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818
C57
ENT

No. 5, SECOND SERIES.

ited States Department of Agriculture,

DIVISION OF ENTOMOLOGY.

8

THE CARPET BEETLE, OR “BUFFALO MOTH.” *

(Anthrenus scrophularie L.)

ANTHRENUS SCROPHULARI®: a, larva, dorsal view; b, pupa within larval skin;
c, pupa, ventral view; d, adult—all enlarged—(from Riley).

GENERAL APPEARANCE AND METHOD OF WORK.

All the year around, in well-heated houses, but more frequently in
summer and fall, an active brown larva a quarter of an inch or less in
length and clothed with stiff brown hairs, which are longer around the
sides and still longer at the ends than on the back, feeds upon carpets
and woolen goods, working in a hidden manner from the under surface,
sometimes making irregular holes, but more frequently following the
line of a floor crack and cutting long slits in a carpet.

DISTRIBUTION.

This insect in the United States is known as a carpet beetle only in
the northern part of the country. Beginning with Massachusetts,
it spread west to Kansas. It is not known as a carpet beetle in
Washington nor Baltimore, and is not common in Philadelphia, but
abounds in New York, Boston, all the New England States, and west
through Ohio, Indiana, Michigan, Wisconsin, Illinois, Iowa, and
Kansas. It is originally a European insect, and is found in all parts
of Europe. It was imported into this country about 1874, probably
almost simultaneously at New York and Boston. It has long been
known on the Pacific Coast, but not, so far as we are aware, in the role
of a carpet enemy.

* This circular is prepared for use in correspondence, and is a compilation only.

2

NATURAL HISTORY AND HABITS.

The adult insect is a minute, broad-oval beetle, about three-six-
teenths of an inch long, black in color, but is covered with exceed-
ingly minute scales, which give it a marbled black-and-white appear-
ance. It has also a red stripe down the middle of the back, widen-
ing into projections at three intervals. When disturbed it plays
possum,”’ folding up its legs and antenne and feigning death. As
a general thing the beetles begin to appear in the fall, and continue
to issue, in heated houses, throughout the winter and following
spring. Soon after issuing they pair, and the females lay their eggs
in convenient spots. The eggs hatch, under favorable conditions,
in a few days, and the larve, with plenty of food, develop quite
rapidly. Their development is retarded by cold weather or by lack
of food, and they remain alive in the larval state, in such conditions,
and particularly in a dry atmosphere, for an almost indefinite period,
molting frequently and feeding upon their cast skins. Under nor-
mal conditions, however, the skin is cast about six times, and. there
are, probably, in the north, not more than two annual generations.
When the larva reaches full growth the yellowish pupa is formed
within the last larval skin. Eventually this skin splits down the
back and reveals the pupa, from which the beetle emerges later.
The beetles are day-fliers, and when not engaged in egg-laying are
attracted to the light. They fly to the windows, and may often be
found upon the sills or panes. Where they can fly out through an
open window they do so, and are strongly attracted to the flowers of
certain plants, particularly of the family Scrophulariacex, but also
to certain Composite, such as milfoil (Achillea millefolium). The
flowers of Spireea are also strongly attractive to the beetles. It is
probable, however, that this migration from the house takes place,
under ordinary circumstances, after the eggs have been laid.

In Europe the insect is not especially noted as a household pest,
and we are inclined to think that this is owing to the fact that car-
pets are little used. In fact, we believe that only where carpets are
extensively used are the conditions favorable for the great increase
of the insect. Carpets once put down are seldom taken up for a
year, and in the meantime the insect develops uninterruptedly.
Where polished floors and rugs are used, or straw mattings and
rugs, the rugs are often taken up and beaten, and in the same way
woolens and furs are never allowed to remain undisturbed for an
entire year. It is a well-known fact that the carpet habit is a bad
one from other points of view, and there is little doubt that if carpets
were more generally discarded in our Northern States the “ Buffalo
bug’? would gradually cease to be the prominent household pest that
it is to-day. The insect is known in Europe as a museum pest, but

has not acquired this habit to any great extent in this country. It is
known to have this habit in Cambridge, Mass., and Detroit, Mich , as
well as in San Francisco, Cal., but not in other localities. In all of
these three cases it has been imported from Europe in insect collections.

REMEDIES.

There is no easy way to keep the carpet beetle in check. When it
has once taken possession of a house nothing but the most thorough
and long-continued measures will eradicate it. The practice of
annual house-cleaning, so often carelessly and hurriedly performed,
is, as we have shown above, peculiarly fayorable to the development
of the insect. Two house-cleanings would be better than one, and if
but one, it would be better to undertake it in midsummer than at
any other time of the year. Where convenience or conservatism
demands an adherence to the old custom, however, we have simply
to insist upon extreme thoroughness and a. slight variation in the
customary methods. The rooms should be attended to one or two
at a time. The carpets should be taken up, thoroughly beaten, and
sprayed out of doors with benzine, and allowed to air for several
hours. The rooms themselves should be thoroughly swept and
dusted, the floors washed down with hot water, the cracks carefully
cleaned out, and kerosene or benzine poured into the cracks and
sprayed under the baseboards. The extreme inflammability of
benzine, and even of its vapor when confined, should be remembered
and fire carefully guarded against. Where the floors are poorly
constructed and the cracks are wide, it will be a good idea to fill the
cracks with plaster of paris in a liquid state; this will afterwards set
and lessen the number of harboring places for the insect. Before
relaying the carpet, tarred roofing paper should be laid upon the
floor, at least around the edges, but preferably over the entire sur-
face, and when the carpet is relaid it will be well to tack it down
rather lightly, so that it can be occasionally lifted at the edges and
examined for the presence of the insect. Later in the season, if
such an examination shows the insect to have made its appearance,
a good, though somewhat laborious, remedy consists in laying a
damp cloth smoothly over the suspected spot of the carpet and
ironing it with a hot iron. The steam thus generated will pass
through the carpet and kill the insects immediately beneath it.

These strenuous measures, if persisted in, are the only hope of the
good housekeeper, so long as the system of heavy carpets covering
the entire floor surface is adhered to. Good housekeepers are con-
servative people, but we expect eventually to see a more general
adoption of the rug or of the square of carpet, which may at all
times be readily examined and treated if found necessary. Where

wi

the floors are bad the practice of laying straw mattings under the rugs
produces a sightly appearance, and, while not as cleanly as a bare
floor, affords still fewer harboring places for this insect.

iin

6

L. O. HOWARD,
Entomologist.

Approved:
J. STERLING MORTON,
Secretary.

WasHINGTON, D. C., September 8, 1894.

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