Seven Ways To Get Rid Of Beetles In Your House

Beetles differ from other winged insects in that one pair of wings has hardened into a wing case that protects the delicate flying wings beneath. More than three hundred thousand known species exist, and many play a vital role in the world’s ecosystems, so if you have a beetle infestation, it helps to know what kind they are.

Seven ways to get rid of beetles, depending on the type of infestation you have, are:

  • Heating
  • Drying
  • Freezing
  • Sanitation
  • Chemical treatments
  • Insecticides
  • Gas.

Identifying the beetle is key to successful eradication, as it will tell you where to focus your efforts and what method works best.

Some beetles can cause damage in the home to wood, furniture, carpets, fabrics, and clothing. Others can be annoying by swarming around lights or leaving bad-smelling streaks on the walls. Often it isn’t the beetles that do the damage but their larvae which generally operate behind the scenes and are seldom visible.

Ways To Get Rid Of Beetles in Your House

Beetles can be a pain to get rid of in the first place. Down below is a list of multiple ways you can make them go away.

1. Heating

Many beetle pests and their larvae can be destroyed by temperatures over 300 C (860 F). For some beetles, heating over 500 C (1220 F) is necessary. Depending on the infested item’s size and nature, it can be put into the oven or left out in direct sunlight if you live in a scorching area.

2. Drying

Beetles need a certain level of humidity and cannot survive if it drops too low. Drying can be achieved by improving ventilation in the infested area, installing a heater, sealing pipes, mending dripping taps, and preventing rainwater from entering walls, basements, and crawl spaces.

3. Freezing

Many beetle infestations can be destroyed by storing the infested item in a freezer at -200C for a week or more. This usually kills eggs, larvae, and beetles. This only applies to items small enough to go into the freezer. If you have a walk-in freezer, larger items can be accommodated than in a chest freezer.

4. Good Sanitation

Beetles feed on hair, pet fur, spilled food items, stored food, dead insects, and other organic matter. Thorough vacuuming of carpets, floors, corners, and under furniture means there is less food available—store food in sealed containers in places with low humidity.

Clothes and other fabrics should be thoroughly laundered and sealed in plastic bags before being put away in storage. Careful ironing of clothes, including hems, cuffs, seams, folds, and other hiding places, will also kill beetles and larvae that live there. Infected foods should be sealed in plastic bags and thrown away.

5. Chemical Treatments

Depending on the type of beetle, certain items such as wooden panels, fixtures, fittings, beams, joists, and furniture can be treated with chemicals that prevent or kill beetle infestations.

These chemicals are liquid solvents or pastes that can be painted or spread over the infected wood. Chemical treatments are not always effective for certain beetle types, so identification is critical.

6. Insecticides

These come in sprays, pastes, traps, and liquids designed to kill certain beetles. You need to get one that works with the particular type of beetle you have, which means you should first identify it. Since many beetles are attracted to light, you may investigate insects congregated around a lamp or other light source useful for identification purposes.

You cannot treat food items and clothing safely with insecticides, so be sure to read the label and use it only according to the instructions. It would be best always to use insecticides as a last resort as many beetle infestations can be eliminated without them.

7. Toxic Gas

In some cases, the item can be sealed in plastic or a chamber and then exposed to toxic gas, such as methyl bromide, in a process called fumigation.

This is seldom, if ever, cost-effective when treating an entire building and may not be worth the health and environmental risks. You would need to use specialists to do this type of treatment as it is too dangerous for a layperson.

Different Types Of Beetles

One thing for sure is to look out for the different kinds of beetles and what they look like, especially so you know what you are dealing with.

Powderpost Beetles

Powderpost Beetles

The name “powderpost beetle” covers several different insects that chew wood into a powder similar to flour. Their larvae burrow tunnels into the wood beneath its surface as they feed and are usually only discovered after people find small round holes and wood powder on the surface. The round holes are caused when the larvae become beetles that chew their way out.

When the eggs hatch, the larvae bore into the wood and feed on it until they turn into beetles which could take between one and five years depending on the species. It is uncommon to spot the beetles because they are primarily nocturnal and secretive. Some of them are attracted to light and may occasionally be seen on windowsills.

By the time you see the beetles, the larvae may already have done extensive damage to wooden structures or furniture in the home. The most destructive powderpost beetles belong to three insect groups, the anobiids, the lyctids, and the bostrichids. There are several species within each group capable of eating wood.

Beetles in the Anobiid group are reddish-brown to dark brown and damage softwoods and hardwoods. Unlike drugstores and cigarette beetles, they don’t usually infest stored food.

