480 BOARD OF AGRICULTURE. [Pub. Doc. 



This shows a difference which the chemist properly characterizes 

 as "infinitesimal" in favor of the glucose-treated foliage. It is 

 also of interest to note that, although careful tests of the foliage 

 of the bushes treated with glucose solutions were made by Mr. 

 Smith for several days subsequent to spraying, no glucose could 

 be found on the leaves after the first shower. 



3. The Physiological Test. 



The test of feeding the poisoned leaves to caterpillars gives, of 

 course, the most reliable results. For this purpose the foliage 

 was allowed to " weather" for eight days, when duplicate lots of 

 ten gypsy moth caterpillars each were fed upon the differently 

 treated leaves until all the insects were dead. The larva? were 

 confined in breeding jars, and the foliage was gathered fresh 

 daily. 



The average results of the duplicate experiments were as fol- 

 lows : — 



No. 1, no glucose : all larvae dead in 17^ days. 



No. 2, 4 quarts glucose to 100 gallons water ; larvae dead in 14^ days. 

 No. 3, 6 quarts glucose to 100 gallons water ; larvae dead in 19 £ days. 

 No. 4, 8 quarts glucose to 100 gallons water ; larvae dead in 16 days. 

 No. 5, 10 quarts glucose to 100 gallons water ; larvae dead in 16 days. 



The extreme range in the time at which these experiments 

 terminated is five days, the test with normally sprayed foliage 

 exceeding slightly the average period. 



On August 5, fifty-two days from the time of spraying, there 

 was commenced an experiment in feeding this poisoned foliage to 

 larvre of the fall web worm as a check with another insect upon 

 the preceding work. No duplicate experiments were run. The 

 results follow : — 



No. 1, no glucose : all larvae dead in 10 days. 



No. 2, 4 quarts glucose to 100 gallons of water: all larvae dead in 10 

 days. 



No. 3, 6 quarts glucose to 100 gallons of water: all larvae dead in 12 

 days. 



No. 4, 8 quarts glucose to 100 gallons of water : all larvae dead in 9 

 days. 



No. 5, 10 quarts glucose to 100 gallons of water: all larvae dead in 12 

 days. 



The results show a range of three days in the dates of closing 

 the tests, the one where normally sprayed foliage was used falling 

 a little inside the average duration of the experiments. 



