Trigonotylus exilis, Schwartz, Michael D., 2012

Schwartz, Michael D., 2012, Two new species of Trigonotylus (Hemiptera: Heteroptera: Miridae: Stenodemini) from western Canada and northwestern United States, Zootaxa 3174, pp. 51-58 : 53-54

Trigonotylus exilis sp. n.

( Figs. 1 D, H, J, 2, 3)

Diagnosis. Coloration of antennal segment I similar to T. brooksi Kelton , but in T. exilis the segment I is 1.2 to 1.3 times the pronotal length, whereas in T. brooksi segment I is less than the pronotal length. Also, in T. exilis antennal segments II and III are clearly thickened, with average length of segments II and III 1.40 and 1.31 mm respectively in the male, and 1.75 and 1.57 respectively in the female. In T. brooksi antennal segments II and III are longer and slender, and not at all thickened, with the average length of segments II and III 2.26 and 2.10 respectively in the male, and 2.40 and 2.30 respectively in the female. Additionally, antennal segments II and III are distinctly reddishbrown in T. exilis but are orange in T. brooksi . The dark antennal segment I will usually distinguish T. exilis from the sympatric T. americanus . In some specimens of T. exilis , the antennal segment I is relatively pale; however, the segment is usually reddish brown in T. americanus and the endosomal spicules of these two both species are diagnostic.

Description. Male. Total length 5.55 (4.70–6.00). COLORATION: Head pale green with longitudinal black line medially and vague black longitudinal line adjacent to each eye; antennal segment I black or dusky with inner margin pale ( Fig. 1 D), antennal segments II and III dull red. Pronotum pale green with double longitudinal fuscous line medially, and single longitudinal black line on each side medio-laterally; scutellum greenish yellow, with longitudinal fuscous lines contiguous with those on pronotum; centre of propleura slightly dusky. Hemelytra pale yellowish-green, with clavus somewhat dusky. Legs yellowish brown with tarsi dusky. Venter pale yellowish-green. STRUCTURE: Clypeus prominent, but rounded anteriorly; frons elevated well above clypeus; eye almost spherical. Antennal tubercle removed from eye by about width of base of antennal segment II; antennal segment I appearing virtually glabrous, and 1.2 to 1.3 times length of pronotum; antennal segments II and III long and slender; labium extending to base of hind coxae; hind tibia not strongly pilose. Genitalia —Endosoma with long straight spicule ( Figs. 1 J, 2), left paramere as in figure 2. MEASUREMENTS: Head width 0.72 (0.68–0.75); vertex width 0.38 (0.33–0.43); antennal measurements 0.77 (0.70–0.85): 2.26 (2.10–2.50): 2.10 (2.00–2.28): 0.68 (0.65–0.75); labial length 1.52 (1.50–1.55); pronotal width 0.90 (0.80–0.98); pronotal length 0.55 (0.50–0.60).

Female. Total length 6.44 (6.35–6.70). COLORATION: Similar male but paler and head with single medial fuscous streak; antennal segment I pale; antennal segments II and III reddish brown. Pronotum and scutellum pale green with double medial longitudinal fuscous line lateral fuscous streaks if present quite vague. STRUCTURE: Antennal segment I with very short, fine, sparse decumbent pubescence, appearing almost glabrous. MEASURE- MENTS: Head width 0.78 (0.77–0.80); vertex width 0.45 (0.44–0.48); antennal measurements 0.90 (0.88–1.00): 2.40 (2.35–2.65): 2.30 (2.23–2.40): 0.74 (0.68–0.80); labial length 1.76 (1.73–1.80); pronotal width 1.08 (1.05– 1.15), pronotal length 0.73 (0.68–0.78).

Holotype: 3, CANADA: British Columbia: Venables Vly. Rd. entrance, Hwy. 97, 23.vi.1996 (G.G.E. Scud- der), deposited in the Canadian National Collection of Insects, Ottawa [CNC].

