8 Everett E. Wehr 



Tabanus Linnaeus I 



The thirteen species of this genus known to occur in Ne- j 

 braska may be separated by the following key : i I 



1. Eyes glabrous 2 



Eyes pilose 9 , 



2. Abdomen with definite white markings 3 



Abdomen without definite white markings 7 



3. Abdomen with a middorsal stripe; a row of gray triangles on , 

 either side 4 



Abdomen not so colored 5 



i. Eyes with a single band in life; thorax uniformly pollinose; 

 costal cells yellowish; length 9, 10-14 mm., S 13 mm costalis 



Eyes with three bands in life; thorax dark colored with gray 

 stripes; costal cells hyaline; length 9, 14-16 mm., S , 12-14 mm. 

 lineola 



5. Wings with first posterior cell closed abdorninalis 



Wings with first posterior cell open 6 



6. Prevaling color of abdomen black; segments 3-5 with large gray 

 triangles, segment 2 of female with a rounded white dot on each 

 side, length 9, 16-19 mm., $ 15-16 mm trimaculatus 



Prevailing color of the abdomen reddish-brown ; segment 2 with 



a gray triangle; length 9, 18-20 mm., $, 19-20 mm sulcifrons 



7. Thorax, in well preserved specimens, densely covered with white 

 pollen; abdomen void of white pubescence 8 



Thorax black, abdomen covered with white pubescence; entire 

 body including wings uniformly black; length 9, 21-25 mm., 

 5, 22 mm atratus 



8. Tibiae with white ring at base; length 9, 18-21 mm.; $, 18-19 

 "^™ punctifer 



Tibiae without white ring at base; length 9, 18 mm stygius 



9. Prevailing color of the whole body yellowish ; ocelligerous tuber- 

 cle absent in both sexes; length 9, 9-10 mm., $, 11 mm bicolor 



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