Tytthus wheeleri Henry

Henry, Thomas J., 2012, Revision of the Plant Bug Genus Tytthus (Hemiptera, Heteroptera, Miridae, Phylinae), ZooKeys 220, pp. 1-114 : 74-75

Tytthus wheeleri Henry sp. n. Figs 150 –52187– 190

Diagnosis.

This species, known from brachypterous males and females (Figs 50, 52) and only one macropterous female (Fig. 51), is distinguished by the small size, overall dark brown coloration with only the basal third of the corium and clavus pale or white, the dark brown antennal segment I, and pale yellowish-brown tibiae.

It is similar to Tytthus montanus in overall brown coloration with the basal area of the corium and clavus pale, but is distinguished from that species by the much smaller size, dark antennal segment I, and pale tibiae. It is also similar to Tytthus alboornatus in overall coloration, but differs in lacking a narrow pale area across the apex of the corium and the dark antennal segment I and pale segment II. All specimens of Tytthus wheeleri at hand, except one macropterous female, are strongly brachypterous and lack a cuneus and membrane on each hemelytron.

Description.

Brachypterous male (n= 10; holotype in parentheses) (Fig. 50): Length to apex of abdomen 1.08-1.28 mm (1.30 mm); length to base of cuneus 0.95-1.05 mm (1.05 mm); width across hemelytra 0.51-0.61 mm (0.56 mm). Head: Length 0.24-0.29 mm (0.26 mm), width across eyes 0.43-0.45 mm (0.43 mm); interocular width 0.26-0.29 mm (0.27 mm). Labium: Length 0.75-0.77 mm (0.80 mm). Antenna: Segment I, length 0.22-0.27 mm (0.26 mm); II, 0.75-0.82 mm (0.83 mm); III, 0.45-0.48 mm (0.51 mm); IV, 0.34-0.40 mm (0.32 mm). Pronotum: Length 0.19-0.21 mm (0.21 mm), basal width 0.40-0.48 (0.43 mm).

Macropterous male: Unknown.

Coloration: Overall coloration dark brown. Head: Dark shiny brown, becoming paler yellowish brown ventrally, yellow spot on inner margin of each eye absent; eyes fuscous, often with a reddish tinge. Antenna: Segment I dark brown; II, pale yellowish brown, sometimes weakly red tinged at apex; III and IV pale yellowish brown. Pronotum: Dark shiny brown; scutellum dark shiny brown with apical half to one third pale yellowish brown. Hemelytron: Dark brown pale translucent yellowish brown to whitish on basal one third to half of corium. Ventral surface: Thorax dark brown, usually red tinged; ostiolar auricle brown, often red tinged; abdomen dark brown laterally, becoming paler ventrally, often tinged with red at base. Legs: Uniformly pale yellowish brown, except for dark brown hind femora with basal third and narrow apex pale yellowish brown.

Structure, texture, and vestiture: Head: Wider than long, impunctate, eyes prominent, frons swollen, interocular width much greater than combined dorsal diameter of eyes. Labium: Extending just past metacoxae to base of abdomen. Pronotum: Impunctate, at most with only a few fine punctures across middle; rectangular, wider than long, lateral margins nearly straight, posterior margin weakly sinuate in brachypterous forms; lateral margins concave, posterior angles widely flared in macropterous form; calli weakly developed; scutellum impunctate, equilateral. Hemelytron: Strongly brachypterous in all but one specimen; corium and clavus fused (claval suture absent), membrane and cuneus absent, remaining corium weakly rounded laterally, truncate posteriorly. Hemelytron of only known macropter with fully developed clavus, cuneus, and membrane having two closed cells. Pubescence short, sparse, with several erect, bristlelike setae on head along basal margin, inner margin of eyes, and on frons.

Male genitalia: Left paramere (Fig. 187): Mitt-shaped; right arm long, stout, apically bluntly rounded; left arm short, apically acute. Right paramere (Fig. 188): Rounded. Endosoma (Fig. 189): S-shaped, apically acute. Phallotheca (Fig. 190): Slender, apically acute.

Macropterous female (n= 1) (Fig. 51): Length to apex of hemelytron 1.80 mm, length to base of cuneus 1.27 mm, width across hemelytra 0.62 mm. Head: Length 0.26 mm, width across eyes 0.42 mm; interocular width 0.27 mm. Labium: Length 0.83. Antenna: Segment I, length 0.22 mm; II, 0.62 mm; III, 0.43 mm; IV, 0.27 mm. Pronotum: Length 0.24 mm, basal width 0.59 mm.

