May 1, 1925 
The Ham Beetle 
861 
the season of low temperatures and 
stored for future consumption. 
According to Perkins {23, p. 126) 
the larvae do not seem to be able to eat 
their way through any covering, and 
thoroughly wrapped hams are not 
therefore exposed to injury. 
In the Philippines this species is con¬ 
trolled in copra by fumigation under a 
tarpaulin with carbon disulphide (10). 
Herrick (14, p . 280) stated that the 
injured parts of infested meats can 
often be cut away. 
Ashbrook, Anthony, and Lund (3, 
p. 25-26) have given an important con¬ 
trol measure, which consists of remov¬ 
ing the original string from smoked 
meats before wrapping them and tying 
of paper it is hardly to be wondered at 
that the theory of abiogenesis has been 
used to explain the presence of purple 
worms in these products. 
Careful screening with fine wire 
cloth (30 meshes per inch), as recom¬ 
mended to exclude the cheese skipper, 
will also be effective against ham 
beetles. 
Reconditioning by trimming off in¬ 
fested parts with a knife is sometimes 
resorted to, especially with bacon. 
The eradication of an infestation will 
be hastened if the meats and rooms in 
which they have been stored are fumi¬ 
gated with hvdrocyanic-acid gas. The 
use of this gas for the fumigation of 
meats has been approved by the Bureau 
Table VII .—Development of individual larvae of Necrobia rufipes 
[Food: Eggs of N. rufipes followed by larvae of Piophila casei] 
Date 
egg 
hatched 
Duration 
First 
instar 
i 
Second 
instar 
1 Third 
1 instar 
Fourth 
instar 
Larval 
stage 
1923 
Days 
Days 
Days 
Days 
Days 
May 13 
8 
6 
10 
13 
37 
13 
10 
6 
j 13 
29 
14 
7 
8 
15 
30 
14 
11 
4 
1 io 
i 11 
36 
14 
7 
8 
8 
10 
33 
14 
7 
8 
8 
j 16 
39 
14 i 
9 
; 6 
1 10 
8 
33 
14 
9 
6 
21 
36 
14 
9 
6 
1 21 | 
36 
14 
9 
! 8 
19 | 
36 
15 
7 
8 
8 1 
13 
36 
15 i 
7 
6 
24 
37 
15 
7 i 
8 
10 i 
25 
15 
7 
8 
10 1 
25 
15 
] 
9 
6 
22 
J 
37 
Date 
egg 
hatched 
Duration 
First 
instar 
Second 
instar 
Third 
instar 
Fourth 
instar 
Larval 
stage 
1923 
Days 
Days 
Days 
Days 
Days 
May 15 
9 
6 
10 
25 
15 
7 
8 
16 
31 
16 
6 
8 
19 
33 
16 
6 
8 
8 
22 
16 
6 
8 
8 
11 
33 
16 
6 
8 
19 
33 
16 
6 
6 1 
10 
22 
16 
6 
8 ! 
19 
33 
16 
6 
8 i 
8 
22 
16 
8 
6 ! 
22 
36 
16 
8 
6 
16 
30 
16 
6 
8 
10 
24 
16 
8 
8 
14 
30 
16 
6 
8 ! 
10 
12 
.... 36 
Note.— Mean temperatures (°F.): May 13, 73°; May 14, 72°; May 15, 74°; May 16, 78°; May 17, 76°.' 
May 18, 73°; May 19, 76°; May 20, 76°; May 21, 76°; May 22, 75°; May 23, 71°; May 24, 72°; May 25, 73°; 
May 26, 74°; May 27, 78°; May 28, 80°; May 29, 82°; May 30, 77°; May 31, 75°; June 1, 77°; June 2, 84°; 
June 3, 86°; June 4, 85°; June 5, 87°; June 6, 85°; June 7, 84°; June 8, 81°; June 9, 75°; June 10, 76°; 
June 11, 75°; June 12, 72°; June 13, 71°; June 14, 72°; June 15, 78°; June 16, 79°; June 17, 80°; June 18, 83°; 
June 19, 84°; June 20, 87°; June 21, 89°; June 22, 89°. 
a new string tightly around the outside 
of the package. This is necessary be¬ 
cause it is impossible to make an insect- 
tight package if a string passes from 
the meat through the wrappings. 
Ordinarily there appears to be slight 
danger of infestation of newly smoked 
pork products by ham beetles. If 
meats are wrapped promptly and 
tightly, there should be no trouble, 
but long-stored hams and sides of 
bacon that are hung up unwrapped or 
packed in crates accessible to the 
beetles are likely to become infested 
during warm weather. 
The ham beetle is able to find an 
entrance to meat which is apparently 
tightly covered, and in view of the 
insect’s ability to reach smoked meats 
protected by several overlapping layers 
of Animal Industry, United States De¬ 
partment of Agriculture (33). 
SUMMARY 
The ham beetle (Necrobia rufipes De 
G.) is widely distributed over the 
warmer parts of the world, frequently 
being found as an inhabitant of stores 
of bones and other inedible animal 
products. Among the islands of the 
Pacific it is a pest of copra. In parts 
of the United States sporadic injury, 
occasionally of considerable extent, is 
done to long-stored hams, shoulders, and 
bacon. 
The adult is a shiny, green beetle 
3.5 to 7 mm. long; the larva is purplish 
and about 10 mm. in length when full 
grown. Both imago and larva are 
