Plaster Beetles

Facts, Identification, & Control

Latin Name

Family Lathridiidae


What Do They Look Like?

Plaster beetle illustration

  • Size: Plaster beetles are very small insects that are usually less than 1 to 3 mm long.
  • Color: They range from yellowish brown to reddish brown to almost black.

How Did I Get Plaster Beetles?

Plaster beetles are small enough to fly or crawl through window screens to get inside. Significant populations may indicate water leaks and mold problems inside the home.

What Attracts Them?
These pests are attracted to:

  • Bright light
  • Dampness and humidity
  • Moldy sawdust
  • Wet mildew or lumber

How Serious Are Plaster Beetles?

Plaster beetles do not cause damage, bite, or spread disease. They contaminate stored foods that are not properly sealed. These beetles are sometimes a serious nuisance in new homes that were build with damp, mildew contaminated lumber.

Signs of Infestation

Homeowners may detect a plaster beetle infestation by finding them on surfaces or in bright lights. Due to their small size, they can be difficult to identify without the aid of magnification.

How Do I Get Rid of Plaster Beetles?

What You Can Do
You can remove adult plaster beetles inside the home by vacuuming them quickly. Ways to prevent them from infesting your home include:

  • Circulating Airflow: Unblock crawlspace vents so that air can circulate. A dehumidifier may be necessary in damp basements.
  • Moisture Control: Eliminate dampness that supports mold or mildew. Search out and repair plumbing leaks. Make sure that gutters and downspouts drain away from the foundation.
  • Sealing Entryways: Exterior doors should be closed tightly. Replace weather stripping that is damaged or missing. Check the screens on windows and crawlspace vents.

What Orkin Does
Your local Orkin technician is trained to help manage plaster beetles and similar pests. Since every building or home is different, your Orkin technician will design a unique program for your situation.

Orkin can provide the right solution to keep plaster beetles in their place and out of your home or business.


Behavior, Diet, & Habits

Where Do They Live?
There must be dampness or high humidity for these plaster beetles to thrive. They sometimes appear in homes after a period of heavy rain. Most of them live outdoors.

Homeowners would discover these beetles when they came out from under the baseboards. Some people call these insects minute brown scavenger beetles or mold beetles. They may gather in large numbers and can be found living in areas such as:

  • Bathtubs and sinks
  • Bird nests
  • Crawlspaces
  • Damp basements
  • Damp fiber and carpet
  • Near lamps and televisions
  • On cheese and fruit
  • Tree bark
  • Under logs and rocks

What Do They Eat?
Plaster beetles feed on the fungi and mildew that form on grains and cereals in pantries as well as in carpeting and wall voids. Wet straw and wet structural lumber can support mold and mildew that these beetles eat.

Plaster beetles got their name when many homes had plaster walls. Mold often grew in new homes inside walls or under wallpaper while the plaster was drying. These beetles fed on the mold inside of the walls.

Life Cycle
Female plaster beetles deposit eggs near fungi food sources. Larvae hatch and begin to feed on the mold spores. They then attach themselves to a surface and pupate into adults. Development time varies and can be as short as about a month to over five months depending on temperature and food availability.