Brachypterous female (n= 10) (Fig. 52): Length to apex of abdomen 1.48-1.68 mm, length to apex of hemelytron 1.23-1.30 mm, width across hemelytra 0.70-0.74 mm. Head: Length 0.26-0.34 mm, width across eyes 0.46 mm; interocular width 0.29-0.30 mm. Labium: Length 0.93-0.96 mm. Antenna: Segment I, length 0.22-0.26 mm; II, 0.72-0.77 mm; III, 0.48-0.54 mm; IV, 0.37-0.40 mm. Pronotum: Length 0.21-0.22 mm, basal width 0.48-0.51 mm.

Etymology.

This species is named after my good friend and colleague, Dr. Alfred G. Wheeler, Jr. (Department of Entomology, Clemson University, Clemson, South Carolina), who discovered and collected all but a few specimens of this very tiny, attractive new species. Dr. Wheeler’s collections from grasses having well-developed crowns have yielded numerous new and interesting Heteroptera .

Hosts.

Collected by A. G. Wheeler on the following hosts: big bluestem, Andropogon gerardii Vitman [ Poaceae ]; bushy bluestem, Andropogon glomeratus (Walt.) B. S. P.; bushy bluestem, Andropogon tenuispatheus Nash [sometimes considered a synonym of Andropogon glomeratus (Walt.) B. S. P. var. pumilus Vasey ex. L. H. Dewey]; Virginia beard grass, Andropogon viriginicus L.; weeping love grass, Eragrostis curvula (Schrad.) Nees; gulf cordgrass, Spartina spartinae (Trin. Merr. ex Hitchc.; and paragrass, Urochloa mutica (Forssk.) T. Q. Nguyen [ Poaceae ].

Distribution.

United States:Arkansas, Florida, Georgia, Kansas, Nebraska, South Carolina, Texas, and Virginia.

Discussion.

All specimens of this new species are brachypterous, except for one macropterous female collected in Highlands Co., Florida (March). That a macropterous female was discovered indicates that macropterous males eventually should be found. Given the small size and considering how difficult it is to collect this species from the crowns of certain bunch grasses, it is not surprising that few undetermined specimens of this species were found in collections.

The tiny brachypterous males (length 1.08-1.30 mm) rank Tytthus wheeleri as possibly the smallest known species of Miridae .

Type material.

