1939] 
Mosquitoes of Massachusetts 
119 
tending to lie in line, or mesonotum with bare areas 
devoid of scales or both : Theobaldia 
6. Pronotal bristles only two stout setae (Fig. 2) ; proboscis 
with black and white scales so arranged as to form 
longitudinal striae; mesonotum with six longitudinal 
lines of white scales : Orthopodomyia 
Pronotal bristles more than two, generally a prominent 
row ; proboscis without longitudinal striae ; mesonotum 
without six longitudinal lines of white scales 7 
7. Wings with scales distinctly large and broad ; first joint 
of all tarsi with broad median rings ; all of the other 
tarsal joints black with basal half white scaled : 
Mansonia 
Wings with scales normal ; tarsi not as above 8 
8. Post-spiracular bristles present; female usually with 
the abdomen pointed and the cerci exserted or tarsi 
with white rings on both ends of joints : Aedes 
Post-spiracular bristles absent ; female with a blunt ab- 
domen ; tarsi without white rings involving both ends 
of joints: Culex 
Larvae 
1. Eighth segment of abdomen provided with a distinct, 
elongate respiratory or air tube (Fig. 8) 2 
Eighth segment of abdomen without a distinct, elongate 
respiratory or air tube (Fig. 9) : Anopheles 
2. Air tube without a pecten (Fig. 12) 3 
Air tube with a pecten (Fig. 8) 5 
3. Air tube about twice as long as wide, the apical por- 
tion sharply attenuated and provided with saw-like 
teeth dorsally for penetrating into plant tissues (Fig. 
12) ; larva found attached to the roots of certain 
aquatic plants : Mansonia 
Air tube about three times as long as wide, tapering 
more or less uniformly to the apex ___4 
4. Air tube with many short single hairs ; larva found in 
the water of the pitcher plant : Wyeomyia 
Air tube without scattered single hairs but with a 
large pair of hair tufts before the middle; abdomen 
