28 



FIRST ANNU^AL REPORT OF THE STATE ENTOMOLOGIST. 



and are applicable to the protection of the Southern cotton fields. Sev- 

 eral of these " Dusting Machines " are described and figured in Bulletin 

 No. 3, of the U. S. Entomological Commission. 



Cost of the Dry Application. — It is estimated that for the protec- 

 tion of tiie potato crop, an acre will require three pounds of Paris green 

 and thirty or thirty-five pounds of flour. This, with the green at its 

 usual price of fifty cents a pound, will make the cost of each applica- 

 tion, without counting the labor, from 82 to 13. If the beetle is very 

 abundant, and the powder should happen to be washed away by fre- 

 quent and hard rains, three or four applications, or even more, may 

 be needed during the season. 



Application of the Liquid. — When but a few plants or small areas 

 are to be poisoned, no other appliances are needed than a small pail and 

 a brush-broom. With the latter in the right hand, the water, at each 

 dipping, may be sufficiently stirred to hold the green in proper sus- 

 pension, and the adhering liquid shaken over tlie plants. When a 

 larger amount of the liquid is necessary, it may be applied with an 

 ordinary watering-pot, provided with a more finely perforated rose than 

 that which commonly accompanies it, which can be made by any tin- 

 man. The contents of the pot will require frequent stirring with a 

 stick, to prevent the settling of the poison. 



For poisoning on a still larger 

 scale, cans of a large size to be 

 strapped upon the back have been 

 devised, and are for sale in some 

 of our principal cities. One of 

 these, shown in operation in Fig. 

 7, is thus described in Prof, 

 Eiley's Seventh Missouri Ileport 

 (1875, p. 15) : 



" It consists of a can capable of 

 lioldiDg about eigbt gallons of liquid, 

 and so formed as to rest easily on the 

 back, to wliicli it is fastened, knapsack 

 fasbion, by adjustable straps, winch 

 reach over the shoulders and fasten 

 across the breast. To the lower part 

 of the can are attached two rubber 

 tubes, which are connected with two 

 nozzles or sprinklers. The inside of 

 the can has three shelves, which help 

 to keep the mixture stirred. There is 

 a convenient lever at the bottom which 

 presses on the tubes and shuts off the 

 outflow at will, and two hooks on the 

 sides near the top oa which to hang the tubea when not in use. On the top is a 



Fig. 7. — Sprinkleii 

 green water. 



tor distiibutnij 



