30 Ittinois NATuRAL History SuRvVEY BULLETIN 
Champaign, Charleston, Chicago, Cypress, 
Danville, Darwin, Decatur, Delavan, Dol- 
son, Dubois, Eichorn, Elizabethtown, Equal- 
ity, Forest Park, Fountain Bluff, Fox Lake, 
Freeport, Galena, Galesburg, Glencoe, Gol- 
conda, Grand Detour, Grand ‘Tower, 
Grandview, Grayville, Hamilton, Hardin, 
Harrisburg, Havana, Herod, Hillsboro, 
Homer, Joliet, Jonesboro, Kampsville, 
Kankakee, Kansas, Kappa, Karnak, Keiths- 
burg, Lawrenceville, Mahomet, Makanda, 
Marshall, Mason City, McClure, Mere- 
dosia, Metropolis, Monticello, Mounds, 
Mount Carmel, Mount Forest, Muncie, 
New Milford, Newton, Normal, Oakwood, 
Oquawka, Oregon, Palos Park, Paxton, 
Quincy, River Forest, Rockford, Rockton, 
St. Anne, St. Joseph, Seymour, Shawnee- 
town, Sparland, Springfield, Starved Rock 
State Park, Ullin, Urbana, Vienna, Volo, 
Ware, Warren, Warsaw, Waukegan, West 
Union, White Heath, White Pines Forest 
State Park, Willow Springs, York, Zion. 
Plagiognathus pallidicornis Knight 
Plagiognathus  politus var.  pallidicornis 
Knight (1923d, p. 435). 
This species is allied to politus Uhler, but 
is easily to be distinguished by its pale anten- 
nae and shorter rostrum. 
Mave.—Length 3.50, width 1.47. Head 
width 0.71,. vertex 0.37. Antennae, first 
segment, length 0.24, black; second, 0.91, 
pale, black at base; third, 0.65, pale; fourth, 
0.39, pale. Rostrum, length 1.21, reaching 
only to middle of hind coxae. General color 
black, moderately shining, pubescence pale, 
base of cuneus with a narrow, pale area; 
ventral margin of propleura, mesoepimera 
and ostiolar peritremes white. 
FEMALE.—Length 3.40, width 1.56; slight- 
ly more robust but very similar to male in 
color and pubescence. 
Known Distrinution.—Connecticut, I]- 
linois, Maine, Massachusetts, Minnesota, 
New Hampshire, New York, Ontario. 
Illinois Records.—AntTiocH: July 5-7, 
193250 P rison ef val sO, GAUSo ene Oste 
Frison, Knight & Ross, 14,19. 
Plagiognathus nigronitens Knight 
Plagiognathus 
p. 435). 
This species is slightly smaller than poli- 
tus Uhler, with a shorter rostrum; the body 
nigronitens Knight (1923d, 
V ol. 227704 rie 
is shining black, with the cuneus uniformly 
black like the corium. 
Mace.—Length 3.00, width 1.20. Head 
width 0.64, vertex 0.33. Rostrum scarcely 
attaining posterior margin of middle coxae. 
Antennae, first segment, length 0.22, black; 
second, 0.78, black, extreme tip pale; third, 
0.66, pale; fourth, 0.45, dusky. Pronotum, 
length 0.53, width at base 1.03. Hemelytral 
margins very slightly arcuate; uniformly 
black, shining; cuneus never pale at base; 
clothed with pale yellowish pubescence. 
Membrane uniformly pale fuscous, a pale 
triangular spot bordering cuneus. Legs 
black, femora light in color at extreme tips; 
tibiae yellowish, spines with black spots at 
bases, hind pair becoming infuscated on 
basal one-third. 
FEMALE.—Length 3.00, width 1.30; very 
slightly more robust than male but very 
similar in coloration. 
Foop PLant.—Ragweed (Ambrosia sp.), 
sunflower (Helianthus sp.). 
Known DistripuTion.—Colorado, Illi- 
nois, Michigan, Minnesota, Mississippi, 
New Jersey, New York, Ohio, Ontario, 
South Dakota. 
Illinois Records.—Eighteen males and 
28 females, taken May 12 to Aug. 1, are 
from Antioch, Champaign, Dubois, Fountain 
Bluff, Goreville, Grand Tower, Metropolis, 
Muncie, Oakwood, Vienna, Volo. 
Plagiognathus flavicornis Knight 
Plagiognathus flavicornis Knight (1923d, 
p. 436) 
This is larger and more robust than nigro- 
nitens Knight and about the same size as 
politus Uhler, but the second antennal seg- 
ment is pale except for a narrow area at 
the base; the cuneus remains uniformly 
black like the corium. 
Matve.—Length 3.50, width 1.60. Head 
width 0.73, vertex 0.38. Rostrum scarcely 
attaining hind margins of middle coxae. 
Antennae, first segment, length 0.28, black, 
apex pale; second, 1.16; third, 0.83, fuscous; 
fourth, 0.55. Pronotum, length 0.61, width 
at base 1.16. General color black, shining, 
including basal margin of cuneus; clothed 
with yellowish to dusky pubescence. Mem- 
brane and veins uniformly dark fuscous. 
Legs black, tips of femora pale; tibiae pale; 
knees and spot at base of spines black; spots 
much reduced or absent on apical one-third. 
FEMALE.—Length 3.30, width 1.60; very 
