GAD- OK BREEZE-FLIES. 



16T 



commonly found in the neighborhood of marshes, and our 

 prairies with their numerous low and swampy places abound 

 in them. Woods and pastures are also frequently visited by 

 them. This is accounted for by the fact that the early 

 stages of this insect are passed below the ground, in wet 

 soil, and even in water. Their eggs are brown or black, 

 spindle-shaped, and are deposited in groups upon aquatic 

 plants and stems of grass. When the sun is very hot in sum- 

 mer these insects are most active, and thousands of them fly 

 about, and frequently torment the larger animals to such 

 an extent as to make them perfectly wild and frantic. The 

 moose and deer, attacked by such tormenters, lose all fear 

 of man and plunge into rivers and lakes to escape their at- 

 tacks; they soon be- 

 come very poor, as 

 they have no rest to 

 feed excepting at night. 

 Even the most rapid 

 animals can not escape 

 these swift tormenters, 

 which descend upon 

 them and, choosing the 

 most tender portions 

 of the skin, bury 

 their powerful probos- 

 cis (fig. 137) in it and 

 do not withdraw it 

 until satisfied with blood. A slight swelling, which soon 

 disappears, shows where the skin is perforated. Their flight 

 is so rapid that they can not only follow an express train 

 but can make excursions into the country at the same time. 

 This is frequently seen when one of them settles upon the 

 window of a fast train in motion, and after awhile darts off 

 some distance soon to return to its resting-place. It is be- 

 lieved that such flies are agents in transmitting virulent dis- 

 eases, when they leave an animal aflected with one of them 

 and introduce their proboscis into the skin of a healthy one. 

 We have a large number of such insects in Minnesota, 

 but all possess a very similar life-history, at least as far as 



Fig. 137.— Mouth-parts of Tabanus. 

 enlarged. Original. 



Greatly 



