16. 
20. 
tN 
ind 
pe 8 
peak 
ILtinois NATURAL History SurvEY BULLETIN 
Ground color of abdomen white or yellow; 
abdominal tergites 1-7 each with a 
narrow, black, transverse Stripe at 
posterior margin or this margin virtual- 
ly without markings............-. 18 
Eyes of living insect brown; outer margin 
of hind wing shaded with brown 
ie pon) es ate tet 14. pudicum 
Eyes of living insect gray; outer margin 
‘of hind wing not shaded........... 16 
Stigmatic area of fore wing shaded with 
dark red, this pigmentation concen- 
trated in basal part of stigmatic area 
9 eae eee an oe 15. vicarium 
Entire stigmatic area of fore wing uni- 
formly stained with yellow-brown. .17 
Abdominal tergites 8 and 9 dark brown, 
with lateral margins white........... 
eee ei Week Ome oem Sa RCS 16. fuscum 
Abdominal tergites 8 and 9 uniformly 
dark DIOWN oes a chs 17. ithaca 
Posterior margin of each tergite 2-7 with 
only minute, black dash on meson.. .19 
Posterior margin of each tergite 2-7 with 
a black line extending completely 
across dorsum; occasional specimens 
entirely lacking marks at these posterior 
WRAY OTS Spats cata ats piss tisha 20 
Mesonotum dark brown; abdomen usual- 
ly with spiracular dots 
heels Rt eee rege 18. mediopunctatum 
Mesonotum chalky white; abdomen al- 
ways lacking spiracular marks of any 
KERGeAR Ge ce tae Ser 19. metriotes 
Abdomen lacking spiracular marks of any 
MER Geko oR Oe Se cee see aie 21 
Abdomen with spiracular dots or oblique 
streaks on at least middle segments. . 
Pa ET hea SE Me Os gs Pe OMG Sa 23 
Articulations of caudal filaments dark 
red-brown throughout; middle and 
hind femora each with a prominent, 
red-brown crossband in middle and at 
CHEREMT Sterns Sirs ko 20. luteum 
Caudal filaments white or a faint yellow 
throughout, articulations not darkened, 
or sometimes basal 2 or 3 articulations 
only of each filament darkened; middle 
and hind femora each with red-brown 
shading at apex only, occasionally 
middle femur with faint shading in the 
BIE Bate yok Stn: Up F raisin. 22 
First fore tarsal segment two-fifths as long 
as second segment. .21. terminatum 
First fore tarsal segment two-thirds to 
five-sixths as long as second segment. 
Mt NS ORE CP 22. lepton 
Abdominal spiracular marks a series of 
short, oblique streaks. ..23. integrum 
Abdominal spiracular marks a series of 
PERS see rs Sad sO Cra RS oth Paner 24 
Mesonotum light clay-colored or yellow- 
BIW TRG oo aes Sonate 25 
Mesonotum dark red-brown or black- 
PRES eek ns ene ure Nn kaie SRP ore 26 
Pink-brown shading almost completely 
covering abdominal tergite 8; mesono- 
tum yellow-brown. ...24. nepotellum 
Pink-brown shading of tergite 8 restricted 
to a median, longitudinal bar; mesono- 
26. 
to 
Vol. 26, Art. 1 
tum light clay-colored.............. 
ines Gans 25. rubromaculatum 
Mesonotum red-brown; stigmatic area of 
fore wing stained a faint pink; only 
apex of mesoscutellum white........ 
iE kN GOS Gn be 26. rubrum 
Mesonotum dark, blackish-brown; stig- 
matic area of fore wing stained light 
brown; entire mesoscutellum white. . 
erly ta BAe eee eee 27; pulchellum 
KEY TO SPECIES GROUPS 
ApvuLt FEMALES 
Fore wing with basal crossveins in first 
radial interspace thickened and dark- 
ened in the middle, as in fig. 317; two 
or three crossveins below bulla thick- 
ened and blackened in the middle, 
these black spots often fused to form a 
short, longitudinal dash 
RRL yah interpunctatum group 
Fore wing with basal crossveins in first 
radial interspace not thickened and 
darkened in the middle; two or three 
crossveins below bulla never thickened 
and darkened in the middle and never 
with a short, longitudinal black dash 
connecting these crossveins 2 
Abdominal tergites 2-8 with three small, 
black marks at posterior margin of 
each: a median, black dot and a pair of 
submedian, transverse dashes........ 
epninae tripunctatum group 
Abdominal tergites not with three small, 
black marks at posterior margin of 
each 
Abdominal tergites 3-8 each with a pair 
of short, submedian, transverse lines at 
posterior margin...) . 0.2 eee 
Pepa Shoes home bipunctatum group 
Abdominal tergites 2— or 3-7 or —8 each 
with a continuous, dark crossline or 
color band at posterior margin, or each 
of these tergites virtually or quite with- 
out markings at posterior margin....4 
Ground color of abdomen tan or yellow- 
brown; tergites 2-7 each with a broad, 
dark brown, transverse band occupy- 
ing posterior fourth to half of tergite. . 
.vicarium group 
Ground color of abdomen light yellow or 
white; tergites entirely unmarked, 
with spiracular dots only, or with a 
narrow, black, transverse line at 
posterior margin of each of some or all 
fergites i... vc ee 5 
Abdomen lacking spiracular marks of any 
Kinde, tposctae ee terminatum group 
Abdomen with spiracular dots or oblique 
streaks....mediopunctatum group, 
pulchellum group 
KEY TO SPECIES 
Mature Nympus 
Gills borne by abdominal segments 1-6 
pointed at apexes, fig. 358 2 
Gills borne by abdominal segments 1-6 
