128 CIVIC BIOLOGY 



they are carried by light and continued winds. With the 

 exception of two species of Culex that breed in salt marshes 

 and migrate for long distances, mosquitoes seldom go more 

 than two hundred yards from where they are hatched. In a 

 town or city away from these marshes the work of extermi- 

 nating mosquitoes is simple and not expensive. Indeed, the 

 class in civic biology can accomplish the task as an interesting 

 and valuable turn at outdoor laboratory work. Before begin- 

 ning the work, however, much more should be learned about 

 the habits and life history of the mosquito. 



Habits and life history. Mosquitoes are nocturnal ; during 

 the bright part of the day they hide under leaves, in grass, in 

 cellars, wells, cisterns, in barns, and in the dark corners of the 

 house. Even the " day mosquito," Aedes, does not fly about 

 or bite in the bright sunlight of midday. As winter approaches, 

 the female mosquitoes seek dark, damp places in cellars, caves, 

 hollow trees, and loose bark in which to hibernate. Can you 

 find them ? 



Mosquitoes may be distinguished from gnats and other 

 mosquito-like insects by the presence of a fringe of scale-like 

 hairs on the margins of the wings. 



Like many other insects, especially those that suck blood, 

 they are strongly attracted or repelled by different people. It 

 is a matter of common experience that some people are annoyed 

 by this class of insects much more than others. Odors like a 

 mixture of oil of tar, oil of pennyroyal, and olive oil are effec- 

 tual repellents, as is also a mixture of cedar oil (one ounce), 

 oil of citronella (two ounces), spirits of camphor (two ounces), 

 If an odor could be discovered that is highly attractive to 

 mosquitoes, it might be effective in ridding a neighborhood of 

 the pests if used in connection with a % trap or some form 

 of sticky fly paper. 



Mosquitoes seem to possess other likes and dislikes. They 

 are attracted to dark colors and are repelled by lighter shades ; 