They can cause severe damage to wooden joists, beams, and other structures of a building and prefer moist wood. As a result, they are commonly found in unheated buildings, basements, crawl spaces and garages, and homes with high humidity. 

These beetles live in beams, subflooring, joists, and other wooden structures in buildings. They infest hardwoods and softwoods, consuming them from the inside. The famous deathwatch beetle and the furniture beetle belong to the Anobiid group.

Deathwatch Beetle

Deathwatch Beetle

The deathwatch beetle is brown and gets its name from the ticking sound caused by bumping its head against the tunnel walls as it bores through the wood.

In the old days, people who watched on the deathbed of a loved one heard this sound and associated it with impending death. Depending on the environmental conditions in which it finds itself, the beetle can complete its life cycle in one year or as many as twelve.  

It lives deep within the timber and can be challenging to get rid of. It is essential to inject insecticide into the exit holes of the adult beetles and spray the wood surface. This beetle can survive multiple re-infestations if the wood is not treated and signaled the death knell for many historic buildings.

The adult beetle does not need to emerge from the wood to mate but can do so while still in the tunnels and cavities beneath the surface.

Surface insecticidal sprays only penetrate the wood to a few millimeters and only if the wood is thoroughly cleaned before spraying. If only certain areas are treated, the beetles will congregate in the untreated areas, usually wooden joints difficult to reach.

Various treatment methods have been tried over the years with varying success. Chemical solvent-based insecticides can be hazardous to human health, so water-based fluid emulsions have been used, but their ability to penetrate the wood is lower.

Pastes that use the same contact insecticides as the fluid emulsions penetrate a bit deeper and are more effective but are difficult to apply to all areas and leave a waxy skin on the treated timber.

The pressurized injection of liquid insecticides through pre-drilled holes penetrates much further and can be more effective, but there is the potential for gallons of it to accumulate in voids or to squirt out of a hole in the wood a little way down the line. There is no guarantee that it will reach the larvae.

The injection of large volumes of insecticide in a solvent such as white spirit can increase fire risk, spoil plaster and other finishes, and damage electrical insulation. It is also unhealthy for the building’s inhabitants. Water-based insecticides cannot be used in pressure irrigation because they will cause the wood to swell.

People have found that smoke treatments are even less effective than spraying treatments and usually only kill spiders.

Gas fumigation, using methyl bromide, is another method that can be effective but requires that the building or area to be treated is adequately sealed, which can be extremely difficult. When combined with the toxic gas hazards, this makes it impractical for use in the types of buildings usually infested by the deathwatch beetle.

Heat sterilization is the latest weapon to join the arsenal in treating a woodboring beetle infestation. Still, deathwatch beetle larvae have been found in the middle of large fire-damaged timbers. The theory is that maintaining a building at 50 degrees Celsius for an hour will kill all wood-borers. Heat is not suitable in areas where wood paneling or fragile wood finishes could be damaged.    

Furniture Beetle

Furniture Beetles

The scientific name of the furniture beetle is Anobium Punctatum, and it is also referred to as a ‘woodworm.’  It is one of many beetles that consume the cellulose in timber in temperate climates. It originates from northern Europe but has spread as far afield as New Zealand and the US’s east coast.

The adult beetle emerges in spring, leaving a small round hole in the wood surface. Upon emerging, the female seeks out wood suitable for egg-laying, leaving a trail of pheromones for the male to follow so that they can mate. They then die, leaving the eggs to hatch.

This beetle only lays its eggs on dead wood where there are cracks and crevices or holes from previous beetles, and it prefers the sapwood of hardwoods and softwoods that have been dead for five or more years. However, it can also infest the heartwood of beech, cherry, birch spruce, alder, or other woods that fungi have weakened.

The longest part of their lifecycle is spent as larvae grayish-white with a dark narrow band over the mouthparts. This is the stage that causes the most damage. It usually takes around three years to complete its lifecycle. The beetle prefers humid but not wet environments and temperatures below thirty degrees Celsius.

Woodworm is commonly found around poorly insulated and ventilated skylights, roof hatches, and the floors of bathrooms and kitchens. With the advent of modern central heating and air conditioning, infestations of this beetle have become rare.

The beetle got its common name from the decay it caused in furniture, which, in the past, was made of cheaper and less durable wood. Drilling test holes and probing of the wood can identify the extent of the damage caused by woodworm, but X-rays have also been used to examine the furniture of historical value.

Reducing the wood’s moisture content through ventilation and drying techniques will destroy the larvae for a year or more. Since this is central heating in buildings, many infestations have been eradicated and are no longer active.

