Description

​

Variegated carpet beetle Length: 3 mm Order Coleoptera ('case-shaped wings') Characteristics Forewings hard and leathery, meeting along the central line of the dorsal surface; forewings membranous, sometimes absent; crushing mouthparts; well-developed thorax; complete metamorphosis with stages of egg, larva, nymph and adult. Family: Dermestidae (skin eaters) Species characteristics Variegated carpet beetle (Anthrenus verbasci) Length of adults: 2 to 4 mm; body strongly convex; variable color: brown or black, with yellow or white spots and scales on the back; ventral surface covered with fine gray-yellow scales; antennae with 11 articles, with clubs with 3 articles at the end, clubs having practically parallel sides; at rest, the antennae are found in folds of the thorax; slightly rounded eyes; legs short, retracting into furrows on ventral surface; brown larvae, bearing 3 tufts of golden hairs at the end of the abdomen. Furniture beetle (Anthrenus flavipes – formerly vorax) Length of adults: 2 to 4 mm; body strongly convex; variable color: brown or black, with yellow or white spots and scales on the back; ventral surface covered with white scales; antennae with 11 articles, with oval clubs with 3 articles at the end; at rest, the antennae are found in folds of the thorax; eyes serrated on the inner side; legs short, retracting into furrows on the ventral surface and covered with a thick layer of yellow scales; brown larvae, bearing 3 tufts of golden hairs at the end of the abdomen. Museum beetle (Anthrenus museorum) Adult length: 2 to 2.8 mm; body strongly convex; variable color: brown or black, with yellow or white spots and scales on the back; antennae with 8 articles, with clubs with 2 articles at the end; at rest, the antennae are found in folds of the thorax; legs short, retracting into furrows on ventral surface; brown larvae, bearing 3 tufts of golden hairs at the end of the abdomen.

​

Fur beetle (Attagenus pellio) Adults oblong in shape, with a length of between 4.5 and 6 mm; black color, but with small spots of white hairs on each side of the elytra; base of thorax also covered with white hairs; larvae with a distinctive tuft of very long hairs that project backwards. Distribution The variegated carpet beetle is a species native to Europe and the United Kingdom, it is commonly found south of a line linking Bristol to the Gulf of Wash (on the east coast, near Nottingham). The furniture beetle has a sub-tropical origin and is more sensitive to cold. Both species parasitize products of animal origin and sometimes plant foods. As a result, they can be found wherever these materials are stored or handled. The carpet beetle is today the most harmful insect on textiles, its success being attributed to central heating, which ensures uniform temperatures, and the increasing use of carpeting, which allows it to thrive. multiply without being disturbed. Additionally, the success of industrial moth control treatments has effectively eliminated its competition. Warm, dry conditions are ideal for beetle development, but they can survive in foods with a very low humidity level, around 11 to 12%. As its name suggests, the museum beetle is generally found in museums, where it is a particular pest dried specimens. It also attacks textiles and has been recorded as a pest of cereals. Fur attack can be found in a wide variety of products, such as furs, skins, textiles and grains. Adult beetles live outdoors, feeding on pollen and nectar, which they collect particularly from umbellifers and spireas. They can also be found snaking up walls and windows. Under a temperate climate, the larvae are particularly visible in autumn, when they wander in search of food and hibernation sites. Beetles thrive in places where they are undisturbed, such as under carpets, around baseboards and in cabinets.Bird and rodent nests, animal remains and dead insects frequently constitute infestation reservoirs. Importance Larval forms can cause Considerable damage to products containing keratin, such as wool, fur, leather, silk and remains of dead animals. Sometimes plant-based products, such as grains and fibers, are also attacked. The damage takes the form of sharp, irregular holes and in textiles it usually appears around seams. No silk webs or droppings are seen, and by the time the larvae are discovered, considerable damage has often already been done. Given the large number of larvae moulting, the discovery of their old coverings tends to make us exaggerate the extent of the infestation. Beetles pose a limited health risk, although they are potential vectors of anthrax. In some cases, the hairs of the larvae cause skin irritations in people exposed to large numbers of insects. Anthrenes.

​

Life Cycles of the Two Most Common Species Variegated Carpet Beetle Mating takes place immediately after the onset of adult life. Females lay between 20 and 100 cream-colored eggs, 0.5 mm long and having thorn-like projections at one end. Over a period of 2 weeks, these eggs are deposited in suitable cracks or cemented with sticky secretions at a potential larval feeding site. After 2 to 4 weeks, the eggs hatch, giving birth to the characteristic larvae (“wooly caterpillars”). ticks, hairy and stocky. Once mature, they measure 4 to 5 mm, are brown and have 3 tufts of golden hairs arranged in pairs on the posterior segments of the abdomen. Their short 5-article legs are well developed, with a single claw on the terminal article. The larvae avoid light and roll up into a ball when disturbed. The length of larval life depends on humidity, temperature and quality of the food. Dirty foods are generally their favorites. During this period, the larvae go through at least 6 molts, but the longer they remain in their larval state, the greater the number of molts.The transformation into a nymph takes place in the last larval envelope, on the same site of development and the nymph stage extends over 10 to 30 days. Adults live between 2 and 6 weeks and are capable of flying towards flowers on which they feed and seek out oviposition sites. Furniture beetle One to three days after its appearance in the state As an adult, the female lays up to 100 eggs, produced in one to three packets. The eggs hatch after 3 weeks, giving birth to larvae whose color ranges from white to brown, including yellow, depending on the color of the food consumed. Their legs are short and well developed and include 5 articles. The larval stage lasts for up to 12 months and the larvae measure 5 mm when finished growing. The nymphs develop in the last envelope. They are white and their lifespan is 2 to 3 weeks. At the end of This period, the beetles appear as adults. Anthrene larva (“wooly caterpillar”) Length: 4.5 mm.

Control The wandering habits of these insects mean that they frequently infest large areas, making their control difficult. Assessing Infestations The first step in controlling carpet beetles is finding the source of the infestation. This could be an old nest, animal remains, wool-based insulation, soundproofing, wool-based furniture, or debris that accumulates between and around floorboards. a) Hygiene/management All sources of infestation must be removed and if possible burned. Routine monitoring and regular cleaning are also important. b) Insecticide control Careful surface spray treatments with residual activity are essential when infestations are heavy, to ensure that the larvae are killed. The treatment of carpets and other valuable furniture must be carried out with care.