Part 2

While most conspicuous in the Northern States, this carpet beetle is frequently found in the latitude of Washington, D. C, and southward Specimens have, recently been sent from Texas and Florida. In a Washington storehouse the contents of a trunk closed for several years were found badly damaged by the larvæ.

The following account is just as applicable to-day as when written many years ago.

Howard, L. 0., in Bulletin 4, new series, Division of Entomology, United States Department of Agriculture, pp. 58-59. 1896.

The adult insect is a small, broad-oval beetle, about three-sixteenths of an inch long, black in color, but is covered with exceedingly minute scales, which give it a marbled black-and-white appearance. It also has a red stripe down the middle of the back, widening into projections at three intervals. When disturbed it "plays 'possum," folding up its legs and antennæ 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 larvæ, with plenty of food, develop quite rapidly. Their development is retarded by cold weather or 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 normal 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 the family Scrophulariaceæ but also to certain Composite, such as milfoil (Achillea millefolium). The flowers of Spiræa 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, probably owing to the fact that carpets are seldom tacked down. In fact, the writer believes that only where carpets are extensively used in this way are the conditions favorable for the great increase of this insect. Carpets once tacked down are seldom taken up for a year, and in the meantime the insect develops uninterruptedly. With the more general use of polished floors, and rugs which are often taken up and beaten, there is little doubt that the "buffalo bug" will eventually cease to be a household insect of importance. The insect is known in Europe as infesting museums, 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, Calif., but not in other localities. In each of these three cases it was imported from Europe in insect collections.

THE BLACK CARPET BEETLE.

Attagenus piceus Oliv.

The black carpet beetle derives its common name from the black, unadorned color of the adult. Its larva is reddish or golden brown, long and slender, with a characteristic tuft of long hairs at the end of its body. It curls up and "plays 'possum" when disturbed. A glance at Figure 5 will be sufficient for the identification of this unique carpet-beetle larva.

Widespread in Europe and Asia, it first attracted attention in America in 1854. Since then it has become widely distributed throughout the United States, often being the most injurious of the carpet beetles, especially in the more southern States. It is the carpet beetle most commonly referred by housewives to the department for identification. It feeds upon household fabrics of wool, feathers, fur, hair, and silk, and also upon cereals and cereal products, seeds, and dried animal remains, hence has many opportunities for existence in warehouses and barns as well as in houses.

=The adult.=--The adult of the black carpet beetle is small, oval, and black, as shown in Figure 4. The adults are present in abundance only during the early summer. In a steam-heated building at Washington, D. C, large numbers of adults were present late in April and during May, but became rather scarce during the first part of June, although single adults were found as late as early in July. The adult flies readily and is often seen crawling on window panes and screens. It is during the adult stage that the black carpet beetle spreads most easily from house to house.

The female beetle lays small, white, fragile eggs upon fabrics, in floor cracks, or in any sheltered spot near its food. The length of life of the parent insect ranges from 3 to 35 days during April, May, and June. Seldom are adults found later than July, except in very warm storage houses.

=The egg.=--The fragile white eggs are very seldom seen, and hatch in warm weather in about 6 to 10 days.

=The larva.=--The golden brown larva, with short, stiff body hairs, and its long tuft of hairs at the end of the body (Fig. 5), attains a length of one-fourth of an inch, exclusive of the tuft of hair at the end of the body. When first hatched it is almost microscopic in size, but increases rapidly under favorable food and climatic conditions. As it grows it sheds its skin from five to eleven times, and possibly oftener. This is of interest, for frequently the cast skins are mistaken for the insect itself, thus unnecessarily alarming the housewife concerning the abundance of this carpet beetle. It required approximately one year for larvæ to become fully grown when fed upon casein. Larvæ hatching during early June and fed upon casein became full grown and transformed to the adult stage during the following April, May, and June. Larvæ fed upon woolen cloth and silk and flour and meal were still only partially grown at the end of one year, indicating that the black carpet beetle may require two years for its development. In India it has been found that certain of these larvæ may require from one to three years for growth.

=The pupa.=--In the pupa stage the insect is white, clothed with fine white hairs (Fig. 6), and helpless. The pupa stage continues from 6 to 16 days during early summer at Washington, D. C, and is seldom found at any other season of the year.

