MOSQUITOS OR CULICIDAE OF NEW YORK STATE 265 



Generic key of culicid larvae 



Mosquito larvae are preeminently important in any work 

 designed to reduce the abundance of adults, because most of it 

 must be done before the mosquitos attain maturity, and ordinarily 

 it is impracticable to breed out the insects in order to ascertain 

 whether a pool is liable to produce an annoying or dangerous 

 species or not. This makes identification of larval forms of great 

 importance, and the following generic table modified from that 

 prepared! by Mr Joliannsen, is given as. an aid in identification, 



a Air tube on last abdominal segment 



h Antennae pendant, with four large, curved, apical spines Corethra 



66 Antennae not pendant 

 c Antennae* fold back against the head and terminate in two or three 



claws Oorethrella 



cc Antennae usually with only a few small erect bristles and one or 

 two pointed processes 

 d Brush projecting sidewise from the mouth, mandibles long, 

 sharply toothed. A large species, half an inch or more 



long Psorophora (cl 1 1 a t a) 



dd Brush of hairs projecting forward from the mouth 



e No ventral brush on last abdominal segment. With two anal 

 blood gills; the peeten of the air tube wanting. Small species 



occurring in water of pitcher plants Aedes (smith! i) 



ee Last segment with ventral brush 



f Anal blood gills dilated; lateral comb of eighth segment a 

 single transverse row of spines with elongate bases ; anal seg- 

 ment without hair tufts before barred area 



Stegomyia (f a s c i a t a) 

 if Anal blood gills slender 

 g Anal blood gills sharply pointed; peeten unidentate, apical 

 2 or 3 distant, flattened; lateral comb of eighth segment 

 with 12 large spines in a single or partly double row 



Aedes (f u s c u s) 

 gg Not as above in all respects 

 h Peeten teeth with semitransparent serrate margin, stel- 

 late hairs on the abdomen, a small species. .Uranotaenia 



hh Not as above Culei 



aa No air tube on last abdominal segment 



b Last segment usually with hooks ; no spiracles apparent; larvae trans- 

 parent, glasslike Sayomyia 



hb Last segment with a flat dorsal area in which may be seen two 

 spiracles 



c Medium sized species with anal segment cylindric. Anopheles 



CO Large species with the anal segment bladderlike ; mandibles strongly 

 developed Eucorethra 



