8 Annals Entomological Society of America [Vol. VI, 



at a glance four distinct data, graphically placed in proper 

 relation to each other, viz: (1) the velocity and direction of 

 the wind per hour intervals, for six or more days, according to 

 the size of paper used; (2) the quantity, species, and sex of 

 mosquitos liberated, time and place of liberation and the color 

 used; (3) the quantity, species, sex, source and color of recovered 

 adults, and (4) the total mosquito catch in all buildings. A 

 simple system of cross-reference to data sheets containing 

 details will save time and energy. 



Tracing cloth, so ruled that the ordinates correspond to the 

 above form, can have recorded thereon the quantity and dura- 

 tion of rainfall, cloudbursts, fogs, barometric pressure, frosts, 

 etc. By superposition on the above tabulated form, the 

 relation, if any, of these factors to flight, will be seen. A similar 

 tracing, made to correspond to the map, should indicate the 

 extent of prairies, forests, forest fires, drainage, marshes, the 

 geology of the region, etc. 



Porcelain cup evaporimeters should be installed at many 

 stations to determine the relative humidity, 



2. Biotic Factors. 



Weekly or biweekly surveys of the entire area should be 

 made for the purpose of locating mosquito breeding areas. 

 These should be charted on smaller maps. If portions of this 

 area are oiled, treated with larvacides, or subjected to noxious 

 fumes, the extent of such pollution should be clearly indicated 

 on the maps. It is necessary to know the time interval from 

 oviposition to the adults for the species studied. When search- 

 ing for Anopheles, particularly the malaria-transmitter, a safe 

 rule is to go to unfrequented places, small puddles in grass 

 land, etc. 



Most mosquitos, particularly the blood-suckers, are most 

 active during and after dusk. It is evident, then, that an 

 investigator should be detailed for night observations. A 

 sweep-net should be used for beating the grass and shrubbery 

 for mosquitos, traps may be set out to intercept or attract 

 adults, or the observer may remain quiet, expose his arm, and 

 note the ferocity of the biting. 



The abundance or scarcity of such predacious animals as 

 dragon flies, robber flies, ants, toads, frogs, fish, bats, etc., 

 should be noted. Marked oscillations in the numbers of mos- 



