Carpet beetles (Family Dermestids)
CONTENTS:
- Pest Status
- Health and safety
- Types of carpet beetle
- Carpet beetle identification
- Life-Cycle
- Where do carpet beetles live?
- What do carpet beetles eat?
- How to check for carpet beetles?
- How to get rid of carpet beetles?
- Carpet beetle treatments
- How to prevent a carpet beetle infestation?
- Carpet beetle frequently asked questions (FAQ)
PEST SNAPSHOT - CARPET BEETLES
- Class: Insecta
- Order: Coleoptera
- Family: Dermestidae
- Health threat: Low – moderate. Severe skin irritation can occur if you come into contact with hairs from larval stage.
- Bite / sting pain: Carpet beetles don’t bite.
- Difficulty to control: Medium – challenge is identifying source of infestation
- Diet: Animal fur and skin
- Main pest season: All year round
- Indoor/Outdoor pest: Indoor
- Carpet beetles belong to a large family of beetles called dermestids, which include a number of significant fabric and store product pests
- There are 3 main species – of carpet beetle in Australia, the Australian carpet beetle (Anthrenocerus Australis), the varied carpet beetle (Anthrenus verbasci) and the black carpet beetle (Attagenus unicolor).
- Carpet beetles are one of the most significant fabric pests, primarily targeting animal based fabrics.
- Successful treatment require identification of the source of infestation and treating areas of larval activity.
Pest Status
Carpet beetles are perhaps the most significant fabric pests eating a wide range of fabrics of animal origin – in particular wool, silk, furs and feather. This means that can cause damage to clothes, carpets, curtain, upholstery and more. They can also be a significant pest of stuff animals in museums.
Health and Safety
Adult carpet beetles don’t bite and they are not know to carry or transmit and diseases. However, the hairs from the carpet beetle larvae cause a very itchy rash (carpet beetle dermatitis) when they come into contact with skin. In a significant infestation there can be quite a few shed skins, and therefore a large number of carpet beetle hairs in the carpet or on the fabric to cause irritation.
Types of carpet beetle
In Australia there are 3 main species of carpet beetle:
- Australian carpet beetle (Anthrenocerus Australis)
- Varied carpet beetle (Anthrenus verbasci), more correctly called the variegated carpet beetle
- Black carpet beetle (Attagenus unicolor).
The variegated carpet beetle is probably the most commonly encountered.
The black carpet beetle is significantly larger than the other carpet beetle species.
There are a number of carpet beetles in the Destermid family, most are invasive, but there is one native species, the Australian carpet beetle, Anthrenocerus australis.
Another member of the demestids family is the khapra beetle, one of the most significant stored product pests globally. The larva and adult can easily be mistaken for carpet beetles. It is not currently in Australia, but there have been a couple of recent incursions.
What do carpet beetles look like?
Bed bugs are insects, so they have 3 pairs of legs. The adults have 2 pairs of wings, the top pair are the protective hard wing covers for the pair of flight wings underneath.
Adult carpet beetles are a small beetles – the Australian and varied carpet beetles are up to 3mm long and the black carpet beetle up to 5mm long. The patterns on the wing cases can be used to help tell them apart, although there are a range of beetles in the wider dermestid family that have very similar colours and patterns.
Carpet beetle larvae are also know as “woolly bears” due to their hairy appearance. Although distinguishing between the larvae of the different species is a job for the experts, all the larvae from the dermestid family have a similar appearance.
Carpet beetle life cycle
Carpet beetles go through complete metamorphosis, with egg, larva, pupa and adult stages.
The life-cycle typically takes anywhere between 2-9 months with the the life cycle being faster in warmer temperatures.
The main pest species – the variegated and black carpet beetles tend to have one generation a year, with the larvae tending to pupate in late winter with the adults emerging in spring. However, some species can have more than one generation a year.
Carpet beetle eggs
Carpet beetle eggs are a creamy colour less than a 1mm in diameter. However, apart for their small size, it is unlikely they will be seen as they are typically laid in hidden areas near or in potential food sources.
Carpet beetle larva
It is the larval stage of the carpet beetle that does all the damage. The larva will go through multiple instars before pupating. The number of instar stages and duration of the larval stage will depend on species, food availability and temperature. They may remain in the larval stages for a year or more depending on the conditions.
When ready to pupate the final stage instar will go into a diapause state until the conditions are right to pupate into an adult – this is often triggered by appropriate daylight period. The larva will then pupate over a period of 2 weeks to emerge as an adult.
Carpet beetle adults
The carpet beetles of most species emerge from their pupae in spring. When there are infestations inside buildings, this is why adults are commonly found on window sills trying to get outside – a good sign you have a carpet beetle infestations.
The adult beetles are short-lived, typically only living for around 2 weeks. Adult carpet beetles feed on pollen. Females can lay up to 90 eggs in a dry spot near a potential food source, which is often a bird nest… or in a wardrobe or on a carpet.
Where do carpet beetles live?
Carpet beetles are found across Australia and indeed worldwide.
Compared to other fabric pests, carpet beetles are more tolerant of lower humidity and so in Australia they can be found in both inland and coastal areas. (Clothes moths prefer a more humid environment and so are found mainly in coastal areas).
Adult carpet beetles are typically found on flowers, where they feed on pollen and nectar. They appear to have a preference for flowers from the daisy family.
Carpet beetle larvae will be found on the food where there are feeding. They typically feed in dark, undisturbed areas – on carpets under heavy furniture, at the bottom of curtains in the folds, in wardrobes and drawers (especially less used areas).
What do carpet beetles eat?
Carpet beetle larvae feed on animal fibres such as wool, fur, silk, feathers and leather. They are one of the few insects that can produce enzymes to digest keratin, the protein found in animal hair. They will also feed on a range of dry foods.
