascade Mountains : North Fork Little Butte Creek 0–50 m below Camp Creek, site NBB 6, 884 m, Medford Bureau of Land Management biomonitoring site, spring-fed stream with low seasonal hydrograph amplitude, 2 nd -growth conifer/ hardwood forest, high logging and roading intensity, cool-cold year-round water temperatures, 3–5 m wide channel, moderate gradient, gravel/cobble substrates, siltation high, high coverage of substrates with aquatic moss and liverwort, 03 October 2001, RWW , 8 larvae ( RWW and TI); Clark Creek , site CLK9, tributary of Butte Creek and the Rogue River, about 915 m, spring-fed stream with cold year-round water temperatures and low seasonal hydrograph amplitude, 2 nd - growth mixed conifer/hardwood forest with high logging and roading intensity, moderate gradient, 1–5 m-wide channel, sand/gravel/cobble/boulder substrates, high siltation, high coverage of substrates with aquatic moss and liverwort, Medford Bureau of Land Management biomonitoring site, 01 October 1992, 194 larvae; 06 October 1993, 1 larva; 03 October 2001, many larvae, RWW ( RWW) .

Josephine County, Klamath / Siskiyou Mountains, Oregon Caves National Park , Cave Creek , benthic biomonitoring samples, 13 June 2012, collected by park service personnel, larvae ( RAI) .

Klamath County, Eastern Cascade Mountains : Cold Creek , 2.4 km upstream mouth, tributary to Johnson Creek , 1509 m, high gradient, moss, liverwort and woody debris abundant, coarse, embedded substrate, spring-fed, cold, year-round water temperature, biomonitoring sample, 16 June 1992, Klamath Bureau of Land Management perspnnel, 178 larvae /m 2 ( RWW); Irving Creek , Winema National Forest, mid-elevation, open coniferous forest, 1.2–1.8 m-wide channel, springfed, cold year-round water temperature, benthic biomonitoring sample, 22 September 1992, Chemult Ranger District personnel, 24 larvae ( RWW) .

Lane County, Western Cascade Mountains : South Fork McKenzie River , side channel, about 600 m, considerable cold water upwelling in this shaded side channel mimics spring conditions, biomonitoring sample, 01 April 2010, the McKenzie Watershed Council personnel, 2 5 th -instar larvae ( RWW); Roney Creek 1.6 km up horse trail, 792 m, 44.1077°N, 122.0187°W, watershed area 4.77 km 2, record extracted from US EPA national database and supplied by A. Herlihy , 1999, larvae; Cullen Creek at river mile 0.3, 408 m, 44.2032°N, 123.9491°W, record extracted from US EPA national database and supplied by A. Herlihy, 1996 larvae; Salt Creek Falls near Willamette Pass, mid-elevation, 07 August 1948, H.H. Ross, 1 male ( INHS); HJ Andrews Experimental Forest , Nostoc Creek , mid-elevation, 29 April 1982, Greg Courtney, 1 5 th -instar larva ( OSAC-E); HJ Andrews Experimental Forest , emergence trap, mid-elevation, Site 2, 44.2145°N, 122.2493°W, 21–25 June 2010, B. Gerth, 1 male ( OSAC-F); Iko Spring , tributary to Indigo Creek , Middle Fork Willamette River basin, about 915 m, dense old-growth coniferous forest; large spring with pools and channels, 6.7–8.9° C water temperature in late summer, sand dominant substrate, large woody debris, moss and liverwort abundant, September 1997, Forest Service personnel, larvae common ( RWW); Huckleberry Creek above 7 th -Creek, 2.4 km east of the Middle Fork of the Willamette River, 9.6 km NE of Oakridge, EPA fertilization study, 11 March 1976, 3 5 th -instar larvae ( OSAC-E); Quartz Creek, mid-elevation, 22 March 1974, OSF , 1 5 th -instar larva (OSAC-E).

Lane County, H.J. Andrews Experimental Forest, Shorter Creek, tributary to Lookout Creek, 19 June 1978, N.H. Anderson, life stage unknown (ROM).

Lincoln County, Oregon Coast Range, Needle Branch Creek, Alsea River watershed , adjacent to the Flynn Creek watershed , about 200 m, 44.5151°N, 123.8545°W, 24 May 2010, B. Gerth, 3 larvae ( OSAC-F) .

Linn County, Western Cascade Mountains : Pyramid Creek tributary, 1203 m, watershed area 0.70 km 2, 44.5493°N, 122.0741°W, record extracted from US EPA national database and supplied by A. Herlihy, 31 July 2002, 7 larvae; Suttle Camp Creek , 790 m, watershed area 2.84 km 2, 44.4398°N, 122.2795°W, record extracted from US EPA national database and supplied by A. Herlihy, 08 July 2003, 1 larva; Monument Peak Campground near waterfall, mid-elevation, 02 August 1969, 1 male, K. Goeden ( Anderson 1976); Big Meadows , North Santiam Highway, Western Cascades, about 1200 m, 03 August 1948, collector unknown, 1 male ( INHS); 1.6 km west of Marion Forks , North Santiam Highway , mid-elevation, 09 August 1952, collector unknown, male, female ( INHS); Willis Creek, North Santiam Highway, midelevation, 17 July 1947, 1 female, collector unknown ( INHS) .

