140 THE MONTANA EXPERIMENT STATION 



planation of the presence of these cutworms in the central portions «_-f 

 large fields. It is well known that the moths do not deposit their 

 eggs on the bare soil. Only two possible explanations seem to be left, 

 namely, that the young caterpillars hatched in the edges of the fields 

 and crawled in, or that the eggs were laid on the young grain in 

 the fall. From dated specimens in our collections at the experiment 

 Station, while not probable, it seems possible that eggs of this species 

 might be laid in abundance as late in the fall as the grain was up 

 and grown to sufficent size for the moths to lay their eggs on it. 



7. Did you notice an unusual number of moths or "millers" 

 about your house or in the grain field during or about September? 



Nearly all answered, no. 



8. Do you irrigate? 



All answered that they do not irrigate grain fields. To our cer- 

 tain knowledge, however, other fields not covered in these replies 

 were more or less affected with the army cutworms. 



SEASONAL HISTORY 



In the fall of 1906 the caterpillars, while very uneven in size, 

 grew to be about half an inch in length on an average. Warm, grow- 

 ing weather continued until unusually late that season and the cater- 

 pillars were so numerous, and, on account of the warm weather, 

 continued to feed so long, that a good deal of grain was eaten. While, 

 generally, cutworms do not make their presence known until spring, 

 in this instance it was known during the fall all through the infected 

 region that the cutworms were there and that damage might be done. 

 When cold weather set in, the caterpillars ceased to feed and re- 

 mained dormant until the spring. Anxious farmers went out in the 

 winter and dug up specimens from under the snow and. on taking 

 them into a warm room, found them to be as lively as ever. With 

 the first starting of vegetation in the early spring the caterpillars 

 were again active and feeding. It would be difficult to state on just 

 what date they began to feed. On southern exposures and in warmer 

 spots the vegetation would naturally start earlier and, correspond- 

 ingly, the cutworms would be active earlier. On the occasion of a 

 visit to the infested wheat fields on the foothills north of Belgrade 

 on April 13. a quantity of the larvae were brought back to the in- 

 sectary to be reared to the adult stage. On that date none were to 



