98 



THE REPORT OF THE 



No. 19 



^'bill " composed of the upper lip and the five slender lances, and the blood is drawn up through 

 the proboscis into the stomach. 



Kinds of Mosquitoes. There are several genera of Mosquitoes, two of which are common, 

 viz., Gtdex and Anopheles. The former, however, is by far more abundant, and the species pungens 

 is the Common Mosquito. 



Anopheles is important as it is the agent in the inoculation of the human body by malaria. 

 The female Anopheles may be distinguished readily from the female Culex by the length of the 

 palpi on each side of the proboscis. In the former the palpi are almost as long as the proboscis, 

 while in the latter they are quite short. (Fig. 55.) 



The resting position of mosquitoes is an interesting study, which may be carried on both 

 summer and winter. In winter the adults cling to the ceilings of attics and basements. [ What 

 is the characteristic resting attitude of Culex on the ceiling and the vertical wall?] (Fig. 56.) 



Fig. 56 —Resting positions of Culex (at left) and Anopheles (at right), enlarged (redrawn from a rough 

 sketch published in the British Medical Journal. (From U. S. Department of Agriculture.) 



How to rid a locality of Mosquitoes. Dr. Howard, of Washington, mentions thiee methods : 

 1. " By the drainage of the swamps or pools in which the mosquitoes breed." 2. "By the 

 use of kerosene on the surface of the waters in which they breed." 3, "By the introduction of 

 fish into Ashless ponds so that they may eat the wrigglers." 



Practical Exercises. 



1. How far do mosquitoes fly from their breeding places ? 



2. Collect a large number of mosquitoes during the summer, and determine, I. the number 

 of males, 2. the number belonging each to Culex and to Anopheles. 



3. The eflfecb of the use of Kerosene on the breeding places of mosquitoes (use 1 oz. for 

 every 15 sq. ft. of surface). 



4. Full-study of life-history of Culex, 



