Flour beetles

Identification

Size: Adult flour beetles usually measure 0.12 to 0.2 inches (3 to 5 millimeters) in length. They have narrow, flattened bodies that allow them to move easily through stored products.

Color: Most flour beetles are reddish brown or dark brown. Their wing covers are smooth and shiny.

Description: Flour beetles are common stored product pests that infest flour, cereal, grains, spices, pet food, and other dry goods. They can survive for long periods inside infested materials and often spread from one product to another. Flour beetles do not bite or harm humans but will contaminate food and cause significant waste.

Flour beetles thrive in warm indoor environments where dry foods are stored. They commonly infest flour, cereal, baking mixes, rice, pasta, spices, dry pet food, and grains in both homes and commercial kitchens. Once inside a food source, they can reproduce quickly. Females lay eggs directly into the product, and larvae feed on the surrounding material until they mature.

Infestations often start with a single contaminated package brought home from a store. Flour beetles can chew through thin packaging, allowing them to spread to nearby items. Over time, infested food takes on a musty odor and may contain small larvae, shed skins, or fine powder created by feeding activity.

Because adults are attracted to light, they may be seen near windows or on countertops. However, the main activity is usually hidden inside stored goods. Eliminating flour beetles requires removing all contaminated products, cleaning the storage area, and sealing replacement food in airtight containers.

Small, narrow beetles with reddish brown or dark brown coloring
Smooth wing covers and slender bodies
Adults often found crawling in or around dry goods
Larvae are small, pale, and wormlike
Infested food may contain fine dust, clumps, or small shed skins
Adults may appear near windows or lights

Live adults or larvae inside flour, cereal, or baking products
Fine powder or dust at the bottom of packages
Musty or stale smell coming from dry goods
Small shed skins or larvae in storage containers
Beetles seen near shelves, cupboards, or pantry areas
Spread of insects to multiple food packages

Store all dry goods in airtight glass or thick plastic containers
Inspect food packages before buying to ensure they are sealed and undamaged
Keep pantry shelves clean and free of crumbs or spills
Rotate food supplies so older items are used first
Avoid keeping large quantities of flour or grain products unless stored properly
Dispose of infested items immediately to prevent spread
Contact professional pest control for recurring or widespread infestations