Epeorus vitreus ( Walker) 1853

Webb, J. M. & Mccafferty, W. P., 2006, Contribution to the taxonomy of Eastern North American Epeorus Eaton (Ephemeroptera: Heptageniidae), Zootaxa 1128, pp. 57-64 : 58-61

Epeorus vitreus ( Walker) 1853

Palingenia vitrea Walker, 1853:555

Heptagenia vitrea ; Eaton, 1871:143; Traver, 1935:365 Rhithrogena vitrea ; Eaton, 1885:254

Epeorus humeralis Morgan, 1911:105

Iron humeralis ; McDunnough, 1924:129; Traver, 1933:118; Traver, 1935:404 Iron rubidus Traver, 1933:158 ; Traver, 1935: 409 N. SYN Epeorus rubidus ; Traver, 1937: 52 N. SYN

Iron vitrea ; Speith, 1940:330 (= Epeorus humeralis Morgan ) Epeorus vitrea ; Burks, 1953:195; Flowers & Hilsenhoff, 1975:210; Peterson, 1989:6 Epeorus vitreus ; Burian & Bednarik, 1994:209

Discussion: Traver (1933) described Epeorus rubidus based on a series of reared specimens from North Carolina ( Traver 1933). Epeorus rubidus male adults were distinguished from those of Epeorus vitreus [as Iron humeralis (Morgan) ] by Traver (1933, 1935) and Speith (1940) primarily by their smaller size. Traver (1933, 1935) stated the wing length of E. rubidus ranged from 8–9 mm and that of E. vitreus ranged from 10– 11 mm. However, Traver (1937) later noted that some specimens of E. rubidus had a wing length up to 10.5 mm. Our examination of material collected from populations throughout much of eastern North America confirms that the range of wing length for E. rubidus includes the range for E. vitreus . Relative to E. vitreus, Traver (1933, 1935) also noted that the eyes of E. rubidus were smaller, the lateral spines on the penes were less distinct, and the thorax was pale yellowish brown rather than yellowish white. We found all of these characters to vary within and among populations.

Traver (1933, 1935) differentiated the larvae of E. rubidus from those of E. vitreus primarily by gill coloration, assigning specimens with reddish colored gills with purple tracheae to E. rubidus and specimens with clear or blackish tinged gills and black tracheae to E. vitreus . We observed a gradation between these two character states in a single population from Mill Creek, TN. Traver (1935) also indicated the posterolateral abdominal projections of E. rubidus were longer and more curved than those of E. vitreus ( Traver, 1935) ; however, we found this character to vary in almost every large series of specimens that we examined. As all of the characters previously thought to distinguish E. rubidus from E. vitreus were found to intergrade within and among populations, we place E. rubidus as a junior subjective synonym of E. vitreus .

Material Examined GEORGIA: 9 larvae, Rabun Co, Betty's Cr 5 mi W Dillard, 20­ VI­1973, B Stark ( PERC); 2 larvae, White Co, 7 mi NW Cleveland, Hwy 129, 19 ­VI­ 1973, B Stark ( PERC); MAINE: 35 larvae, Somerset Co, Caratunk, Pleasant Pond Str, 24­ VI­1966, R + D Koss ( PERC); MASSACHUSETTS:1 ɗ adult, Hampshire Co, Amherst, 6­VII­1944, JR Traver ( PERC); 1 ɗ adult, Hampshire Co, Amherst, 19­VI­1956, JR Traver ( PERC); NEW YORK: 3 ɗ adults, 18 Ψ adults, St. Lawrence Co, Ft. Jackson, St. Regis R, 21­VI­1932, L Harper ( PERC); 2 larvae, St. Lawrence Co, St. Rd. 3, 1.5 mi E Cranberry L at bridge, VI­15­1976, WP McCafferty, M Minno, AV Provonsha ( PERC); NORTH CAROLINA: 1 ɗ genitalia (slide mounted), Buncombe Co, Flat Cr at Black Mtn, VI­6­1929, JR Traver ( PERC); 1 ɗ adult, Burke Co, Linville Falls, 3­VI­1940, CP Alexander ( PERC); 1 ɗ adult, Haywood Co, GSMNP, Cataloochee Cr at Rd 284, 10 ­VII­ 1983, B Kondratieff (VTU); 1 ɗ adult, 5 Ψ adults, Swain Co, unnamed trib Ravens Fk, upstream bridge to Ranger Stn, 31­VII­2001, DR Jones + RC Harrington ( PERC); 2 ɗ adults, Watauga Co Valle Crucis, 27­V­1936 JR Traver ( PERC); 1 ɗ adult, 2 ɗ subimagos, 1 larval exuviae, Watauga Co, Valle Crucis, 29­V­1936, JR Traver ( PERC); 3 ɗ adults, Watauga Co, Banners Elk, 31­V­1936, JR Traver ( PERC); PENNSYLVANIA: 21 larvae, Chester Co, East Br White Clay Cr, 0.6 mi W London Grove, 26­V­1980, DH Funk ( PERC); TENNESSEE: 2 ɗ adults, 2 Ψ adults, Blount Co, GSMNP, Cades Cove Ranger Station, at light, 35° 36' 10” N 83° 46' 36”W (NAD27), 13­V­2001, CD + RP Randolph, LM Jacobus ( PERC); 3 larvae, Blount Co, GSMNP, Forge Cr at Parsons Branch Rd, 35° 35' 03”N 83° 50' 17”W (NAD27), 18­V­2001, CD + RP Randolph, LM Jacobus ( PERC); 18 larvae, Blount Co, GSMNP, Cades Cove, Mill Cr near Rabbit Creek Trailhead, 35° 35' 26”N 83° 51' 10”W (NAD27), JM Webb + LM Jacobus ( PERC); VIRGINIA: 1 ɗ adult with associated exuviae, 4 larvae, Rappahannock Co, Hughes R at Rt. 707, 7 ­VII­1979, B Kondratieff (VTU); 1 ɗ adult, Montgomery Co, Mill Cr at Rt 785, 5 ­VI­1978, B Kondratieff (VTU); 5 ɗ adults, Giles Co, Big Stoney Cr at Rt 635, 13 ­VII­1977, B Kondratieff (VTU); 5 ɗ adults, Washington Co, Tumbling Cr at Rt 747, 29 ­VIII­1979, B Kondratieff (VTU); 2 ɗ adults with associated exuviae, Tazewell Co, Stations Spring Cr at Burkes Garden, 14­V­1979, B Kondratieff (VTU).

