2G6 BOARD OF AGRICULTURE. [Pub. Doc. 



The natural breeding place of the army worm is said to be 

 on the ])orders of swamps, where the grasses common to such 

 places furnish suitable food for the insect, and from 

 such localities in favorable years large numbers emerge 

 to bring devastation upon surrounding fields. 



There has been considerable controversy among en- 

 tomologists concerning the number of annual broods of 

 this insect. In the southern sections of the United 

 States there are, according to Prof. L. O. Howard,* 

 possibly as many as six annual broods, while in New 

 England there are undoubtedly two broods yearly. 

 This last statement may not hold true for the cranberry 

 region of Cape Cod, where the army worm frequently 

 causes much damage. From studies made on the Cape 

 during 1894 Mr. C. P. Lounsbury f came to the con- 

 clusion that the insect was there probably single- 

 brooded. 



The question of the stage in which the army worm 

 passes the winter has an important bearing upon the 

 number of annual broods. It is generally conceded that 

 in this region the insects pass the winter as partially 

 grown caterpillars (from the fall, or second, brood), 

 which attain their full growth the following spring, 

 transform and give rise to moths which lay their eggs 

 in grass and grain. 



These views concerning the number of annual broods 

 and the question of hibernation find additional support 

 in a peculiar feature of the outbreak of this season. 

 Many of the fields worst damaged by the insect were 

 those sown in the spring of this year. I found during 

 the first week in July innumerable small larvae not 

 over one-third to one-half an inch in length scattered 

 throughout these spring grain fields, and at a greater 

 distance from grass lands than these diminutive insects 

 could possibly have travelled. Clearly then the eggs 

 from which these insects came must have been laid in 

 the grain fields by moths emerging from the hibernat- 

 ing brood of the previous season . 



\j * Circular No. 4, 2d series, U. S. Dept. A^r., Div. of Entomology, 1894. 

 Fig. 3. t Bulletin 28, Hatch Experiment Station, 1895. 



