Beetle ID: Wing Covers, Common Beetles and Look-Alikes

• Chewing mouthparts, unlike true bugs' sucking mouthparts.
• Hardened elytra meet in a straight line down the middle of the back, versus true bugs whose folded wings overlap into a triangle/X pattern.
• Complete metamorphosis with 4 distinct stages (egg, larva, pupa, adult).
• Carpet beetle adults have rounded bodies and short antennae, resembling small lady beetles but much smaller.
• Beetle larvae are grublike and legless, or have only three pairs of legs near the head (not caterpillar-like).

People most often mix beetles up with:

• True bugs

Open the other page and compare its list against the marks above; the differences are usually in the antennae, wings or the way the body is divided.

Some beetles are beneficial predators (e.g. ground beetles), while others (wood-boring, pantry, carpet beetles) are structural or stored-product pests.

Found indoors (pantry, fabrics, wood) and outdoors in gardens/landscapes.

Get as close as your camera will focus, from directly above, in daylight or a bright lamp. Include the whole body with the legs and antennae in frame; a second shot from the side shows wings and body segments. Put a coin or ruler next to it for scale. For a bite or a bug found on skin or bedding, photograph the bug itself, not the mark. The app names the likely group; use the list above to confirm.

• Hard wing covers that meet in a straight line. A beetle's front wings (elytra) are hardened into a shield over the flying wings and meet in a straight line down the middle of the back (Texas A&M; University of Kentucky). The Wildlife Trusts note some beetles have short covers that do not hide the whole abdomen.
• Chewing mouthparts. Beetles always chew. True bugs, the most common look-alikes, have a sucking beak: Texas A&M suggests looking under the head for a ridge running from the tip backward. True bug front wings are only half hardened, with the outer half see-through.
• Shape of the plate behind the head and the antennae. The Wildlife Trusts use the pronotum, the plate behind the head, as a key feature; longhorn beetles are named for their long antennae.

Beetle larvae are long, with three pairs of jointed legs at the front and no fleshy claspers at the rear, which separates them from caterpillars (Texas A&M). See grubs.

All sizes and descriptions below are from UC IPM pest notes.

• Carpet beetles: 1/10 to 1/8 inch, round, short antennae, solid black or mottled white, brown and yellow; adults gather on window sills and drapes. The larvae look like fuzzy or hairy maggots and eat wool, silk, leather, fur, feathers and pet hair.
• Sawtoothed grain beetle: about 1/10 inch, slender, flat and brown, with six saw-like teeth along each side of the thorax.
• Drugstore beetle: about 1/8 inch, light brown, with lengthwise grooves on the wing covers.
• Cigarette beetle: about 1/8 inch, cylindrical, light brown, with smooth wing covers.
• Red and confused flour beetles: about 1/7 inch, flat, oval and shiny reddish-brown. The red flour beetle's antennae end abruptly in a three-segment club; the confused flour beetle's widen gradually to a four-segment club.

Beetles in flour, cereal or spices point to a pantry infestation; beetles on a window sill with damaged wool nearby point to carpet beetles.

• Ladybirds (lady beetles): the 7-spot ladybird has seven spots; the introduced harlequin ladybird varies from 0 to 21 spots (Wildlife Trusts). Both adults and larvae eat aphids (UC IPM).
• Longhorn beetles: long antennae; often on flowers such as umbellifers and thistles (Wildlife Trusts).
• Stag beetles: up to 75 mm, the males with huge antler-like jaws (Wildlife Trusts).
• Soldier beetles and ground beetles: common in gardens and grassland (Wildlife Trusts).
• Garden pest beetles: Japanese beetle, Colorado potato beetle, cucumber beetle, Mexican bean beetle and flea beetle (Gardener's Supply). See garden insect identification to match them to the damage.

Photograph the beetle from directly above so the wing covers, the plate behind the head and the antennae are all visible, and add a side view if you can. Put a coin or ruler next to small beetles; many household beetles are only 1/10 to 1/8 inch long. Photograph it and InsectLens identifies it. BeetleIdentification.org is a free site to check the result by US state or to compare two beetles side by side.

