Dec. 22,1923 
Biology of Four-Spotted, Bean Weevil 
613 
Table II .—Life history records of 61 pairs of Bruckus quadrimaculatus, together with 
a summary of the results of their oviposition, September 18 to October 1 $, IQIQ —Con. 
1 
Pair No. 
Date parent weevils emerged 
and mated. 
Adult life 
of parent 
weevils. 
Eggs. 
Emergence of 
progeny. 
Developmental 
periods of progeny. 
Male. 
£ 
a 
2 
Hatched. 
Produced adults. 
Males. 
Females. 
1 
3 
Maximum. 
Average. 
Nuvu 
Per 
Per 
Num* 
Num - 
Days. 
Days. 
ber. 
cent. 
cent . 
ber. 
ber. 
Days. 
Days. 
Days . 
42 . 
Sept. 22 
14 
18 
96 
75 
66 
35 
28 
102 
172 
123 
43 . 
23 
7 
II 
76 
50 
37 
13 
15 
112 
171 
134 
44 . 
23 
( a ) 
15 
82 
62 
52 
24 
19 
no 
168 
128 
45 . 
23 
16 
16 
87 
74 
63 
27 
28 
IO9 
167 
133 
46 . 
23 
14 
14 
104 
58 
48 
25 
25 
119 
175 
134 
47 . 
23 
i 5 
15 
68 
69 
44 
II 
19 
103 
173 
134 
48. 
24 
12 
14 
86 
70 
42 
15 
21 
Il6 
174 
138 
49 . 
24 
15 
15 
67 
72 
63 
17 
25 
114 
169 
132 
50 . 
24 
14 
18 
76 
80 
67 
25 
26 
no 
175 
125 
5 i. 
2 5 
17 
18 
101 
5 o 
45 
23 
22 
118 
217 
150 
52 . 
25 
14 
17 
80 
Si 
40 
15 
17 
117 
206 
139 
53 . 
26 
13 
15 
61 
82 
77 
27 
20 
116 
181 
133 
54 . 
26 
12 
IO 
38 
55 
53 
IO 
IO 
118 
217 
137 
55 . 
26 
16 
20 
49 
59 
41 
11 
9 
116 
176 
r 38 
56. 
26 
17 
C) 
53 
70 
43 
8 
15 
117 
188 
138 
57 . 
27 
14 
17 
98 
50 
35 
19 
15 
115 
212 
142 
58. 
27 
18 
15 
65 
48 
25 
6 
10 
128 
157 
*43 
59 . 
27 
18 
15 
86 
55 
27 
8 
15 
117 
154 
136 
60. 
Oct. 1 
17 
l6 
64 
80 
47 
17 
13 
131 
221 
162 
61. 
2 
i 5 
17 
87 
68 
38 
*7 
16 
131 
203 
162 
Average . 
13 
15 
82 
67 
55 
23 
22 
126 
Grand 
total .. 
5 > °°4 
1,429 
I, 32O 
0 Escaped. 
Note. —Preoviposition period one da> in all cases. 
The parent weevils required from 31 to 48 days of summer weather 
for their own development, although they were all produced, with the 
exception of a few of the males and four females, from eggs laid the same 
day. The preoviposition period of the parent females was one day or 
less, as eggs recorded for the first day were deposited during the first 
day after emergence and mating; the females lived longer than the 
males; the average number of eggs per female was 82; an average of 67 
per cent of all the eggs hatched, and 55 per cent produced adults. The 
emerged adults which resulted from these eggs were nearly equally 
divided as to sex, 52 per cent being males and 48 per cent females. The 
highest percentage of hatching of the eggs of any female was 89 per cent 
(No. 40) and the lowest 38 per cent (No. 29). The three females (Nos. 
4, 5, and 6) which laid the largest number of eggs also had required the 
shortest periods for their own development—31, 33, and 33 days—which 
suggests that inherent vigor and favorable conditions, indicated by 
rapid growth, may result in unusual fecundity. In the case of the eggs 
which hatched, but from which no adults resulted, it was found that the 
larva usually died after penetrating but a short distance into the cowpea; 
that is, the greatest larval mortality occurred very early in life. 
