Plagiognathus flavicornis Knight, 1923

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 : 78-79

Plagiognathus flavicornis Knight Figures 7 , 16 , 24

Plagiognathus flavicornis Knight, 1923: 436 (n. sp.).

DIAGNOSIS: Recognized by the castaneous coloration of dorsum (fig. 7), dorsal vestiture of recumbent, dark, simple setae, antennal segment 2 being dark at base—but only onetenth the length of segment—and pale distally (fig. 16), and trochanters dark. Similar in size and coloration to dark­colored fuscosus specimens; separated by greater length of antennal segment 2 relative to the width of head (table 1), antennal segment 2 only very narrowly dark at base, and by the dorsum having only dark or weakly golden, recumbent, simple setae. Trochanters almost entirely pale in fuscosus , but largely dark in flavicornis . Coloration of antennae, size, and dorsal vestiture of simple setae similar to dispar and punctatipes but the femora in those species pale with dark spots.

REDESCRIPTION: Male: Relatively broadbodied, of moderate size, greatest width at about level of apex of claval commissure; total length 3.18–3.64, length apex clypeus–cuneal fracture 2.20–2.56, width across pronotum 1.02–1.12. COLORATION (fig. 7): Dorsum entirely castaneous, except frons and sometimes vertex lighter, base of cuneus or adjacent corium narrowly pale; membrane fumose, veins fumose except pale along posterior margin of cells; antennal segment 1 castaneous except for a pale apical annulus, segment 2 black on basal one­tenth, remain­ der of segment pale (fig. 16), segments 3 and 4 infuscate; labium mostly castaneous; venter castaneous except ventral margin of propleuron pale; coxae, trochanters, and femora (except for pale apex) castaneous; tibiae pale, dorsal tibial spines with heavy dark spots at bases; tibiae dark at articulation with femora. SURFACE AND VESTITURE: Dorsum weakly granular, smooth, weakly shining. Vestiture of dorsum composed of recumbent, dark to weakly shining, simple setae. STRUCTURE: Body appearing rather broad as viewed from above, lateral corial margins distinctly convex and declining laterally, giving dorsum a rounded appearance; frons moderately tumid and more or less distinctly bulging beyond anterior margin of eyes in dorsal view, clypeus visible from above; anteocular distance equal to diameter of antennal segment 1; head projecting below eye by 2 times diameter of antennal segment 1; labium reaching to about apex of hind coxae. GENITALIA (fig. 24): Body of vesica relatively stout and strongly curving, more or less U­shaped, base of vesica reaching to about level of secondary gonopore; posterior apical spine long, more or less erect, weakly curving, anterior spine more strongly angled relative to body of vesica, attenuated, and only weakly and gradually angled near apex; flange on vesica moderately broad, reaching to about midpoint of gonopore.

Female: Very similar to male in coloration and body form. Total length 3.42–3.63, length apex clypeus–cuneal fracture 2.36– 2.51, width across pronotum 1.14–1.19.

HOST: Myrica gale (Myricaceae) (Knight, 1923). Specimens examined during the present study have labels indicating their occurrence on Pinaceae , Poaceae , and Salicaceae . I am inclined to believe this species is a Myrica feeder.

DISTRIBUTION: Quebec and Ontario south to Massachusetts and New York.

DISCUSSION: This taxon is remarkably similar in general appearance to dark specimens of fuscosus , and the two can be easily confused if the vestiture is rubbed. Plagiognathus flavicornis is much less common in collections than fuscosus , however, and would appear to be more strongly host specific.

SPECIMENS EXAMINED: CANADA.— Ontario: Barrhaven, 2 km W Woodie Dr. on Robertson Rd., July 18, 1991, M. D. Schwartz, Larix laricina (Pinaceae) , 1♀ (CNC). Ottawa, July 12, 1919, J. Mc­ Dunnough, 1♀ (CNC). Ottawa, July 30, 1912, Beaulieu, paratype: 13 (CNC). Perth, July 1, 1980, D. J. E. Brown, 13 (CNC). Tillsonburg, July 14, 1955, L. A. Kelton, ex Salicaceae , 23, 7♀ (CNC). Quebec: Gatineau National Park , Harrington, July 30, 1981, D. J. E. Brown, ex Poaceae , 43, 18♀ (CNC). La Trappe, July 5, 1923, J. Ouellet, 1♀ (TAMU). Ladysmith, July 24, 1958, L. A. Kelton, 13 (CNC). USA.— Massachusetts: Barnstable Co.: Woods Hole, July 15, 1918, C. E. Olsen, 1♀ (USNM). Dukes Co. : Oak Bluffs, August 3, 1918, C. E. Olsen, paratype: 13 (USNM). Essex Co. : Beach Bluff , August 18, 1914, H. M. Parshley, 2♀ (CAS). Swampscott, August 1, 1914, H. M. Parshley, 1♀ (CAS). Middlesex Co. : Holliston, July 6, 1900, N. Banks, 1♀ (AMNH). Michigan: Livingston Co. : No specific locality, July 25, 1943, R. R. Dreisbach, 1♀ (USNM). New York: Albany Co. : Rensselaerville, July 17, 1944, Kendeigh, 13 (USNM). Genesee Co. : Batavia, July 11, 1914 – August 2, 1915, H. H. Knight, paratypes: 23, 1♀ (CAS, USNM) ; holotype male (USNM). Vermont: Windsor Co.: Woodstock, A. P. Morse, 2♀ (AMNH) .

Figures

Fig. 7. Habitus figures of Nearctic Plagiognathus spp. (see p. 263 for localities).

Fig. 16. Antennal segments 1 and 2 of Nearctic Plagiognathus spp.

Fig. 24. Male genitalia of Nearctic Plagiognathus spp.