20 DIPTERA OF MINNESOTA. 



Stegomyia fasciata, which is the direct cause of the spread of yellow 

 fever; to various flies, among them the dangerous Screw-Worm 

 Fly, which lay their eggs in wounds and external cavities of men 

 and animals, causing suffering and frequent death, and particularly 

 to our common, ever present house fly, which is a constant menace 

 as a carrier of disease germs. It is said on good authority that 

 while only about 250 men were killed in battle during the Spanish- 

 American war, we lost 5,000 through the agency of house flies. 

 This refers to the carrying of typhoid germs from hospital trenches 

 to the food and other effects of our men while in camp. 



While denouncing the above pests, we must not lose sight of 

 the fact that we also find in this same order some beneficial forms, 

 notably the Tachina Flies, which, very abundant as far as indivi- 

 duals go, are of marked assistance to the farmer and gardener, by 

 parasitizing injurious caterpillars and preying upon grasshoppers 

 and other pests. We also have the Syrphus Flies, the larvae of 

 many of which feed upon plant lice, nor must we overlook the benefit 

 which we derive indirectly from the removal of carrion and decay- 

 ing vegetable matter through the work of the maggots of Blow 

 Flies, Flesh Flies, and others. These points are emphasized in the 

 following treatise in connection with the useful species. However, 

 in mentioning this fact it may be well to bear in mind that the same 

 is true of a number of injurious orders, wherein we find some 

 redeeming features, but not sufficient to remove these orders from 

 under the ban. 



We quote Osten-Sacken, a prominent worker in Dipterology, 

 who has the following to say regarding this group: 



Diptera during the past century have gradually risen in public estimation, 

 especially among men of science. The superiority of their organization has 

 been recognized by systematists, and observers of living specimens have noticed 

 peculiarities in their behavior which prove a higher development of their 

 faculties than of those of other orders. 



Diptera, more than all other insects, show a distinct love of freedom, while 

 Hymenoptera, with all their perfections, betray drill. Owing to their organiza- 

 tion, Diptera have more control over their motions than any other insects, in 

 consequence of which there is a remarkable stamp of individuality in their 

 actions. They can suddenly arrest their flight, and poise in the air; they can 

 not only swarm, but dance in cadence, or gambol in the air in the most extraor- 

 dinary manner. It is principally the males who dance, play and frolic together; 

 during courtship they perform most ludicrous antics. Schiller said: "The ani- 



