May, 1953 
Abdominal sternites without midventral 
(alo) 55 ceria Sey ea ae eee 2. dubium 
3. Abdominal tergites 2-6 or —7 with large, 
bright red spot near either lateral mar- 
ginofeachtergite....... 3. parvulum 
Abdominal tergites 2—6 lacking large, sub- 
lateral, bright red spots; sometimes 
with a brown spot near each spiracle. .4 
4. Abdominal tergites 2-6 each with a pair 
of submedian, red-brown dots and a 
short, median, longitudinal, red line. .. 
4. myrsum 
Abdominal tergites 2—6 each with a pair 
of submedian, red or red-brown dots, 
but longitudinal, median, red line want- 
[CPV ERE aN ee alent png eA Os 5. veteris 
Mature Mate Nympus 
1. Caudal filaments each with alternating 
brown and white crossbands from base 
to apex; each abdominal gill with a 
subapical, brown spot. ..3. parvulum 
Caudal filaments white, each with a brown 
crossband in middle; apex of each fila- 
ment may or may not be brown..... 2 
2. Caudal filaments each with a brown cross- 
band in middle and another at apex... 
RES Ee ere ae ee 4. myrsum 
Caudal filaments each with a brown cross- 
bandsinemiddleyonly:< esi. 2. 3 
3. Abdomen with median, ventral, dark spots 
on posterior margins of sternites 3— or 
4-6 or-7...........1. punctiventris 
Each abdominal sternite may have a pair 
of submedian, dark dots or streaks, but 
middle sternites lack median dots at 
posterior margins......... 2. dubium 
1. Pseudocloeon punctiventris 
(McDunnough) 
Clocon punctiventris McDunnough (1923: 45). 
Mave.—Length of body 3.5-4.5 mm., of 
fore wing +5 mm. Head very dark brown, 
almost black; antennae dark brown, becom- 
ing light toward apex of flagellum of each. 
Thorax dark brown, almost black; legs very 
light yellow, with coxae and trochanters 
brown, and each fore femur shaded with 
smoky brown; wings hyaline. First abdom- 
inal segment light brown; tergites 2-6 white, 
without markings, except that there may be 
faint, black spiracular dots; sternites 2-6 
white, with a black or dark brown, median 
dot on posterior margin of each; apical 
abdominal segments red-brown, median 
black or dark brown dot may be present on 
posterior margin of each of segments 7 and 
8; genital forceps faintly tinted with tan, 
apical forceps segment twice as long as 
broad; cerci white. 
FEMALE.—Length of body 4.0-4.5 mm., 
of fore wing 5.0-5.5 mm. Head and thorax 
Burks: THE MAyF igs oF ILLINOIS 137 
light brown. Abdomen tan, heavily shaded 
with black tracheal markings; median 
ventral dots large, black, present on poste- 
rior margins of sternites 1-6 or —7. 
NympH.—Length of body 4.5-5.5 mm. 
Head and thorax brown and tan; legs white 
or light yellow, with femora vaguely shaded 
with brown in the middle and at apex of 
each. Abdomen tan, with brown markings: 
first and second tergites almost entirely 
brown, lighter on posterior margins near 
posterolateral angles; tergites 3 and 4 tan, 
each with a pair of brown, submedian dots 
and lateral margins shaded with brown; 
tergite 5 mostly brown, lighter on meson; 
tergite 6 entirely brown except for a pair 
of submedian, tan dots at posterior margin; 
tergite 7 mostly brown, tan on meson and at 
posterolateral angles; tergites 8 and 9 tan, 
with a pair of submedian, brown dots on 
each, tergite 9 often also vaguely shaded 
with brown at lateral margins; abdominal 
sternum tan, a pair of submedian, brown 
dots present on each sternite, a median, 
dark brown dot on posterior margin of each 
of sternites 3-7, apical sternites vaguely 
shaded with brown; gills with pinnately 
branched, black or dark brown tracheae; 
caudal filaments light yellow, with a dark 
brown crossband in middle of each. 
Known from Illinois, Ohio, and Ontario. 
Illinois Records.—Mount CarMet: at 
light, June 18, 1947, Burks & Sanderson, 
1g. Oaxkwoop, Salt Fork River: May 2, 
1943, H. H. Ross, 26 ; May 6, 1936, Ross 
& Mohr, 14; June 4, 1948, B. D. Burks, 
24. SERENA, Indian Creek: May 12, 1938, 
Ross & Burks, 16, 12; May 16, 1938, B. 
D. Burks, 3 N. Wotr LaKke: Hutchins 
Creek, May 12, 1939, Burks & Riegel, 3 N. 
2. Pseudocloeon dubium (Walsh) 
Cloe dubia Walsh (1862:380). 
The male lectotype of this species is in 
the Museum of Comparative Zoology. This 
specimen is somewhat broken, but agrees 
quite well with the current concept of the 
species. 
Mave.—Length of body 3-5 mm., of fore 
wing 4.0-5.5 mm. Head brown; each an- 
tennal scape and pedicel brown, flagellum 
white; each compound eye, in life, with 
faceted area of upper portion tan, columnar 
area yellow, and lower portion brown. 
Thorax dark, rich brown, almost black; 
