658 EXPERIMENT STATION RECORD. 



nicotin) 1 : 1,800. From 2 to 8 gals, of this combination spray should be applied 

 per tree, at a high pressure, and in a very thorough manner, as only thrips that 

 are hit VA'ill be killed. The spraying experiments have shown that 3 thorough 

 applications at the proper times result in from 20 per cent to 60 per cent more 

 " fancy " fruit in the sprayed as compared with the uusprayed blocks. 



Occurrence of Euthrips pyri in New York State, P. J. Parrott (Science, 

 n. ser., S-'i (1911), No. 86 J/, p. 04)- — The author reports the discovery of Euthrips 

 pyri in New York orchards. During the spring of 1911 specimens of injured 

 blossom clusters were received from Germantown and other localities along 

 the Hudson Eiver. The peculiar blighting of pear blossoms in various localities 

 in the State during the past several years, which has been attended by con- 

 siderable loss in the fruit yields, is thought to have been due to this pest. 



Tests which have been conducted indicate that the thrips may be effectively 

 combated by slight changes in the scheme of spraying which the author is 

 encouraging growers to adopt for the control of the pear psylla. 



The pear psylla, P. J. Parrott (West. N. Y. Hort. Soc. Proc, 56 (1911), pp. 

 73-82, figs. 6). — The year 1910 is reported to have been notable for the over- 

 whelming invasion of pear orchards in western New York by this insect. By 

 midsummer the foliage of most of the pear orchards was scanty, blackened, and 

 badly discolored. In some instances the fruit dropped and failed to mature, 

 thus reducing the yield. 



Observations made at Lockport showed the adults to be appearing on March 

 26, eggs being laid on April 2 and hatched on April 19. On the basis of obser- 

 vations and experiments, the author considers the most practical preventive 

 and remedial measures to consist of (1) clean culture, (2) removal and de- 

 struction of the bark of trees on which the pest is hibernating, (3) spraying of 

 trunks and large limbs with miscible oil, kerosene emulsion, or whale-oil soap 

 to destroy those that are hibernating, (4) spraying of trees just before the 

 leaves appear with lime-sulphur wash to destroy eggs, and (5) spraying of 

 trees with kerosene emulsion, whale-oil soap, or tobacco extract at summer 

 strengths to kill newly hatched nymphs. 



The cabbage aphis (Aphis brassicae), G. W. Herrick and J. W. Hungate 

 (New York Cornell 8ta. Bui. 300, pp. 717-746, pis. J,, figs. 5).— The cabbage 

 aphis, which is of European origin, found its way into this country more than a 

 century ago and is now a pest throughout the United States, having been de- 

 scribed in the bulletins of 23 state experiment stations. In 1890, 1903, and 

 1908 it was very numerous, widespread, and destructive in New York State, the 

 year 1903 being particularly an aphis year. More inquiries were received by 

 the Cornell Station in 1909 and 1910 regarding this aphis than any other insect 

 pest. 



"Aside from cabbages, this aphis attacks and injures turnips, cauliflowers, 

 Brussels sprouts, rape, kohl-rabi, collard, kale, and broccoli. It is often found 

 on the seed stalks of radish, and it frequently destroys seed stalks of cabbage. 

 In addition to these, it has been found on shepheixi's purse, field cress (Isatis 

 tinctoria), white mustard (Brassica alha), charlock (B. [Sirxtpis} arvensis), 

 black mustard (B. nigra), wild radish (Baphanus raplianistrvm), B. fructu- 

 losa, B. adpressa, and Dlplotaoois tenuifolia." The authors' observations lead 

 them to conclude that while it is possible that this aphis may have an alter- 

 nate food plant, it does not always depend upon it. 



Studies of its life history, which are reported in detail, include technical 

 descriptions of the several forms. The authors found that there were 30 

 generations in approximately 1 year with an average for each generation of 

 12* days. There may be 16 generations from March 31 to October 2, and all 

 of these may be born in the field in some seasons. It was found that 1 female 



