Eighth Report of the State Entomologist. 



189 



cut- worm, Agrotis ypsilon (Rott.) — one of our most abundant species, 

 common almost everywhere over the United States and Canada, and 

 occurring throughout Europe, in the East Indies, the Hawaiian islands, 

 and elsewhere. [The caterpillar and the 

 moth thit it produces are shown in 

 Figure 36.] A peculiarity of this species, 

 and one that would seem to add to the 

 amount of injury that it may cause the 

 onion grower, is the unusually long time 

 that it is present with us. It is almost 

 the 'earliest of the Agrotis species to make 

 its appearance in the winged state. I have 

 taken it as early as May 30th, and in col- 

 lections made by me " at sugar," have 

 observed it every night through the 

 months of June, July, and August, over 

 half the nights of September, and con- J^'^.^^^^^'i^^lXZ^l^^^^l^^^. 

 tinning until the last week of October. °^ ^^'^^^ <^' ''^^ '"°*^- CAf ter miey.) 

 This would seem to indicate that its caterpillars are in the ground 

 and continue their depredations through most of the spring and 

 summer months. Whether this is the result of a long period of 

 egg-laying of the moth, giving us the caterpillars at various stages of 

 growth throughout the season, or if there are two or more ovei'lapping 

 broods, we are unable to say. Of some of the cut-worms, we could 

 safely predict that they would disappear from view and their injuries 

 cease within a limited time — a week or two, — but of the black cut- 

 worm, no such gratifying prediction can be made. It may speedily disap- 

 pear or its trouble may continue for several weeks longer. The size of 

 the worms at present will enable you to form some opinion of their future 

 operations. Those sent me are nearly full-grown. If nearly all are of 

 this size — an inch and one-fourth in length when at rest — I would 

 expect that their work would cease within two weeks from this time, 

 when they should stop feeding, bury in the ground and form a cell for 

 their pupation, from which they would emerge later as the winged 

 moth. But if many of the larvae are still small, you would be com- 

 pelled to look forward to a longer battle with them. What shall be 

 done with them to stop their ravages ? This is the important question 

 with the onion growers. 



If I am able within a few days to go and look over the ground, I 

 will do so, for then I could give you better advice. In the mean time 

 I will suggest some means which, from the known habits of cut-worms, 

 should afford very material relief. I presume that they feed mostly at 

 night and spend the day within the ground near the plants at about an 



