Pleotrichophorus oestlundii (Knowlton 1927)

Pleotrichophorus oestlundi (Knowlton)

Capitophorus oestlundi Knowlton, 1927:235–237 [lectotype: apt.v.f., Brigham, Utah, 25–IX–1926, GFK, on Chrysothamnus nauseosus; in GFK coll.]; 1929:11.—Knowlton and Smith, 1936a:110–111; 1937:151.—Gillette and Palmer, 1934: 153.—Knowlton, 1935b:137; 1941:138; 1946:6; 1948:123; 1954:8–9.—Palmer, 1952:263–264.

Pleotrichophorus oestlundi (Knowlton).—Hille Ris Lambers, 1953:115; 1969:167.

DIAGNOSIS.—A rather distinctive species with numerous (4–10) flattened or funnel-shaped setae on dorsum of cauda of apterous vivipara. The thick cover of fan-shaped setae on the head (mean df is 51.50 ± 1.31, n = 100) and body, strongly spiculate dorsal integument and moderately long cornicles (.17–.46 mm) which average 1 ⅓ times (1.37 ± .03, n = 100) as long as cauda are additional diagnostic characters.

DESCRIPTION.—Apterous Viviparous Female: Color in life bluish green to apple green, with white pruinosity covering body in summer aptera, acquiring slight reddish cast in fall, later turning reddish to reddish brown (Knowlton, 1927). Cleared specimen pale with antennal joints between a.s.III and IV, tips of a.s.V, entire a.s.VI, entire tarsi and tips of rostrum dark. Body 1.54–2.27 (1.89, n = 88) mm long, .41–.55 (.478, n = 95) mm wide across eyes. Head with moderately developed laterofrontal tubercles, mesofrontal rather well produced, frontal integument spiculate dorsally and ventrally; mf usually 2p, lf 4–10 (usually 6) on each side, vlf 1p, df 40–73 (51.50 ± 1.31, n = 100), vf 14–31 (23.10, n = 92), pc usually 2p, ac 4–7, and md 3–6 (usually 3 or 4) on each lobe; dorsal setae widely expanded funnel- to fan-shaped, sessile; ventral setae except ac and some of md similar to but more narrowly expanded than df’s; mf .0176–.0374 (.0294, n = 354), df–1 .0132–.0396 (.0305, n = 184) mm long. Antennal segment I conspicuously produced on inner distal margin, imbricate-spiculate, with 8–19 (usually 11 or 12) small rod-shaped or knobbed setae in addition to basal pointed one on dorsum. A.s.II imbricate, usually with rod-shaped or knobbed setae. A.s.III imbricate, with small setae, longest less than ⅓ basal diameter of segment; bearing 1–4 (1.6, n = 173) sensoria. A.s.IV and V subequal, slightly more than ¾ a.s.III in length; a.s.VI with unguis 4 ¾ to 7 ½ times (6.01, n = 105) as long as base.

Tergum slightly sclerotic; densely imbricate-spiculate between setal bases; densely covered with uniformly fan-shaped setae. Cauda with acute but rounded apex, with slight basal constriction; spiculate; with usually 3 pairs of pointed lateral setae and 4–10 (6.27, n = 90) flattened or funnel-shaped ones on dorsum. Cornicles moderately long (.17–.46, m = .354, n = 185), extending to about level of caudal bases, 1.00 to 1.75 times (1.37 ± .03, n = 100) as long as cauda; cylindrical, with slight basal and apical thickening on mesal margin, imbricate-spiculate. Legs with 3, 3, 3 hairs on first tarsal joints. Rostrum IV+V rather slender, tapering to acute point, with posterior margins slightly convex; .09–.12 (.101, n = 94) mm long, .75–1.00 (.86 ± .02, n = 100) as long as second hind tarsal segment; with 1 basal, 2 dorsal, and 3 lateral pairs of setae, ml and pi setae about 3/4 as long as al.