A sudden run of beetles usually has one of five causes, and each points to a different source:

• Carpet beetles on window sills. Adults feed on pollen outdoors, fly in from flowers and are drawn to sunlight (UC IPM). Their larvae are the problem, feeding on wool, fur, feathers and pet hair.
• Lady beetles on walls in autumn. Multicolored Asian lady beetles gather on houses from about the start of October, on sunny afternoons after a cold night, looking for wall voids and attics to spend the winter (Penn State Extension). The Wildlife Trusts note the harlequin ladybird does the same in the UK.
• Beetles in the kitchen. Pantry beetles arrive in infested food or damaged packaging (Clark Pest Control).
• Beetles near an attic or dead insects. Larder beetles lay eggs on insects that died over winter in attics (Penn State Extension).
• Small beetles on window sills with fine powder below woodwork. Powderpost beetles emerging from wood: UC IPM lists exit holes and new beetles on window sills as signs of an active infestation.

• Powderpost beetles: brown to red, leaving tiny round holes and very fine frass like talcum powder; they attack hardwoods such as oak, ash, hickory, mahogany and walnut (UC IPM).
• Deathwatch beetles: reddish to dark brown, with slightly grittier frass, mostly in softwoods such as Douglas-fir (UC IPM).
• False powderpost beetles: dark brown or black, usually about 1/4 inch, with coarse frass that is hard to dislodge (UC IPM).
• Larder beetle: dark brown, about 1/3 inch, with a band of pale yellow hairs across the front half of the wing covers, usually with six dark spots. The hairy larvae, about 1/2 inch, have two curved spines at the tail and feed on dried meat, cheese, pet food, fur and feathers (Penn State Extension).

The fabric and pantry beetles are listed in the section above.

Clark Pest Control's point applies to nearly every house beetle: most infestations require finding and removing the infested item, not just spraying.

• Pantry beetles: check everything in the cupboard, discard infested food and move the rest to sealed containers (Clark Pest Control; UC IPM).
• Larder beetles: clean out the food source; infested items can be heated to 140°F for half an hour or frozen at 0°F for 3 to 4 days (Penn State Extension).
• Carpet beetles: clean and vacuum wool, fur and feathers where larvae feed (UC IPM).
• Lady beetles: seal cracks around windows, doors and siding, and vacuum clusters that get in (Penn State Extension).
• Wood borers: small items can be heated to 120 to 140°F for 6 hours or frozen at 0°F for 72 hours; for structural wood, UC IPM advises replacing infested wood where possible, and a professional inspection is the confirmation.

Research and drafting for this page used AI assistance. Every figure, date and quotation was then checked line by line against the sources listed at the bottom of the page, each of which was opened while writing. Nothing here is a diagnosis. If a bite, sting or contact with an insect is followed by trouble breathing, swelling of the face or throat, spreading redness, fever or any symptom that worries you, get medical care; in the United States Poison Help (1-800-222-1222) is free and open 24 hours a day.

Beetles are the largest order in the animal kingdom. BeetleIdentification.org gives about 350,000 species worldwide and roughly 25,000 in North America; the Wildlife Trusts give over 400,000 worldwide and over 4,000 in the UK. The totals differ by source, but the point is the same: a general beetle list cannot show them all, and narrowing by region first cuts the field to the few thousand you could actually meet.

The features that do the narrowing are the ones the Wildlife Trusts name: the pronotum (the hard plate just behind the head), the elytra (the hardened wing cases), leg shape, antenna length and size. Two cases trip people up. Some beetles have short wing cases that leave much of the abdomen bare, so they do not look like beetles at first glance (Wildlife Trusts). And beetle larvae have three pairs of jointed legs at the front and, unlike caterpillars, no clasper legs on the hind segments (Texas A&M AgriLife).

Most small beetles found indoors belong to two groups: beetles living in stored food, and carpet beetles living on animal fibres. Where you find it is the fastest clue.

