16 
BULLETIN 13&3, U. S. DEPARTMENT OF AGRICULTURE 
Tahle 2. — Data concerning period of oviposition and adult longevity of the granary 
weevil 
No. 
Date 
weevil 
emerged 
Date 
first egg 
was laid 
Length 
of pre- 
oviposi- 
tion 
period 
Date 
last egg 
was laid 
Length 
of ovi- 
position 
tion 
period 
Number 
of eggs 
laid 
Date of 
death 
Length 
of life 
1 
1920 
Feb. 26 
6. 
...do 
...do 
...do 
...do 
May 25 
7 
June 17 
8 
Aug. 15 
9 
Aug. 24 
10 
Oct. 17 
11 
12 
...do 
1921 
Sept. 5 
13 
Sept . 6 
14 
15 .. 
16 
...do 
...do 
.do.— 
17 
Sept. 7 
18 
Oct. 25 
..do... . 
..do.... 
..do..„ 
..do.... 
..do.... 
..do.... 
..do.... 
..do.... 
..do.... 
..do.... 
..do.... 
..do.... 
..do.... 
Nov. / 
Nov. I 
-do.... 
..do.... 
1920 
Mar. 19 
Mar. 18 
Mar. 24 
Mar. 20 
Mar. 19 
June 2 
June 23 
Aug. 27 
Sept. 4 
1921 
Mar. 3 
Feb. 24 
Sept. 18 
Sept. 19 
Sept. 15 
Sept. 18 
Sept. 15 
1922 
Feb. 2 
Jan. 28 
Jan. 31 
Feb. 1 
Jan. 30 
Feb. 1 
...do.... 
Feb. 2 
Feb. 1 
._do.... 
Feb. 2 
Jan. 31 
Feb. 5 
Jan. 31 
Feb. 1 
Mar. 10 
Feb. 18 
Mar. 19 
Mar. 6 
Days 
1920 
June 14 
May 29 
June 11 
..do.... 
Aug. 30 
Aug. 31 
Sept. 15 
1921 
June 10 
Apr. 10 
June 30 
July 22 
1922 
Apr. 21 
May 12 
June 12 
May 8 
June 7 
May 7 
Sept. 24 
Apr. 21 
July 21 
June 5 
July 28 
June 9 
July 7 
May 27 
Apr. 20 
June ' 9 
June 26 
Aug. 2 
May 29 
Apr. 13 
June 14 
Aug. 6 
May 25 
June 5 
Days 
87 
72 
79 
83 
164 
90 
84 
215 
235 
270 
232 
265 
65 
71 
14,-, 
128 
130 
197 
36 
135 
126 
234 
181 
184 
74 
114 
200 
177 
166 
210 
95 
130 
242 
78 
L08 
1920 
June 18 
June 15 
June 23 
June 18 
Sept. 1 
Sept. 2 
Sept. 20 
1921 
2.54 June 27 
77 May 18 
Sept. 15 
Aug. 20 
1922 
Apr. 25 
May 24 
June 30 
May 15 
June 16 
May 25 
Oct. 8 
May 1 
Aug. 4 
June 9 
July 31 
June 12 
July 17 
July 10 
May 1 
June 12 
Aug. 7 
Aug. 23 
June 5 
Apr. 20 
July 21 
Aug. 14 
June 1 
July 5 
Days 
113 
110 
118 
113 
188 
100 
95 
316 
267 
333 
307 
232 
200 
297 
251 
283 
348 
188 
283 
227 
279 
230 
265 
258 
188 
230 
286 
302 
223 
177 
256 
279 
205 
239 
METHOD OF EGG LAYING 
The beetles lay their eggs within the seeds of most of our common 
grains. A hole is excavated within the grain equal to the length of 
the slender proboscis of the female. When this is completed to the 
satisfaction of the beetle, she withdraws her proboscis and turning 
around swings the abdomen about until the cavity is located. The 
ovipositor is then thrust into the cavity and an egg deposited. 
Before the ovipositor is withdrawn a translucent mass of gelat- 
inous material is discharged on top of the egg and is tamped down 
level with the surface of the seed. This plug of gelatinous material 
quickly hardens, holding the egg in place and forming a protective 
covering for it. 
The eggs are laid in all parts of the seeds but usually near one end. 
It is probably mechanically easier for the weevil to bore a hole at 
either end of the seed, owing to the need of a good foothold during 
the operation. 
