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Family 

 SIMULID^. 



Although undistinguished in the British Islands by any English 

 name, the members of this family, of which it is probable that our 

 fauna includes at least a dozen species, are only too well-known to 

 all those who have had occasion to enter their haunts. The famil)- 

 consists of the single genus Simiiliitin, which is universally dis- 

 tributed, and of which some sixty-six species, difficult to distinguish 

 from one another, have been described up to the present time. The 

 females of some of these flics, which are among the most dreaded 

 of all blood-sucking Diptera, sometimes occur in enormous swarms, 

 and by their attacks upon horses, mules, and cattle, especiall}' in 

 certain parts of the United States, occasion great losses among these 

 animals, besides molesting human beings. In the district of South 

 Hungary called the Banat the Columbacz Midge {Simidinm colitin- 

 baczcnse, Sc/ioiib.) has been notorious for more than a hundred years 

 owing to the destruction caused by it among cattle. 



In appearance Simulida; are small black or gre)-ish flies, not 

 exceeding 4 mm. in length, with a conspicuously humped thorax, 

 short straight antenna;, broad and delicate iridescent wings, stout 

 legs, and a short proboscis which is not visible from above. The 

 males, which are incapable of sucking blood, are fond of dancing in 

 the air in the sun ; as a rule they arc much darker in coloration than 

 the females, and are often velvety black, with silvery markings on 

 the front of the thorax. 



The preliminary stages are passed in running water. The eggs 

 are deposited in a compact la\er or gelatinous mass on stones or 

 plants close to the water's edge. The larval stage lasts for about 

 four weeks in the summer, though longer in cold weather, and the 

 winter is passed in this stage. In shape the larva is somewhat like 

 a tiny leech, broadening out posteriorly, where it is attached by 

 means of a sucker to a stone, the stem of a water-plant, a dead leaf, 

 or other object. The larva is able to shift its position by crawling in 

 a looping fashion, but usually remains in a more or less erect position. 



