5 
. Seales of the comb of the eighth segment smooth, bluntly rounded. In 
hollow trees and rain barrels ______________- Ochlerotatus triseriatus Say. 
Seales of comb sole-shaped with trifid apex. The yellow-fever mosquito. 
Stegomyia calopus Meigen, 
foeeoar seement Tinged-by the plates: M15 ite) te) Aa ete aeons 44 
Anal segment not completely ringed by the plate ______________________- 50 
44. Air tube over twice as long as wide, its pecten of 19 to 22 teeth _________ 45 
Air tube twice as long as wide or less, its pecten of 12 to 14 teeth _______ 48 
45, Seales of the comb with the central spinule shorter than the body of the 
seale; pecten of the air tube of equal teeth _____._____-____-.._-__1- 46 
Seales of the comb with central spinule as long as the body of the seme: 
pecten of the air tube longer outwardly___________________.__________- 47 
46. Air tube two and one-half times as long as wide; comb scales moderate. 
48. 
49, 
The Atlantic coast salt-marsh mosquito _ Ochlerotatus sollicitans Walker. 
Air tube three times as long as wide; comb scales long. In rain puddles, 
with a southern distribution _______________ Ochlerotatus mitchella Dyar. 
. Air tube pecten reaching to beyond the middle of the tube; lateral comb of 
21 scales in nearly three rows ________ Ochlerotatus trivittatus Coquillett. 
Air tube pecten not reaching to the middle of the tube; comb of 17 scales 
in two imperfect rows. An early spring species. 
Ochlerotatus awroides Felt. 
Seales of the comb feathered on the sides, with central thorn. 
Aédes infirmatus Dyar and Knab.! 
Scales of the comb evenly feathered; no central thorn_________________- 49 
Air tube one and one-half times as long as wide; pecten teeth broadly ellip- 
tical. In puddles along the Atlantic seaboard_ Ochlerotatus damnosus Say.” 
Air tube twice as long as wide; pecten teeth narrowly elliptical. An early 
SpRINOVSpPeCles see = Ochlerotatus inconspicuus Grossbeck. 
. Air tube four times as long as wide; trachez narrow, angled. An early 
Spin euspecicsaee= sme | ei se 2s - Ochlerotatus fitchit Felt and Young. 
Aum tiube three pimes asslon® as wide or less. -2= 92) ee 51 
. Anal plate small; gills very large, sack like, spotted. 
Ochlerotatus varipalpus Coquillett. 
Anal plate over half encircling the segment ; anal gills moderate or small_ 52 
. Comb scales tapered, a single median spinule stouter or larger than the 
MCS eee eee ee Mee tl eels ele 59 
Comb scales bluntly rounded, the median spinule resembling the others__ 59 
. Both of the hair tufts on the front.of the head multiple_-_--___-_________ 54 
The lower head tuft single or double (rarely three) _____________________ 56 
. Subdorsal prothoracie hairs single. In temporary pools. 
Ochlerotatus canadensis Theobald. 
Ochlerotatus nivitarsis Coquillett. * 
Supaormal prochoracic hairs multiple:=...+- 2+. 3 3212.5 See eee 5D 
. Weakly colored ; tufts of ventral brush short-stemmed. In puddles near 
the sea along the Atlantic coast _________ Ochlerotatus cantator Coquillett. 
Darkly colored ; tufts of the ventral brush long-stemmed. An early spring 
species in the Northwest ___-___-_-__- __ Ochlerotatus pullatus Coquillett. 
ilo wemheadehardouple. (or triple). 2 28 ee i 
ower head hair Single: —2. 4.22 == - = a aT. ea CES eS eens FAO 
1 Ochlerotatus confirmatus (in part). 
2 Ochlerotatus teeniorhynchus. 
’ Imperfectly known, 
