246 INTRODUCTION TO GENERAL SCIENCE 



179. THE STINGS OF INSECTS 



The pain caused by stings is due chiefly to formic acid or 

 to some irritant which is injected; that is, the effect is chem- 

 ical. Ammonia, since it neutralizes an acid, is good to allay 

 the pain. 



There is a secondary effect, however, for which the insects 

 are not responsible, and which is due to the bacteria or pro- 

 tozoa which they inject at the time they sting. Yellow fever 

 and malaria are caused only by the bite of a certain kind of 

 mosquito which injects protozoa. Similarly, the " sleeping 

 sickness " is due to another species of protozoa which is 

 injected by the bite of a fly, similar to the tsetse fly. 



We can reduce the number of mosquitoes and finally exter- 

 minate them from a given locality by preventing the growth 

 of their larvae, commonly called " wigglers." This can be 

 accomplished by pouring crude oil upon the surface of the 

 water where they swarm. 



References : 



1. 1304:170. Swamps and Malaria. 



2. 1501 : 154. Insects' Stings and Bites. 



3. 1503 : 185-186. Mosquitoes and Flies Transmit Disease. 



4. 1901 : 214-220. Malaria and Yellow Fever Mosquitoes. 



5. Farmers' Bulletin No. 155. How Insects Affect Health in 



Rural Districts* 



a. 1308 : 143-145. Man's Enemies. 

 6. 1505 : 160-161. Mosquito Fevers. 



c. 1506 : 269. Malaria from Mosquito Bites. 



d. 1507:132-135. Malaria and Mosquitoes. 



e. 1509 : 189. Malaria and Mosquitoes. 



/. 1904 : 103-109. Malarial Fever and Yellow Fever. 

 g. 1904:110-116. Mosquitoes and their Control. 



