298 Journal of Agricultural Research voi. xxn.No. 6 



the land has been reseeded the worms often attack sprouting grain and 

 sometimes even gnaw into the kernels before they germinate. 



The larvae feed during both day and night. Freshly cut plants 

 have been found repeatedly during the day and cutworms have been 

 found with their heads inside the sheath of the plant in the act of feeding 

 on the central stem. In the rearing boxes no difference could be noticed 

 between the amount of day and of night feeding. 



According to observations made by Strickland and reported by Gibson 

 (7) it is the habit of the larva — 



to travel over the surface of the soil and when a suitable plant for attack is found 

 it immediately burrows and feeds just below the surface. 



In our observations we have never vdtnessed this habit. Considerable 

 time has been spent during the late afternoon and evening in heavily 

 infested fields, and except in rare instances we have never seen Porosa- 

 grotis orthogonia larvse above ground. On the other hand, we have 

 closely examined hundreds of newly attacked plants where there was no 

 sign that the soil had been disturbed at the surface by the burrowing of 

 the larva. In order to find out whether the worms would work from 

 one plant to another without coming to the surface, wheat seedlings 

 were started 3 inches apart in a flat in the greenhouse, and when the 

 wheat was up about i inch 12 half-grown cutworms were placed in one 

 end of the flat. At the same time a line of plaster of Paris was placed 

 across the center of the flat so that any traveling of the worms over the 

 surface at the center would be indicated by lines through the plaster of 

 Paris. The seedlings at the end of the flat where the worms were intro- 

 duced were immediately attacked, and within a week all of the seedlings 

 in the flat had been cut off below the surface of the soil and without any 

 indication that any of the larvae had crossed the plaster of Paris line. 



If it were the natural habit of Porosagrotis orthogonia to travel over 

 the surface of the ground in getting from plant to plant, it would come 

 in contact with poisoned bran mash scattered on the ground, and it 

 seems as if there would be no difficulty in controlling it by the ordinary 

 methods. The fact that poisoned bran mash is useless against Porosa- 

 grotis orthogonia, together with our field and insectary observations, leads 

 us to believe that it very rarely comes to the surface in getting from one 

 plant to another but instead moves underground, generally along the 

 drill row. 



We have received occasional reports from farmers stating that pale 

 western cutworms had been seen feeding above ground during and im- 

 mediately following rains, but only one instance of this kind has come 

 under our own observation. This was at Willow Creek on June 27, 

 1920. A light thunder shower at 6.30 p. m. cooled the air and wet the 

 ground to the depth of i inch. As soon as the storm was over, numer- 

 ous cutworms were seen crawling over the surface in a wheat field that 