Paratypes: CANADA: British Columbia: 13, 7 mi. E. Ind. Res., Oliver, 8.vii.1959 (L.A. Kelton) [CNC]; 13 1Ƥ, Anarchist Mt., Osoyoos, 6.vii.1959 (R. Madge) [CNC]; 1Ƥ, Anarchist Mt., nr. Osoyoos, 2000 ft, No. 325, 13.vi.1954 (N. Anderson) [CNC]; 13, Carquille rest area, 7.vii.1982 (G.G.E. Scudder) [CNC]; 143 24Ƥ, Christina Lk. 12.vii.1970 (L.A. Kelton) [AMNH; CNC; USNM]; 13, Cranbrook, Pinus ponderosa , 23.vii.1959 (L.A. Kelton) [CNC]; 2Ƥ, Fairview, White L., 11.vi.1994 (G.G.E. Scudder) [CNC]; 13, Fairview, White L., SATH habitat, SWm, BGxh1, pan trap WL P-10, 13.vi–20.vi.1995 (J. Jarrett) [UBC]; 2Ƥ, Fairview, White L., 29.vi.1996 (G.G.E. Scudder) [UBC]; 5Ƥ, Fairview, White L., big sage assoc., BGxh1, SWm, 7.vii.1996 (G.G.E. Scudder) [UBC]; 13 1Ƥ, Kamloops, 29–31.vii.1954 (G.J. Spencer) [UBC]; 23, Kelowna, 14.vii.1950 (B.P. Beirne [CNC]; 13, McIntyre Cr., Oliver, 4.vii.1959 (L.A. Kelton) [CNC]; 13, Merritt, 10.vii.1963 (G.G.E. Scudder) [CNC]; 1Ƥ, OK Falls, 8.vii.1974 (L.A. Kelton) [CNC]; 1Ƥ, Oliver, 27.vi.1959 (L.A. Kelton) [CNC]; 1Ƥ 3Ƥ, Osoyoos, Anarchist Mt., 13.ii.1970 (L.A. Kelton) [CNC]; 1Ƥ, Osoyoos, Haynes Ecol. Res., sweeping Hesperostipa comata ssp. comata , 2.vi.1994 (G.G.E. Scudder) [UBC]; 13, Osoyoos, Mt. Kobau, PPxh1, WAw, pitfall trap K 1-2, 14.vi–9.vii.1995 (J. Jarrett) [UBC]; 13 1Ƥ, Princeton, Old Hedley Rd., 4.5 km E, 14.vii.1991 (G.G.E. Scudder) [CNC]; 13 1Ƥ, Quilchena, 29.viii.1962 (G.G.E. Scudder) [UBC]; 13 1Ƥ, Soda Cr., 16.vi.1963 (G.G.E. Scudder) [UBC; CNC]; 13, id., 8.vii.1949 (R. Stace-Smith) [CNC]; 23 4Ƥ, Summerland, 10.vii.1975 (L.A. Kelton) [CNC]; 13, id. [Scudder Coll.]; 33 7Ƥ, Summerland, Ag. Canada Stn., 29.vi.1990 (R.A. Cannings, H. Nadel) [RBCM]; 23 2Ƥ, Vaseux L., 4.vi.1961 (G.G.E. Scudder) [Scudder Coll.; UBC]; 2Ƥ, Vaseux L., CWS Reserve, Purshia assoc., BGxh1, AN:F, 7.vii.1996 (G.G.E. Scudder) [UBC]; 13 1Ƥ, Vaseux L., Wildlife Reserve, 8.vii.1997 (G.G.E. Scudder) [CNC; UBC]; 33 2Ƥ, same data as holotype [CNC; Scudder Coll.]; 23 1Ƥ, Walhachin, 15.vi.1963 (G.G.E. Scudder) [CNC; UBC]; 13, Westbank, 30.vi.1955 (Wilson, Wakefield) [CNC]; 1Ƥ, Westwick L., Cariboo, 23.vi.1961 (G.G.E. Scudder) [UBC]; 13 2Ƥ, White Lake, Oliver, 29.vi.1959 (L.A. Kelton) [CNC]; 53 1Ƥ, White Lake, Okanagan Falls, 30.vi.1990 (R.A. Cannings, H. Nadel) [RBCM]. UNITED STATES: California: Lassen Co.: 93 5Ƥ, Susanville, “muridacon grass” ( Poaceae ), 17.vi.1959 (L.A. Kelton) [CNC]. Modoc Co.: 23, 24.7 mi NW of Canby, 41.69638°N 121.20732°W, 1375 m, 0 1 Jul 1979 (R.T. Schuh and B.M. Massie) (AMNH). Siskiyou Co.: 13, 2 mi SW of Lava Beds National Monument, Medicine Lake Road, Pseudoroegneria spicata ssp. spicata (Poaceae) , 26.vi.1979 (M.D. Schwartz) [AMNH]; 13, 3Ƥ, 4 mi NW of Lava Beds National Monument Headquarters, Pseudoroegneria spicata ssp. spicata (Poaceae) , 26.vi.1979 (M.D. Schwartz) [AMNH]. Oregon: Crook Co.: 13 1Ƥ, Ochoco National Forest, T14S R18E S11, Achnatherum thurberianum (Poaceae) , 22.vi.1979 (M.D. Schwartz) [AMNH]. Klamath Co.: 13, 7 mi E of Bly, Poaceae , 21.vi.1980 (P.W. Oman) [AMNH]. Lake Co.: 43 6Ƥ 11 mi NW of Silver Lake on Hwy 31, Pseudoroegneria spicata ssp. spicata (Poaceae) , 25.vi.1979 (M.D. Schwartz) [AMNH]; 43 4Ƥ, 11 mi N of Silver Lake, 25.vi.1979 (R.T. Schuh) [AMNH]. Wheeler Co.: 1Ƥ, 2 mi W of Mitchell on Hwy 26, Pseudoroegneria spicata ssp. spicata (Poaceae) , 22.vi.1979 (M. D. Schwartz) [AMNH]; 23 2Ƥ, id., Pseudoroegneria spicata ssp. spicata (Poaceae) , 22 Jun 1979 (R.T. Schuh) [AMNH]; 13 Mitchell, Ericameria nauseosa (Asteraceae) , 22.vi.1979 (M.D. Schwartz) [AMNH]. Utah: Cache Co.: 103 22Ƥ, Blacksmith Fork Canyon, on UT State route 101, 02.vii.1981, Pseudoroegneria spicata ssp. spicata (Poaceae) (M.D. Schwartz) [AMNH]; 83 Green Canyon Trail, Poaceae , 27.vi.1980 (M.D. Schwartz) [AMNH]. Washington: Benton Co.: 33 4Ƥ Hanford Site ALE, dirt rd off of 1200 Ft. Rd, 46.40766°N 119.55765°W, 19.vi.1995 (R.S. Zack) (WSU); 1Ƥ Hanford Site ALE, radio telescope, 46.39248°N 119.58541°W, 06.iv.1995 (R.S. Zack) (WSU).

