20 
museum of this Department, my attention was attracted by an accumu- 
lation of powder and dust about the edges of an exhibit of peanut oil 
cake, and another of Indian turnip bulbs. A great number of the 
larva? and their cast skins were found under and on the under surface 
of the cakes ; also in flour and meal prepared from peanuts. The Indian 
turnip bulbs were very old and dry, and might have been on exhibition 
twenty years or more. 
When this insect infests a substance of similar color and consistency 
to flour or meal only a few larva? are sufficient, on account of their 
extraordinary habit of frequently molting, to occasion alarm. In fact, 
appearances are much worse than the reality. Thus, in a small box of 
peanut meal in which these larva? had taken up their abode, about forty 
larval skins had accumulated when examined September 27, completely 
covering one-half of the surface of the meal, and giving the impression 
of a whole colony of the insects. 
After the experiences narrated I was prepared for almost anything, 
and was expecting that as this species was as nearly omnivorous as the 
preceding, it would in time be found like them to be granivorous. Hav- 
ing convinced myself by the process of "reasoning by analogy" that 
the insect must be a grain feeder, I had resolved to experiment with a 
view of ascertaining if the species would feed upon cereal food. A 
compulsory delay of a few days saved me the trouble. While the 
Division of Entomology was moving into new quarters a bag of "Sas- 
katchewan fife" spring wheat, formerly kept in stock for gratuitous 
distribution, and described on the label as a hard, amber variety with 
an exceedingly heavy grain, was unearthed, in which the larva of this 
insect was living, there being present no other insects except a colony 
of Anthrenus and a single stray Silvanus. In fact, this grain is so 
hard and flinty that weevils would not flourish on it. 
Soon afterwards I found larva? in another lot of wheat infested with 
Silvanus, and in corn containing Calandra oryza and other small bee- 
tles. About the same time, Mr. Frank Benton brought me larva? found 
in beehives, where they apparently fed upon propolis, or bee glue. 
There are several recorded instances of Dermestes lardarius feeding 
upon wax, 1 or, more property speaking, honeycomb, and it is therefore 
fairly certain that Trogoderma has the same habit, although not previ- 
ously reported in beehives. 
Among the divisional notes I find one recording the receipt of six 
larva? of this species in a box of red pepper, from a correspondent in 
Utah, November 22, 1882. These larva? were kept in the box of pepper 
for a year, at which time fifty- four cast larval skins were noticed. The 
box was examined January 14, 1887, or over four years from the time 
of its receipt, when two larva? and seventy more cast skins were found, 
but no trace of beetles, although it had been kept closed, so that it 
was impossible for either larva? or adults to escape. It is very obvious 
See Lintner's 6th Rept., pp. 122-123; Dubini(L'Ape e il suo Governo, 1881, p. 266). 
