12 NORTH AMERICAN DIPTERA 



and add about half an inch of sawdust; wedge this in with a ball of 

 cotton, place in the sun for half an hour and the bottle is ready for use. 

 The cyanide should be broken into small lumps but need not be particu- 

 larly fine. It must be remembered that c\janide is a deadly -poison and 

 extreme care is necessary in handling it. Do not use it unless you arc 

 properly instructed, and if you do, be sure to destroy by burning or 

 burying all paper, pieces of wood, etc., which the cyanide might have 

 touched and wash thoroughly in running tap water hammers, etc. used 

 in crushing the material, as well as your hands. Never handle cyanide 

 if there is an open sore upon the hands. A little extra care may be 

 worth a lot. It might not be amiss to note here that the most efficient 

 antidote for cyanide poison is the intra-venous injection of methelyne 

 blue, one of the best known aniline dyes. 



Flies and Disease 



As agents in the spread of diseases of mammals the Diptera un- 

 doubtedly rank first in importance among the insects. The chief carriers 

 of diseases are, of course, the biting flies belonging to the families Psy- 

 chodidae, Simuliida, Culicidae, Tabanidai, Glossinidae, Ceratopogonidge 

 and Muscidae. Species of Flehotomus carry papataci fever, verruga or 

 Oroya fever, kala-azar and oriental sore. Other names are applied to 

 these diseases. The mosquitoes carry blackwater fever, yellow fever, 

 dengue, filariasis and malaria. Onchocerciasis is carried by species of 

 Eusi'imdium. A form of filariasis is believed to be carried by a species of 

 Culicoides and species of Chrysops are known to transmit the disease. 

 Tularemia, anthrax and trypanosomiasis are other diseases transmitted 

 by Tabanids. The stable-fly, Stomoxys calcitrans, is known to carry a 

 number of species of trypanosomes and may also be responsible for the 

 spread of poliomyelitis (infantile paralysis), although no definite proof 

 has been obtained. Sleeping sickness is carried by the Tse-tse flies. 



In addition to carrying diseases the biting flies themselves cause a 

 great deal of irritation by their bites, especially in the vicinity of water. 

 Life is often made miserable in northern regions by tlie hordes of 

 mosquitoes and black fiJes while the sportsman is plagued by almost all 

 the biting forms while in the woods and bathers come in for much 

 undesired attention from no-see-unis, mosquitoes and Tabanids, par- 

 ticularly the so-called "green-heads", along the coastal regions. 



The house fly carries on its body the germs causing typlioid fever, 

 dysentery, cholera, anthrax and conjunctivitis, while a few other flies 

 carry other diseases. Considerable has been written about myiasis 

 caused by the larvae of flies living in the human body. If we except the 



