How to Get Rid of the Longhorned Beetle

Things You'll Need

  • Ax or saw

  • Incinerator or fireplace

  • Imidacloprid Insecticide

  • Wood preservative

  • Paint brush

  • Medium-grit sandpaper

  • Spray bottle

  • Wood insecticide

Beetles that live in the garden typically pose no threat to your home.

Like many insects, long-horned beetles often infest gardens and the moist wood within a house. These beetles, about 5/8 inch to 1 inch long, are typically found along the United States' western and eastern coastlines. While traditional long-horned beetles can be removed using the typical techniques of insecticide, Asian longhorned beetles require special removal. To avoid the spread of infestation, items infested by Asian beetles must be quarantined and be destroyed by incineration.

Asian Longhorned Beetles

Step 1

Determine if the beetles are Asian longhorned beetles. These beetles are about 1 inch long and are black with white spots. They are typically found outside in lumber, trees and logs.

Step 2

Look for the small holes that these beetles drill into wood. According to the U.S. Department of Agriculture (USDA), Asian longhorned beetles typically drill holes that are 3/8 inch wide.

Step 3

Cut away infested branches using a saw or ax. If an entire tree is infested by beetles, cut it down.

Step 4

Incinerate infected lumber, branches and trees. The USDA-created quarantine rules about Asian longhorned beetles forbid transporting any "host materials" in order to avoid spreading the beetle infestation to new areas. The only approved method of wood removal is incineration.

Step 5

Spray the remaining trees and lumber with imidacloprid insecticide.

Longhorned Beetles

Step 1

Eliminate sources of moisture from your garden or home. According to online ePestSupply, beetles are drawn to moisture. Turn off sprinklers that reach wood, fix leaking pipes and clean up spills quickly.

Step 2

Open a can of wood preservative and apply it to any beetle-infested wood using a paintbrush. Wait for 12 to 24 hours and apply a second coat. Wood preservative prevents moisture buildup.

Step 3

Examine infected wood to determine if it is sealed. Sealed wood is shiny in color and smooth to the touch. If the wood is sealed, sand it with a medium-grit sandpaper. Wipe away the sawdust. If wood is not sealed, it does not need to be sanded.

Step 4

Fill a spray bottle with an insecticide designed to work with wood. The wood insecticide should contain termiticide and fungicide in order to kill the beetles attacking the wood.

Step 5

Spray the wood insecticide over the surface of the wood. Spray liberally in outdoor area, applying insecticide to soil as well a any wood furniture. Apply imidacloprid insecticide to any nonwooden objects of surfaces such as walls, metal furniture and lawn ornaments.


Follow the specific directions on the back of the insecticide bottle.

Imidacloprid insecticide is sold under many brand names. These names include Admire, Gaucho, Mallet, Merit, Premise and Prothor.


Keep your pets in a pen or enclosure until insecticide is washed away by rain. Insecticide can lead to illness or death if ingested.