Measurements (in mm) of lectotype and 4 paralectotypes (from Brigham and Trenton, Utah): BL 1.70–1.90 (1.80), We .43–.50 (.462); a.s.III .45–.52 (.472), a.s.IV .35–43 (.390), a.s.V .33–.42 (.372), a.s.VI .10–.13 (.114) + .58–.70 (.646); cornicles .26.34 (.302), cauda .24–.27 (.256); hind tibiae .84–.91 (.872), hind ta–2 .11–.13 (.118), rostrum IV+V .09–.10 (.096); mf .0220–.0330 (.0286), and df–1 .0286–0374 (.0312). Proportions of a.s.III:IV:V, 1: .76–.89 (.83): .73–.84 (.79); VIu/VIb 5.00–5.91 (5.52); co/ca 1.08–1.28 (1.19); rostrum IV+V/ hind ta–2 .75–.91 (.82).

Alate Viviparous Female: Color in life bluish green (Knowlton, 1927); cleared specimen with body pale, mesothorax, areas around ocelli, abdominal, pleural and marginal sclerites, apices of cornicles and cauda brown, antennal joints between a.s.III and IV, IV and V, apices of a.s.V, entire a.s.VI, tips of rostrum and entire tibiae darker brown. Head chaetotaxy much like apterous female but df setae relatively fewer (30–38, m = 33.8, n = 12), all setae less expanded, funnel- rather than fan-shaped. Sensoria on a.s.III 8–14, with mean of 10.1 for 16 segments. Abdomen also like that of aptera but with 3 pairs of rows of sclerites: mesal spinal ones small and oval, pleurals larger, transverse and marginals oval, larger than spinals; dorsal setae widely expanded, funnel-shaped; dorsal caudal setae 3–8 (5.7, n = 12), more elongate, pointed, merely blunt or slightly flattened at apices.

Measurements (in mm) of 10 specimens (from Cove and Cove Fort, Utah, 20–VIII–1955): B.L. 1.85–2.03 (1.94), We .40–.46 (.430); a.s.III .54–.63 (.605), a.s.IV .45–.54 (.478), a.s.V .44–.54 (.478), a.s.VI .12–.15 (.132) + .74–.87 (.817); cornicles .30–.39 (.343), cauda .26–.27 (.264); hind tibiae 1.06–1.25 (1.16), hind ta–2 .11–.13 (.122), rostrum IV+V .10–.11 (.105); mf and df–1 .0154–.0352 with mean of .0234 and .0249, respectively. Proportions of a.s.III:IV:V, 1: .78–.91 (.83): .73–.81 (.79); VIu/VIb 5.40–7.00 (6.22); co/ca 1.15–1.46 (1.29); rostrum IV+V/ hind ta–2 .77–92 (.85).

Oviparous Female: Color in life red to brownish red (Knowlton, 1927). Morphologically similar to viviparous female except as follows: head with relatively fewer df setae (32–45, m = 37.7, n = 15), sparser dorsal body hairs; a.s.VIu/VIb ratio smaller (4.77–6.41, m = 5.39, n = 29); cornicles slightly shorter (.19–.27, m = .223, n = 32), their ratio to cauda relatively smaller (m = 1.14, n = 32); dorsal caudal hairs longer with pointed, blunt or knobbed tips; subgenital plate bearing more and pointed setae; hind tibiae enlarged and armed with numerous pseudosensoria on basal ⅓.

Measurements (in mm) of 5 paralectotypes (from Brigham, Utah): B.L. 1.61–1.75 (1.69), We .43–.48 (.460); a.s.III .47–.50 (.489), a.s.IV .37–.41 (.391), a.s.V .36–.41 (.384), a.s.VI .11–.13 (.120) + .60–.71 (.643); cornicles .21–.25 (.223), cauda .18–.20 (.192), hind tibiae .86–.90 (.878), hind ta–2 .12–.13 (.123), and rostrum IV+V .10. Proportions of a.s.III: IV:V, 1: .78–.83 (.90): .75–.82 (.77); VIu/VIb 4.77–6.41 (5.54); co/ca 1.05–1.32 (1.18); rostrum IV+V/ hind ta–2 .77–.83 (.81).

