472 



Wirth and Stone: Diptera 



high; abdomen granulose; raesonotum smooth; meso- 

 pleura microrugulose or granulose on anteroventral 



part; Great Basin region of California 



compar Cresson 1934 



— Face and head very broad, the former as broad as high, 

 the latter nearly twice as broad as high; mesonotum 

 strongly granulose 2 



2. Abdomen irregularly, longitudinally rugulose; Cali- 

 fornia, very common truncatula Loew 1878 



— Abdomen transversely rugulose, strongest on 2nd and 

 3rd tergites; all tergites smooth laterally; Nevada 

 County canadensis Cresson 1934 



Key to Adults of the California Species of 



Hyadina 



1. Scutellum with sides conspicuously opaque black; 



mesonotum subshining black; California 



binotata (Cresson) 1926 



— Scutellum and mesonotum uniformly densely brownish 

 pollinose; mesonotum with grayish spots and stripes; 

 southern California pruinosa (Cresson) 1926 



Key to Adults of the California Species of 



Lytogaster 



1. Frons and mesonotum smooth, at most minutely punc- 

 tate; scutellum granulose; 3rd antennal segment 1/2 



again as long as broad; Los Angeles County 



flavipes Sturtevant and Wheeler 1954 



— Frons, mesonotum, and scutellum rugulose and granu- 

 lose; 3rd antennal segment as broad as long; California 

 gravida (Loew) 1863 



Genus Dimecoenia Cresson 



This is a Neotropical relative of Ephydra and very 

 similar to it in the immature stages. Hennig (1943) 

 has described the immature stages of D. caesia 

 (van der Wulp) from Chile and zurcheri (Hendel) from 

 Paraguay. 



Key to Adults of the California Species of Dimecoenia 



1. Hind tarsus of male with prominent black hair tufts; 



southern and central California 



austrina (Coquillett) 1900 



— Hind tarsus of male without hair tufts; southern Cali- 

 fornia spinosa (Loew) 1864 



Genus Hydropyrus Cresson 



This genus contains only the species hians (Say), 

 found in very alkaline lakes from Nebraska to the 

 West Coast. At Mono Lake, California, this species 

 becomes very abundant, and in historical times the 

 puparia which were washed ashore in enormous wind- 

 rows were collected and eaten by the Pah-Ute Indians 

 who called this food "koo-chah-bee." Aldrich (1912) 

 has given an excellent and very detailed account of 

 the biology and immature stages of this species. 



hians (Say) 1830. 



Borax Lake, Lake County; 



Owens Lake, Inyo County; 



Mono Lake, Mono County; 



Trona, San Bernardino County 



Subfamily EPHYDRINAE 



Tribe EPHYDRINI 



Genus Setacera Cresson 



Johannsen (1935) described the immature stages of 

 S. atrovirens (Loew) from a brine pool near Ithaca, 

 New York, and of S. needhami Johannsen from Laguna 

 Beach, California. The immature stages are not 

 separable from those of Ephydra. 



Key to Adults of the California Species of Setacera 



1. Males with tuft of long hairs at apex of at least hind 

 tibia 2 



— Males without distal hair tufts on mid- or hind-tibia; 

 Placer County aldrichi Cresson 1935 



2. Males with hair tufts on mid- and hind-tibiae 3 



— Males with hair tuft at apex of mid-tibia only; Los 

 Angeles and San Diego counties. . .durani Cresson 1935 



3. Middle femur of male with flexor cluster of long hairs 

 on basal 1/3; southern and central California 



needhami Johannsen 1935 



— Middle femur of male without basal cluster of long 



hairs; southern and central California 



pacifica (Cresson) 1926 



Genus Ephydra Fallen 



Species of Ephydra are highly specialized and exclu- 

 sively aquatic, being commonly known as "brine 

 flies." Habitats range from fresh-water ponds and 

 lakes to the highly saline and alkaline ponds and 

 sinks of desert and semidesert regions (Aldrich, 1912). 



a, 



1935). 



Fig. 14:59. Ephydra, immoture stages. a,b, E. riparia Fall.: 

 "arva; b, puparium. c, E t cinerea Jones, larva (Johannsen, 



