MOSQUITOS OR CULICIDAE OF NEW YORK STATE 259 



by drainage, sealing, supplying small fish which will feed on the 

 wrigglers, in case this is possible, or treating the surface with 

 kerosene or other oil. 



It will usually be necessary to supplement the above measures 

 by carefully screening dwellings, so as to exclude the few remain- 

 ing insects. This is particularly important in the case of Ano- 

 pheles, because of its disease-carrying possibilities. Living mos- 

 quitos may be stupefied in closed rooms by burning pyrethrum 

 powder, which should be moistened somewhat and molded into 

 little cones and then dried in the oven. These cones may be 

 lighted at the tip and will then smolder slowly, filling the room 

 with a not unpleasant smoke which appears to stupefy the mos- 

 quitos. It is said that two or three of these cones will give relief 

 during the entire evening, provided the windows are closed. Dr 

 Howard also calls attention to the modification of a device fre- 

 quently used for catching house flies. It is nothing more than a 

 tin cup or inverted can cover nailed to a stick and containing a 

 small quantity of kerosene. It is pushed up under a mosquito 

 resting on the ceiling, and as the insect attempts to fly it is caught 

 by the oil and destroyed. Such a device would be very convenient 

 if used in the early evening, to rid sleeping chambers of the pests. 



Salt marsh and other wild mosquitos. Mosquitos belonging to 

 this group are usually troublesome only in the vicinity of the 

 seashore, and the common salt marsh mosquito, u 1 e x s o 1 - 

 1 i c i t a n s , is by all odds the most serious pest of them all. 

 Acquaintance with its breeding habits has taught us that the 

 larvae occur usually within 100 to 250 feet of the shore, and that 

 they develop largely in places reached only by the higher tides, 

 numbers of eggs hatching after each high tide or heavy rain, 

 thus providing a series of swarms throughout the season. The 

 obvious thing is to either so ditch and drain that no pools will 

 remain after the retreat of high tides, or else by a series of dikes 

 exclude the tides and in this way render large tracts unsuitable 

 for breeding purposes. Extensive areas can be treated in this 

 way, and if diking is followed by proper drainage and reclama- 

 tion, many acres of land exceedingly valuable for agricultural pur- 



