74 Appendix A. 



(Reduced from original) 



Adult mosquitoes, as a rule, do 'not bite when the temperature is below 

 65 degrees Fah. The development of the young is greatly retarded by cold, 

 and is completely arrested in. freezing weather. Larvas frozen in the ice 

 will, hov/ever, complete their development with the appearance of warm 

 weiUlier. Adult females may live two months or more in summer, and are 

 capable, after hibernation begins, of withstanding any degree of cold. They 

 winter in caverns, in cold cellar^ and garrets, stables, etc. The males die 

 socn after birth, and are not known to survive the winter. 



EXTERMINATION AND PREVENTION OF MOSQUITOES. 

 As has been explained, mosquitoes require for their development standing 

 water. They cannot arise in any other way. A single crop soon dies and 

 disappears unless the females find water en which their eggs may be laid. 

 In order to prevent mosquitoes, therefore, the requirement is simple : 



NO STANDING Vv^ATER. 



Pools of rain, water, duck ponds, ice ponds, and temporary accumulations 

 due to building ; marshes, both of salt and fresh water, and road-side drains ; 

 pots, kettles, tubs, springs, barrels of water, and other back-yard collections, 

 should be drained, filled with earth, or emptied. 



Running streams should have their margins carefully cleaned and cov- 

 ered with gravel to prevent weeds and grass at the water's edge. 



Lily ponds and fountain pools should, if possible, bo abolished ; if not, the 

 margins should be cemented or carefully graveled, a good stock of minnows 

 put in the water, and green slime (Algje) regularly cleaned out, as it col- 

 lects. 



Where' tanks, cisterns, wells or springs rrMst he had to supply water, the 

 openings to them should be closely covered with wire gauze (galvanized to 

 prevent rusting), not the smallest aperture being left. 



When neither drainage nor covering is practicable, the surface of the 

 efanding water should be covered with a film of light fuel oil (or kerosene) 

 which chokes and kills the larvse. The oil may be poured en v/ith a can 

 or from a sprinkler. It will spread itself. One ounce of oil is suiE- 

 cient to cover 15 square feet of water. The oil shoidd be renewed once a 

 ■week during warm weather. 



Particular attention should be paid to cess-pools. These pools when un- 

 covered breed mosquitoes in vast numbers ; if not tightly closed by a ce- 

 mented top or by wire-gauze, they should be treated once a week with an 

 excess of kerosene or light fuel oil. 



Certain simple precautions suffice to -protect persons living in malarial 

 districts from infection: 



First : — Proper screening of the house to prevent the entrance of the mos- 

 quitoes (after careful search for and destruction of all those already present 

 in the house) and screening of the bed at night. The chief danger of in- 

 fection is at night (the ^nopheles bite mostly at this time). 



Second : — The screening of persons in malarial districts who are suffering 

 if rem malarial fever, so that mosquitoes may not bite them and thus become 

 infected. 



Third : — The administration of quinine in full doses to malarial patients 

 to destroy the malarial organisms in the blood. 



