Plagiognathus nigronitens Knight

SCHUH, RANDALL T., 2001, Revision Of New World Plagiognathus Fieber, With Comments On The Palearctic Fauna And The Description Of A New Genus (Heteroptera: Miridae: Phylinae), Bulletin of the American Museum of Natural History 2001 (266), pp. 1-267 : 174-175

Plagiognathus nigronitens Knight Figures 10 , 18 , 28

Plagiognathus nigronitens Knight, 1923: 435 (n. sp.).

Plagiognathus nigritibialis Knight, 1964: 148 (n. sp.). NEW SYNONYMY.

Plagiognathus nicholi Knight 1964: 147 (n. sp.). NEW SYNONYMY.

DIAGNOSIS: Recognized by small size and generally black coloration (fig. 10), including body, antennae (fig. 18), and most of legs. Most similar in size, general appearance, and coloration to amorphae (fig. 5), astericola (fig. 6), and possibly morrisoni (fig. 10); easily separated by those species having appressed, weakly scalelike setae on dorsum, thoracic pleuron, and venter of pregenital abdominal segments, whereas nigronitens with golden, shining, recumbent, simple setae on pronotum, scutellum, and anterior one­half of corium and clavus and dark, recumbent, simple setae on posterior one­half of corium. Plagiognathus nigronitens and males of astericola with antennal segment 2 entirely black; nigronitens sometimes with antennal segment 2 white on distal one­fourth to onethird as in amorphae (fig. 10) (see Discussion below).

REDESCRIPTION: Male: Relatively small, elongate ovoid; total length 2.84–3.17, length apex clypeus–cuneal fracture 1.96– 2.19, width across pronotum 0.92–1.02. COLORATION (fig. 10): General coloration nearly black, posterior margin of vertex weakly pale to pale; membrane and veins fumose, posterior margin of veins and adjoining small, triangular patch at posteromesial margin of cuneus pale; antennal segment 1 entirely dark, without obvious pale apical annulus, segment 2 dark or pale on apical onehalf (fig. 18) (see Discussion below), segments 3 and 4 pale; labium castaneous; venter, including metathoracic scent­gland evaporatory area, entirely castaneous to nearly black; coxae, trochanters, and all but apex of femora castaneous; dorsal tibial spines with black spots at bases; tibiae black at articulation with femora; tibiae sometimes mostly black on proximal one­half of dorsal surface, much of ventral surface pale or nearly so. SURFACE AND VESTITURE: Dorsum weakly transversely rugulose, dull to very weakly shining. Vestiture of dorsum composed of recumbent, golden, shining, simple setae on pronotum, scutellum, and anterior one­half of corium, posterior half of corium with dark, dull, simple setae. STRUCTURE: Body relatively broad, flattened; frons nearly straight across in dorsal view, barely projecting beyond anterior margin of eyes, clypeus not visible from above; anteocular distance 0.5 times diameter of antennal segment 1; head projecting below eye by 0.6 times diameter of antennal segment 1; labium short, not quite reaching apex of middle coxae. GENITALIA (fig. 28): Body of vesica strongly curving, base of vesica reaching level of secondary gonopore; posterior apical spine smoothly curving, anterior spine slightly longer than posterior and more strongly curving subapically; flange moderately broad, reaching to about base of secondary gonopore.

Female: Coloration as in male; body more strongly ovoid. Total length 2.78–3.10, length apex clypeus–cuneal fracture 1.98– 2.14, width across pronotum 0.94–0.98.

HOSTS: Apparently breeds on Helianthus spp. and Solidago spp. (Asteraceae) , although also recorded from a variety of other plants.

DISTRIBUTION: Widely distributed in eastern North America, although not known from the Maritime Provinces or from the Gulf Coast.

DISCUSSION: Most specimens assigned to nigronitens have antennal segment 2 entirely black. Specimens recorded from Jasper County, Indiana, Douglas County, Kansas, Benton County, Missouri, and Magnolia, North Carolina, have the distal half of antennal segment 2 pale and are consistently smaller than those with antennal segment 2 entirely black. The genitalia of specimens with the two types of antennal coloration are substantially similar, however, and for this reason I am not treating them as separate species. This situation merits closer examination in the field.

Knight (1964) stressed the variation in length of the labium as important in discriminating his new species nicholi and nigritibialis ; there is some variation in the length of the labium, but my observations suggest that it is not consistent with other characteristics, such as overall size or antennal coloration. For these reasons I have chosen to treat all specimens as pertaining to a single species. Other external features and the male genitalia indicate that nicholi Knight is the same as nigronitens Knight. Comparison of the holotype of nigritibialis Knight with the holotype and other specimens of nigronitens indicates that the coloration of the tibiae in this species can be quite variable, with the hind tibiae being heavily infuscate over much of their length in the holotype of nigronitens .

