Tytthus montanus Carvalho & Southwood

Henry, Thomas J., 2012, Revision of the Plant Bug Genus Tytthus (Hemiptera, Heteroptera, Miridae, Phylinae), ZooKeys 220, pp. 1-114 : 36-39

Tytthus montanus Carvalho & Southwood Figs 21 –23148– 151

Tytthus montanus Carvalho and Southwood 1955: 32 (orig. descrip.); Carvalho 1958: 157 (cat.); Henry and Wheeler 1988: 458 (cat.); Schuh 1995: 249 (cat.).

Diagnosis.

This species is distinguished by the overall dark brown to nearly black coloration, with the basal thirds of the corium and clavus white, the pale yellow antennal segment I and black segment II, the dark brown metafemur, and pale yellow tibiae. It is known from only two macropterous males (Fig. 21), one macropterous female (Fig. 22), and numerous brachypterous females (Fig. 23).

Tytthus montanus is similar to Tytthus wheeleri in having mostly dark brown hemelytra with only the base pale or white but is distinguished from that species by the larger size (2.70 mm vs. less than 2.00 mm in Tytthus wheeleri ), pale yellow antennal segment I, red-streaked pro- and mesofemora, and dark brown metafemur (versus entirely pale yellow legs in Tytthus wheeleri ). It is also similar to Tytthus alboornatus but is distinguished by the distally dark hemelytron (versus distally white or pale cuneus or pale area across posterior margin of hemelytra in brachypters).

Description.

Macropterous male (n=1; holotype in parentheses) (Fig. 21): Length to apex of hemelytron 2.83 mm (2.75 mm), length to base of cuneus 1.98 mm (1.75 mm), width across hemelytra mm. Head: Length 0.38 mm (0.37 mm), width across eyes 0.64 mm (0.64 mm), interocular width 0.34 mm (0.32 mm). Labium: Length 0.98 mm (0.93 mm). Antenna: Segment I length 0.27 mm (0.30 mm), II 0.93 mm (0.93 mm), III 0.56 mm (missing), IV mm (missing). Pronotum: Length 0.45 mm (0.43 mm), basal width 0.72 mm (0.74 mm).

Coloration: Head: Dark reddish brown (holotype) to black; pale yellow interocular spot near inner margin of eye indistinct; eyes dark brown to nearly black. Labium: Mostly pale yellow, with segment I and apex of segment IV dark brown. Antenna: Segment I pale yellow, narrowly fuscous at base; segments II mostly fuscous to black, with only base pale yellow; segments III–IV nearly black (segments II–IV yellowish brown in holotype). Pronotum: Uniformly dark brown (holotype) to black. Mesoscutum: Uniformly dark brown (holotype) to black. Scutellum: Uniformly dark brown (holotype) to black. Hemelytron: Largely dark brown (holotype) to black, with only basal third of corium and clavus white; membrane translucent brown to smoky black. Ostiolar evaporative area: Dark reddish brown (holotype) to black. Ventral surface: Uniformly dark reddish brown (holotype) to black. Legs: Coxa pale yellow, reddish brown or black at bases; pro- and mesofemora pale yellow, lightly tinged with pale orange to more reddish brown with bases pale (holotype), metafemur dark reddish brown (holotype) to dark brown, with basal one third and apex pale yellow; pro- and mesotibiae pale yellow to more reddish brown with bases pale, metatibia yellow (holotype) to dark brown; tarsi and claws pale yellow.

Structure, texture, and vestiture: Head: Shiny, impunctate, width subequal to length; buccula very narrow, tapering posteriorly, ending at level before middle of eye. Labium: Extending to bases of mesocoxae; segment I not extending to base of head. Antenna: Segment I with only very short, fine, recumbent setae, with two erect, subapical, bristlelike setae; segment II thickly set with short, recumbent setae, intermixed with a few more erect, short setae on distal half. Pronotum: Shiny, with a glaucous sheen over weakly defined calli, impunctate; anterior angles rounded, lateral margins concave, strongly flaring at posterior angles; posterior margin weakly sinuate; sparsely set with short, fine, recumbent setae. Mesoscutum: Shiny, impunctate, with a few scattered, recumbent setae. Scutellum: Shiny, impunctate, with a few short, fine, recumbent setae. Hemelytron: Macropterous, cuneus and membrane fully developed, extending well beyond apex of abdomen; evenly set with scattered, short, fine, recumbent setae.

