Weevils are beetles, and they belong to one of the largest animal groups on Earth. Orkin notes that weevils are beetles and that this family has more species than any other beetle group. The different types of weevils run from pantry pests the size of a sesame seed to a lanky New Zealand giant known as the giraffe weevil.
For most Americans, the first weevil they meet is an unwelcome one, wriggling out of a bag of flour or rice. Others cost farmers and foresters millions, and a few are harmless oddities of the forest floor. This article covers 15 weevils and weevil relatives, including how to spot each one and what it eats.
Keep one rule of thumb in mind while reading. True weevils have elbowed antennae and often a long, curved snout. Several groups below are cousins that bend that rule, and the text flags each one. For a wider look at the beetle and bug world, see this overview of types of insects.
| Weevil | Main Food or Host | Where Americans Are Most Likely to Meet It |
|---|---|---|
| Boll weevil | Cotton buds and bolls | Southern cotton country |
| Grain weevil | Whole-kernel grains | Pantries, mills, bins |
| Wheat weevil | Wheat, corn, barley | Stored grain |
| Maize weevil | Corn, rice, sorghum | Pantries and farm storage |
| Rice weevil | Rice and other grains | Kitchens and warehouses |
| Sitka spruce weevil | Young spruce leaders | Pacific Northwest forests |
| Acorn weevil | Acorns and nuts | Oak woodlands |
| New Zealand giraffe weevil | Rotting native wood | New Zealand only |
| Bean weevil | Dry beans and legumes | Pantries and bean storage |
| Biscuit weevil | Biscuits, spices, dried goods | Kitchen cabinets |
| Fungus weevil | Fungi on dead wood | Woodlands |
| Leaf-rolling weevil | Tree and shrub leaves | Forests and orchards |
| Primitive weevil | Various host plants | Mostly the Southern Hemisphere |
| Straight-snout weevil | Wood and seeds | Tropical and eastern forests |
| Pine flower weevil | Conifer pollen cones | Pine forests |
Key Insight: Estimates of weevil diversity vary by source and by how families are counted. One field guide cites over 35,000 species worldwide, while Terminix cites more than 60,000. Treat any single number as a rough guide.
1. Boll Weevil
The boll weevil (Anthonomus grandis) is probably the most famous insect in American farm history. It devastated the U.S. cotton crop in the 1920s. Its late 19th century invasion of American cotton fields also prompted agricultural reforms and new pest management methods. Enterprise, Alabama, even put up a monument to the insect in 1919, after the damage pushed local farmers toward other crops.
According to Orkin, this cotton-damaging beetle averages about 6 mm long. It feeds on the buds and flowers of the cotton plant. Boll weevils live along the Gulf Coast in Texas. The life cycle moves fast:
- The female lays eggs singly in punctures her snout makes in squares and bolls.
- The white, legless larva feeds and pupates inside the square or boll.
- Development from egg to adult takes about three weeks.
- Adults spend the winter in ground trash near old cotton fields.
2. Grain Weevil
“Grain weevil” is a catch-all name for the genus Sitophilus. Michigan State University Extension says grain weevils include three small species: the rice weevil, the granary weevil, and the maize weevil. They are common stored grain pests that sometimes infest whole-kernel foods in pantries.
The damage happens where you cannot see it at first. Larvae develop inside whole corn, wheat, and rice kernels, and the adults chew out through tiny round holes. Those pinholes are the giveaway that a product is infested.
A pantry check works better than any spray. MSU Extension advises finding the infested food and removing it, then scrubbing the cupboards. Weevils are not the only invaders that show up in kitchens, so it also helps to know the ants that get into houses.
Pro Tip: Check every opened package of whole-kernel food, birdseed included, for weevils or tiny holes. Garage birdseed bins are a common source of kitchen infestations.
3. Wheat Weevil
The wheat weevil (Sitophilus granarius) is the species most people picture when they hear “grain weevil.” Orkin points out that the wheat weevil is commonly called the granary weevil. The two names describe one insect.
Important Note: Wheat weevil, granary weevil, and grain weevil often overlap in pest-control writing. Wheat weevil and granary weevil are the same species. Grain weevil is the looser label for the whole Sitophilus group.
Adults measure about 3 to 5 mm and are reddish-brown with no distinguishing marks. They cannot fly. That means they spread when people move infested grain, not through the air. The FDA’s stored grain fact sheet calls the granary weevil, along with the rice weevil, one of the most destructive stored grain insects.
The Wikipedia entry on the wheat weevil lists two home checks. Dropping suspect grains in water can reveal an infestation, because infested kernels float. It also recommends tight-lidded metal containers kept in the refrigerator or freezer, and buying grain in small quantities.