SPECIMENS EXAMINED: CANADA.— Alberta: Drumheller , August 11, 1957, A. and J. Brooks, 13 (CNC). Manitoba: Aweme, July 17, 1930, R. M. White, 2♀ (CNC). Bincarth, July 18, 1954, Brooks and Wallis, 13, 3♀ (CNC). Boissevain, July 17, 1953, Brooks and Kelton, 173, 15♀ (CNC). Elva, July 8, 1948, R. D. Bird, 13 (CNC). Horton, July 25, 1953, Brooks and Kelton, 1♀ (CNC). Horton, July 28, 1958, A. and J. Brooks, 23 (CNC). Pine Mound, July 31, 1958, A. and J. Brooks, 1♀ (CNC). Turtle Mt. Forest Reserve, Internation Peace Gardens, July 17, 1958, R. L. Hurley, 1♀ (CNC). Turtle Mt., July 17, 1953, Brooks and Kelton, 53, 12♀ (CNC). Turtle Mt., July 28, 1953, Brooks and Kelton, 3♀ (CNC). Virden, July 10, 1953, Brooks and Kelton, Solidago glycyrrhiza (Asteraceae) , 123, 16♀ (CNC). Virden, July 12, 1953, Brooks and Kelton, 23 (CNC). Ontario: Exeter, July 12, 1962, Kelton and Thorpe, 1♀ (CNC). Fuller, July 4, 1964 – July 12, 1971, D. G. Reid and C. C. Loan, Solidago canadensis (Asteraceae) , 123, 5♀ (CNC). Gore Bay, July 10, 1961, G. Brumpton, 23, 1♀ (CNC). Lakefield, June 28, 1962, G. Thorpe, 1♀ (CNC). Leamington, June 26, 1921, G. S. Walley, 23, 2♀ (CNC). Marmora, July 10, 1952, J. R. Vockeroth, 13, 4♀ (CNC). Norwich, July 19, 1962, Kelton and Thorpe, 13 (CNC). Oakland, July 17, 1962, Kelton and Thorpe, 63, 9♀ (CNC). Orillia, June 29, 1962, G. Thorpe, Salix sp. (Salicaceae) , 13, 2♀ (CNC). Ottawa, July 1, 1914, G. Beaulieu, 43, 3♀ (CNC). Ottawa, July 3, 1912, E. P. Van Duzee, 13 (CNC). Pt. Elgin, July 2, 1962, G. Thorpe, 13 (CNC). Queenston, July 8, 1955, L. A. Kelton, 1♀ (CNC). Simcoe, July 2, 1915, N. G. Crawford, 1♀ (CNC). Sundridge, July 13, 1961, G. Brumpton, 43, 5♀ (CNC). Tillsonburg, July 14, 1955, L. A. Kelton, 53, 5♀ (CNC). Vienna, July 18, 1962, Kelton and Thorpe, Salix sp. (Salicaceae) , 13, 2♀ (CNC). Waterford, July 17, 1962, Kelton and Thorpe, 23, 1♀ (CNC). Quebec: Cap Rouge, July 10, 1953, R. Lambert, 1♀ (CNC). Otter Lake, July 24, 1958, L. A. Kelton, 13 (CNC). Quyon, July 22, 1958, L. A. Kelton, Salix sp. (Salicaceae) , 1♀ (CNC). Shawville, July 22, 1958, L. A. Kelton, 13 (CNC). Thurso, August 20, 1958, L. A. Kelton, 13 (CNC). Saskatchewan: Estevan, July 23, 1958, A. and J. Brooks, 13, 1♀ (CNC). Lebret, July 5, 1951, A. R. Brooks, 43, 3♀ (CNC). Wood Mountain, August 5, 1955, A. R. Brooks, 13, 3♀ (CNC). USA.— Colorado: Archuleta Co.: Pagosa Springs, C. H. Baker, 13 (USNM). Costilla Co.: Fort Garland, July 6, 1982, D. A. and J. T. Polhemus, 13 (JTP). Fort Garland, Ute Creek Ranch, August 11, 1925, H. H. Knight, 13, 5♀ (USNM). Fort Garland, Ute Creek Ranch, August 11, 1925, H. H. Knight, paratypes ( nicholi ): 23 (CNC). Douglas Co.: Waterton, Head of Hiline, June 16, 1978, J. T. Polhemus, 13 (JTP). Waterton, June 4, 1981 – June 16, 1981, D. A. Polhemus, 33, 4♀ (JTP). Jefferson Co.: Red Rocks Park, July 7, 1983, D. A. Polhemus, Helianthus sp. (Asteraceae) , 33, 8♀ (JTP). Larimer Co.: Estes Park, July 10, 1964, H. H. Knight, 43, 4♀ (USNM). Fort Collins, June 12, 1900, 2♀ (USNM). Connecticut: Mansfield Center, June 21, 1959 – July 14, 1967, J. A. Slater, 