Etymology. Named in reference to the thin and slender body conformation, exilis, Latin.

Hosts. The species of Trigonotylus feed on grasses or sedges exclusively. The documented hosts of T. exilis are all grasses ( Poaceae )—Thurber's needlegrass, Achnatherum thurberianum (Piper) Barkworth ; needle and thread, Hesperostipa comata ssp. comata (Trin. & Rupr.) Barkworth [formerly Stipa comata ]; and bluebunch wheatgrass, Pseudoroegneria spicata ssp. spicata (Pursh) A. Love. A number of specimens was also collected on unidentified species of Poaceae . We consider the two specimens taken on rubber rabbitbrush, Ericameria nauseosa (Pall. ex Pursh) G.L. Nesom & Baird (Asteraceae) and ponderosa pine, Pinus ponderosa C. Lawson (Pinaceae) as sitting records.

Distribution. Figure 3. In the intermountain grasslands from Soda Creek to Osoyoos in the arid southern interior of British Columbia and east of the Cascade Range in the United States from Hanford, Washington south to Lassen County, California and in apparent disjunct populations of Wasatch Range of Cache County, Utah.

Figures

FIGURE 1. Trigonotylus species. A – G. Antenna, dorsal view, scale = 0.5 mm. A. T. americanus. B. T. antennatus. C. T. caelestialium. D. T. exilis. E. T. flavicornis. F. T. setosus. G. T. viridis. H – I. Dorsal habitus, scale = 2.0 mm. H. T. exilis. I. T. setosus. J – K. Endosoma, left lateral view, scale = 0.2 mm. J. T. exilis. K. T. setosus.