Epeorus punctatus ( McDunnough) 1925

Iron punctatus McDunnough, 1925:189 ; Traver, 1935:409 Epeorus punctatus ; McDunnough, 1929:177

Larval Description: Body length 6.0–8.0 mm; caudal filaments 8.0–9.0 mm. General color light brown with pale markings.

Head: Head capsule subrectangular, brown with pair of pale triangular spots on anteromedian margin and large pale spot on anterolateral margin ( Fig. 1 ). Labrum ( Fig. 2 ) dorsally with two long simple setae laterally and two or three long simple setae medially, ventrally with many long simple setae near lateral margin, approximately 2.0X wider than long. Mandibles as in Figs. 3 and 4 . Maxillae ( Fig. 5 ) with single fimbriate seta at base of cluster of apical spines; posterior margin of first segment of palp with sparse row and apical cluster of sharp robust setae.

Thorax: Coloration light brown with pale markings. Pronotum with transverse ridge. Femora ( Fig. 6 ) with subdorsal row of long simple setae and dorsal row of three or four short robust setae; anterior face with both fine and paddle shaped robust setae, more numerous basally; ventral margin with fine setae and few robust setae basally; apices with dorsal projection bluntly pointed ( Fig. 7 ); color brown with pale markings and dark spot centrally. Tibiae pale with basal and medial brown bands. Tarsi brown. Tarsal claws with four or five denticles on inner margin.

Abdomen: Terga light brown with various pale markings and median row of long fine setae; tergum 1 mostly light brown; terga 2–10 with submedian pair of dark spots with dark shading extending posteriorly (except tergum 6), and laterally with oblique dark mark surrounded by pale area. Terga 2– or 3–7 with minute posteromedian tubercle. Posterolateral spines short, with dorsal (outer) and ventral (inner) pair subequal in length ( Fig. 8 ). First pair of gill lamellae ( Fig. 9 ) not enlarged anteriorly; lamellae of gills 2–6 as in Fig. 10 ; lamellae of gills 7 not folded longitudinally. Cerci with small spines at articulations and dorsal row of fine setae.

Diagnosis: Larvae of Epeorus punctatus are differentiated from those of all other North American Epeorus species by the following combination of characters: the lamellae of the first pair of gills are not enlarged anteriorly; the apex of the hindfemur has a bluntly pointed projection; the setae of the subdorsal row on each femur are simple; and the dorsal and ventral posterolateral spines of the abdomen are subequal in length. Epeorus punctatus appears to be most similar to E. subpallidus . Male adults of E. punctatus are most reliably differentiated from those of E. subpallidus by the absence of lateral spines on the penes. Additionally, the abdominal terga of E. subpallidus are darkened only medially on the posterior margin and there are not any dark markings laterally; in E. punctatus there is a dark line along the entire posterior margin of each abdominal tergum that broadens laterally and there are also small, dark lateral maculae. The thorax of E. subpallidus is a pale yellowish brown whereas that of E. punctatus is a dark chestnut brown. Larvae of E. punctatus are smaller in size than those of E. subpallidus ; the femoral flanges of the former are bluntly pointed rather than sharply pointed; and the pair of small pronotal protuberances of E. subpallidus are absent in E. punctatus .

Material Examined: WEST VIRGINIA: 2 ɗ adults, 3 Ψ adults with 4 associated exuviae (1 slide­mounted in Euparal), 1 larva, Fayette Co, Meadow R at Rt 19, 15 ­IX­ 1982, B Kondratieff (VTU).

Figures

FIGURES 1 – 10. Epeorus punctatus. 1, head capsule; 2, labrum; a: dorsal, b: ventral; 3, left mandible; 4, right mandible; 5, maxilla; 6, hind femur; 7, apex of hind femur; 8, abdominal segment 7; 9, Gill 1, lamella; 10, gill 6, lamella.