In the kitchen or pantry (sizes from University of Minnesota Extension):

• Sawtoothed grain beetle: about 1/10 inch, slender, flat, brownish-red to almost black, with a row of saw-like teeth along each side of the thorax. Dried fruit, cereals, nuts, macaroni, seeds.
• Drugstore beetle: about 1/8 inch, oval and brown, head bent down so it looks humped; it can fly. Spices, grain products, dried flowers, even paper and books.
• Cigarette beetle: 1/8 inch, oval and brown, head bent down, often seen at windows. A wide range of dried plant products.
• Flour beetles: 3/16 inch, reddish-brown, elongate oval. Flour, bran, cereals, dried fruit, nuts, chocolate.
• Spider beetles: 3/16 inch, reddish-brown, long legs, look like small spiders.
• Weevils (granary, rice, maize): under 3/16 inch, dark brown, with a snout pointing forward from the head; they live in whole grains and seeds, rarely in flour.

On carpets, wool, closets and window sills: carpet beetles. Virginia Tech's fact sheet gives adults of about 1/4 inch (6.4 mm), dark with coloured marks on the back, often found at windows indoors and on flowers outdoors in summer. The damage is done by the bristly larvae, which eat wool, fur, feathers, hair and silk, and wander from room to room; their shed skins are often mistaken for live larvae.

For a room-by-room list of other indoor insects, see household bug identification.

Finding one beetle means you should check every susceptible package, because University of Minnesota Extension notes there can be more than one infested source. Its method: shine a flashlight on the top surface of each product, or pour the contents onto a cookie sheet, and throw away any food that turns out to be infested. Check spices, dried flowers, pet food as well as flour and cereal, since University of Minnesota Extension lists spices and dried flowers among drugstore beetle foods and pet food among warehouse and cabinet beetle foods.

For carpet beetles, look where the larvae feed: under furniture, along carpet edges, in stored wool and in closets, and look for shed larval skins (Virginia Tech).

Wikipedia puts described beetles at about 400,000 species, roughly a quarter of all described animal species, in four suborders. Most beetles you will see belong to a handful of very large families (species counts from Wikipedia; examples and marks from the sources named):

• Weevils: about 97,000 species, the largest family. The pantry weevils have a snout projecting forward from the head (University of Minnesota Extension).
• Rove beetles: about 48,000 species. Short wing cases leave much of the abdomen bare, as in the long, slender, black devil's coach horse (Wildlife Trusts).
• Leaf beetles: about 35,000 species. Example: the small, shiny rosemary beetle (Wildlife Trusts).
• Scarabs: about 35,000 species. Examples: the large, iridescent green rose chafer, and the stag beetle at 50 to 75 mm (Wildlife Trusts).
• Ground beetles: about 35,000 species. Example: the metallic green tiger beetle, up to 15 mm (Wildlife Trusts).
• Longhorn beetles: about 25,000 species. Example: the black-and-yellow banded wasp beetle (Wildlife Trusts).
• Jewel beetles: about 14,000 species.

Size alone varies enormously: Wikipedia lists the smallest known beetle at about 325 micrometres and the Hercules beetle at 16.7 cm or more. For a longer searchable list, BeetleIdentification.org lets you browse by US state and InsectIdentification.org lists 281 beetles that can be filtered by colour.

Work through the checks in this order; each one removes most of the candidates.

• Where it was: stored food, fabric, wood, a plant, under a log, or at a light. This alone separates pantry beetles and carpet beetles from garden beetles.
• Size in millimetres: measure against a ruler. The pantry beetles above are about 2.5 to 5 mm (1/10 to 3/16 inch, University of Minnesota Extension); a bloody-nosed beetle reaches 23 mm and a stag beetle 50 to 75 mm (Wildlife Trusts).
• Antennae: length, colour banding and whether they look knobbly (Wildlife Trusts); a snout in front of the head means a weevil (University of Minnesota Extension).
• Wing cases: covering the whole abdomen or short with the abdomen showing; their pattern and markings (Wildlife Trusts).
• Pronotum, legs and eyes: the shape and marks of the plate behind the head, leg colour and thickness, and eye size separate many look-alikes (Wildlife Trusts), such as native and Asian lady beetles.

Then photograph it from above and from the side with the antennae visible. InsectLens names the beetle from a photo; for a pantry beetle, keep one in a sealed bag in case you want your local extension office to confirm it.