ENTOMOLOGICAL SOCIETY OF ONTARIO. 



The eggs hatch in about a week after being laid. The young caterpillars, in the first 

 stage, can drop by means of a thread, and move -with a loop-like motion. At this time, 

 they are of a light greenish color, and thus resemble the plants on which they fef d, and 

 escape the notice of their enemies. The larva passes through five moults, at intervals of 

 three or four days until it reaches the sixth stage, and is fully developed in about four 

 weeks. The caterpillar is about one and a half inches in length, of a dark gray color, 

 with blackish stripes, and numerous white lines along the back. In many specimens ex- 

 amined by the writer, comparatively few were light colored, until about the close of the 

 attack, and then, the light ones were much more common. Some claim that the dark color 

 is due to exposure. The length of time before complete development of the larva is 

 reached depends a great deal upon temperatuie, and may vary from 16 to 28 days. 



The mid-summer brood usually takes a shorter time than that of the fall. During 

 the day they avoid the rays of the sun by hiding under clods, pieces of boards, chips, etc., 

 and about 5 p. m. they emerge to feed. 



In making observations about noon with Mr. Reavley near Marshville, we were sur- 

 prised that so few worms could be seen at that hour, in a field badly attacked. 



But on turning over sods among the cats, we found them in great numbers. We 

 counted over 30 occupying a space no larger than the hand, and, in some parts, more 

 than 50 to the square foot. 



In a small patch of late oats on the Reavley farm scarcely a blade was left. The 

 worms abandoned the ripening oats near by, and congregated upon the patch of late oats, 

 no doubt, because they were more succulent. 



Every stalk had from one to five worms upon it, and many were eaten to within 

 three inches of the ground. They feed chiefly during the night, and sometimes in cloudy 

 weather. Where they are in great numbers, they make a peculiar sound, which can be 

 heard distinctly, while they are feeding, and cutting off the stalks and heads of grain. 

 Under ordinary conditions, they do not travel, but live much as many other species of 

 the cut worm family do (Noctuidae) to which they belong feeding by night, and hiding by 

 day. However when food becomes scarce, they then undertake to march for new feed- 

 ing grounds. 



They stop at no obstacle, death only will make them halt. A piggery at the college 

 impeded their progress for some days. They never attempted to go around it, but in vain 

 tried to scale its walls, and kept constantly dropping, yet always ready to try the ascent 

 again. 



From observations made, as to this rate of travel, while crossing the lane between 

 two fields they were seen to move two feet a minute (40 yards per hour.) 



With us they usually appeared active from 4 o'clock p. m., and after that continued 

 to move in great numbers, in all directions, and not in a definite line of march. While 

 feeding, they devoured the leaves and then nipped off the head, which falling to the 

 ground was no longer touched. In attacking some bearded wheat they nibbled off the 

 awns, and only partially fed upon the grain. Oats, timothy, wheat, rye, and barley are 

 their favorite plants ; they also feed readily on corn, if young and tender ; but they 

 seem to have no inclination for any plants not in the order gramineae unless forced by 

 hunger. In a hay field, they will leave the clover and devour every plant of timothy. 

 Several of our fields had excellent crops of young clover ; these were left untouched, while 

 the oats and wheat were continually fed upon. In bringing some caterpillars from Humber- 

 stone, pea plants were put in the box with them for food, but they were scarcely touched 

 in two days. 



The following are results reached during our observations regarding the plants upon 

 which they (eed, oats, barley, wheat, and corn they readily devoured. 



Clover. This was eaten very sparingly and was left if wheat or oats were intro- 

 duced into the boxes containing caterpillars. Clover was put in the boxes on Mon- 

 day, by Tuesday night it was hardly touched, but they began to feed upon it on Wednes- 

 day. They ate it n only when nothing more attractive was obtainable. 



