New York Agricultural Experiment Station. 613 



patches. If they were confined to onions and cabbages as food 

 plants, it would not be necessary to spray so often, in fact, it 

 would be cheaper to spray the whole field once or twice; but, as 

 they are not, the method of using set-onions will prove to be the 

 cheaper. 



This pest did not occur in destructive numbers on the Orange 

 county onion fields. 



Red Spider. 



Early in June, 1896, I received a letter from Mr. W. D. Barns, 

 of Middle Hope, N. Y., stating that the young upper shoots of 

 the raspberries were being destroyed by an aphis, or by a 

 spider. Later in the season he sent us some of the infested 

 leaves. The trouble proved to be the work of the grayish-green 

 form of the " Red Spider " {Tetranychus telarius, var,). 



This pest has surely been on the increase on out-of-door plants 

 for the past three or four years. Whether a series of compara- 

 tively dry seasons has favored their increase or whether some 

 other conditiohs foster them, is a question. 



Spraying with kerosene emulsion was recommended by some of 

 the fruit-growers in the vicinity of Middle Hope. The emulsion 

 would undoubtedly work well on some plants, but with this sub- 

 stance it would be a hard matter to reach the spiders on the 

 leaves of raspberries, for the simple reason that the spiders are 

 too well protected by the rough, hairy surface of the raspberry 

 leaves. The kerosene emulsion was undoubtedly the best rem- 

 edy that could have been applied at the time the trouble was 

 first discovered, June 10. 



From what has been seen of the habits of this pest, it is believed 

 that the majority of their winter eggs are deposited on the leaves 

 instead of on the stems, as is the habit of the true "Red Spider." 

 Careful examination of raspberry canes from infested fields, 

 kindly furnished in December, 1896, by Mr. C. Gr. Velie and Son, of 

 Marlborough, N. Y., showed no trace of the eggs on the canes. 

 They have been observed the latter part of April under oak and 

 chestnut trees, swarming over the grass and ascending the trunks 

 of the trees. 



