Fig. 169- — Culex erraticus. 

 of the air tube. 



larva: A, apex of abdomen, lateral aspect; B, dorsum of head. Ventral tufts are shown for both sides 



One or both of head hairs 5 and 6 either multiple 

 ( Fig. 166B ) , or very short ( Fig. 169B ) 3 



3. Head hair 6 long and single, head hair 5 short and 



double to multiple { Fig. 169B ) 4 



Head hair 6 triple to multiple, similar to head hair 5, 

 both hairs long ( Fig. 166B ) 5 



4. Lateral comb scales arranged in a loose cluster (Fig. 



169/1); head hair 5 with 4 or more branches (Fig. 

 169B); body having an almost velvety covering of 



minute spicules erraticus 



Lateral comb scales more numerous than in Fig. 169/4 

 and forming a mucii more crowded cluster; head 

 hair 5 double or triple; body having only a sparse 

 covering of spicules peccator 



5. Air tube very long and slender (Fig. 168/1), 6 to 8 



times as long as its width at end of pecten; tufts 



scattered and weak salinarius 



Air tube either not more than 5 times as long as its 

 width at end of pecten (Fig. 166/4 ), or with strong 

 clustered tufts ( Fig. 165/1 ) 6 



6. Air tube usually 6 times as long as its width at end 



of pecten, sinuate but of almost uniform thickness 

 throughout; with all tufts near ventral margin ( Fig. 



165/4) tarsaiis 



Air tube usually 3.5 to 5 times as long as its widtii 



at end of pecten, somewhat vasiform. definitely 

 thickest near end of pecten; with the penultimate 

 tuft distinctly more dorsal than, and out of line with, 



the others ( Fig. 166/4 ) 7 



7. Air tube 4 to 5 times as long as its width at end of 

 pecten; 2 central hair tufts with a maximimi of 3 

 or 4 brances each (Fig. 166/4) pipiens 



Air tube less than 4 times as long as its width at end 

 of pecten; 2 central hair tufts with 5 to 10 branches 

 each (Fig. 167/4) quinquefasciatus 



Specimens intermediate between these rwo conditions 



are probably hybrids 



hybrid pipiens x quinquefasciatus 



Key to Species of CULISETA (Larvae) 



The larvae of this genus occur chiefly during spring in 

 marshes having permanent water; occasionally they breed 

 in stump holes and permanent ponds or pools. 



1. Air tube with a row of abtiut 12 iiair tufts along ven- 



tral margin (Fig. 172/4) melanura 



Air tube with only a single ventral hair tuft on each 

 side at or near ba.se of tube ( Fig. PM) 2 



2. Air tube short and stout; pecten consisting of about 



10 basal sclerous teeth and, beyond these, a series 

 of long fine single hairs (Fig. l~0/4") . . . .inornata 



40 