4. Maize Weevil
The maize weevil (Sitophilus zeamais) looks almost identical to the rice weevil. The two were once thought to be the same species. It is often more destructive in maize-growing regions and infests corn, rice, sorghum, and other cereals.
In American kitchens, maize weevils feed on beans, flour, corn, pasta, and bread. Adults are reddish-brown and grow to about one-eighth of an inch. The ability to fly sets them apart from the granary weevil. This table compares the three Sitophilus species you are most likely to find at home:
| Trait | Granary Weevil | Rice Weevil | Maize Weevil |
|---|---|---|---|
| Flight | Cannot fly | Flies, drawn to light | Flies |
| Typical size | One-eighth to one-quarter inch | About one-eighth inch | About one-eighth inch |
| Wing-cover markings | None | Four reddish or yellowish spots | Reddish-brown, very similar to rice weevil |
| Favorite food | Wheat, corn, barley | Rice and whole grains | Corn, with rice and sorghum |
5. Rice Weevil
The rice weevil (Sitophilus oryzae) is a staple of American pantry complaints. Terminix describes it as dark brown with light patches on the wing covers, and it bores into rice kernels to breed. WebMD says the adults have four reddish or yellowish markings, can fly, and are attracted to light.
Its breeding method explains why infestations feel sudden. One female can lay 300 to 400 eggs, chewing a hole in a kernel, depositing one egg, and sealing the hole with fluid. The grain looks normal while the larva grows inside.
Common Mistake: Assuming rice weevils only bother rice. Weevils usually infest grains and starches like rice, flour, pasta, and cereals. Inspect the whole shelf, not one box.
6. Sitka Spruce Weevil
Not every weevil lives in a pantry. The Sitka spruce weevil is the Pacific Northwest name for Pissodes strobi, a bark weevil that Orkin lists elsewhere as the white pine weevil. Bark weevils in this genus infest conifers by feeding on bark and inner tissues.
The target is the leader, the topmost vertical shoot of a young Sitka spruce (Picea sitchensis). Females lay eggs in the leader, and the larvae feed beneath the bark and kill the shoot. The tree then sends up a side branch to replace it, and the trunk often ends up forked or crooked.
That damage matters to timber growers in coastal Oregon, Washington, and British Columbia. Foresters have found that planting seedlings in shaded or mixed stands lowers attack rates. Adults are small, dark brown, and speckled with patches of lighter scales, so most people notice the dead, drooping leaders long before they see the insect.
7. Acorn Weevil
Acorn weevils (Curculio species) wear one of the most extreme snouts in North America. In acorn weevils, the snout can actually be longer than the body. The tip of the snout carries small, saw-like teeth.
The female uses that snout like a drill. She bores into a developing acorn, lays an egg inside, and the larva eats the kernel. The grub-like larvae hatch a few days after the eggs are laid. Later the larva chews a round exit hole and drops to the soil to pupate.
CirrusImage notes that the long-snouted acorn weevils belong to Curculio, while the short-snouted ones belong to Conotrachelus. Nut weevils in the genus Curculio also attack chestnuts and hazelnuts. If you collect acorns to plant, drop them in water and discard floaters and any with small round holes. Readers in the Northeast can find more regional bugs in this list of insects in New York.
8. New Zealand Giraffe Weevil
The New Zealand giraffe weevil (Lasiorhynchus barbicornis) is the showpiece of the weevil world. Weevil forms range from tiny granary pests to the dramatically elongated giraffe weevil. Males carry a thin, stretched snout that makes up much of their length, and the whole insect can reach roughly 9 centimeters (about 3.5 inches).
The species lives only in New Zealand. Males use their long snouts to guard females and fight rivals, while shorter-snouted females chew holes in dead wood to lay eggs. Larvae develop inside rotting trunks of native trees such as karaka and pukatea.
American insect fans can put its size in context. The palmetto weevil is the largest North American weevil, at over an inch long. The giraffe weevil is still roughly three times longer. For other oversized bugs, the Amazon rainforest insect guide is a good next stop.
9. Bean Weevil
The bean weevil (Acanthoscelides obtectus) is a pantry pest of dry beans. Terminix describes it as about one-sixth of an inch long and olive-brown, with brown or gray spots on the wing covers. It infests whole beans and other legumes, in storage or on crops.
It also breaks the usual weevil look. Bruchidae, the family that includes the cowpea weevil, lack the elongated snout of typical weevils. Entomologists often call these seed beetles. The short, blunt face makes them look more like tiny ticks with wings than long-nosed weevils.
Adults and their round exit holes show up in pinto, kidney, and black beans bought in bulk. Larvae develop inside a single bean, so the damage stays hidden until the adults emerge. Orkin lists the cowpea weevil among the most common stored product weevils. Discard any bean with a small round hole, and freeze new bulk purchases before they join the pantry.
