245 



The results of investigations of Psylla pyricola for the last five 

 years are recorded, and have already been noticed [R.A.E., A, viii, 

 44; ix, 523, 525]. During 1919 apphcations were made wherever 

 honey-dew appeared on the lower surfaces of the leaves with 1 gal, 

 commercial liquid lime-sulphur to 40 gals, water, 1-5 lb. powdered 

 lead arsenate being added to each 50 U.S. gals, mixture. If the 

 weather was hot, self-boiled lime-sulphur was substituted. In some 

 cases attempts were made to meet hot weather conditions and prevent 

 scorching of foliage by reducing the strength of the liquid concentrate 

 by using 1 gal. to 50 or 60 gals, water. The liquid concentrate gave 

 the best results ; with self-boiled lime-sulphur the treatment had 

 to be much more thorough to kill as large a percentage. The lead 

 arsenate was added to control side-worm injury with excellent results. 

 The apphcation was made from below and at a pressure of 2501b. 

 During autumn, before all the leaves were off, the weather became 

 cold and the Psyllids were found cUnging to the twigs and branches, 

 which were sprayed with winter-strength soluble oil till the weather 

 became warmer. When winter finally came the pest had completely 

 disappeared, and this spray was again used when it reappeared in the 

 spring. 



Larvae of Cydia pomonella were observed entering apples at points 

 other than the blossom end during two distinct periods, one early 

 and the other late in the season. A prompt and thorough application 

 of an arsenical spray gave complete control until the coating was broken. 

 The three main problems for the control of Cydia pomonella in New 

 Jersey appear to be concerned with the comparative value of the three 

 sprays usually recommended for its control ; the type of material 

 and the method of its application ; and the finding of a relation between 

 the time that the spray should be appHed and the development of 

 the trees. The author considers that the three sprays are absolutely 

 essential. Lead arsenate is the best insecticide. Experiments were 

 made to test the relative value of dusts and sprays. Though the former 

 can completely cover the foliage and fruit, they are not so effective 

 as spraying, as they do not stick. Data for the present season on the 

 third problem are not yet available. 



The various experiments undertaken each year since 1913 with 

 insecticidal dusts are recorded, and the conclusions arrived at are that 

 lead-arsenate-sulphur-lime is a satisfactory substitute for self-boiled 

 Hme-sulphur for the control of curcuho, scab and brown rot of peach. 

 The lead-arsenate-sulphur dust, in view of its relative failure to effect 

 control of codling moth and plum curculio, cannot be considered a 

 satisfactory substitute for present well-known sprays in the control of 

 these insects on apple. A thorough investigation should be undertaken 

 to find forms of dust that will stick to apple fruit and foliage as well 

 as or better than liquid mixtures. 



Peterson {\.). A Preliminary Report on the Use o! New Mechanical 

 Protectors for the Control of the Peach Tree Borer, Sanninoidca 

 exitiosa. Say. — Rept. New Jersey Agric. Expt. Sta., 1919-20, 

 New Bnmsimck. N.J., 1921, pp. 461-468, 2 plates, 1 table. 

 [Received 9th March 1922.] 



A description is given of new mechanical protectors and experiments 

 with them for the control of Aegeria [Sanninoidea) exiliosa (peach 

 tree-borer). These were devised as a substitute for the tarred paper 

 collars, which have not effected complete control. 



