Sept. 15, 1925 
Behavior of Phytophaga destructor Say 
571 
fatalities. Of the total number of flies emerging in the control, 601, 
or 54 per cent, were males, and 512, or 46 per cent, were females, in 
this case indicating a very fair degree of equality in the proportion of 
sexes. Another interesting point, although to be expected, is that of 
the recovery of the greater percentage of males in comparison with 
the females in each cage except the dark cage D. Excepting the 
cage C, there does not seem to be any choice indicated by the per¬ 
centage of efficiency when the cages are run indoors. 
A hygrothermograph was run in cage A, and temperature and 
humidity charts (Table II) were kept. 
Table II .—Temperature and humidity , La Fayette , Ind. % March 15 to 24, 1920 
Date 
Temperature 
Humidity 
Mini¬ 
mum 
Maxi¬ 
mum 
Average 1 
Mini¬ 
mum 
Maxi¬ 
mum 
Average 1 
° F. 
o F 
o p 
Percent 
Per cent 
Per cent 
Mar. 15 ..... 
65 
75 
70.5 
38 
49 
43.8 
Mar. 16.... 
60 
72 
65.8 
35 
40 
38.4 
Mar. 17.... 
58 
70 
64.4 
34 
36 
34.-7 
Mar. 18... 
58 
68 
64.2 
36 
39 
37.5 
Mar. 19.... 
62 
68 
64.6 
37 
44 
39.7 
Mar. 20.... 
58 
74 
68.1 
35 
38 
36.2 
Mar. 21..... 
62 
77 
71.4 
33 
36 
34.2 
Mar. 22.... 
65 
77 
71.1 
33 
37 
35. ( 
Mar. 23.... 
68 
76 
73.5 
31 
37 
34. 2 
Mar. 24.... 
69 
78 
72.4 
36 
44 
40.6 
1 The average is the arithmetical mean of readings at 2-bour intervals. 
THIRD TRIAL, LA FAYETTE, IND., APRIL 22 TO MAY 12, 1920 
The third trial was made in the same manner as the second, with 
the two main exceptions that the cages were placed under natural 
conditions outdoors and arranged in a row, as shown in Figure 2, B. 
Flaxseeds for this trial were collected and kept under as nearly 
natural conditions as possible until placed in the cages. One thou¬ 
sand flaxseeds were placed in each cage and protected from the sun's 
rays by small canopies of cheesecloth over each box. The results 
obtained are as follows: Cage A, 78 females, 191 males, total 269; 
B, 74 females, 88 males, total 162;. C, 20 females, 12 males, total 32; 
D, 130 females, 233 males, total 363; E, 49 females, 100 males, total 
149; F, 39 females, 55 males, total 94; control, 524 females, 240 
males, total 764. 
Cage D is again indicated to be the most efficient, and it is unfor¬ 
tunate indeed that this cage should impose conditions which are 
further from natural conditions than those of any of the variously 
devised cages of the experiments., Although in this trial, as proved by 
the control, the emergence was heavy, the number of flies recovered 
by the cages falls far below the indoor records. From 1,000 flaxseeds 
of the control 764 flies were obtained, a yield of 76 per cent. This 
comes very close to the indoor record, which was 74 per cent. 
Attempts at further trials of these cages on May 11 and again on 
June 18, 1920, were made by placing flaxseeds m refrigeration to 
retard their development until after the natural emergence had 
occurred in the field. For some reason a sufficient emergence was 
