1913] Determining the Flight of Mosquitos 19 



and the men cautioned to be as quiet as possible, and if they 

 must move about, to so do with little commotion. Contrary 

 behavior shews mosquitos away. It seems these gnats wait at 

 the door till the occupant is quiet. The mosquitos caught in a 

 given tent during each hour interval, should be placed in a pill- 

 box, and this one properly labeled, containing in addition to 

 what had already been indicated, the particular hour's catch 

 represented. 



D. Collections with a Beating Net: Important clues bearing 

 directly upon the movements of adult mosquitos will be 

 obtained by systematic sweeping in the grass and shrubbery, 

 using for this purpose a large entomological beating net. The 

 adults thus captured should be placed into pill-boxes, these 

 labeled to show the place where caught, character of the vege- 

 tation, and hour when captured. The note book should 

 contain data concerning the temperature, wind direction, 

 velocity, humidity, cloudiness, smoke, etc. The writer noted 

 from a series of sweepings that Anopheles albimanus Wiede. and 

 certain Culices (C qninquefasciatus Say et Mansonia titillans 

 Walker) were more abundant in the grass when the winds were 

 above four miles per hour, than when these winds were less. Its 

 bearing upon the problem can only be determined after a series 

 of careful tests. 



E. Examination of Adults: The mosquitos in a single pill- 

 box should be emptied upon a piece of glass plate under which 

 is a white blotter or paper. With a camel's hair brush these 

 are spread over the plate and each specimen is wetted with a 

 testing solution containing three parts of glycerine, three of 

 alcohol and one of chloroform. If any color is present upon any 

 mosquito, it will be revealed as soon as the testing solution 

 reaches it, diffusing outward. Thus each colored specimen 

 becomes a distinct nucleus of diffusion — hence non-colored 

 adults cannot receive through accident some of the diffusing 

 color and thus confuse the observer. The number, species, sex, 

 date and where captured, of all recovered mosquitos, should 

 appear on the data sheets and charts. In addition, a record 

 should be kept of the total mosquito catch, properly tabulated. 



It is advisable that only one person be detailed for this 

 examination, and care must be exercised to select a man free 

 from either amnesic or general color blindness. His working 

 table must be kept clean. He should make preliminary tests 



