22 MEDICAL ENTOMOLOGY 



a. Antenna, three-jointed, terminal segment annulated, and 

 not possessing the arista of the housefly and its allies. 



b. Last tarsal segment, note the claws, pulvilli and empodium 

 between. 



c. Head, note the large compound eyes, separated in the female 

 and contiguous in the male; note the sexual difference in size of 

 mouthparts. 



EXERCISE lOc 



THE HORSEFLIES 



Systematic Study. 



Family Tabanidae, antennae porrect, without arista, medium 

 sized to large flies. 



1. Genus Tabanus, hind tibiae without spurs, third seg- 

 ment of the antennae with a well developed basal process, ex- 

 amples, T. stygius, the black and white horsefly; T. punctifer; 

 T. atratus, the black horsefly; T. costalis, the greenhead; and 

 T. lineola, the lined horsefly. 



2. Genus Chrysops, (Earflies or Deerflies) hind tibiae with 

 spurs at tip, third segment of the antennae composed of five 

 annuli; second segment of the antennae but little shorter than 

 the first; wings with a dark picture; examples, C. niger and C. 

 bruneus. 



Draw one example each of the two genera mentioned above. 



EXERCISE 11 



THE HOUSEFLY (MUSCA DOMESTICA) AND THE STABLEFLY 

 (STOMOXYS CALCITRANS) 



ORDER DIPTERA, FAMILY MUSCID 



A Comparative Study. 



It will be remembered that while these two species of flies 