Holotype: ♂ (00162128)(USNM): UNITED STATES: South Carolina:Richland Co.: Spears Creek Church Road, 3.8 km S. of Pontiac, 06 May 2000, A. G. Wheeler, Jr., Eragrostis curvula ( Poaceae ). Paratypes: UNITED STATES:Arkansas:Ashley Co.: Rt. 82, 13.5 km W. of Crossett, 19 May 2000, A. G. Wheeler, Jr., Eragrostis curvula ( Poaceae ), 1 ♀ (00162145) (USNM). Florida: Miami-Dade Co.: Homestead, 14 Mar 1947, R. H. Beamer (UK). Brevard Co., CR-520, 0.5 km E of Orange Co., nr St. Johns River, W of Cocoa, 11 April 2004, A. G. Wheeler, Jr., ex Urochloa mutica , 1 ♂ (macropterous) (USNM). Highlands Co.: Archbold Biological Station, Hufty Tract, 17 Apr 1998, T. J. Henry, A. G. Wheeler, and T. & M. Yasunaga, Andropogon glomerata ( Poaceae ), 3 ♀♀ (00162151 - 00162153) (USNM). Rt. 70 at Lake Annie, SW of Lake Placid, 17 Mar 1999, A. G. Wheeler, Jr., Andropogon glomerata ( Poaceae ), 2 ♂♂ (00162116, 00162117), 3 ♀♀ (00162118 - 00162120) (USNM). Levy Co.: Manatee Springs State Park, 6 mi. W. of Chiefland, 16 Mar 1999, A. G. Wheeler, Jr., Eragrostis virginicus ( Poaceae ), 2 ♂♂ (00162134, 00162135) Andropogon virginicus ( Poaceae ), 1 ♂ (00162127) (USNM). Polk Co.: Rt. 27, 2.4 km N. of jct. CR-54, NW of Loughman, 26 Feb 2002, A. G. Wheeler, Jr., Eragrostis curvula ( Poaceae ), 4 ♂♂ (and 1 nymph) (00162121 - 00162123, 00162125), 1 ♀ (00162126) (USNM); 13 Apr 2002, A. G. Wheeler, Jr., Eragrostis curvula ( Poaceae ), 1 ♀ (00162133) (USNM). Georgia:Columbia Co.: Dixie Mountain, Serpentine Barren, near Pollards Corner, 06 May 1996, A. G. Wheeler, Jr., Andropogon gerardii ( Poaceae ), 1 ♂ (00162137) (USNM). Peach Co.: Rt. 49, SW of Byron, 25 Sep 1996, A. G. Wheeler, Jr., Andropogon virginicus ( Poaceae ), 1 ♂ (and 1 nymph), (00162139) Andropogon spp. ( Poaceae ), 1 ♂ (00162138) (USNM). Nebraska:Keith Co.: Rt. 61 at Kingsley Drive, 8 mi. N. of Ogallala, 15 Jun 1998, A. G. Wheeler, Jr., 2 ♂♂ (and 2 nymphs) (00162141, 00162144) (USNM). Kansas: Jefferson Co.: Rockefeller Tract, ca 5 mi N of Laurence, 9-15 June 1976, A. Slater, 1 ♂, 3 ♀♀ (AMNH). South Carolina:Aiken Co.: Rt. 19, 3 mi. N. of Aiken, 18 Aug 1996, A. G. Wheeler, Jr., Eragrostis curvula ( Poaceae ), 1 ♂ (00162131) (USNM). Lancaster Co.: Forty Acre Rock, 04 May 1996, A. G. Wheeler, Jr., Andropogon gerardii ( Poaceae ), 1 ♂ (00162150) (USNM). Laurens Co.: Rt. 25, 3.3 km N. of Saluda River, NNE of Ware Shoals, 21 Oct 2001, A. G. Wheeler, Jr., Eragrostis curvula ( Poaceae ), 1 ♂ (00162129) (USNM). Pickens Co.: Glassy Mountain East of Pickens, 10 May 1997, A. G. Wheeler, Jr., Eragrostis curvula ( Poaceae ), 1 ♀ (00162136) (USNM). Glassy Mountain Heritage Preserve, E. of Pickens, 24 May 2003, A. G. Wheeler, Jr., Eragrostis curvula ( Poaceae ), 1 ♂, 1 ♀ (USNM). S-39-143, 2 km W of Eastatoe Creek, 34.96833°N, 82.865°W, 05 Oct 2001, A. G. Wheeler, Jr., Eragrostis curvula ( Poaceae ), 1 ♀ (00162130) (USNM), 1 ♀ (00162148) (USNM). Texas:Burnet Co.: Rt. 71, 2 km SW of Spicewood, 07 Jun 2003, A. G. Wheeler, Jr., Muhlenbergia lindheimeri ( Poaceae ), 1 ♂ (00162149), plus 1 ♀ (USNM). Gillespie Co.: Rt. 16, 15 km NE of Fredericksburg, 30.36°N, 98.75°W, 27 May 2001, A. G. Wheeler, Jr., Muhlenbergia lindheimeri ( Poaceae ), 1 ♂ (00162157) (USNM). Farm Rd 1888, 2.4 km NW of Kendall Co. line, SE of Luckenbach, 28 May 2001, A. G. Wheeler, Jr., ex Muhlenbergia lindheimeri ( Poaceae ), 1 ♀. Gonzales Co.: Palmetto St. Park, Ottine, 29E35.63'N, 97E35.12'W, 15 May 2006, A. G. Wheeler, Jr., ex Spartina spartinae , 3 ♂♂, 1 ♀ (USNM). Virginia:Mecklenburg Co.: Elm Hill SGM at Clyde’s Pond, 11 May 1995 - 29 May 1995, VMNH Survey, 2 ♀♀ (00162155, 00162156) (USNM). Sussex Co.: SW of Littleton, chub sandhill, 01 Jun 1996, A. G. Wheeler, Jr., Andropogon sp. ( Poaceae ), 1 ♂ (00162132) (USNM).