No. 4.] 



THE AiixMY ^^'ORM. 



271 



Fig. 6. 



and, if properly done, without dan<ier to stock feeding on 

 the stover. Where the army Avorm is particularly abundant 

 it may be advisable, in order to prevent migration, to spray 

 grass land or to burn 

 over the fields at 

 once. For this lat- 

 ter purpose the " Cy- 

 clone burner" (Fig. 

 G), originally de- 

 signed for burning 

 l)rush land infested 

 by the gypsy moth, 

 will be found of 

 value. It may be 

 made by mounting a 

 small force pump on a ten or fifteen gallon tank, and con- 

 necting the pump by means of a short piece of oil hose with 

 a one-half-inch iron pipe at the end of which a cyclone nozzle 

 may be attached. The pipe should be about ten feet in 

 length and have a wooden casing for convenience in hand- 

 ling. The tank should be filled with cheap crude oil. The 

 oil is forced out at the nozzle, and 1)y igniting the spray at 

 the nozzle a flame results, which destroys every living thing 

 with which it comes in contact. The cyclone burner may 

 also be used to good advantage for destroying worms col- 

 lecting in the furrows. 



On cranberry bogs Mr. Lounsbury * recommends wide 

 water-filled ditches as the best means of checking the spread 

 of the insect. 



Natural Exemies. 

 Among the natural enemies of the army worm, birds are 

 entitled to chief recognition. It is a well-known fact that 

 smooth-skinned larvae form a favorite article of the diet of 

 insectivorous birds, and a field infested by army worms 

 makes a feedins: o-round to which the birds assemble from 

 considerable distances, and there find food for themselves 



cal compounds now in use. Further experimentation, however, and, more partic- 

 ularly, the practical use of the poison on a large scale in the field, will be necessary 

 to accurately determine its value. 

 * Bulletin 28, Hatch Experiment Station, isa"). 



