178 
15, 1938, B. D. Burks, 14; Nippersink 
Creek, June 12-29, 1938, B. D, Burks, 
36, 112, 30 N. Sr. CwHarzes: at light, 
June 9, 1948, Burks & Stannard, 1¢é. 
SrerLinc: June 7, 1939, Burks & Riegel, 
bas 
25. Stenonema rubromaculatum 
(Clemens) 
Heptagenia rubromaculata Clemens 
(1913:256). 
Mate.—Length of body 8-9 mm., of fore 
wing 9-10 mm. Face below antennal sockets 
white, vertex pinkish yellow except at pos- 
terior margin, where it is white; eyes in life 
pearl-gray; each antennal scape and pedicel 
light brown, flagellum light yellow. Thoracic 
notum light clay colored, occasionally tinged 
with olive-gray; each pleuron white or pale 
yellow, with a brown spot at base of each 
coxa, semimembranous area of mesopleuron 
anterior to base of fore wing and dorsal to 
spiracle pale flesh color; sternum light yel- 
low; all legs yellow, fore coxa shaded with 
brown, femur with a median and an apical 
red-brown band, apex of fore tibia and 
apical segment of each tarsus shaded with 
brown; wings hyaline, stigmatic area of fore 
wing shaded with yellow-brown, basal area 
suffused with red; all veins and crossveins 
of fore wing brown, anterior ones of hind 
wing tan, others hyaline; crossveins near 
bulla, in fore wing, usually not crowded. 
Abdomen light yellow or white; fine, black, 
transverse line at posterior margin of each 
tergite 1-7, black or dark brown spiracular 
dots present; meson of tergite 8, all of ter- 
gite 9, and all but white, posterior margin 
of tergite 10 pinkish brown; abdominal ven- 
ter light yellow to white; genitalia, fig. 354, 
light yellow to white; caudal filaments white, 
articulations dark brown. 
NympH.—Length of body 8-10 mm. Head 
dark brown, freckled with pale dots, a pair 
of large, pale spots lateral to each compound 
eye. Pronotum with a broad, pale area at 
each lateral margin and, usually, a sub- 
lateral, pale spot near either margin; each 
tarsal claw with two ventral denticles near 
tip. Abdominal dorsum without conspicuous 
color pattern, nearly uniform dark brown, 
sometimes with minute, light-colored spots 
on meson and near lateral margins of middle 
and apical tergites; venter white, with vari- 
able, dark brown color pattern: usually two 
pairs of submedian dots on each sternite, as 
ItLtinois NaturAL History Survey BULLETIN 
Vol. 26, Art. 1 
well as a third pair near anterolateral angles, 
the areas between these dots filled in on some 
darker specimens to produce a mushroom- 
like figure on each of sternites 3— or 48; 
sternite 9 usually with lateral and basal 
margins brown, so as to make a somewhat 
rectangular pattern; posterolateral angles 
of segments 3—9 spinelike, those on segment 
9 small; caudal filaments brown. 
Known from Illinois, Massachusetts, New 
Brunswick, Nova Scotia, Ontario, Quebec. 
Illinois Records. — Oakwoop: June 5, 
1948, Burks & Sanderson, 14; June 6, 
1925, T. H. Frison, 103; June 9, 1926, 
Frison & Auden, 4¢; July 8, 1946, B. D. 
Burks, 1¢. 
26. Stenonema rubrum (McDunnough) 
Ecdyonurus ruber McDunnough (1926:192). 
Mave.—Length of body 7-8 mm., of fore 
wing 8-9 mm. Face below level of ocelli 
white, vertex deep orange-brown; antennae 
pale yellow; eyes in life pearl-gray. Tho- 
racic pro- and mesonotum red-brown, apex 
of mesoscutellum white, with a red area just 
anterior to this; metanotum yellow, with a 
red stain on meson; semimembranous area 
of each mesopleuron anterior to base of fore 
wing and dorsal to spiracle orange-brown, 
sometimes with a pinkish cast; pleuron pale 
yellow, except for a pinkish brown stain 
dorsal to each fore and middle coxa; sternum 
pale yellow; fore leg yellow-tan, with brown 
shading in middle and at apex of femur, at 
apex of tibia, and at apexes of tarsal seg- 
ments; first tarsal segment three-fifths as 
long as second segment; middle and hind legs 
yellow, with red-brown shading in middle 
and at apex of each femur, and dark brown 
shading at apexes of tibiae and tarsal seg- 
ments; wings hyaline, faint pink shading in 
stigmatic area of each fore wing, humeral 
cell shaded with dark brown, veins and 
crossveins orange-brown, no crowding of 
crossveins at bulla. Abdomen light yellow, 
a rather broad, dark, orange-brown cross- 
band at posterior margin of each tergite 1-7, 
large spiracular dots present; apical tergites 
bright orange-brown with, usually, red shad- 
ing overlying ground color; abdominal ven- 
ter light yellow; genitalia, fig. 355, pale yel- 
low; caudal filaments pale yellow or white, 
articulations dark brown. 
NympH.—Length of body 8-9 mm. Each 
tarsal claw with two minute denticles on 
Se fa Se rN Lis hep ah 
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§ 
