173 



In neither case was the mfestation as severe as that recorded by 

 Lind, Rostrup and Ravn [see this Review, Ser. A, iii, p. 698] in 

 Denmark. The beetles disappeared by the end of May and a second 

 brood was not observed. The attack occurred in both cases when 

 the plants were very young and at a stage when they are most likely 

 to receive a severe check. In view of the seriousness of the attacks 

 on spring-sown corn in Russia, it is advisable to watch for any 

 extension of this pest. 



Lees (A. H.). The Best Time for Lime-Spraying Fruit Trees. — Jl. Bd. 



Aqric, London, xxiii, no. 11, February 1917, pp. 1091-1095, 2 

 plates. 



It was formerly thought that the period just before the buds begin 

 to swell, or at first sign of swelling, was the best time for lime-spraying, 

 but subsequent experience has tended to suggest that a later period 

 is advisable. Eggs of the apple sucker [Psylla mali) begin to hatch 

 early in April, those of the rosy apple aphis {Aphis kochi) about 

 mid-April. The best results in the control of these two most 

 important apple pests are therefore obtained by beginning to spray 

 rather before 10th April. If ordinary lime mixture is employed, 

 consisting of 20 lb. hme to 10 gals, water, spraying should be as !ate 

 as possible before the eggs begin to hatch, since a coat of lime does 

 not remain effective for an unlimited time. As its action is mechanical 

 rather than chemical, its effectiveness depends upon there being a 

 firm coat over the twigs at the time the eggs hatch. Fresh Hme in 

 lumps of 98 per cent, purity should be used. In slaking, the mixture 

 should be allowed to get as hot as possible and this should be effected, 

 if possible, at least six hours before use, as this increases the adhesive 

 power. The diluted lime wash should be strained through a one- 

 sixteenth inch metal sieve and the mixture should be applied through 

 a machine and nozzle especially adapted for lime sprays. Experiments 

 to test the possible injury to plants by late spraying have shown 

 that lime-spraying may be carried out for apple trees up to the 27th 

 April, when the flower is nearly out ; though apples are occasionally 

 damaged by late spraying, the conditions under which damage occurs 

 are not yet fully understood. 



UossARD (H. A.l & Eastwood (G. R.). County Co-operation to control 

 Hessian Fly.— Mthhj. Bull. Ohio Agric. Expt. Sta., Wooster, i, 

 no. 8, August 1916, pp. 230-232. [Received 27th February 1917.] 



This paper indicates the results of the efforts made in Miami county 

 to reduce the Hessian fly {Maijetiola destructor) [see this Review, 

 Ser. A, iv, p. 194]. An inspection in November revealed no larvae 

 or pupae in the fields, though the plots on the County Experiment 

 Farm sown in September were practically destroyed. Large numbers 

 of larvae and pupae were however found in self-sown wheat in uncut 

 fields. An examination on 28th June 1916 showed better results 

 than had been anticipated, scarcely 5 per cent, of infestation occurring 

 in the worst fields. 



