344 NEW YORK STATE MUSEUM 



and our animals axe repelling substances, such as stinking oils 

 and smudges. A number of repellents are sold, and some of them 

 are very good, for instance the " Black-fly cream," made in 

 Portland Me. Our fishermen and hunters frequently use a mix- 

 ture of kerosene oil and mutton tallow, with which the exposed 

 parts are greased. For animals any of the strong smelling oils 

 can be used, but repeated applications are apt to hurt them or 

 to remove the hair. Oil of tar is a simple and easily applied 

 wash. To make it, a quantity of coal tar is placed in a large 

 shallow receptacle in which is stirred a small quantity of oil 

 of tar, or oil of turpentine, or any similar material. After fill- 

 ing the receptacle with water it is kept undisturbed for sev- 

 eral days, when the animals to be protected are washed with 

 the impregnated water whenever necessary. Smudges are the 

 best as a protection and the animals soon realize their pro- 

 tection and crowd to them for shelter, even refusing to leave 

 them when needed elsewhere. As the black flies are active 

 during the day only, and the mosquitos toward® evening and 

 night, dwellers in our northern woods have a bad time of it 

 and sometimes suffer very greatly on their account. It is easy, 

 however, to drive these tormenters from houses or tents. By 

 burning inside of them a little Pyrethrum powder (Persian or 

 Dalmatmp insect powder) upon a piece of bark these intruders 

 are eitjier killed or so stupefied that they do not bite for some 

 time. This method is in general use in the houses and stores 

 of the Hudson Bay Company, and the writer has always used 

 it successfully in his numerous trips. The fumes of the burn- 

 ing insect powder are not very offensive, at least not nearly so 

 much so as the poisonous bites of such insects as black Hies 

 i;».Hd mosquitos. Lugg&r^ 



Structural characters 



There is but one genus of the family Simuliidae, Simulium, 

 which possesses the characters of the family. 



The eggs of the known species are deposited in a compact 

 layer on the surface of rock over which water is flowing in sit- 

 uations as shown on plate 32. Their ishape is elongate ellipsoidal, 

 but they are usually closely packed with the long axis vertical 

 and hence assume a polyhedral cross section. Eggs of the dif- 

 ferent species doubtless vary in size, those of the larger spe- 

 cies (e. g. S. p i c t i p e s) measuring .40 by .18mm. In 



IMinn. Agric. Exp. Sta. 1896. Bui. 48, p.207. 