53, 4♀ (AMNH). Illinois: Jackson Co.: Fountain Bluff, May 15, 1932, Frison, Ross, Mohr, 1♀ (AMNH). Scott Co.: Princeton, Cattail Bog, July 2, 1937, Mohr and Burke, 13 (AMNH). Indiana: Cass Co.: Logansport, July 5, 1979, T. J. Henry, 23, 5♀ (USNM). Jasper Co.: No specific locality, July 6, 1935, A. W. Tripp, 13, 1♀ (USNM). Iowa: Boone Co.: No specific locality, June 22, 1962, J. C. Schaffner, 13 (TAMU). Dickinson Co.: Silver Lake, T100N R38W, July 8, 1963, J. C. Schaffner, 53, 3♀ (TAMU). Kansas: Douglas Co.: 6 mi NE of Lawrence, Rockefeller Tract, June 15, 1976, T. W. Oldham, 6♀ (TAMU). Linn Co.: No specific locality, 862 ft, July 1, 1915, R. H. Beamer, 2♀ (KU). Riley Co.: near Manhattan, July 1, 1965, J. Cornell and H. D. Blocker, 23 (OSU). Maryland: Wicomico Co.: Johnson Wildlife Refuge , June 20, 1981, T. J. Henry, 13, 14♀ (USNM). Massachusetts: Essex Co.: Beach Bluff, July 24, 1914, H. M. Parshley, 1♀ (CAS). Danvers, July 3, 1900, paratype: 13 (CAS). Hampden Co.: Springfield, July 13, 1905, paratype: 13 (CAS). Middlesex Co.: Holliston, N. Banks, 1♀ (AMNH). Minnesota: Hennepin Co.: Minneapolis, July 5, 1922, Arthur Hartig, 13, 3♀ (USNM). No specific locality, July 12, 1919, H. H. Knight, paratypes: 23, 2♀ (USNM). Norman Co.: No specific locality, June 20, 1922, A. A. Nichol, paratypes ( nicholi ): 13, 1♀ (CNC); holotype ( nicholi ) (USNM). Mississippi: Alcorn Co.: Corinth, May 25, 1931, H. G. Johnston, 33, 9♀ (TAMU). Prentiss Co.: Booneville, May 26, 1931, H. G. Johnston, 2♀ (TAMU). Stone Co.: Wiggins, April 25, 1931, H. G. Johnston, 53, 10♀ (TAMU); holotype male ( nigritibialis ) (USNM). Missouri: Benton Co.: Jct Hwys 65 & 32, June 17, 1982 – June 4, 1983, R. L. Blinn, Helianthis mollis (Asteraceae) , 43, 2♀ (USNM). Vernon Co.: 4 mi E of Milo, July 13, 1966, J. C. Schaffner, 13 (USNM). 4 mi E of Milo, June 13, 1960, J. C. Schaffner, 43, 5♀ (TAMU). Osage Prairie, June 4, 1983, R. L. Blinn, Helianthus mollis (Asteraceae) , 13, 3♀ (DAR). New Jersey: Bergen Co.: Ram­ sey, July 6, 1912, 1♀ (AMNH). New York: Albany Co.: Rensselaerville, Huyck Preserve, June 29, 1977, R. T. Schuh, 23 (PDA). Rensselaerville, Huyck Preserve, June 29, 1977, R. T. Schuh, 23, 9♀ (AMNH). Rensselaerville, July 17, 1944, Kendeigh, 1♀ (USNM). Allegany Co.: Alfred University, July 31, 1988, A. G. Wheel­ er, Jr., Lonicera sp. (Caprifoliaceae) , 4♀ (PDA). Delaware Co.: Cadosia, July 6, 1974, K. R. Valley, Pastinaca sativa (Apiaceae) , 23 (PDA). Genesee Co.: Batavia, July 27, 1915, H. H. Knight, 2♀ (CNC, USNM). Batavia, July 27, 1915, H. H. Knight, paratypes: 23, 2♀ (CAS); holotype male (USNM). Monroe Co.: Honeoye Falls, July 23, 1915, M. D. Leondard, 1♀ (PDA). Oneida Co. : near Sangerfield on Rt 20, September 6, 1973, A. G. Wheeler, Jr., Solidago sp. (Asteraceae) , 1♀ (PDA). St. Lawrence Co.: Cranberry Lake, July 8, 1920, R. J. Sim, 1♀ (PDA). Suffolk Co.: Oyster Bay, Planting Fields Arboretum, July 1, 1982, A. G. Wheeler, Jr., 33, 1♀ (PDA). Tompkins Co.: Ithaca, Cornell University, June 27, 1982 – July 8, 1979, A. G. Wheeler, Jr., 73, 4♀ (PDA). Michigan Hollow, May 25, 