REPORT ON MOSQUITOES. i6i 



of floating vegetation — even over floating or partially sub- 

 merged leaves, where it is safe from most aquatic enemies. The 

 head of this larva is unusually movable and can be completely 

 rotated ; in fact the larva makes rather a practice of feeding with 

 tlie bottom of its head at the surface of the water, while it floats 

 otherwise naturally, back up. As the larva increases in size it 

 tends to lose its speckled appearance and becomes more uniform, 

 ranging from gray to black in one direction and to bright green 

 in another. Mr. Seal considers this a protective character and 

 finds a direct relation between the color of the larva and its habi- 

 tation. He finds the green form over Cahomha and other green 

 plants in the tubs, the darker ones in the fringe of brown or dark 

 green Confervas at the sides. How completely they are thus 

 protected ]Mr. Seal records later: "I find we have been unsuspic- 

 iously fostering Anopheles in small ponds where we have fish. 

 They are hidden so completely from the fish and are sO' difficult 

 to observe among plants at the surface that they easily escape 

 detection without very close scrutiny." 



The length of larval life varies according to the season, but 

 from seven to ten days in mid-summer may be considered normal. 

 The early spring brood requires at least two wrecks, and the 

 larvae found in October linger even longer in the laboratory — 

 specimens taken outdoors in November ha^^e certainly been in 

 that stage during most of October. 



The pupa resembles that of Culex, but the abdomen is more 

 sharply cur\'-ed and the breathing tubes are much shorter, more 

 dilated at the tip. The pupal period also varies according to 

 circumstances; the shortest period — five hours — occurred in Mr. 

 Brakele}''s breeding, and in my own it has ranged from one to 

 three days. As long a period as ten days has been recorded ; but 

 this must be rare. 



As tO' the number of broods that occur during the season, it is 

 impossible to speak definitely. Development is so irregular that 

 in permanent breeding places all stages may be found at any 

 time during the summer, and l)roods, strictly speaking, do not 

 occur. When a female is ready she oviposits, w^iether her sisters 

 of the same age are in condition to do so or not, and so we have 

 a continuous development from early spring until freezing 

 weather sets in. 



JJ'here Does Anopheles Breed?' 



This can be answered in one word — everywhere ! I have had 

 larvae in the trap pails in my back yard and have found no 



II MO 