Multnomah County, Western Cascade Mountains, Columbia River Gorge, Wahkeena Creek headwater spring, 450 m, large volume spring, 6°C year-round water temperature, dense forest canopy, 21 June 1989, RWW, 2 males; 05 July 1989, RWW, 2 males, 1 female; 19 July 1989, RWW, 2 males, 3 females; 16 August 1989, RWW, 4 males, 2 females, RWW ( TI) .

Tillamook County, Oregon Coast Range, headwater tributary of the Trask River , 45.3678°N, 123.464°W, emergence trap, 10 August 2009, B. Gerth, 1 male ( OSAC-F) .

Washington ( WA): Chelan County, Eastern Cascade Mountains, Middle Shaser Creek , near Cashmere , tributary of Peshastin Creek , about 900–1200 m, 09 July 2008, benthic biomonitoring samples, larvae ( RAI) .

Mount Rainier National Park, Western Cascade Mountains : Longmire Springs, about 900 m, 25 July 1953, K.M. Fender, 9 males ( CAS) ; boggy stream 2.7 km north of Highway 706 on Westside Road, 17 August 1999, Kondratieff, Lechleitner & Zuellig, 2 females ( CSU) ( Ruiter et al. 2005) ; large spring-fed stream 3.06 km north Highway 706, west side of road, 13 July 2004, Kondratieff, Lechleitner & Zuellig, 1 male ( CSU) ( Ruiter et al. 2005) ; Falls Creek at Carbon River, 16 August 1999, Kondratieff, Lechleitner & Zuellig, 1 male ( CSU) ( Ruiter et al. 2005) ; Ohanapecosh River at oil spill, site o29–00a, benthic sample, 23 August 2010, B. Samora, 7 immature pupae ( RWW) .

Olympic National Park, unnamed small stream at about mile 3 on Queets River Road , 30 m, 47.7880°N, 124.1977°W, 03 June 2013, JL, 10 males, 2 females ( JL) .

Pierce County, Mount Rainier, White River, 20 to 24 July (no year given), A.L. Melander, holotype male for Palaeagapetus nearcticus Banks, 1936 . The White River flows north from the flanks of Mount Rainier. Highway 410 parallels the river from its mouth to near the headwaters on the NW side of Mount Rainier, so the collection probably was made somewhere along this highway.

Thurston County, Puget Sound Lowlands, Thompson Creek, about 100 m, forested streams and springs, benthic biomonitoring sample, 23 July 2011, Thurston County Stream Team, 1 5 th -instar larva (RWW).

Whatcom County, Western Cascade Mountains , Mount Baker, small stream, 1829 m, 29 August 1946, collector unknown, 1 male ( INHS) .

Figures

FIGURE 1. Palaeagapetus nearcticus male and female. Male (A–I): A, head, left lateral; B, head and thorax, dorsal; C, right wings, dorsal; D, abdominal segments V–X, left lateral; E, genitalia, left lateral; F, same, dorsal; G, same, ventral; H, I, lateral appendage, left lateral. Female (J, K): J, abdominal segments V–X, left lateral; K, vaginal apparatus, ventral. Abbreviations: 1–5=1st to 5th apical forks; V–X= abdominal segments V–X; tX= tergite X. Setal warts (B): a= anterior setal wart, am= anteromesal setal wart, p=posterior setal wart, pl=posterolateral setal wart. Genitalia: ia=inferior appendage (paired): dl=dorsal lobe of inferior appendage, vl=ventral lobe of inferior appendage; la ap=lateral appendage (paired): db=dorsal branch of lateral appendage; mb=middle branch of lateral appendage, vb=ventral branch of lateral appendage; ph, phallus.

FIGURE 2. Palaeagapetus nearcticus pupa and newly emerged adult. Pupa (A–D): A, dorsal; B, left mandible, dorsal; C, anterior hook plate, dorsal; D, posterior hook plate, dorsal. Newly emerged adult: E, wing erection of newly emerged adult, left lateral, see text.

FIGURE 3. Instar analysis of Palaeagapetus nearcticus larvae by head-width distribution.

FIGURE 4. Palaeagapetus nearcticus final instar larva. A, larva, dorsal; B, head, dorsal; C, same, ventral; D, labrum, dorsal; E, right mandible, ventral; F, left mandible, ventral; G, right pronotal plate, dorsal; H, right pleura and legs on thorax, right lateral; I, dorsal tergite on segment IX, dorsal; J, right anal leg, right lateral.

FIGURE 5. Palaeagapetus nearcticus early instar larva, eggs on liverwort, case of final instar larva and feeding trace. Early instar larva (A–G): A, 4th instar larva, right, lateral; B–D, right lateral parts of abdominal segment II of 4th (B), 3rd (C) and 2nd (D) instar larvae, dorsal; E–G, dorsal tergites of segment IX of 4th (E), 3rd (F) and 2nd (G) instar larvae, dorsal. Eggs (H and inset): eggs on liverwort. Case (I), dorsal. Feeding trace (J): cells of the liverwort showing feeding trace, see text.

FIGURE 6. Occurrence of 5 development stages of Palaeagapetus nearcticus in British Colombia (B), Washington (W), Mary’s Peak in Oregon (M), other localities in Oregon (O), and California (C) in 1948–2012. Grey bands indicate the supposed main annual life cycle in all study sites.

FIGURE 8. Distribution map. The arrow indicates that the new records from Newfoundland should not be overlooked.