2l8 



NuTTALL and Shipley have made some 

 laboratory experiments on the influence of colour, 

 and find that navy blue is the colour most pre- 

 ferred by A. maculipennis, and yellow the one most 

 shunned. 



As, however, the Anopheltnae at least are 

 nocturnal in their habits, and prefer biting un- 

 clothed portions of the body, the colour of one's 

 clothing will not be much protection. If white 

 or yellow socks can prevent the persistent attacks 

 of Stegomyia, it would indeed be a practical boon. 

 To various trees and plants has been ascribed a 

 repellent effect upon mosquitoes. None of these 

 statements has, so far, borne a critical examination. 



Length of Life of Mosquitoes 



The length of life of mosquitoes, under suit- 

 able conditions, is probably considerable ; several 

 weeks to months. In captivity they may, if suit- 

 ably housed and constantly fed, be kept alive for 

 days, weeks, and even months. A mosquito kept 

 some time in captivity becomes infirm, and readily 

 falls into the water whilst laying its eggs. It also 

 finds difficulty in hanging on to smooth glass, 

 and even though a rough surface is supplied the 

 insect is constantly found on the bottom of the 

 cage resting in a horizontal position. After laying 

 eggs, such infirm mosquitoes generally die the 

 same night. In nature, Anophelines certainly remain 

 alive in huts for one or two months and possibly 

 longer. After the drying up of all breeding- 

 places, the winged Anop/zeZ/nes do not much diminish 

 in number for several weeks. If the drying up 

 continues, the numbers gradually diminish, but 

 specimens may be caught up to two months or 

 more afterwards. 



