PACKAGE EXPERIMENTS; 1907-8. 



29 



moisture. In Nos. 83 to 86 fruit from barrels was packed in the 

 usual way, wrapped and unwrapped, in commercial apple boxes. 



The first examination for scale on the treated fruit was begun on 

 December 14 and concluded December 24, and reexamination was 

 done from January 3 to 8, using fruit from the top, middle, and 

 bottom of barrels each time. 



In all tests in 1907-8 theplan was adopted of holding the fruit in a 

 warm room, where the temperature was from 70° to 75° F., for two 

 days previous to examination to bring about a more marked discol- 

 oration of the dead scales and eliminate as much as possible any 

 doubt as to their exact condition. The method of treatment was 

 found to blacken the dead scales without exception, and there was 

 never any question as to whether the insect was dead or alive. The 

 essential features of the test are given in the subjoined table: 



Table XII. — Effect of fumigation with hydrocyanic-acid gas on scales and fruit in dif- 

 ferent hinds of packages . (Package series, 1907-8.) 



Experi- 

 ment 

 No.— 



Variety of 

 apple. 



Kind of package. 



Rate at 

 which 

 potas- 

 sium 

 cyanid 



was used. 



Length of 

 exposure. 



Num- 

 ber of 

 scales 

 ex- 

 amined. 



Effect on 

 scales. 



Effect on 

 fruit. 



71 



72 



Baldwin. . 

 ...do. 



Barrel, iron header in bot- 

 tom. 



do 



do 



..do 



Gr. per 

 cu. ft. 

 0.30 



.30 

 .30 

 .50 

 .30 

 .30 

 .30 

 .50 

 .30 



.30 

 .30 

 .50 

 .30 

 .30 

 .30 

 .30 



1 hour 



3 hours 



All night. . 



3 hours 



1 hour 



3 hours 



All night. . 



3 hours 



1 hour 



3 hours 



All night. . 



3 hours 



...do 



All night. . 



3 hours 



All night. . 



4,228 



3,602 

 4,899 

 4,207 

 4,898 

 2,879 

 4,562 

 3,677 

 4,603 



4,391 

 3,657 

 4,257 

 2,690 

 2,355 

 3,263 

 2,985 



All dead. 



...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 



...do.... 

 ...do.... 

 ...do.... 

 ...do.... 

 ...do.... 



...do 



...do.... 



No injury. 

 Do. 



73 



74 



...do 



do . 



Do. 

 Do 



75 



do 





Do 



76 



77...... 



78 



79 



80 



...do 



...do 



...do 



...do 



...do 



do 



Barrel with 20 f-inch auger 



holes in each end. 

 do 



Do. 

 Do. 

 Do. 



Do. 



Do 



81 



...do... 



...do 



Do 



82 



...do 



...do 



...do 



do 



Do 



83 



84 



Box, fruit unwrapped 



do 



Do. 

 Do. 



85 



. do 





Do 



86... 



...do. . 



...do... 



Do 











It will be noted from the table that in every case the treatment 

 was entirely effective in killing the scale insects and that no injury 

 resulted to the fruit. 



To corroborate these results, several of the tests were repeated, 

 using fruit from the same source, but held longer in cold storage, 

 namely, until February 5. The Baldwin and Roxbury Russet 

 varieties were used and after fumigation were kept in the outhouse 

 mentioned. The percentage of live scales in untreated Baldwins at 

 time of fumigation was 24.4 and on the Roxbury Russet 70. In 

 these tests it will also be noted (Table XIII) that all scales were 

 killed and without injury to the varieties of fruits used. 



