84 MISC. PUBLICATION 336, U. S. DEPT. CF AGRICULTURE 
27. Air tube with four or five pairs of hair tufts beyond pecten, the subapical 
pair laterally out of line (fig. 20); hairs usually little, if any, longer 
than’ diameter iol Cully esas eee ai ea Te 28 
Air tube with five pairs of long tufts, the proximal pair attached near or 
before end of pecten, none out of line. [Air tube about 4:1.] 
C. tarsalis 
28. Air tube long and slender, 7 or 8:1, sides nearly parallel; frontal head 
hairs usually with three or four branches SU Er SR es ee ae Se el 29 
Air tube stouter, about 4:1. head hairs usually with five or more 
| 0) S20 ORE) OVS) spate one me SE HAs aPivat fe 5 ee ee tw ec UN eee C. quinquefasciatus 
C. pipiens 
29. Thorax with fine spicules (best observed toward sides); lateral hair 
of anal segment usually single; basal (or proximal) tufts of air tube 
usually double or long and single, occasionally triple__ C. nigripalpus 
Thorax glabrous; lateral hair of anal segment usually double, occasion- 
ally single; basal tufts of air tube usually with three or four branches, 
oceasiomallliy: sw tlicss ws eres ee ore ae rene C. salinarius 
30. Pecten spines fringed on one side nearly to tip; ventral tufts of air tube 
long. (those nearest base about twice diameter of tube or more), 
multiple and finely feathered_=—_=_—~=__ === _ Culex (Melanoconion) 32 
Pecten spines with one to four coarse side teeth; air tube with compara- 
tively short tufts (little, if any, longer than diameter of tube). [Air 
tubeslong Gi 0K (yD ok. ee a ee SL eee | 
31. Head hairs long, usually single, the lower pair or both hairs occasionally 
double; air tube slightly expanded toward tip, with four or five 
paired ventral tufts beyond pecten (none at base) ; comb a patch of 
seales, the single scale rounded and fringed apically; body finely 
PLEO SC ce ser Be co ka Na ee C. apicalis 
Lower head hairs single, the upper ones shorter and multiple; air tube 
with a tuft of hairs at base and with a row of about 12 short, sub- 
equal tufts on midventral line; comb a single row of tong barlike 
SCC Ses ea ALA sate eae Se Culiscia melanura 
32. Air tube long and slender, 5 or 6:1, with four to six pairs of ventral hair 
Air tube short (about 3:1), with ‘about eight. pairs of very long hair 
tufts, basal two within pecten. [Comb of eighth segment of 8 to 12 
Scales in a curved or irregular row, the single scales long and pointed, 
unfringed; a stalked ovoid gill at base of antenna; head hairs small, 
usually single, upper ones sometimes double; thorax slightly spicular. ] 
Culex pilosus 
383. Lower head hairs single, upper ones shorter, double or triple; body 
sparsely spicular; comb with the seales in a patch, each scale rounded 
and fringed apically; air tube slightly flared at tip______ C. peccator 
Lower head hairs long, single, upper ones short, multiple (four or more) ; 
body usually densely spicular-pilose; comb with one irregular or par- 
tially double row of scales, the individual scales long and pointed and 
fringedsont basal hal fis oo Be ee ae ee ee ae eee C. erraticus 
tufts beyond pecten_____ neat Eee ea | 
PSOROP HORA 
34. Mouth brushes formed of stout prehensile hairs (each hooked at tip 
and with a row of comblike teeth along the side) (fig. 25, D). [Air- 
tube pecten with numerous teeth, which are prolonged into hairs; tuft 
of air tube a single long hair.] Very large predacious larvae________ 35 
Mouth brushes normal, ciliform. [Pecten with a few strong, widely 
spaced teeth; tuft of air tube sometimes very small.]_-__--__________ 36 
35. Lateral hair of anal segment with three or four branches near base 
P. ciliata 
Lateral hair of anal segment single or forked some distance from base: 
teeth of pecten somewhat stouter than in P. ciliata______ P. howardii 
36. Antenna very large, inflated apically, two long bristles at outer third in 
addition to central hair tuft; air tube small with a paired tuft of very 
LOWS LATS 5 SEE LUTTE Ss ST ee P. discolor 
Antenna not inflated; air tube large, inflated, ventral tuft small or 
ODSOlEEC HL ah alas: UPR OEE aoe nee BARE EME ETE, 8D £ SS rer 
Sip Eleads hairs, Gouble Onesie] ema eae ra a SR ar a 38 
Both upper and lower head hairs muliiple2=— ==. P, confinnis 