Short-term treatment with insecticides or timber treatment chemicals is not cost-effective for buildings because penetration is limited and does not affect the larvae in the wood’s depths. The environmental and health hazards posed by using toxic chemicals and gases outweigh such treatments’ efficacy.

More recently, localized deep treatments using chemicals such as organoboron, which can penetrate deeper into the wood in damp conditions, have been recommended. It can be difficult to maintain chemical concentrations at toxic levels within the treated timber in buildings, so using these chemicals is seldom cost-effective.

The most effective way of dealing with infestations of movable wooden items such as furniture is to subject them to temperatures higher than fifty degrees Celsius for some time. Raising the temperature also affects the humidity, and when the wood dries out, the larvae can no longer consume it, so they die. However, the heat treatment of a whole building in this way can be expensive.

The larvae can also be killed by freezing. Still, since they can survive at temperatures below freezing in the wild, they must be instantly subjected to temperatures below -200 C.  Repeatedly freezing and thawing the wood may be necessary to ensure that all the larvae are dead.

Carpet Beetles

Carpet Beetles

Carpet beetles eat carpets, wool, silk, skins, leather, and fur and people sometimes mistake signs of an infestation for clothes moths. Adults are small and oval-shaped, ranging from black to various mottled patterns with yellow, brown, white, or orange. The beetle itself only eats flower pollen, but its larvae will consume multiple fabrics.

The larvae are tan to brown, slow-moving bristly or hairy bugs that molt as they grow, leaving their sheddings behind. They graze along the surface of materials resulting in worn areas and holes. They only feed on organic materials, not synthetics, and eat sweaters, scarves, rugs, blankets, comforters, leather upholstery, carpeting, and feathers.

Lint, hair, dead insects, and other organic debris accumulating inside floor vents or under baseboards can also provide carpet beetle feeding grounds. Some species will even eat pet food, cereals, and seeds.

Laundering or dry-cleaning clothes thoroughly before putting them in long-term storage helps prevent infestations. Using tight-fitting plastic containers for storage also keeps them out. Expensive furs can be put into cold storage. Putting items in plastic bags with mothballs, naphthalene crystals, or flakes will only be effective if there is sufficient vapor concentration.

Cedar closets and chests do not protect fabrics from these beetles because they are not usually sealed, so the volatile oils are not at sufficiently high concentrations.

Thoroughly vacuum rugs, carpets, furniture, vents, and floors helps prevent infestation, and accumulations of dead insects such as flies should be avoided. Birdseed, pet food, and cereals should be stored in airtight containers.

To get rid of carpet beetles, locate all infested items by carefully checking hems, folds, creases, and undersides of susceptible fabrics. Items beyond redemption should be sealed in plastic bags before being discarded, while salvageable ones should be dry-cleaned or laundered. The heat from washing machines and driers kills eggs and larvae.

Insecticidal sprays can be used on carpets and rugs and around room edges, underneath furniture, and at the bottom of closets. However, they can stain or damage clothing, so they should only be used as directed on the label.

Glue traps are effective at revealing infestations and can be baited or not. They can be placed in areas where the insects are likely to occur but bear in mind that different types of carpet beetles are attracted to different odors, so it’s essential to identify the beetle before using baited traps.

They can also be killed by putting the item in a household freezer. The temperature should be lower than or equal to -200C, and the articles should be stored for at least a week. This is sufficient to kill all life stages of the beetle within seventy-two hours.

To prevent carpet beetles from going unnoticed for long periods, it is best to regularly inspect clothing cupboards, suitcases, chests, and other unsealed storage containers holding items they like to eat.

Cigarette Beetle

Cigarette Beetles

These bugs get their name due to their preference for stored tobacco, but this is not their only food source. They lay their eggs directly on food stores in pantries and cupboards and eat a wide variety of food products, including dried fruit, pet food, rice, spices, herbs, nuts, coffee beans, cereal, and animal-based products. They can chew through cardboard and other packaging to get to the food, so storing it in airtight glass or plastic containers is best.

Cigarette beetles occur worldwide and have a long history of disgust among humans. The food and tobacco products they infest are covered with their feces and body parts. They are reddish-brown and, when disturbed, will pull in their legs and heads and play dead. Dusk is their preferred time of day, but their activities continue throughout the night. The larvae are white and hairy, and the insect’s lifecycle lasts between forty and ninety days.

Cigarette beetles can also infest potpourri, dried plants and floral arrangements, wreaths, and bookbinding paste. As with other beetles, it is the larval stage that causes the most damage.

Locating infested items, wrapping them in heavy plastics, and discarding them is essential. All food containers should be periodically checked. It is not advisable to consume tobacco products or food items infested by cigarette beetles. Non-food items can be placed in the freezer for seven days to kill all stages of the bug. Heating infested items in a hot oven for an hour can also kill them, but not all things are small enough to fit or suitable for heating.

