Mayfly Species Heptagenia pulla (Golden Duns)

Mesonotum light reddish brown; abdominal tergites largely dark reddish to purplish brown, sternites with median reddish shading; genitalia as shown in fig. 94.

Frontal portion of head pale; a brownish transverse streak across carina below bases of antennae. Vertex dark brown. Pronotum dark brown. Remainder of thoracic notum paler reddish brown; a purplish brown streak above the fore coxa, more or less continuous with one of two dark marks anterior to wing roots. Pleura yellowish; above and on each side of middle and hind coxae are two dark spots; faint dark markings between middle and hind legs. Sternum pale reddish brown. Fore femora and tibiae yellowish, tips reddish brown; in fresh specimens, both joints often washed with red-brown. Basal fore tarsal joint about 1/6 the length of the second. Tarsus whitish, joints faintly reddish. Middle and hind legs pale yellowish white; ‘knees’ reddish; claws and distal tarsal joints tinged with red. Basal tarsal joint of hind leg shorter than second one. Wings hyaline; longitudinal and cross veins brown, the latter somewhat thicker than longitudinals in anterior portion of fore wing. Stigmatic area somewhat opaque, clouded, 6 to 7 basal costal cross veins, about 15 beyond bulla.

Abdominal segments 1-6 semi-hyaline; 7-10 opaque. Tergites largely dark reddish to purplish brown, leaving the antero-lateral angles whitish. A narrow pale mid-dorsal line and pale lunate submedian marks on each tergite; posterior margins darker purplish brown. Apical tergites tinged with yellowish red. Sternites 1-6 pale yellowish white; posterior margins rather widely reddish, mid-ventral area tinged with pinkish or light red. Abdomen appears annulate, due to dark posterior margins of segments. Tails pale whitish, joinings distinctly dark red-brown. Penes rose-pink at tips. The species is allied to Heptagenia julia, but it is considerably larger; the two pairs of median spines on penes are unequal in size, while in julia all four spines are approximately equal. The western Heptagenia solitaria is apparently very close to this species, also.