Alate Male: Similar to alate viviparous female except as follows: df setae fewer (11–20, m = 17.10, n = 7), relatively shorter; sensoria more on a.s.III (19–33, m = 27.9. n = 10), present also on a.s.IV (13–30, m = 22.1, n = 9) and a.s.V (13–22, m–18.4, n = 7); cornicles much shorter (.11–.16, m = .134, n = 7) subequally as long as cauda (.86–1.23, m = 1.01, n = 7); cauda shorter, acutely triangular, not constricted, dorsal setae all pointed. Aedeagus angular but with smooth apex.

Measurements (in mm) of 4 paralectotype (from Trenton and Brigham City, Utah): BL 1.39–1.53 (1.44), We .38–.43 (.395); a.s.III .50–.54 (.523), a.s.IV .40–.45 (.424), a.s.V .36–.41 (.388), a.s.VI .11–.12 (.113) + .60–.70 (.643); cornicles .11–.13 (.12), cauda .12–.14 (.135); hind tibiae .87–.97 (.93), hind ta–2 .12–.13 (.123), rostrum IV+V .10, mf .0154–0242 (.0196), and df–1 .0132–.0220 (.0207). Proportions of a.s.III:IV:V, 1: .75–.85 (.80): .69.77 (.73); VIu/VIb 5.00–6.36 (5.73); co/ca .79–1.23 (.86); rostrum IV+V/ hind ta–2 .77–83 (.81).

HOSTS.—Chrysothamnus greeni, C. nauseosus var. graveolens and var. nauseosus, C. parryi, C. plattensis, C. viscidiflorus, and Chrysothamnus sp. It has been collected from Artemisia like A. tridentata.

DISTRIBUTION.—Widely distributed in the western United States, records include Arizona, California, Colorado, Idaho, Montana, Nevada, Oregon, Utah, and Washington.

TYPES (designated from “cotypes” available).—Lectotype: apt.v.f. with data given above; specimen at 11:00 o’clock on slide containing 3 paralectotypes in GFK collection. Paralectotypes (all collected by GFK, on Chrysothamnus nauseosus at different dates and localities): 3 apt.v.f. on same slide as lectotype and 7 apt.v.f. and 17 apt. ny. also with same data as lectotype but mounted on 6 other slides (GFK coll.); 3 ovip.f., 1 al.m. and 1 apt.ny., Brigham City, Utah, 9–X–1926 (OWO coll.); 3 apt.v.f. and 4 apt.ny., Lehi, Utah, 23–VI–1926 (OWO coll.); 3 apt.v.f., 8 apt.ny., and 2 altd. ny., Trenton, Utah, 29–IX–1926 (GFK coll.); 3 ovip.f., 2 al.m., 3 apt.ny., and 1 altd.ny., Trenton, Utah, 15–X–1926 (OWO coll.); 3 apt.v.f., and 5 apt.ny., Preston, Idaho, 24–VI–1925 (OWO coll.) and 1 apt.v.f., 8 ovip.f., 2 al.m. and 9 apt. ny., Logan, Utah, 18–X–1926 (EOE coll.).

SPECIMENS EXAMINED.—Aside from types, numerous specimens of all morphs from the following localities: ARIZONA: Fredonia. CALIFORNIA: Big Bear City and Big Bear Lake in San Bernardino Co., Bridgeport in Mono Co. and San Bernardino Mts. at Cienega Seca. COLORADO: Cache la Poudre, Cache la Poudre Canyon, Elk Springs and Wolcott. IDAHO: Big River Narrows, Franklin, Montepelier, and Riverdale. MONTANA: Crown Springs. NEVADA: Winnemucca. ORECON: Klamath Falls, UTAH: Amalga, Arches National Monument, Beaver, Beaver Canyon, Bridges National Monument, Brigham, Brigham Canyon, Brigham City, Cedar Valley, Clear Creek, Cove, Cove Fort, Delta, Dewey, Draper, Emery, Fort Duchesne, Glendale, Gusher, Hanna, Heber, Hobble Creek, Honeyville, Huntsville, Kanab, Kanab Creek, Logan Canyon, Logan Green Canyon, Losee, Maeser, Magma, Mantua, Provo Canyon, Salina Canyon, Scipio, Sigurd, Smithfield, Soldier Springs, Torrey, Trenton, Vernal, Vernal Creek, Weber Canyon, Wildcat Canyon, and Woodruff. WYOMING: Jackson and Jackson Hole.