120 Ituinois NarurAL History SurvEY BULLETIN 
has a recurved, dorsal flap. There are three 
well-developed caudal filaments. 
Centroptilum includes 22 Nearctic species, 
only 3 of which occur in Illinois. 
Characteristics for the separation to spe- 
cies of the females and nymphs in this genus 
have not yet been found. 
KEY TO SPECIES 
Apu.tt MALEs 
1. Entire mid-dorsal area of the abdomen 
shaded with dark red... .3. quaesitum 
Dorsal area of abdomen not entirely 
shaded with red; tergites 2-6 white or 
faintly yellow, with small spots or 
lines:of redvor black.4). Sa wen coh 2 
2. Posterior margin of each of middle ab- 
dominal tergites with a pair of trans- 
verse, sublateral, red lines; longitudinal, 
black spiracular lines present at lateral 
margins of tergites 2-6.........-..+% 
EN AN Pee Sea 2. rufostrigatum 
Abdominal tergites without transverse, 
red lines; only black spiracular lines 
BICSENES.. boven veo es pe Waleba 
1. Centroptilum walshi McDunnough 
Centroptilum walshi McDunnough (1929: 173). 
Mate.—Length of body and of fore wing 
6 mm. Head pale yellow, upper portion of 
each turbinate eye yellow in life, each an- 
tenna yellow, flagellum faintly tinted with 
tan in basal third. Thorax pale yellow, 
shaded with light brown on median dorsal 
area; legs light yellow to white, a minute, 
longitudinal, black line present on ventral 
side of each posterior femur; wings com- 
pletely hyaline, hind wing five times as 
long as broad, with two longitudinal veins. 
Abdomen pale yellow, almost white, with 
irregular, longitudinal, black spiracular line 
at each lateral margin of tergites 1-7, and 
tergites 8-10 entirely but lightly shaded with 
tan; forceps pale yellow, second forceps seg- 
ment with a prominent tubercle on mesal 
margin, and apical margin of forceps base- 
plate evenly rounded from side to side, fig. 
267; caudal filaments white. 
FEMALE.—Length of body and of fore 
wing each 5.5-6.5 mm. Entire body pale 
green when insect is alive, quickly fading to 
light yellow; thorax lacking brown shading, 
but abdominal tergites heavily blotched lat- 
erally with black and apical abdominal ter- 
gite shaded with brown. 
Known from Illinois, lowa, and Kansas. 
Illinois Records.—Bearnstown : at light, 
Vol. 26, Art. 1 
June 13, 1946, Mohr & Burks, 22. Homer: 
June 30, 1925, T. H. Frison,; Peéyeaeee 
Oakwoop: June 8-9, 1926, Frison & Auden, 
16,39. Srervine: at light, June 22, 1948, 
L. J. Stannard, 1¢. Ursana: June 1, 1941, 
TH. Frison:- 29. 
2. Centroptilum rufostrigatum 
McDunnough 
Centroptilum rufostrigatum McDunnough 
(1924: 95). 
Centroptilum bistrigatum Daggy (1945:389). 
New synonymy. 
I have studied types of both rufostrigatum 
and bistrigatum and find them unquestion- 
ably of the same species. 
Mave.—Length of body and of fore wing 
4.5-5.0 mm. Head very dark brown, an- 
tennae light brown; upper portion of each 
compound eye bright yellow in life. Thorax 
dark brown, lighter brown on venter; wings 
hyaline, hind wing four and one-half times 
as long as broad, with two longitudinal 
veins, three or four faint crossveins, and 
with the costal projection long and hooked; 
legs yellowish white, coxae light brown. 
First abdominal segment tan, segments 2-6 
white, segments 7-10 dark brown above, 
white below, a pair of transverse, sublateral, 
red lines present at posterior margin of 
each of tergites 2-8, usually these red marks 
on tergites 7 and 8 visible only on living 
specimens or specimens preserved in alcohol; 
longitudinal, black spiracular lines usually — 
present at lateral margins of tergites 2-6; — 
genitalia, fig. 268, white, apical forceps seg- — 
ment minute; caudal filaments white. 
FEMALE.—Length of body 4.5-5.0 mm., 
of fore wing 5-6 mm. Head and thorax 
light brown, dorsum of abdomen uniformly 
light brown, with transverse, red lines at — 
posterior margins of tergites as in male; 
longitudinal, black spiracular lines of male — 
replaced by heavy, black spiracular blotches 
at lateral margins; legs and caudal filaments” 
white. 
Known from Illinois, Manitoba, Minne-— 
sota, New Brunswick, and Wisconsin. 
Illinois Records——KANKAKEE: July 10, 
1925, T. H. Frison, 1. Oakwoop: July” 
30, 1939, B. D. Burks, 12. 4 
3. Centroptilum quaesitum McDunnough 
Centroptilum quaesitum McDunnough 
(1931b:87). 
