Shiny Spider Beetles

Facts, Identification, & Control

Latin Name

Mezium affine


What Do They Look Like?

  • Size: Adult shiny spider beetles range in size from 1.5 to 3.5 mm.
  • Color: These beetles are solid colored. Their color varies from dark red to black.
  • Characteristics: They get their name from their long legs and oval shaped bodies that make them look like spiders. They have wing covers that give them a “humped” appearance.

How Did I Get Shiny Spider Beetles?

Shiny spider beetles are pests that infest stored food products. These beetles can spread from one package to another when homeowners fail to store dry foods in airtight jars. These pests lay their eggs in almost all food products, especially if they are moist or moldy.

People often buy tainted goods from stores without realizing infestations. Shoppers may be able to spot evidence of moistness and the beetles themselves in highly infested packages.

How Serious Are Shiny Spider Beetles?

Residents may need to throw out large volumes of food contaminated with these pests’ waste and webbing. Shiny spider beetles ruin more food with their webbing and droppings than they actually eat.

Signs of Infestation

The adult beetles and holes in packaging can indicate activity. Inside packaging, some webbing might be observed. Cool, dark places see the most shiny spider beetle activity, but since they are nocturnal, homeowners are not likely to observe these insects until populations become very large.

How Do I Get Rid of Shiny Spider Beetles?

What You Can Do
Inspecting and cleaning are the key steps in eliminating shiny spider beetles. It is important to find everything that they have infested. Steps to control and prevent these insects in your home are:

  • Empty pantry and cabinet shelves
  • Throw away infested packages
  • Vacuum empty shelves
  • Store new food products in sealed glass or plastic containers

What Orkin Does
Your local Orkin technician is trained to help manage shiny spider 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 shiny spider beetles in their place and out of your home or business.


Behavior, Diet, & Habits

These beetles are one of the most common spider beetle species in the United States. They are often confused with American spider beetles, which are cream-colored.

There are several other species, including:

What Do They Eat?
Shiny spider beetles prefer to feed on moldy food. They also feed on any food products that have been stored for a very long time and are out of condition for use by people. These pests feed on the following:

  • Animal droppings
  • Dead insects
  • Paper
  • Pet food
  • Stored seeds
  • Woolens

Where Do They Live?
Common places you may find shiny spider beetles include:

  • Bakeries
  • Bird nests
  • Hotels
  • Houses
  • Rat nests
  • Warehouses

Life Cycle

Female shiny spider beetles deposit their eggs inside piles of bat, bird, or rodent droppings. When their eggs hatch, larvae feed and grow. While they are feeding, larvae spin silken webbing and spin silken cocoons to change into adults. Adults sometimes stay in their cocoons for a few days before coming out to find a mate.

Length of development depends on temperature and the amount of food they have available.