=Seasonal history.=--Since the greater part of the life cycle is passed in the larva stage, the facts previously mentioned indicate that the black carpet beetle may have only one generation each year, although it may require two or three years for the same development. From the observation of the writer, made in houses, warehouses, and in the laboratory at Washington, there seems little doubt that a very large percentage of the insects have one generation each year. Farther north, or under less favorable climatic and food conditions, a generation may require two or even three years. At any rate, the adults are on the wing during early summer and the eggs for new infestations are laid then.

THE VARIED CARPET BEETLE.

Anthrenus verbasci L.

The varied carpet beetle is similar in shape to the common carpet beetle, but is a trifle smaller. It is called the "varied" carpet beetle because the color pattern on the back of the beetle varies considerably with the arrangement of the white, brownish, and yellowish scales. Figure 7 presents a common arrangement of the scales. The underside of the body is thickly clothed with white scales. This insect is a European pest now well established in widely separated parts of the United States. It has been found more often perhaps feeding upon seeds in museums than upon clothing, though its larvæ do attack woolen goods, feathers, hair, and silks.

Anthrenus scrophulariae L.

The larvæ are not unlike other carpet beetle larvæ of the genus Anthrenus. In Figures 8 and 9 are shown the newly hatched and the mature larvæ. When unmutilated, they posses on each side at the end of the body three dense tufts of bristles and hairs. If suddenly alarmed, the larvæ erect these tufts and spread the bristles and hairs out so as to form beautiful round balls.

During late spring and early summer, when the insect transforms to the adult stage in greatest numbers, the adults are driven by instinct to seek the bright sunshine and the pollen of certain flowers. In this respect they are not unlike other species of carpet beetles, the adults of which may be found also upon flowers. Some think that Viburnum or Spiraea bushes planted near the house will lure carpet beetles from the house. It is probably true, however, that the beetles, before leaving the house, lay a large percentage of their eggs, so that the attraction the sun and flowers have for them is of so little practical value to the householder that it is not worth while to depend upon flowers to lure the adults from the house.

The varied carpet beetle in the adult stage flies about in tremendous numbers. During May, 1922, the writer could capture them by the thousands upon at least 30 species of flowers found in public gardens in Washington, D. C. Single white roses often attracted more than 100 beetles, while a single stalk of a common herbaceous Spiraea harbored more than 1,000 specimens. The beetles often fly in large numbers rather high above the ground. A gentleman after painting a portion of the tin roof of his house during early May returned 24 hours later to complete the painting, only to find that during the interim an average of two varied carpet beetles to the square inch had become entangled in the fresh paint. The writer observed two adults fly into his city apartment in Washington through an open window during early March, 1922. These flights of adults are of extreme importance to the householder, because they emphasize how readily carpet beetles may spread from house to house during spring and early summer. Window screens will exclude all except the smallest specimens if they fit tightly, but the average removable screen does not fit tightly enough to prevent adult carpet beetles from crawling into the house between screen and window frame.

H. S. Barber.

THE FURNITURE CARPET BEETLE.

Anthrenus fasciatus Herbst.

The carpet beetle or dermestid here discussed has had no common name, but may be called the furniture carpet beetle (Fig. 10). It, too, is a European pest introduced into this country. It has been reported from Algeria, Spain, Greece, southern Russia Mesopotamia, and the East Indies It was first recognized in America during 1911, from specimens sent the American Museum of Natural History, New York City, from an upholsterer in Augusta, Ga. The specimen were taken from the curled hair of furniture upholstered 12 to 15 years previous to 1911. Investigation indicated that the hair used in this furniture came from Russia. The pest was not again noted in America until April, 1915, when it was found seriously damaging an upholstered chair in the White House. Since then, particularly during the last several years, many pieces of furniture and mattresses in different sections have been reported badly damaged.

So called because, like the other carpet beetles, it belongs to the family Dermestidae.

In all instances the furniture was upholstered with curled hair and moss, and in some cases the hair had been completely devoured by the larvæ, in association with smaller numbers of the common carpet beetle, the black carpet beetle, and the webbing clothes moth. (Figs. 11 and 12.)