1912.] PUBLIC DOCUMENT — No. 31. 17 



different fertilizers employed. The crop where nitrate of soda 

 is applied, indeed, showed a small average decrease. ]]oth acid 

 phosphate and high-grade snlfate of potash show a very small 

 average increase, — not in either case enough to cover the cost 

 of the fertilizer material applied. The resnlts of the year, 

 therefore, do not lend enconragement to the belief that the use 

 of fertilizers on bogs of as good productive capacity as that 

 belonging to the station will bo followed by a profitable increase 

 in the crop. It is important, however, to point out that the 

 a|)plication of fertilizers this season was not made until about 

 the middle of July. It seems probable that this is too late for 

 the best results. 



Dr. H. J. Franklin furnishes the following report concerning 

 some of his principal lines of investigation during the past two 

 years : — 



Cranhcrnj Investigations, 1910. 



I. INSECTS.* 

 Of the important cranberry pests heretofore known, those which 

 received attention were the fruit worm, tlie fire worm and the cran- 

 berry girdler. 



The Fruit Worm {Mineola vaccina (Riley)). 



Experiments in submerging- cocoons containino- larvfn of this in- 

 sect, for varying lengths of time during the fall of 1900 and winter 

 and spring of 1910, were carried on without very satisfactory results, 

 due, perhaps, to failure to perfectly imitate natural bog conditions. 



Spraying experiments were also carried on, the insecticides used 

 being mostly combinations of adhesives and arsenicals. The combina- 

 tion found most effective consisted of the following mixture in 50 gal- 

 lons of water : — 



Pounds. 



Resin fish-oil soap, 41/, 



Bordeaux mixture: — 



(a) Stone lime, .......... 4 



(6) Copper sulfat.o, ,3 



Paris green, ............ 1 



As the soap had adhesive and spreading qualities, and the Bordeaux 

 mixture gave body to tlie combination and also acted to some extent 

 as an adhesive, this combination spread over the smooth surface of 



• Dr. U. T. Fernakl has aided Dr. Franklin in the insect work in an advisory way, and for his 

 helpful sussestions Dr. Franklin acknowledges his indebtedness and expresses his appreciation. 