In the natural environment, carpet beetles will eat dead animal carcasses. So often the source of an infestation inside the house may be from a dead rat or possum in the roof or sub-floor.
The adult beetles feed on pollen from flowers, which is why they are often found on window sill – trying to get out after pupating inside.
Damage: They will chew irregular holes in fabrics. In carpets the damage will be in the dark, undisturbed areas such as under heavy furniture and along the edges of carpets and rugs, as the larvae will often hide and feed from underneath.
Key Behaviours
Adult carpet beetles live outside and feed on flowers. Carpet beetles on the window sill trying to get out are a sure sign of an infestation somewhere inside the house.
Although the adults appear in spring and throughout summer, the larvae will be active (and eating your fabrics!) all year round.
Although adult carpet beetles are attracted to the light and feed on flowers, carpet beetle larva prefer dark undisturbed areas, which is why damage can go unnoticed for a period of time.
How to check for carpet beetles?
If you spot adult carpet beetles on the window sill trying to get out, it is a sure sign you have a carpet beetle infestation somewhere in the house. However, it can be tricky to find where the larvae are feeding.
Here are the top spots to look:
- Woollen carpets or rugs, especially under furniture
- Woollen curtains
- Clothes in wardrobes and drawers that contain wool, silk, fur or feathers
- Bird nests or dead animals in the roof void
- Open dried food in the pantry
Look for the carpet beetle larvae or their shed skins (which still look like larvae).
However, be very careful and even consider wearing gloves when looking for carpet beetles, as the hairs from carpet beetle larvae can be very irritating.
How to get rid of carpet beetles?
To successfully get rid of carpet beetles, it is necessary to find all the sources of infestation.
This can be a challenge for homeowners, so often it is better to engage a professional pest manager.
- The first step in the process is to identify the source of the problem. Carpets and rugs (especially along the edges of rooms and under furniture), in clothes wardrobes and drawers, and in the roof void and sub-floor (looking for carcasses) are the first places to look.
- Any damaged clothes, food or dead carcasses need to be bagged up and thrown out.
- For any undamaged clothes, they should be placed in bags, sealed and placed in the sun for several hours to kill the larvae and any eggs. If the clothes are delicate and you are concerned about how the heat may impact them, they should be inspected individually and then washed in as hot a wash as the label suggests.
- The pest manager will spray any clothes storage areas with a suitable product to kill any eggs, larvae or adults still present are eliminated. If the infestation area is carpet, curtain or other fabric it will need to be treated similarly.
- Prevention of future problem should focus on regularly vacuuming of carpets (especially under heaving furniture) and making sure that clothes are stored in sealed bags at the end of each season
- Having well-fitted insect screens to prevent adult carpet beetles from flying in from outside will also help
It is also suggested to avoid having wool insulation as this can also provide a food source for carpet beetles.
Carpet beetle treatment – Carpet beetle spray
A successful carpet beetle treatment is often best achieved with the homeowner and professional pest manager working together to ensure all sources of the carpet beetle infestation are detected and treated.
All wardrobes and clothes drawers need to be emptied of clothing so that all areas can be sprayed. Whereas it is tempting only to deal with obviously infested clothes and treat the areas those clothes were stored, with the eggs very difficult to spot, it is recommended that it should be assumed that all clothes are infested. Rolling the dice and carrying out only a partial clothes inspection, runs the significant risk of carrying out an incomplete treatment and the infestation continuing.
Infested carpets and rugs need to be thoroughly vacuumed, making sure the edges are lifted and vacuumed underneath.
For materials that cannot be heated or frozen it is then necessary to treat any infested or suspected areas of activity with an insecticide spray. A professional pest manager will use a suitable product, spraying the inside of drawers and wardrobes, the edges of carpets, rugs and under furniture. The product will be selected to ensure there is no damage to the fabric. These specialist sprays are suitable for use on carpets where children and pets may come into contact with the treatment. These sprays also have a residual effect and so protect the areas from potential re-infestation for several months.
Treatment of any infested wool insulation in the roof is a bit more problematic. A pest manager can apply a dust treatment to the roof void which can be effective. However, as the treatment won’t reach inside or underneath the insulation, in extreme cases, the insulation may need to be thrown out.
How to Prevent a Carpet Beetle Infestation?
- Regularly vacuum under furniture and along edges and corners of rooms
- Make sure unused clothes are checked and stored away in sealed containers at the end of the season
- Ensure well fitted insect screens are in place to prevent adult beetles flying in and if possible avoid having flowering plants to close to any windows and doors
- Check any flowers brought into the house for adult beetles
Learn more about where carpet beetles normally live and how carpet beetle infestations start…
Carpet Beetle FAQ
What are the signs of carpet beetles?
Adult beetles on the window sill trying to get out, is a sure sign of a carpet beetle infestation inside the house.
Damage to animal fabrics is a sign of carpet beetle infestation – clothes moths typically only attack plant based fabrics (eg. cotton) and silverfish prefer starchy materials, in particular paper.
Carpet beetle larvae or their spend skins on carpets, rugs, curtains or amongst clothes will help identify carpet beetles as the pest causing the damage.
Their droppings, which are the size of coarse sand (and likely the colour of the fabric on which they are feeding), will also be found at the feeding sites.
What does carpet beetle damage look like?
There are a number of clues which together can be used to determine whether the damage to a fabric has been caused by carpet beetles:
- Carpet beetles generally prefer animal material
- Heavy damage tends to be concentrated in a few areas, rather than a few holes spread across the fabric
- The damage will normally occur in dark, undisturbed areas
- There should be the presence of the hairy carpet beetle larvae or their spent skins (clothes moths often produce webbing)
Information on other fabric pests.
