aM ae ain a) Hi ‘¥ i; 14) as a ‘ os ie oe fe en ay, a hd a Hi re oO Aad Ay UMA : ‘ +08 te is ' wy. We ae m ot, ay oF aera Deo ane is Fae - Ph : i , ie pay eae 2 di: ‘ oe : ae ae a ag st, _ ‘ a Rt HE Nas n ian “i we i i mee. i. ni ne CR 7 oe Ter 7 ce on i 0 + : _ A) wn wae 7) ie sat ie “0 Pe Via © Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. a as a ae ae ae | ; cot : ) ant F P wt sv! Vin hee yr a ia) ae es oon Ws “ ee | Pan 2) 7 CIRCULAR NO. 36, SECOND SERIES, REVISE. Issued January 15, 1908. United States Department of Agriculture, BUREAU OF ENTOMOLOGY, L. O. HOWARD, Entomologist and Chief of Bureau. THE TRUE CLOTHES MOTHS. (Tinea pellionella et al.) By C. Lb: MARLATT; Entomologist and Acting Chief in Absence of Chiefs, The destructive work of the larve of the small moths commonly known as clothes moths, and also as carpet moths, fur moths, ete., in woolen fabrics, fur, and similar material during the warm months of summer in the North, and in the South at any season, is an altogether too common experience. The preference they so often show for woolen or fur garments gives these insects a much more general interest than is perhaps true of any other household pest. The little yellowish or buff-colored moths sometimes seen flitting about rooms, attracted to lamps at night, or dislodged from infested garments or portieres, are themselves harmless enough, and in fact their mouth-parts are rudimentary, and no food whatever is taken in the winged state. The destruction occasioned by these pests is, therefore, limited entirely to the feeding or larval stage. The killing of the moths by the aggrieved housekeeper, while usually based on the wrong inference that they are actually engaged in eating her woolens, is, nevertheless, a most valuable proceeding, because it checks in so much the multiplication of the species, which is the sole duty of the adult insect. The clothes moths all belong to the group of minute Lepidoptera known as Tineina, the old Latin name for cloth worms of all sorts, and are characterized by very narrow wings fringed with long hairs. The common species of clothes moths have been associated with man from the earliest times and are thoroughly cosmopolitan. They are all probably of Old World origin, none of them being indigenous to the United States. That they were well known to the ancients is shown by Job’s reference to ‘‘a garment that is moth eaten,’’ and Pliny has given such an accurate description of one of them as to lead to the easy identification of the species. That they were early introduced into the United States is shown by Pehr Kalm, a Swedish scientist, who took a keen interest in house pests. He reported these tineids to be abundant in 1748 in Philadelphia, then a straggling village, and says that clothes, worsted gloves, and other woolen stuffs hung up all summer were often eaten through and through by the worms, and furs were so ruined that the hair would come off in handfuls. 2 What first led to the association of these and other household pests with man is an interesting problem. In the case of the clothes moths, the larve of all of which can, in case of necessity, still subsist on almost any dry animal matter, their early association with man was probably in the réle of scavengers, and in prehistoric times they probably fed on waste animal material about human habitations and on fur garments. The fondness they exhibit nowadays for tailor-made suits and other expensive products of the loom is simply an illustra- tion of their ability to keep pace with man in his development in the matter of clothing from the skin garments of savagery to the artistic - products of the modern tailor and dressmaker. Three common destructive species of clothes moths occur in this country. Much confusion, however, exists in all the early writings on these insects, all three species being inextricably mixed in the descriptions and accounts of habits. Collections of these moths were submitted some years ago by Professors Fernald and Riley to Lord Walsingham, of Merton Hall, Eng- land, the world’s au- thority on tineids, and from the latter’s careful diagnosis it is now possible to sepa- rate and recognize Fig. 1.—Tinea pellionella: Above, adult; at right, larva; at the different species left, larvain case. Enlarged (from Riley). Sr, A | | easily. The common injurious clothes moths are the case-making species (Tinea pellionella L.), the webbing species or Southern clothes moth ( Tineola biselliella Hummel), and the gallery species or tapestry moth (Trichophaga tapetzella L.). | A few other species, which normally infest animal products, may occasionally also injure woolens, but are not of sufficient importance to be here noted. THE CASE-MAKING CLOTHES MOTH. The case-making clothes moth (Tinea pellionella L.) (fig. 1) is the only species which constructs for its protection a true transportable case. It was characterized by Linnzeus, and carefully studied by Réaumur, early in the last century. Its more interesting habits have caused it to be often a subject of investigation, and its life history will serve to illustrate the habits of all the clothes moths. The moth expands about half an inch, or from 10 to 14 mm. Its head and forewings are grayish yellow, with indistinct fuscous spots on 3 the middle of the wings. The hind wings are white or grayish and silky. It is the common species in the North, being widely distributed and very destructive. Its larva feeds on woolens, carpets, etc., and is especially destructive to furs and feathers. In the North it has but one annual generation, the moths appearing from June to August, and, on the authority of Professor Fernald, even in rooms kept uniformly heated night and day it never occurs in the larval state in winter. In the South, however, it appears from January to October, and has two or even more broods annually. The larva is a dull white caterpillar, with the head and the upper part of the next segment light brown, and is never seen free from its movable case or jacket, the construction of which is its first task. If it be necessary for it to change its position, the head and first segment are thrust out of the case, leaving the thoracic legs free, with which it crawls, dragging its case after it, to any suitable situation. With the growth of the larva it becomes necessary from time to time to enlarge the case both in length and circumference, and this is accomplished in a very interesting way. Without leaving its case the larva makes a slit halfway down one side and inserts a triangular gore of new mate- rial.