38 NEW YORK STATE MUSEUM 



In addition to the parasitic flies mentioned above, there are a 

 number of four-winged parasites which render material aid in check- 

 ing this species. . Predaceous beetles, especially the common ground 

 beetles and their voracious larvae, are sometimes abundant and 

 destroy many of the pests. 



Native insectivorous birds are also valuable allies in controlling 

 this pest. The chipping sparrow, English field sparrow, song spar- 

 row; robin, flicker, bluebird, blackbird, kingbird, cowbird, catbird, 

 pheasant, yellow-legs and upland plover, being recorded ^ as feeding 

 upon army worms; the robin being considered one of the most 

 efficient. Mr A. C. Weeks of Brooklyn cites in the local press ^ one 

 case in which birds quickly cleared an infested field. Poultry and 

 toads are also credited with devouring many of the caterpillars. 



A deadly bacterial infection sometimes destroys large numbers of 

 the pests. Unfortunately the efifectiveness of this disease appears to 

 be very dependent upon favorable climatic conditions and is there- 

 fore of limited value. 



Adverse climatic conditions have an important infiuence and it 

 has been held that a dry season followed by a wet one is likely to be 

 an army worm year, though probabilities based upon any such data 

 must of necessity ignore the extremely valuable services rendered by 

 natural enemies. It is very likely that large numbers of the insects 

 succumb to the rigors of our winter climate, otherwise the first brood 

 of the caterpillars would probably be more injurious than later genera- 

 tions, owing to the smaller amount of forage available in the spring. 



Control measures. Clean culture, which in this instance means 

 the elimination of walls, brush and stone piles with their usual margin 

 of coarse, rank vegetation, is an important step in discDU aging 

 oviposition by the moths and thus preventing an oubreak. 



Little can be done to save a field generally in.esced with army 

 worms, aside from cutting and harvesting the crop at once in order 

 to prevent further injury. 



It is important to meet an outbreak at its inception. In early 

 July it is not a difficult task to find the caterpillars some days before 

 they are usually seen. The thickest portion of a field should be 

 examined for their small, black or brown droppings and injury to the 

 lower leaves of the grass or grain. If these signs of injury a'e present, 

 the army worms may be found hidden under loose shelter of any 

 kind on the ground or just below the surface. Knowing the con- 

 ditions it is then comparatively easy to decide whether or not to cut 



^ 1914 Fernald, H. T. Mass. State Board of Agric, Cir. 22, p. 11. 

 2 1914 Brooklyn Daily Eagle, Aug. 6, p. 3. 



