392 



Wirth and Stone: Diptera 



— First segment of hind tarsus without a median pale ring 



11 



10. Spiracular and postspiracular bristles present (fig. 

 14:16j); abdominal tergites with many pale apical 

 scales, frequently forming a triangle 



Psorophora Robineau Desvoidy 



— Spiracular and postspiracular bristles absent; abdominal 



tergites with laterobasal pale spots 



Mansonia Blanc hard 



11. Postspiracular bristles present; spiracular bristles 

 absent; female abdomen pointed at tip . . . .Aedes Meigen 



— Postspiracular bristles absent; female abdomen blunt 

 at tip 12 



12. Spiracular bristles present, yellowish; mostly large 

 mosquitoes Culiseta Felt 



— Spiracular bristles absent; medium to small mosquitoes 



Culex Meigen 



Larvae 



— Respiratory horn open at tip, the opening of the internal! 

 spiracle at its base (fig. 14:16A,i) (CULICINAE) 4| 



2. Thoracic respiratory organ more or less spindle-shaped,! 

 with an almost closed spiracle at or near tip (fig. 

 14:15/-A) 3 



— Thoracic respiratory organ more or less flaring, with 

 an open spiracle near middle. . . . Eucorethra Underwood 



3. Membrane of paddles of anal fin flexible and folded 

 with midrib and reinforcing ribs on inner and outer 

 margin, the latter finely serrate; respiratory horn 

 swollen (fig. 14:15/-A) Chaoborus Lichtenstein 



— Membrane of paddles rigid; abdomen not so elongates 

 respiratory horn less swollen Corethra Meigen I 



4. Lateral hairs of abdominal segments placed almost' 

 exactly at corners Anophelini 



— Lateral apical hairs well before apical corners 5! 



5. Outer part of paddle produced beyond tip of midrib 



T oxorhynchitini 



— Outer part of paddle not longer than midrib Culicini 



1. Antennae prehensile, with long and strong apical 

 spines (fig. 14:14) (CHAOBORINAE) 2 



— Antennae not prehensile and lacking the strong apical 

 spines (fig. 14:17/) (CULICINAE) 4 



2. Eighth abdominal segment with an elongate dorsal air 

 tube or respiratory siphon (fig. 14:14a). Corethra Meigen 



— Eighth abdominal segment without an elongate air tube 

 or respiratory siphon 3 



3. Air sacs present in thorax and 7th abdominal segment 

 (fig. 14:146) ....' Chaoborus Lichtenstein 



— Air sacs absent; 8th abdominal segment with a well- 

 developed spiracular disc with prominent valves (fig. 

 14: 14c) Eucorethra Underwood 



4. Eighth abdominal segment without a respiratory siphon 

 (fig. 14:l6e) Anopheles Meigen 



— Eighth abdominal segment with a respiratory siphon 

 (fig. 14:17/) ■• 5 



5. Mouth brushes prehensile, each composed of 10 stout 

 rods Toxorhynchites Theobald 



— Mouth brushes not or rarely prehensile, composed of 

 30 or more hairs 6 



6. Siphon without a pecten (figs. 14:17<i,e) 7 



— Siphon with a pecten (figs. 14:17o-c) 9 



7. Anal segment without a median ventral brush but with 

 a pair of ventrolateral tufts only . . . .Wyeomyia Theobald 



— Anal segment with a median ventral brush (fig. 14:17) 



8 



8. Distal half of siphon adapted for piercing underwater 

 plant tissue (fig. 14: 17d) Mansonia Blanchard 



— Siphon not adapted for piercing plant tissue (fig. 14: 17c) 



Orthop odomyia Theobald 



9. At least lower head hair single and coarse, spinelike; 

 head longer than wide Uranotaenia Lynch 



— Both head hairs slender, branched or unbranched; head 

 wider than long (fig. 14:17/) 10 



10. Siphon with a pair of large basoventral hair tufts (fig. 

 14:176) Culiseta Felt 



— Siphon without a pair of large basoventral hair tufts 



11 



11. Siphon with 3 or more pairs of ventrally located hair 

 tufts (inserted below the lateral line) . . Culex Linnaeus 



— Siphon with 1 or rarely 2 pairs of ventrally located hair 

 tufts 12 



12. Tufts of ventral brush not inserted in saddle (fig. 

 14:17/) Aedes Meigen 



— Tufts of ventral brush inserted in saddle which com- 

 pletely rings anal segment (fig. 14: 17c) 



Psorophora Robineau Desvoidy 



Pupae 



1. Respiratory horn either almost closed apically or with 

 the spiracular opening near its middle (fig. 14:15/-/)) 

 (CHAOBORINAE) 2 



California Species of Culicidae 



Subfamily CHAOBORINAE 



Genus Eucorethra Underwood 



Eucorethra underwoodi Underwood 1903. Humboldt to 



Mariposa County 



Genus Chaoborus Lichtenstein 



Key to Adults of California Species 



1. Wings unspotted; Modoc County 



flavicans (Meigen) 1818 



Fig. 14:14. Chaoborinae larvae, a, Corethra ci'ncfi'pes Coq., 

 b, Chaoborus sp.; c, Ecorefhra underwoodi Und. (o,c, Matheson, 

 1944; b, Peterson, 1951). 



