188 Forty- fifth Report on the State Museum. 



A New Onion Pest, Agrotis ypsilon (Rott). 

 The following editorial notice in the Canastota [N. Y.] Journal, of 

 June 20th, 1891, refers to a new insect pest that had recently made its 

 appearance and was the occasion of considerable alarm: 



Onion growers in the vicinity of Canastota are dismayed by the 

 appearance of a pest that is making fearful havoc in some of the onion 

 fields lying north and west of this village. The pest was first seen 

 about a week ago. Growers noticed that their onions were getting 

 thin and the plants appeared to be dying. Investigation, however, 

 disclosed the fact that the plants were being eaten by a voracious 

 dark-colored worm. The worms were of all sizes up to about one inch 

 and a quarter in length and the thickness of a lead pencil. They 

 seemed to work in spots, some parts of a field being overrun with 

 the worms while in other places no traces of the pest could be found 

 until they had migrated from the infested portions. Where they 

 appeared, they were very numerous and quickly ate all the vegetation, 

 including weeds. 



The muck land lying north of Canastota, and in the adjoining por- 

 tion of the town of Sullivan, is peculiarly favorable to the profitable 

 culture of onions, and great quantities of them have been raised during 

 the past five or six years. Hundreds of acres were sown to the fra- 

 grant vegetable this spring. Tne work of the worms will be of incal- 

 culable damage to the crop. The loss at present is estimated at 

 one-fourth of the total acreage. 



Examples of the caterpillar, as they proved to be, were received 

 from the editor, Mr. P. F. Milmoe, with request for their examination 

 and for aid in the emergency. Reply was returned, under date of 

 June 17th, as below: 



Editor of Journal. — Dear Sir: Yours of yesterday, informing 

 me of the severe attack in the onion fields of your vicinity, and accom- 

 panied by specimens of the depredator, is just received, and I send 

 immediate reply. 



These sudden outbursts of insect injury are not infrequent occur- 

 rences, and are often impossible to account for satisfactorily. On 

 reading your note, I confidently expected to find, in this instance, a 

 repetition of the attack made in the spring of 1885 upon the onion 

 fields in Goshen and vicinity, in Orange county, N. Y., whereby many 

 acres of onions were destroyed and serious losses inflicted, as described 

 in Prof. Riley's Report to the Commissioner of Agriculture for that 

 year (pp. 270-275), through the operations of the dark-sided cut-worm, 

 Agrotis messoria Harris. 



The examples you have sent me show it to be a different insect — a 

 cut-worm, but of another species. So far as I can determine from the 

 larval characters, which are somewhat variable, and show marked 

 differences of feature in the different stages of growth, this is the black 



