448 



Wirth and Stone: Diptero 



never fenestrate; tergites 3 and 4 always with a black 

 spot on each side. coquillettii Hine 1904 



41. Discal cell hyaline discalis Williston 1904 



— Discal cell infuscated 42 



42. Body jet black pechumani Philip 194 1 



— Body not entirely black 43 



43. Tergite 2 with a double geminate spot 



coloradensis Bigot 1892 



— Tergite 2 with a small black anteromedian quadrate 

 spot asbestos Philip 1949 



Genus Chrysozona Meigen 

 Chrysozona americana (Osten Sacken) 1875. 



Genus Glaucops Szilady 

 Glaucops fratellus (Williston) 1887. El Dorado County 



Genus Atylotus Osten Sacken 



Atylotus incisuralis (Macquart 1847). Siskiyou to Tulare 

 (= Tabanus insuetus Osten Sacken 1877) 



Genus Tabanus Linnaeus 



Certain hairy eyed species with an ocelligerous 

 tubercle have been placed in the genus Hybomitra 

 Enderlein by Philip, and Middlekauff adopted this 

 procedure, but it appears to be more properly con- 

 sidered as no more than a subgenus. 



Key to the California Species of Tabanus 



1. Vertex of female with a distinct denuded ocelligerous 

 tubercle; of male with an elevated, anteriorly shining 

 tubercle (in doubtful cases eyes are densely pilose) 

 (Hybomitra) 2 



— Vertex without such tubercle; if raised in male then 

 completely pollinose (eyes bare, or sparsely pilose, 

 or in certain males densely pilose) (Tabanus) 22 



2. Females, eyes not contiguous 3 



— Males, eyes contiguous 14 



3. Entirely black; including pubescence and pollinosity; 



Modoc County to Santa Cruz County 



procyon (Osten Sacken) 1877 



— Not entirely black 4 



4. Abdomen broadly orange brown laterally, tergites 2 and 

 3 usually unicolorous orange to margins; the median 

 black area usually constricted on tergite 3; sublateral 

 pale spots not conspicuous 5 



— Abdomen not broadly orange laterally; if paler laterally, 

 the median dark area is rather broad and not constricted 

 on tergite 3; sublateral pale spots, if present, distinct 

 10 



5. Hind tibial fringe well developed, mostly golden orange; 

 length usually 18 mm. or more; prescutal lobe yellowish; 

 Mendocino, San Mateo, and Santa Cruz counties .... 



calif ornica Marten 1882 



— Hind tibial fringe weak, or, if well developed, not 

 golden orange, frequently black; prescutal lobe reddish; 

 usually less than 18 mm 6 



6. Antenna black, rarely with a little orange on 2nd and 

 base of 3rd segments; 3rd segment narrow, with obtuse 

 dorsal angle and little if any dorsal excision; vein 

 R 4 often with a stump 7 



— Not with this combination of characters 9 



7. Frons slightly less than 3 times as high as wide, the 

 sides nearly parallel philipi Stone 1938 



— Frons about 4 t'imes as high as width at base, usually 

 somewhat divergent above 8 



8. Venter of abdomen with mostly yellowish hair, although 

 there may be some scattered black hairs medianly; 

 Del Norte County to Inyo County 



sonomensis sonomensis Osten Sacken 1877 



— Venter of abdomen almost uniformly clothed with fine 

 black hair, the yellowish hair usually sparse except 

 along incisures; Del Norte County to Inyo County 

 sonomensis phaenops Osten Sacken 1877 



9. Subcallus pollinose; Plumas County to Mono County 



haemaphorus Marten 1882 



— Subcallus denuded; Del Norte County to Madera County 



captonis Marten 1882 



10. Subcallus denuded, shining H 



— Subcallus pollinose 13 



11. Prescutal lobe black (Trinity County to Kern County) 

 rhombicus Osten Sacken 1876 



— Prescutal lobe reddish brown 12 



12. Stump vein usually present; length 15 mm. or more; 

 front usually more than &\/ 2 times as high as width at 

 base; Shasta, Plumas, and Mono counties 



tetricus tetricus Marten 1883 



— Stump vein usually absent; length 14 mm. or less; 

 front about 3 times as high as width at base; Modoc 

 County to Alpine County melanorhinus Bigot 1892 



13. Stump vein usually present; pollen of head gray; Shasta, 

 Plumas, and Inyo counties, tetricus hirtulus Bigot 1892 



— Stump vein rarely present; pollen around face usually 

 faintly tinged with yellow; Lassen, Tuolumne, and Mono 

 counties opacus Coquillett 1904 



14. Entirely black, including palpus procyon Osten Sacken 



— Not entirely black 15 



15. Abdomen broadly orange brown laterally, the median 

 black area usually constricted on tergite 3; sublateral 

 pale spots not conspicuous 16 



— Abdomen not broadly orange brown laterally; if paler 

 laterally, the median dark area rather broad and not 

 constricted on tergite 3; sublateral pale spots, if 

 present, distinct 19 



16. Antennae red with black annuli c calif ornica Marten 



— Antennae with black more extensive 17 



17. Venter with black hair rather sparse, and, at least 

 sublaterally a considerable amount of yellowish hair 

 18 



— Venter with only black hair 



sonomensis phaenops Osten Sacken 



18. Second sternite with a large black median spot; 2nd 

 palpal segment stout, but apex not acute 



sonomensis sonomensis Osten Sacken 



— Second sternite with scarcely any black medianly; 2nd 

 palpal segment stout, with apex acute 



haemaphorus Marten 



19. Prescutal lobe black (subcallus denuded) 



rhombicus Osten Sacken 



— Prescutal lobe pale, reddish orange 20 



20. Subcallus denuded melanorhinus Bigot 



— Subcallus pollinose 21 



21. Stump vein present tetricus Marten 



— Stump vein absent opacus Coquillett 



22. Females; eyes not contiguous 23 



— Males; eyes contiguous 31 



23. Abdominal tergites with both median and sublateral 

 pale spots, those of median row may be contiguous 

 but do not form a parallel-sided stripe 24 



— Abdominal tergites without sublateral pale spots, or 

 median row of spots contiguous forming a parallel- 

 sided stripe 25 



24. Eyes sparsely pilose (high power); furcation without a 

 black spot; Modoc County to Inyo County 



Iqticeps Hine 1904 



— Eyes bare; furcation with a black spot (Sierra County 

 to Los Angeles County monoensis Hine 1924 



25. Abdomen unicolorous black or rarely with a median row 

 of small whitish triangles 26 



— Median dorsal row of spots contiguous, forming a more 

 or less distinct parallel-sided stripe 28 