Male genitalia: Left paramere (Fig. 148): Mitt-shaped; right arm longest, stout, distally blunt; left arm short, blunt. Right paramere (Fig. 149): Oval. Endosoma (Fig. 150): C-shaped to weakly S-shaped. Phallotheca (Fig. 151): Slender, apically acute.

Macropterous female (n = 1) (Fig. 22): Length to apex of hemelytron 2.65 mm, length to base of cuneus 1.87 mm, width across hemelytra 0.94 mm. Head: Length 0.37 mm, width across eyes mm, interocular width 0.32 mm. Labium: Length 0.91 mm. Antenna: Segment I length 0.22 mm, II 0.59 mm, III 0.40 mm, IV 0.40 mm. Pronotum: Length 0.42 mm, basal width 0.72 mm.

Very similar to the two macropterous males in overall shape and structure, differing in the significantly shorter antennal segments and in having all femora and the basal halves of the tibiae dark brown to fuscous.

Brachypterous female (n = 5) (Fig. 23): Length to apex of hemelytron 1.85-2.20 mm, length to base of cuneus 1.53-1.75 mm, width across hemelytra 0.77-0.86 mm. Head: Length 0.38-0.42 mm, width across eyes 0.61-0.62 mm, interocular width 0.32-0.34 mm. Labium: Length 0.88-0.91 mm. Antenna: Segment I length 0.22-0.24 mm, II 0.64-0.78 mm, III 0.35-0.42 mm, IV 0.34-0.35 mm. Pronotum: Length 0.37-0.40 mm, basal width 0.56-0.58 mm. Similar to macropters in overall color pattern, but like the macropterous female, differing from males in the shorter antennal segment and darkened femora.

Similar in color to the macropterous males and the one macropterous female, but differing especially in the nearly quadrate pronotum that has only weakly flared posterior margins and the brachypterous hemelytron with a greatly shortened cuneus (fra cture still visible on most specimens) and a much abbreviated membrane lacking any trace of areoles (Fig. 23).

Host.

No specific host. Specimens from Arizona were swept from a dry grass and flower meadow in eastern Arizona; the one male from Utah was beaten from the bases of bunch grasses.

Distribution.

Described and previously known only from Montana. Arizona and Utah represent new state records.

Discussion.

Although I have considered the series of 18 females collected in Arizona by Leonard Kelton (CNC) conspecific with the holotype male and one other male taken in northern Utah, I note that all femora of this southern population are uniformly dark except at the bases, whereas the Montana and Utah males have pale front and middle femora and only the hind femora dark. In addition, the actual measurements of the antennal segments are considerably smaller in these females than males, a variation not observed in other species.

Type material examined.

Holotype ♂ (macropterous) (00162198) (USNM): UNITED STATES:Montana:Granite Co.: Drummond, July 10, 1935, Oman.

Other specimens examined.

UNITED STATES:Arizona:Apache Co.: Big Lake, Apache National Forest, 33.88667°N, 109.41667°W, 2774 m, 12 Aug 1967 - 14 Aug 1967, L. A. Kelton, 18 ♀♀ (00112047 - 00112061, 00112063, 00161925 - 00161926) (CNC). Utah:Cache Co.: 0.4 mi off Rt 89 along Franklin Basin Rd, 41.93555°N, 111.57222°W, 2004 m, 17 Jul 2001 - 18 Jul 2001, T. J. Henry and A. G. Wheeler, Jr., 1 ♂ (00161897) (USNM).