Moths / Beetles - General Information

Flour Beetles

There are several species of Flour Beetles, the 2 most common being: The Confused Flour Beetle and The Rust-Red Flour Beetle.

Flour Beetles are mainly pests of cereal products and commonly found in bakeries and flour mills & some times domestic premises. Apart from cereals other products may be attacked, such as, oil seed, oil cake, nuts, dried fruit, spices, chocolate, bones and other animal products. Requires heated premises to survive the winter. You may encounter them in a kitchen or food store. Often eggs from beetles are in foodstuffs, pet food or bird food we consume but if the foodstuffs are ‘left’ a long time before being used or you were sent older stock from the warehouse/shop then the eggs have a chance to hatch out & complete their life cycle. This applies to most stored product pests.

Life-cycle

Up to 450 eggs are laid at the rate of 2-10 per day, depending on temperature. The white eggs are sticky and soon get covered with debris. At 22-27 C they hatch in 6-14 days. The larvae are white tinged with yellow and pass through 5-15 moults before reaching a full-grown length of 5 mm. This takes 3-9 weeks. Pupae lie in the same foodstuff as the larvae and darken from their original white before emerging after 9-17 days. Adults feed on the same food as the larvae and live 15-20 months. There may be 5 generations per year.

Treatment

Carpet, Larder Beetles & Moths
There are 4 main species of ‘Carpet Beetles’ with similar habitats and life-styles; Varied Carpet Beetle, Furniture Carpet Beetle, Museum Beetle and Fur Beetle. These species are pests of animal and occasionally food products. Consequently, they may be found wherever these commodities are stored or handled. Carpet Beetles are now one of the major pests of textiles, their success being attributed to central heating, which ensures uniform temperatures, and to the increasing use of wall-to-wall carpeting, which allows the insects to breed undisturbed. Furthermore, the success of industrial mothproofing treatments has effectively removed the moth challenge. Warm, dry conditions are ideal for their development, but they can survive in foodstuffs of very low moisture content, e.g. 11-12%.
The Museum Beetle, as the name suggests is commonly found in museums where it is a particular pest to dried specimens.
The Fur Beetle may be found in a wide variety of products including furs, skins, textiles and grain.
Adult Carpet Beetles live outdoors on pollen and nectar. The larvae are particularly evident in autumn when they wander in search of food and hibernation sites. Carpet Beetles thrive in situations where they remain undisturbed, for example beneath carpets, around skirting boards and in wardrobes. Bird and rodent nests, animal remains and dead insects are frequently reservoirs of infestations. Larval forms can cause considerable damage to keratin-containing products such as wool, fur, leather, silk and dried animal remains. Damage takes the form of clean, irregular holes. Because of the large number of larval moults, when cast larval skins are seen they tend to exaggerate the extent of the infestation.

Life Cycle

This is the life cycle of the varied Carpet Beetle; the other types of beetles mentioned above have similar life cycles.
Mating occurs immediately after the adults emerge from the pupa stage. The females produce 20-100 eggs over a period of 2 weeks and these are deposited or stuck to a potential larval feeding site. These hatch after 2-4 weeks to give the hairy, squat “woolly bears”. This stage can survive up to 10 months and will hibernate through the winter. The length of larval life, as with most insects and larvae, depends upon humidity, temperature and quality of diet. They generally moult at least 6 times but sometimes more. Pupation takes place in the spring and last 10-30 days. The adults live for 2-6 weeks and are able to fly to the particular flowers on which they feed and to search for egg laying sites.

Moths

In the United Kingdom, the case making clothes moth is much less important than the webbing clothes moth as a pest. It can be found throughout the country, but is most common in the southern counties. It is particularly capable of damaging hair and feathers, but will also feed on spices, tobacco, hemp, and skins. The moth derives its common name from the small silken case that the larva spins about its body and carries about wherever it feeds, thrusting its head and legs out in front (see picture below).

