- Halteres brown or black 5 



4. Scutellum brown; hind tibia y3llow with broad subbasal 

 and narrow apical brown rings; mesonotum uniformly 

 grayish-brown pruinose; large species (3.9 mm); Ala- 

 meda and Tulare counties . . varicolor (Coquillett) 1902 



- Scutellum yellow; hind tibia brown with middle 3rd 

 yellow; mesonotum with prominent black vittae; small 

 species (2.5 mm.); widespread in California 



setulosa (Loew) 1861 



5. Mesonotum uniformly dull brown; hind femora spinose 

 6 



- Mesonotum shining black or dull black with silvery 

 pollinose areas; hind femora with or without spines 



7 



6. Antennae with flagellar segments yellow at bases; 

 legs yellow with indistinct brown bands; Humboldt, 

 San Mateo, and San Luis Obispo counties 



sordida Wirth 1952 



- Antennae and legs uniformly dark brown; Modoc County 



modocensis Wirth 1952 



7. Mesonotum with anterior corners silvery pollinose and 

 with broad median dull-black stripe; Mariposa and Los 

 Angeles counties pulverea (Coquillett) 1901 



- Mesonotum shining black, at most with 2 short, narrow, 

 submedian, silvery lines 8 



8. Mesonotum with pair of narrow submedian white lines 

 on anterior 1/2; Mono and Plumas counties 



bilineata Wirth 1952 



- Mesonotum uniformly polished black 9 



9. Femora and tibiae entirely black; San Luis Obispo 

 County flavitarsis Malloch 1914 



- Femora and tibiae of fore legs broadly yellow-banded; 

 Kern County expolita (Coquillett) 1901 



0. Halteres with knob yellow or white 11 



- Halteres with knob brown or black 14 



1. Hind tarsal claws of female very large and unequal; 

 costa produced past tip of radial cell to 0.9 of wing 

 length; mesonotum uniformly grayish, granular pruinose; 

 Monterey County granulosa Wirth 1952 



- Hind tarsal claws of female small and equal; costa to 

 0.8 of wing length, not produced past tip of radial cell; 

 mesonotum otherwise 12 



2. Mesonotum uniform jet black; fore tibia yellow; only 

 apex narrowly dark; Kern, Riverside, and Imperial 

 counties coloradensis Wirth 1952 



- Mesonotum pollinose gray with darker vittae; fore 

 tibiae annulate 13 



3. Fore tibia with single narrow brown ring in middle, 

 absent on mid and hind tibiae; mesonotum pearly gray 

 with broad, median, anterior, reddish-brown vitta; San 

 Joaquin Valley glabra (Coquillett) 1902 



- All tibiae with broad submedian and apical brown 

 bands; mesonotum dark pollinose gray with submedian 

 anterior lines and posterior lateral spots brown; Modoc, 

 San Benito, and San Luis Obispo counties 



biannulata Wirth 1952 



4. Thorax shining black with short, submedian, anterior 

 pair of silvery linas on mesonotum; fore- and midlegs 

 dark brown with narrow yellow rings; widespread. . . . 



bivittata (Coquillett) 1905 



- Thorax uniformly dull, reddish brown with dense, long 



pubescence; legs yellowish to brown; widespread 

 opaca (Loew) 186 1 



Genus Probezzia Kieffer 



According to Mayer (1934), the pupae of this genus 

 cannot be separated from those of Johannsenomyia. 

 Che North American species have been revised by 



437 

 Wirfh ond Stone: Diptera 



Wirth (1951). There is only one known California 

 species. 



flavonigra (Coquillett) 1905. 

 (fig. 14:39A-». 



Great Basin and 

 Central Vallej 



REFERENCES 



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 HILL, M. A. 



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MALLOCH, J. R. 



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NIELSEN, A. 



1951. Contributions to the metamorphosis and biology of 

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