212 



their consumption by cutting or shredding before the mild weather of 

 the next spring. Silos should be more generally utilised in the infested 

 area, as the borers are unable to withstand the heat generated by 

 fermentation. 



Hartzell (F. Z.) & Strickland (L. F.). Plant Lice Injurious to Apple 

 Orchards : in. The Delayed Dormant Spray Jor the Control of 

 Rosy and Green Apple Aphids. — New York Agric. Expt. Sta., 

 Geneva, N.Y., BuU. 487, April 1921, 41 pp., 1 fig., 4 plates, 

 12 tables. [Received 23rd February 1922.] 



This paper deals with the continuation of experimental work on 

 the delayed dormant spray for the control of Aphis sorbi, Kalt. (rosy 

 aphis) and A. pomi, DeG. (green apple aphis) [R.A.E., A, iv, 273; 

 V, 328]. 



The life-history, habits, food-plants, nature of injur}^ and the 

 economic importance of A. pomi are discussed [cf. R.A.E., A, iv, 

 484 ; viii, 17, etc.], and the measures essential to adequate control, 

 such as proper pruning, the use of a mixture toxic to the insect, and 

 the proper time and application of the material are described. 



Freezing temperatures occurred on the 24th and 25th April 1919, 

 and destroyed so many of the Aphids that no conclusive data can be 

 secured from the spraying experiments of that year. The experi- 

 ments undertaken in 1920 are given in detail, and the results are 

 tabulated ; from these the following conclusions have been arrived 

 at : — Comparisons between counts made in the spring and those in 

 the summer show clearly that the extent of the season's infestation 

 cannot be predicted from the number of Aphids present just after 

 the eggs have hatched. The pest can be controlled for the entire 

 season by means of the delayed dormant spray, consisting of 2J gals, 

 lime-sulphur, f pt. nicotine sulphate, and 100 gals, water. If 

 San Jose scale is present, the lime-sulphur should be increased to 

 11 gals. The spray should be thoroughly applied when the young 

 leaves of the terminal buds have protruded about half-inch. If 

 summer migrants heavily infest the trees, a midsummer appHcation 

 of nicotine and soap may be required in addition [R. A.E., A, viii, 29]. 

 The pressure should not fall below 200 lb., and 400 lb. is even better. 

 The lower surfaces of the branches and leaves must be reached. A con- 

 siderable amount of material is necessary for large trees, and with 

 mature trees this varies from 7-^ to 14J U.S. gals. 



Department of Entomology. — 34th Ann. Rept., 1920-21, Purdue Univ. 

 Agric. Expt. Sta., Lafayette, Indiana, 1921, pp. 22-23. [Received 

 23rd February 1922.] 



The peach-tree borer [Aegeria exitiosa] occurs throughout the State 

 and is probably increasing. During the spring of 1921 experiments 

 with paradichlorobenzene gave almost 100 per cent, control, and it 

 is hoped this method will become more generally adopted. 



The cabbage or radish maggot [Phorbia brassicae] may be successfully 

 controlled by the application of corrosive sublimate in solution, two 

 applications being required for cabbages and cauliflowers. It was 

 apphed at the rate of 1 oz. to 10 U.S. gals, of water, or as a dust forming 

 a 1 per cent, dust mixture with gypsum or hydrated hme. One treat- 

 ment with the liquid was effective against this fly on radishes. 



