852 
Journal of Agricultural Research 
Vol. XXX, No. 9 
The beetles appear in May and June, 
according to Howard {16, p. 105-107), 
and never seem to oviposit except 
where the meat is more or less exposed. 
He also stated that E. A. Schwarz 
found adults in midwinter at Detroit, 
Mich., and Cambridge, Mass. 
Herrick (IJ, p. 278) reported that 
pupation takes place in the more fibrous 
parts of ham, or sometimes in a near-by 
beam. The globules of white substance 
which form the cocoons are emitted 
from the mouth of the larva. 
Of the biology of the ham beetle as a 
copra pest, Dupont (7) wrote that “it is 
supposed to be a purely predacious 
insect, feeding on dipterous and micro- 
lepidopterous larvae,” but it was not 
known whether or not it attacks the 
larvae of Oryzaephilus surinamensis L. 
(the saw-toothed grain beetle), which 
are also abundant in copra stores. 
LIFE-HISTORY INFORMATION 
OVI POSITION 
The act of oviposition has never been 
observed by the writers; presumably 
the eggs are deposited when the insects 
are in darkness. Owing to their car¬ 
nivorous appetites the beetles devour 
eggs which are exposed, and the females 
usually deposit them in crevices inac¬ 
cessible to the mandibles of roving 
adults. 
Following unsatisfactory oviposition 
trials with pieces of stale bacon at¬ 
tached to strips of cardboard, Petri 
dishes were used in which the only suit¬ 
able place for oviposition was between 
small squares of dark-colored cardboard 
held together with a paper clip. In 
dishes which were greasy throughout, 
oviposition was sparse until clean dishes 
and dry cardboard were provided. It 
Table I.— Incubation period of Necrobia rufipes, 1922 
Date 
eggs 
Hatching 
began 
Mini¬ 
mum 
incuba- i 
Temperatures during 
each period b 
Date 
eggs 
Hatching 
began 
Mini¬ 
mum 
incuba- 1 
Temperatures during 
each period b 
were 
laid a 
tion 
period 
Max. 
Av. 
Min. 
were 
laid a 
| 
tion | 
period 
Max. 
■ 1 
Av. 
1 
Min. 
Mar. 28 
Apr. 5 
Days 
8 
°F. 
79 
O p 
66 
o p 
53 
Sept. 24 
Oct. 2 
Days 
8 
op 
75 
i 
°F. 
68 
o p 
60 
May 9 
May 15 
6 
82 
74 
70 
25 
Oct. 3 
8 
75 
68 l 
60 
11 
May 16 
5 
82 
75 
70 
26 
Oct. 4 
8 
74 
68 
60 
12 
May 17 
5 
77 
74 
69 
27 i 
Oct. 5 
8 
77 
69 
60 
15 
July 19 
4 
82 
77 
69 
28 
...do_ 
7 
77 
70 
66 
20 
July 24 
4 
84 
79 
72 
29 
Oct. 6 
7 
79 
70 
65 
21 
July 25 
4 
89 
81 
72 
30 
...do_ 
6 
79 
71 
65 
25 
July 29 
4 
84 
78 
71 
Oct. 1 
Oct. 7 
6 
79 
72 
65 
Aug. 16 
Aug. 20 
4 
88 
81 
73 
2 
...do_ 
5 
79 
72 
65 
19 
Aug. 25 
6 
83 
75 
66 
3 
Oct. 8 
5 
79 
73 
67 
20 
...do_ 
5 
80 
74 
66 
6 
Oct. 11 
5 
78 
73 
67 
21 
Aug. 26 
5 
80 
74 
66 
9 
Oct. 17 
8 
77 
68 
59 
23 
Aug. 28 
5 
81 
77 
68 
10 
Oct. 18 
8 
77 
68 
59 
24 
Aug. 29 
5 
81 
76 
69 
11 
Oct. 20 
9 
77 
67 
59 
25 
Aug. 30 
5 
81 
76 
69 
12 
Oct. 21 
9 
77 
67 
59 
26 
Aug. 31 
5 
81 
75 
69 
13 
...do_ 
8 
77 
67 
59 
27 
Sept. 1 
5 
80 
75 
69 
14 
Oct. 23 
9 
77 
67 
58 
28 
Sept. 2 
5 
80 
74 
68 
15 
Oct. 24 
9 
75 
67 
58 
29 
Sept. 4 
6 
80 
75 
68 
16 
Oct. 26 
10 
77 
67 
58 
30 
_. .do_ 
5 
80 
75 
68 
17 
Oct. 27 
10 
77 : 
67 
58 
31 
Sept. 5 
5 
82 
76 
68 
18 
Oct. 28 
10 
77 
67 
58 
Sept. 1 
...do.... 
4 
82 
76 
68 
19 
Oct. 30 
11 
77 ■ 
66 
58 
2 
Sept. 6 
4 
82 
77 
72 
20 
Oct. 31 
11 
77 
65 
56 
3 
Sept. 7 
4 
84 
78 
73 
25 
Nov. 5 
11 
77 S 
66 
56 
4 
Sept. 8 
4 
85 
79 
75 
26 
...do_ 
10 
77 > 
66 
56 
5 
Sept. 9 
4 
85 
79 
75 
27 
Nov. 7 
11 
77 
66 
56 
6 
Sept. 10 
4 
85 
78 
75 
28 
...do_ 
10 
77 
66 
56 
7 
Sept. 11 
4 
85 
78 
75 
Nov. 3 
Nov. 14 
11 
77 
67 
58 
8 
Sept. 12 
4 
83 
78 
75 
4 
...do_ 
10 
77 
67 
58 
9 
Sept. 13 
4 
83 
78 
75 
6 
Nov. 16 
10 
77 
67 
58 
10 
Sept. 14 
4 
83 
76 
70 
7 
Nov. 17 
10 
77 : 
67 
58 
11 
Sept. 15 
4 
83 
76 
70 
8 
Nov. 18 
10 
77 
67 
58 
12 
Sept. 16 
4 
81 
75 
70 
12 
Nov. 22 
10 
76 
66 
56 
13 
Sept. 19 
6 
81 
72 
58 
16 
Nov. 29 
13 
77 
64 
49 
14 
Sept. 20 
6 
81 
71 
58 
17 
Dec. 2 
15 
79 
64 
49 
15 
Sept. 21 
6 
81 
70 
58 
24 
Dec. 7 
13 
79 
64 
49 
16 
Sept. 23 
7 
80 
70 
58 
28 
Dec. 9 
11 
79 
65 
53 
20 
Sept. 28 
8 
76 
68 
60 
29 
Dec. 13 
14 
79 
66 
53 
21 
Sept. 29 
8 
76 
68 
60 
Dec. 1 
! Dec. 14 
13 
79 
66 
53 
22 
Sept. 30 
8 
76 
68 
60 
2 
...do_ 
! 12 
79 
66 
53 
23 
Oct. 2 
9 
76 
l 
69 
60 
1 _ 
a Number of eggs laid each day varied from about 25 to 100. 
b Average temperatures computed from thermograph readings every 2 hours. 