10. Biscuit Weevil
The biscuit weevil is a nickname for Stegobium paniceum, better known as the drugstore beetle. It is not a true weevil. It has no snout, and entomologists place it in a different beetle family, but its habits match the weevil pantry-pest pattern closely enough that the name stuck.
Adults are tiny, reddish-brown, and about 2 to 3 mm long. Larvae feed on biscuits, bread, flour, dried herbs, spices, and pet food. They have also been found in books and dried botanical specimens, which is where the “drugstore” name comes from.
A similar mix-up exists with flour pests. Orkin lists “flour weevils” under the family Tenebrionidae, which means they are flour beetles. Both cases show why pest-control names do not always match insect taxonomy.
Pro Tip: Spices are the usual hiding place for biscuit weevils. Check old paprika, chili powder, and tea tins first, since infestations there can go unnoticed for months.
11. Fungus Weevil
Fungus weevils belong to the family Anthribidae. Entomologists list them among the weevil families alongside the primitive weevils. Most have short, broad snouts and antennae that are not sharply elbowed.
As the name says, they live around fungi. Adults and larvae feed on fungus-infested dead wood, bark, and shelf fungi in forests. That makes them recyclers, helping break down dead timber. Their mottled gray and brown bodies blend into lichen-covered bark, which makes them hard to spot.
One member is a pest. The coffee bean weevil (Araecerus fasciculatus) damages stored coffee beans, cocoa, and dried foods in warm climates. Gardeners in the United States are far more likely to see a harmless woodland species than this tropical storage pest. Wood-dwellers raise a fair question about termites, and the different types of termites article explains how those wood eaters differ.
12. Leaf-Rolling Weevil
Leaf-rolling weevils are among the best builders in the insect world. Their larvae roll and feed inside the leaves of plants like apples and grapes. The mother does the construction, cutting a leaf and folding it into a tight cylinder, with an egg tucked inside.
These insects belong to the family Attelabidae. Subgroups include the leaf-rolling weevils, the tooth-nosed snout weevils, and the leaf roll thieves. Head-clipping weevils in this family are defined by an exaggerated snout.
- Look for neat, cigar-shaped rolls on oak, hazel, birch, or fruit tree leaves.
- Check for a clean, straight cut along the leaf edge, which a caterpillar would not leave.
- Expect small, shiny, often reddish or black adults with a short, broad snout.
Gardeners rarely need to act. The rolls do cosmetic damage, and the pests are low-risk compared with grain weevils. Many gardeners prefer to let beneficial insects handle the rest, and the different types of ladybugs are good allies to attract.
13. Primitive Weevil
Primitive weevils are an older branch of the weevil family tree, centered on the family Belidae. They are distinguished by straight antennae, unlike the elbowed antennae of true weevils. The term is sometimes used more loosely for several early-branching families, including Nemonychidae and Brentidae, which are covered below.
Most belid species live in the Southern Hemisphere, with many in Australia, New Zealand, and South America. They tend to be long, narrow beetles with a modest snout. Larvae bore into plant tissue, often in conifers and in southern flowering trees, so they are woodland creatures, not household pests.
Primitive weevils matter to scientists more than to farmers. Their straight antennae and simpler snouts hint at how true weevils evolved. Weevils live on every continent except Antarctica, thriving everywhere from forests and gardens to grain storage facilities.
14. Straight-Snout Weevil
Straight-snout weevils make up the family Brentidae, and they are some of the most dramatic-looking beetles you can find. Many species are long, slender, and nearly rod-shaped, with a straight snout that extends the line of the body. The New Zealand giraffe weevil described earlier belongs to this family.
In the eastern United States, the best-known member is the oak timberworm (Arrhenodes minutus). Its larvae tunnel into the heartwood of oaks and other hardwoods, usually in trees already stressed or wounded. The adult is a narrow, reddish-brown to black beetle, and males often have longer snouts than females.
The family also includes the small, pear-shaped seed weevils, which are tiny and often tied to clover, beans, and other plants. This is why straight-snout weevils vary so much in shape, from slim wood borers to compact seed feeders. Their shared trait is the straight, non-elbowed antenna and snout structure.
15. Pine Flower Weevil
Pine flower weevils are the quietest members of the clan. They belong to the family Nemonychidae, and the group is also called pine flower snout beetles. The family is tied closely to conifers, and adults visit the pollen cones in spring.
Larvae develop inside those male cones, feeding on pollen and cone tissue. Adults are small, hairy, and usually brown or gray. They are rarely seen and almost never cause meaningful harm to trees, so they are a good reminder that not every weevil is a pest.
Understanding the different types of weevils helps you respond sensibly. A grain weevil in the pantry needs prompt action, while a leaf roll on an oak needs nothing. Match the weevil to the problem, and you can save both food and effort. For identification help, a university extension office or a local insect diagnostic lab can confirm a species from a sample.