April, '09] JOURNAL OF ECONOMIC ENTOMOLOGY I39 



hand, the unsprayed trees in one orchard (/. c, p. 15) had 74% and 

 95% good apples. Surely, it does not take extraordinary^ spraying to 

 secure 100% perfect fruit where 95% are perfect on unsprayed trees. 

 In the orchard showing the most perfect fruit four sprayings were 

 given, but there were no check trees left unsprayed. So far as we 

 can ascertain, this is the evidence by which the supreme efficacy of the 

 new methods is ''shown." In 1907, however, ]\Ielander and Jerme^^ 

 give the results of spraying sixty-three trees with various brands of 

 arsenate of lead in an orchard in which the unsprayed trees had but 

 42% good fruit. The trees sprayed four times had an average of 

 96.5% good fruit. A power sprayer and Bordeaux nozzles were used 

 in 1907, but nothing is said about the efficacy of thorough work at 

 the time of the first spraying. However, 96.5% good fruit were se- 

 cured against 98% in 1908, and the 1907 records are certainly much 

 more accurately given. Furthermore, in one plot in 1907 the fourth 

 spraying was omitted and gave but 84% good fruit, though it had the 

 first three sprayings. Concerning this Melander and Jerme there re- 

 mark: "The greatly increased percentage of worms in these trees, 

 clearly shows the necessity for this last spraying, which must be given 

 for success," which conclusion is based on much better evidence than 

 that offered in 1908. to show that it is )wt necessary. Also in Bulletin 

 77 of the Washington Station (p. 64) Melander and Jerme have shown 

 that fairly good results were secured when the first spraying was 

 omitted in an orchard where 56% was wormy on unsprayed trees. 



The writer does not wish to be understood as disbelieving in the 

 value of driving the first spray into the lower calyx cavity, where va- 

 rieties and climate make such a method possible, but he does wish to 

 see some experimental evidence which will fairh' demonstrate the de- 

 sirability of such spraying, and particularly to support the claim that 

 one thorough spraying with but one pound of arsenate of lead per 

 barrel is sufficient, if rightly applied, when the evidence submitted 

 goes to show the great value or necessity of also spraying the foliage 

 and apples, in addition to the spray in the calyx in order to satisfacto- 

 rily control the Codling ^loth. 



3. Method of Experimentation. — Several years ago^^ the writer 

 showed the absolute necessity of treating several trees alike in order 

 to get an average upon which a comparison of different treatments 

 might be made, on account of the variation in individual trees treated 

 alike. Yet experimenters have gone on counting but one or two trees 



"Bulletin 81. Wash. Agr. Exp. Sta., p. 6. 

 "Delaware Agr. Exp. Sta. 13th Kept., Table VII. 



