48 
THE PLUM CUECULIO. 
Table XI. — Combined weekly egg-laying records of all beetles of the plum curculiofor each 
locality and percentage of eggs deposited within two, four, six, and eight weeks from 
confinement. 
Localities. 
ft 
9 a 
fc5 
Total number of eggs laid each week by all beetles of 
the respective localities. 
3 5 
o i 
02 
gcoo 
S St3 ft 
College Park, Md 
Youngstown, N. Y. . 
North East, Pa 
Washington, D. C . . . 
Myrtle, Ga 
Siloam Springs, Ark 
Douglas, Mich 
Total 
192 
81 
232 
58 
254 
72 
760 
186 
183 
213 
62 
300 
2.59 
414 
201 
197 
242 
41 
343 
329 
'234 
94 
153 
176 
673 
423 
192 
204 
54 
128 
50 
619 
229 
140 
48 
108 
83 
545 
536 
13 
23 
37 
6(5 
21 
40 
350 
153 
32 
46 
46 
130 
1,104 
2,471 
1,294 
787 
1,224 
688 
4,724 
1,414 
1,963 
1,767 
810 
537 
Localities. 
College Park, Md 
Youngstown, N. Y 
North East, Pa 
Washington, D. C 
Myrtle, Ga 
Siloam Springs, Ark 
Douglas, Mich 
Maximum 
number of 
eggs per 
individ- 
ual. 
Averages for all locali- 
ties combined 
257 
122 
557 
154 
3SS 
201 
Minimum Average 
number of number 
of eggs 
per indi- 
eggs per 
individ- 
ual. 
126 
1 
4 
25 
vidual. 
274. 55 
161. 75 
78.70 
306.00 
76.44 
162. 76 
78.56 
144.85 
Percentages of total eggs deposited by 
end of— 
Second 
week. 
50.82 
29.21 
33.54 
36.35 
17.44 
11.71 
23.40 
26.56 
Fourth 
week. 
79.27 
62.82 
70.52 
33.21 
76.59 
Sixth 
week. 
91.01 
89.41 
83.48 
87.90 
68.31 
57.83 
99.08 
Eighth 
week. 
93.40 
97.52 
94.15 
96.24 
81.10 
76.58 
100.00 
LENGTH OF EGG STAGE. 
Little exact information as to the period of incubation of eggs of 
the plum curculio is to be found in the earlier accounts of this insect. 
Trimble (Insect Enemies of Fruits, p. 29) states that if the weather 
be cloudy and cool, a week or 10 days is required for the eggs to 
hatch, but that in very hot weather the young grubs will escape in 
4 or 5 days. Riley and Howard state that from 3 to 10 days are 
required for the egg stage, depending upon the weather. Other 
writers have given about the same periods. In 1904, in Illinois, 
Crandall determined the length of time required for hatching of 6 
eggs as approximately 4^ days for 4 and 4 days 9 hours for the other 
two. His observations were made on eggs kept under laboratory 
conditions. 