Household hygiene practices such as vacuuming and cleaning up spills and areas where infested items were stored help prevent re-infestation. The use of chemical insecticides is usually unnecessary, but some are available for cigarette beetles. Residual insecticides for these beetles can be applied to crevices, shelves, cracks, and storage areas but should always be used as per the label’s instructions.

American Spider Beetle

American Spider Beetles & Whitemarked Spider Beetles

There are many species of spider beetles, so-called because when viewed from above, their shape resembles a spider. American spider beetles are a pest that infests food products in the home. White marked spider beetles are found in crawl spaces, attics, damp basements, and sometimes pantries and prefer spoiled food products. They both deposit body parts and feces on stored food and cause spoilage.

American spider beetles also leave webbing and cocoons in food and damage fabrics, and their presence often indicates other pests like rats and bats. Both types of spider beetle are nocturnal, preferring dark hiding places in the day, and are therefore hard to spot.

American spider beetles are sometimes confused with bedbugs as they are also reddish-brown and have a similar globular body shape. Their legs are covered in yellow hairs. They will eat flour, dried mushrooms, animal skins, seeds, beans, books, wool, wheat, silk, cereals, and many other foods and prefer high humidity areas. White marked spider beetles are light-brown with yellow hairs and also like damp places. They have patches of white hair across their wings.

Reducing humidity is key to getting rid of a spider beetle infestation, so repairing leaking pipes and sealing damp cracks and crevices helps. Installing heating equipment such as central heating or various kinds of heaters will also reduce humidity. Sanitation practices in the home, such as thorough vacuuming, cleaning food spillages, and getting rid of rodent and bird nests, dead insects, and spoiled foods, are also necessary.

Stored food should be inspected regularly and kept in sealed containers. Older food products should be used before newer ones as infestations of the Whitemarked spider beetle can spread from infested products to fresh ones. Cold and heat can kill eggs, larvae, and adult beetles. The larvae are cream-colored and have light brown heads.

Insecticides can be sprayed in corners, cracks, and crevices and around areas where infested items were stored but make sure they are suitable for spider beetles. Contaminated food should be thrown out in sealed plastic bags, and potential food sources should be eliminated as far as possible. Spider beetles don’t bite people or pets.

Larder Beetle

Larder Beetles

These large oval insects are usually black with a yellowish band across their wing cases and feed on cured meat and other stored food. Their larvae will eat books, feathers, fur, and insulation, as well as food. While they don’t cause structural damage to the home, they can contaminate food and animal products with their feces and sheddings and make holes in things.

Stuffed animals and trophies are a favorite, but they can also infest pet food, animal feed, and bird or rodent nests in crawl spaces, attics, and voids in walls. They prefer foods with high protein content, such as dried meat, hides, fish meal, animal skins, cheese, and dog biscuits. Large populations occur in places where hygiene is poor.

They can damage plywood, cork, polystyrene insulation, fiberglass, soft sapwood, and plastic water pipes. The larvae are wormlike, hairy, and reddish-brown with a backward curving pair of spines on their tail and bore into wood, insulation, and books looking for a safe place to pupate.

The first step is to find the source of the infestation, remove it and safely dispose of it. Eliminate potential food sources by storing them in sealed containers and cleaning thoroughly with a vacuum cleaner. Seal crevices and cracks around the home and use residual insecticides around the exterior of the building. Insecticidal surface sprays are vital if the infestation is extensive.

Conclusions

It helps to know what kind of beetle you are dealing with to treat and infestation effectively. Prevention is as important as treatment because re-infestations are common. Vigilance regarding the state of your home and items within it, such as food, clothing, carpets, curtains, furniture, fixtures, and wooden structural components, is essential to avoid extensive damage. Sanitary household practices and sealed storage containers often go a long way in preventing and eliminating these household pests.

References

https://www.buildingconservation.com/articles/beetle/beetle.html

https://entomology.ca.uky.edu/ef616

https://www.britannica.com/animal/deathwatch-beetle

https://www.orkin.com/other/beetles/anobiid-powderpost-beetles

https://www.buildingconservation.com/articles/woodworm/woodworm.htm

https://entomology.ca.uky.edu/ef601

http://entnemdept.ufl.edu/creatures/urban/stored/cigarette_beetle.htm

https://extension.umn.edu/product-and-houseplant-pests/larder-beetles

Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and an FHA 203k Consultant. I started PestControlInsider.com to help people better understand pest control and what they can do about invasive insects, rodents, reptiles, and other mammals around their homes.

Recent Posts