1974, A. G. Wheeler, Jr., Alnus sp. (Betulaceae) , 13 (PDA). North Carolina: Unknown Co.: Magnolia, May 26, 1964, J. F. Cornell, 1♀ (USNM). North Dakota: Benson Co.: No specific locality, July 17, 1941, 13 (DAR). Oliver Co.: 2 mi E of Hensler, July 20, 1978, L. A. Schutz and J. W. Smith, 43, 5♀ (DAR). Pennsylvania: Bedford Co.: Pleasantville, July 2, 1980, A. G. Wheeler, Jr., Achillea millefolium (Asteraceae) , 23 (PDA). Berks Co.: Leesport, July 1, 1970, 13, 1♀ (PDA). Butler Co.: Butler, Eisler Nurseries, July 13, 1978, 23, 1♀ (PDA). Centre Co.: Scotia Barrens, July 9, 1979 – June 25, 1988, K. R. Valley, A. G. Wheeler, Jr., 33, 2♀ (PDA). Cumberland Co.: Mount Holly Springs, July 7, 1964, F. B. Negley, 1♀ (PDA). Dauphin Co.: Dauphin, July 4, 1900, 13 (PDA). E of Harrisburg at Nye and Willoughby Rds, June 10, 1975, A. G. Wheeler, Jr., Vitis sp. (Vitaceae) , 13 (PDA). Harrisburg, East Harrisburg Cemetery, June 4, 1979, A. G. Wheeler, Jr., Azalea sp. (Ericaceae) , 13 (PDA). Harrisburg, June 26, 1967, G. B. Sleesman, 33, 4♀ (PDA). Hershey, June 1, 1975, A. G. Wheeler, Jr., Nepeta ca­ taria ( Lamiaceae ), 13 (PDA). Middle Paxton Township, Rt 443, Fishing Creek Valley School, June 22, 1978, A. G. Wheeler, Jr., Potentilla sp. (Rosaceae) , 33, 1♀ (PDA). Erie Co.: Girard, Elk Creek Nursery, July 9, 1976, A. G. Wheeler, Jr., Althaea rosea (Malvaceae) , 13, 1♀ (PDA). Luzerne Co.: Newport Township, July 10, 1969, C. L. Semmel, 3♀ (PDA). Rice Township, Andy Pond, July 14, 1979, A. G. Wheeler, Jr., Rosa sp. (Rosaceae) , 1♀ (PDA). Pike Co.: Shohola Township, July 11, 1969, C. L. Semmel, 13 (PDA). Unknown Co.: Patton, July 6, 1906, M Wirtner, 13 (PDA). Westmoreland Co.: Charter Oak, July 2, 1917, H. B. Kirk, 2♀ (PDA). Greensburg, July 22, 1903, M. Wirtner, 13 (PDA). Greensburg, July 3, 1901, 13, 1♀ (PDA). South Dakota: Roberts Co.: 11 mi SE of Rosholt, Lake Traverse, July 3, 1974, B. Tollefson, 2♀ (UCB). Unknown Co.: Copa, June 1, 1921, H. C. Severin, 2♀ (USNM). Texas: Dallas Co.: No specific locality, April 23, 1938, R. K. Fletcher, 13, 1♀ (TAMU). No specific locality, July 1, 1936, S. Jones, 13 (USNM). Virginia: James City Co.: Williamsburg, May 24, 1986, A. G. Wheeler, Jr., 13 (PDA). West Virginia: Greenbrier Co.: Alvon on Rt 92, July 25, 1978, A. G. Wheeler, Jr., Populus tremuloides (Salicaceae) , 1♀ (PDA). Jefferson Co.: No specific locality, August 23, 1980, T. L. Mason, Jr., 1♀ (PDA). Shepherd College, May 30, 1980, A. G. Wheeler, Jr., 1♀ (PDA). Mineral Co.: Paterson Creek Road near Grant County line, June 10, 1970, A. G. Wheeler, Jr., Ulmus americana (Ulmaceae) , 13, 1♀ (PDA). Tucker Co.: Blackwater Riv­ er, Canaan Valley, Rt 22, July 17, 1977, T. J. Henry, 1♀ (USNM). Dolly Sods Wilderness Area, June 17, 1978, A. G. Wheeler, Jr., Achillea millefolium (Asteraceae) , 1♀ (PDA). Wisconsin: Dunn Co.: Colfax , August 9, 1916, J. G. Saunders, 13 (PDA).

Figures

Fig. 10. Habitus figures of Nearctic Plagiognathus spp. (see p. 263 for localities).

Fig. 18. Antennal segments 1 and 2 of Nearctic Plagiognathus spp.

Fig. 28. Male genitalia of Nearctic Plagiognathus spp.