covered with wide overlapping scales. A small 

 annoying species widespread and often abundant 



in Illinois erraticus 



Top of head entirely covered with wide overlapping 

 scales except occasionally for a narrow mesal line 

 of narrow scales. An eastern and southern species 

 found rarely in southern Illinois peccator 



Key fo Species of CULISETA (Females) 



1. Dorsum of abdomen with only very dark, purplish 



scales; wing less than 4 mm long. An eastern 

 and central woodland species not yet found, but 



to be expected, in Illinois melanura 



Dorsum of abdomen with scattered tawny or paler 

 scales or bands of such scales; wing more than 

 5 mm long 2 



2. Wing with a mixture of light scales and dark scales; 



tarsus without pale bands but with a sprinkling of 

 pale scales. A widespread marsh species common 

 throughout Illinois in April and May . . . .inornata 

 Wing with dark scales only; first 1 or 2 tarsal seg- 

 ments with slight but distinct pale bands at each 

 end 3 



3. Middle dorsal segments of abdomen each with a 



wide and conspicuous basal band of white scales. 

 A Holarctic species local in northern Illinois. . . . 



morsitans 



Middle dorsal segments of abdomen each with an 

 apical and a basal pale band, the bands incon- 

 spicuous and composed of light brown scales. A 

 rarely collected species known only from Minne- 

 sota and northern Illinois minnesotae 



Key to Species of ORTHOPODOMYIA (Females) 



Two species of this genus, aiba and signifera, have been 

 found in Illinois, but the two species can be identified to 

 date only in the larval stage. They are rarely collected in 

 light traps. Neither bites man. 



Key to Species of PSOROPHORA (Females) 



1. Wing length over 6.5 mm, usually 7 to 8 mm; 



mesonotum having a narrow mesal band of scales 

 flanked by a linear bare polished band on each 

 side (Fig. 11); hind femur with a prominent 



tuft of hairs at apex (Fig. 13) 2 



Wing length under 5 mm, usually 3.°' to 4.^ mm; 

 mesonotum with entire area scaled; hind lemur 

 (Fig. !■)) without a well-marked tuft of hairs 

 at apex 3 



2. Mesonotum with mesal hand of scales yellow, hind 



tibia and tarsus very bushy (as shown in drawing 

 on cover of this publication). An eastern and 

 tropical species widespread and sometimes com- 

 mon in both open and wooded habitats in Illinois 



ciliata 



Mesonotum with mesal band of scales black, hind 

 tibia and tarsus pubescent but not unusually 

 bushy. A southern and tropical woodland species 



sometimes locally abundant on floodplains in 

 Illinois howardi 



3. Hind tarsus entirely purple 4 



Hind tarsus partly white, often with all segments 



banded with white or some all white 5 



4. Dorsum of abdomen with apical yellowish bands 



that are slightly broken on the meson. A south- 

 ern and tropical woodland and pasture species 

 found locally in the southern half of Illinois. . . 

 q'anescens 



Dorsum of abdomen with only small lateral white 



spots, as in Fig. 58. Variant specimens of 



varipes 



3. Most of the tarsal segments each with apex dark 

 and base with a white band, as in Fig. 13; wing 

 having a mixture of dark scales and white scales 

 6 



Most of the tarsal segments each entirely dark or 

 entirely light; a leg may be banded but with an 

 alternation of entirely dark and entirely light 

 segments; rarely one segment may be banded; 

 wing having all dark scales 7 



6. Wing mostly dark scaled but with a fairly even speck- 



ling of white scales; basal segment of hind tarsus 

 nearly black, but with two bright white bands, a nar- 

 row one at extreme base and a wider one at middle 

 of segment. A widespread American species of 

 temperate and tropical open habitats, locally abun- 

 dant throughout Illinois confinnis 



Wing with white scales grouped into definite lines 

 or patches on some veins; basal segment of hind 

 tarsus mostly white scaled but with dark scales 

 intermingled uniformly along its entire length. 

 A southern and Mexican species of open habitats, 

 locally abundant throughout Illinois discolor 



7. Mesonotum golden scaled over its entire area. An 



eastern and tropical woodland species widespread 



along floodplains in Illinois ferox 



Mesonotum with mesal half black scaled, lateral 

 portions white scaled, scales of the two colors 

 forming longitudinal bands 8 



8. Hind tarsus having next to last segment completely 



or partly white, the last one black. A southern 

 and tropical woodland species widespread along 

 floodplains in the southern half of Illinois.... 



varipes 



Hind tarsus having the last 2 or 21/2 segments white, 

 the remainder black 9 



9. Apex of femur, or "knee," with a narrow v.hite 



band. An eastern and southern woodland species 

 widespread along floodplains in Illinois, .horrida 

 Apex of femur dark, without a band. A midwestern 

 species not yet known, but to be expected, in 

 woodlands of Illinois longipalpis 



KEYS TO CULICIDAE MALES 



Some oi tlic |\»rts named in these keys are illustrated 

 in Fis;. 65; others are included in the diagnostic drawings 



14 



