THE HOUSEFLY 



353 



They belong to the suborder Orthorrhapha and in the group of short antennae flies 

 (Brachycera). Five posterior cells are always present. 



The antennae consist of three segments. No arista. The epipharynx is tube 

 like, the hypopharynx has a groove and both are awl-shaped. The pair of maxillae 

 are serrated and the mandibles lancet like. They have rather coarse maxillary 

 palps. The labellae are prominent at the extremity of the fleshy labium. They are 

 thick set flies and rarely show color. The body of the larva has eleven segments 

 with a small but distinct head. The eggs are deposited in masses on the leaves or 

 stems of plants about marshy places. The larva is carnivorous. 



Tabanus autumnalis. Is about % inch long; it is dark in color, and has four 

 longitudinal bands on the thorax. The last joint of the antennae has a crescentic 

 notch. The wings do not overlap. 



Haematopota pluvialis. In the Hosmatopota there is no crescentic antennal notch, 

 and the wings overlap. The abdomen is narrower than in Tabanus. The brimp, one 

 of the Hcematopota, bites man severely. 



FIG. 85. Common housefly (Musca domestica): Puparium at left; adult next, 

 larva and enlarged parts at right. All enlarged. From circular 71 (by L. O. 

 Howard), Bureau of Entomology, U. S. Department of Agriculture. 



Pangonia beckeri. The genus Pangonia is characterized by a very long, slender, 

 and more or less horizontal proboscis. 



Chrysops dispar. Chrysops has three ocelli, in this respect differing from the 

 genera Tabanus and Hcematopota. The wings are widely separated and spotted. 

 The antennas of Chrysops are especially long and slender. Chrysops and Hcemato- 

 pota produce the greatest amount of pain from their bites. The Tabanidoe except 

 Chrysops are not implicated as intermediate hosts in the transmission of disease. By 

 their bites, however, they may transmit disease directly, as with anthrax. Two 

 species of Chrysops, C. dimidiata and C. silacea, have been found to transmit 



Filaria loa. 



Muscidae 



The Muscidce, Sarcophagidae, and (Estridae are calyptrate Cyclorrhapha. 

 Musca domestica. The common housefly, Musca domestica, is the best example of 

 this family. 

 23 