Sometimes in a severe infestation, larvae may crawl up on a wall in large numbers, dragging their cases behind them. In domestic situations the first time you may notice Moth or Carpet Beetle damage is when a piece of standing furniture is moved. Moth/Carpet Beetle damage usually occurs in carpets on undisturbed areas. Bird and rodent nests, animal remains, old wasp/bee nests and dead insects are frequently reservoirs of infestations. Description:
Adult case making clothes moths have a 1/2-inch wingspread. The adult is somewhat smaller and more brownish than the webbing clothes moth, and has 3 dark spots on the wings, but the spots become less discernible if the wing scales are worn off. Hind wings are smaller, lighter, and fringed with hair and scales. The males are smaller and lighter in colour than the females, and are active fliers. The females are sluggish, and fly only for short distances. The first thoracic segment of the larva, at first brown, later becomes black, and is divided by a longitudinal band.
Biology Females live about 30 days and lay 100 to 300 eggs. The larva stage lasts 50 or more days, (depending on temperature) and the pupa stage is passed in the case or cocoon. There are about 2 generations a year. The larva can turn within its case and feed on food material at either end without altering the position of the case. If the case is removed from the larva when it is very near pupation, the larva will die. Rarely will the larva spin a web directly on the material on which it is feeding, but will usually attach its case to the material by means of silken threads. Pupation takes place within the case after both ends have been sealed with silk. There were found to be 3 or 4 generations a year at 26 ° ± 8 °C (79 °F) and 82% ± 10% relative humidity when larvae were fed on woollen fabrics impregnated with 5% yeast (CChem, 1956).

Control and Treatment

The best way to combat carpet beetles and clothes moths is to vacuum all carpet areas. Rooms should be cleaned often enough to prevent the accumulation of lint, hair, and other carpet beetle and clothes moth food materials.

Larder Beetle

The adult larder beetle is dark brown and approximately 1/3 inch in length. The basal halves of the wing covers are densely covered with coarse, pale yellow hairs. Six dark spots are usually in the yellow band. The under surface of the body and legs are covered with fine yellow hairs.

Life cycle

Outdoors the life cycle of this insect is regulated by the seasons; indoors it may breed continuously throughout the year. Eggs are laid in batches of 6-8, with the total per female being about 200. The larvae are dark coloured and covered with dark brown hairs. Two curved spines on the last body segment characterise it. Like the adult, the larva is densely covered with hairs. The larvae pass through five or six moults (five times if male, and six if female), during the 35 to 80 days of their lives. The larvae have a strong tendency to remain in dark places. Just before the larvae pupate they begin to migrate, and are often encountered by homeowners at this time. These older larvae often bore into materials such as wood, cork, or insulation looking for a place to pupate. The pupa period lasts about 15 days. The adult’s mate soon after emerging and eggs are laid near a food source. If conditions are ideal, a generation may be completed in 40-50 days.

Damage and Habitat

Major damage occurs from larval feeding and the boring of the larvae before pupation. Larder beetles will attack stored ham, bacon, other meats, cheeses, tobacco, dried fish, dried museum specimens, and pet foods, for example. All of these conditions are available in, meat processing plants, renderers, butchers, fishmongers, delicatessen counters in supermarkets and, of course, beneath and behind cookers and refrigerators in the kitchen of a domestic dwelling. The larvae will bore into any commodity containing meat products; they have also been known to bore into structural timbers. Tests have shown that they can bore into lead with ease and tin with some difficulty. The boring is for the purpose of providing a protected place for pupation, not for feeding.
Larder Beetle infestations may arise from old meat, dead rodent/bird carcasses or bird’s nests. One particular problem with this pest is that once the larvae have finished feeding and are ready to pupate they crawl some distance from the feeding site and will burrow quite deeply into walls or cavities. Here they pupate and will emerge for up to 12 months afterwards. This makes treating these beetles may have to be carried out over a long period of time.

Demand CS First Aid Measures:

Eye contact: Immediately irrigate with eyewash solution or clean water holding the eyelids apart, for at least 15 minutes. Obtain immediate medical attention. Skin contact: Take off immediately all contaminated clothing. Wash skin immediately with water, followed by soap and water. Such action is essential to minimise contact with skin. Contaminated clothing should be laundered before reissued. Inhalation: Remove patient from exposure, keep warm and at rest. Obtain medical attention as a precaution. Ingestion: If swallowed seek medical advice immediately and show the container, label or this information sheet, if possible. Do not include vomiting.
Medical advice: If the amount of chemical is judged to be less than a lethal dose,
observe the patient and treated symptomatically. If gastric lavage is considered
necessary, prevent aspiration of gastric material, Consider
administration of activated charcoal and laxative.

Emergency Phone Numbers:
*Sorex 0151 420 7151
*Ficam Tel: 01223 870312

National Poisons Information Service: 0171 955 5095.
MAFF: 0171 238 3000
HSE: 01256 473 181.

*Registered trade marks and/or names.