180 



with rapid and wide variations in temperature. The cold seemed 

 to have no detrimental influence on the eggs of the green apple aphis 

 ( Aphis pomi), which was very abundant in some apple orchards, 

 reaching its maximum destructiveness about 15th July. Spraying 

 was begun too late to be really effective. The conclusions reached 

 as a result of organised effort to combat this Aphid are that infestation 

 is generally severest in plantings with considerable succulent growth 

 on trunks and large limbs, or where the orchards adjoined or were 

 interplanted with young trees. In regions where this pest is annually 

 destructive, or where infestation is expected, reliance should be placed 

 on a delayed dormant treatment with lime-sulphur and nicotine 

 sulphate, with a supplementary spraying during midsummer of 

 nicotine sulphate and soap if the Aphids threaten to develop in 

 destructive numbers. 



While lime-sulphur solution and lead arsenate will probably continue 

 to form the bulk of the insecticides to be applied to fruit trees, a good 

 deal of interest is being aroused in calcium arsenate, which has fre- 

 quently been found a satisfactory substitute for lead arsenate and 

 is economical in use. There is much, however, yet to learn with respect 

 to its manufacture and its effect on orchards under New York con- 

 ditions. Only reliable brands should be used, and manufacturers' 

 directions should be followed ; for the commoner chewing insects 

 the spray recommended is fib. dry calcium arsenate to 50 U.S. 

 gals. Bordeaux mixture or lime-sulphur solution with 2 or 3 lb. of 

 slaked lime. 



The use and abuse of spray-guns is discussed. The use of dry 

 substitutes for lime-sulphur solution is increasing, and attention is 

 called to several points to be considered in using the various sulphides 

 and polysulphides now on the market. A table shows the dilution 

 required for several of the more widely advertised dry sulphur 

 preparations. Soda and potash-sulphide sprays have proved in the 

 station experim.ents more caustic to opening buds and leaves than 

 lime-sulphur or barium-sulphur preparations. As a general rule, 

 arsenicals should not be used with the former sprays, owing to 

 foliage injury. 



x^gainst San Jose scale the sulphides and polysulphides of different 

 bases, when used with similar ratios of sulphur, have proved equally 

 effective. Dilutions of one-half the strength at present recommended 

 showed a high rate of toxicit^^ In view of the high price of lime- 

 sulphur, a dilution of one gallon of the concentrate to 15 gals, of water 

 may be relied upon where the spraying can be done thoroughly or 

 where the pest is not serious. 



Felt (E. P.). European Corn Borer. — Proc. 1st Ann. Meeting N.Y. 

 Hortic. Soc, 1919, pp. 216-218. [Received 10th February 1921.] 



An account is given of the European corn borer [Pyransta nubilalis] 

 as occurring in Massachusetts [R.A.E., A, vii, 224; ix, 132, etc.], 

 and the danger of its spread is emphasised. 



Crosby (C. R.). The Control of the Apple Redbugs. — Proc. 1st Ann. 

 Meeting ^\Y. Hortic. Soc, 1919, pp. 220-221. [Received 

 10th February 1921.] 



The most injurious species of redbug in New York State is Lygidea 

 mendax, which usuallv hatches while the trees are in blossom. The 



