464 



Parrott (P. J.) & HoDGKiss (H. E.). The Status of Spraying 

 Practices for the Control of Plant Lice in Apple Orchards. — New 



York Expt. Sta., Geneva, N.Y., Bull. no. 402, April 1915, 

 pp. 193-210, 2 figs., 2 plates. 



The foliage and fruit of apple trees in New York are subject to attack 

 by Aphis pomi, A. sorhi and A. avenae. Experiments in recent years 

 indicate that the most effective and satisfactory means of protecting 

 the young fruit is the destruction of the aphids on the expanding buds. 

 The best spraying mixtures are nicotine solution, oil emulsions or 

 soap preparations. The physical features of the locahty of the orchard 

 have a marked influence on the development of the buds. The time 

 for effective spraying will therefore vary with individual orchards, 

 as well as with different varieties of apples. The following periods 

 in the life-history are susceptible to attack by spra5ang mixtures : — 

 The egg- stage, the time of hatching and collecting on the green ends 

 of the opening buds, the time of maturing of the stem-mothers and 

 the first appearance of their young, and the occasion of the appearance 

 of autumn migrants and egg-laying females on apple trees. The eggs 

 of the green aphis are destroyed to some extent by lime-sulphur 

 preparations and oil emulsions. Newly hatched lice are very suscep- 

 tible to spraying mixtures, while the leaves and flowers are protected 

 from injury in the partly opened buds. Late spraying for stem- 

 mothers and their young often proves unsatisfactory owing to the 

 curled state of the leaves at this period. The destruction of autumn 

 migrants is attended by practical difficulties, but theoretically, should 

 prevent the deposition of eggs for the next year. As a result of experi- 

 ments carried out in 1913, it was found that a thorough spraying with 

 lime-sulphur and nicotine solution at the time when the buds were 

 showing green at the ends was most effective. Spraying just before 

 flowering had no appreciable effect. Applications made 10 days after 

 blossoming did not give satisfactory results because of the stunted 

 condition of many young apples, the extent of curling of the leaves, 

 and the numbers of aphids which escaped the spray. 



Surface (H. A.). Spray for the Apple Aphis now. — Zool. Press Bull, 

 Div. of Zoology, Pennsylvania Dept. Agric, Harrisburg, Pa., 

 no. 313, 26th April 1915. 



Apple trees should be sprayed during April for Aphis pomi and San 

 Jose scale {Aspidiotus perniciosus), with dilute lime-sulphur solution. 

 The spray should be in the proportion of 1 part concentrate to 10 

 parts water. If spraying is not done until after the leaves have been 

 curled by the aphis, a nicotine solution must be used. For cherry 

 aphis, a solution containing 1 part concentrate to 50 parts of water 

 should be used. 



Stewart (V. B.) & Leonard (M. D.). The R61e of Sucking Insects 

 in the Dissemination of Fire Blight BsiCtena.—Phytopatholo^, 

 Baltimore, Md., v, no. 2, April 1915, pp. 117-123. 



While all insects which occur on host plants are responsible for 

 carrying the fire bfight organism, Bacillus amylovorus, from plant to 



