DUSTING AND SPRAYING CURCULIO AFTEE HARVEST. 
Table 5. — Summary of results from post-harvest dusting, 1921. 
Average 
number of beetles 
per tree. 
Period. 
Platl 
(dusted 
twice). 
Plat 2 
(dusted 
once). 
Plat 3 
(not 
dusted). 
Beetles. 
3.50 
4.06 
Beetles. 
5.97 
6.29 
Beetles. 
.'). 3.') 
10.90 
..56 
.32 
2.34 
3.78 
6.78 
1.16 
2.19 
2 1.43 
3.29 
5.18 
9.07 
.21 
.79 
2 3. 72 
Per cent. 
6.00 
Per cent. 
13.23 
Per cent. 
2 69.53 
Compared with period before dusting. 
2 Increase. 
The second application to plat 1 was in all probability ineffective, 
owing to the fact that a heavy rain fell soon after the dust was 
applied, washing off a quantity of the material. In the summary of 
results the figures on percentage decrease or increase of beetles per 
tree in each plat show that the increase on the check or untreated 
plat was enormous. This was due, as stated before, to the heavy 
emergence of second-generation adults soon after the first dusting 
was given to plats 1 and 2. The results obtained on the check plat 
show that, while the dust did not materially decrease the number of 
beetles during the course of the experiment, it did prevent the heavy 
increase from the emergence of second-generation adults which would 
have occurred had the dust not been applied. 
RESULTS OF INSECTARY WORK IN 1921. 
Considerable insectary work was done in conjunction with the 
field experiments. Adult curculios collected from the different plats 
were brought to the insectary daily and kept under observation in 
battery jars. About 2 inches of moist sand was placed in the bottom 
of each jar, and the jar was covered with cheesecloth. Fresh peach 
foliage was added as needed. The curculios with foliage from the 
several plats were confined in separate jars to determine the killing 
effect of the poison. The beetles with foliage from the dusted plats 
were, of course, checked against those from the untreated plat. 
Ten beetles were confined in each jar, and there were 9 jars for each 
plat (27 jars in all). Thus 90 curculios from each of the three plats 
were collected between August 15 and September 3, and daily exami- 
nations were made for records on mortality. Table 6 gives the daily 
record of the mortality of the beetles. 
