326 



nicotine dusts controlled the Psyllid with equally good results, when 

 the application was comparable, but that the lime dust covered better. 

 Spraying \\ith 2h U.S. gals, lime-sulphur. 50 lb. hydrated hme, 

 1 U.S. "pt. nicotine ""sulphate and 100 U.S. gals, water at a pressure 

 of 3001b., an average of 5-3 U.S. gals, being used per tree, gave 

 a killing efficiency of 98-7 per cent., which is practically what was 

 reported in the previous year [R.A.E., A, x, 211]. These experiments 

 were made to prove the" number of appHcations necessary each year 

 to control P. pyricola. The conclusions arrived at are that a heavy 

 lime-nicotine spray, when thoroughly applied at the proper time, 

 will kill 98 per cent, or more of the hrst brood. If the orchard is not 

 isolated serious reinfestation will occur. It is beHeved that a single 

 apphcation in an isolated orchard will protect it for the entire season, 

 if made as soon as the eggs have hatched and before any adults have 

 emerged. An instance is given of an attempt at dusting for nymphs, 

 but it was not sufficiently successful to be recommended to growers. 



Strickland (L. F.). Co-operative Experiments with Lime-nicotine 

 Dust against Hard Shell Nymphs and Adults.— P/'oc. 67th [4th] 

 Ann. Meeting N. Y. State Hortic. Soc, Rochester, N. Y., 1922, 

 pp. 55-65, 5 tables. 



Experiments are described on the killing power of lime-nicotine 

 dust on hard shell nymphs and adults of the third generation of the 

 pear psylla [Psvlla pyricola], and the results are tabulated. The 

 value of drifting dusts is discussed, and redusting operations described. 

 Data on the study of the migrations of the first and second brood 

 adults show that the migration of the second brood is relatively limited. 

 Investigations also indicate that the quince is preferred as a food-plant 

 to plum, apple and peach. In any operation in the control of this Psyllid 

 the condition of the trees shows whether the application has been 

 successful. If even a very small area of green surface escapes treatment, 

 hundreds of nymphs and adults will remain untouched. The trees 

 should be moderately low-headed and the branches properly spaced. 

 A heavy lime-nicotine spray should be directed against the first and 

 second brood n\^mphs, or an application of lime-nicotine dust should 

 be made for the hard shell nymphs and adults of the first or second 

 generation. 



Strickland (L. F.). Control of Codling Moth in Western New York. 



Proc. 67th [4th] Ann. Meeting N. Y. State Hortic. Soc, Rochester, 

 N. Y., 1922, pp. 65-73, 3 tables. 



For several years it has been felt that the usual strength of 2|lb. 

 lead arsenate to each 50 U.S. gals, of spray is not sufficient to kill 

 the young larvae of the codling moth [Cydia pomonella] when they 

 are emerging from the eggs and before they get through the skin to 

 enter the apple. Experiments are described of spra>ing orchards 

 in the calyx period and again when oviposition was known to be 

 definitely started. The calyx application was made as soon as all the 

 petals had dropped with the usual formula, but the second application 

 contained 51b. of lead arsenate (instead of 2^) to each 50 U.S. gals, 

 of material. There was a very marked reduction in the total number 

 of apples injured, but as there was only a slight infestation in 1920, 

 partly owing to a parasite, Trichogramma rninutmn, and to the 

 season, further data are necessary. 



