10 Types of Beetles in Delaware (and How to Identify Each One)
September 22, 2026
Delaware may be the second-smallest state in the country, but its beetle population tells a much bigger story. Databases tracking beetles across the state list well over 200 confirmed species, and researchers with the Delaware Division of Fish and Wildlife note that water beetles reach high levels of diversity in isolated wetlands, especially vernal pools and Coastal Plain seasonal ponds, making the state a likely hotspot for water beetle diversity. From backyard gardens to Atlantic beaches, the types of beetles in Delaware span a surprising range of shapes, colors, and lifestyles.
Some of these insects quietly recycle nutrients and pollinate wildflowers. Others chew through wooden beams, invade pantries, or threaten entire tree species. This guide walks through ten beetles a person is likely to encounter across the First State, along with the traits that make each one identifiable in the field.
| Beetle | Typical Habitat | Primary Diet | Impact |
|---|---|---|---|
| Dung Beetle | Pastures, fields, forest edges | Animal dung | Beneficial |
| Large Rove Beetle | Under logs, moist soil | Small insects, decaying matter | Beneficial |
| Powderpost Beetle | Seasoned hardwood, furniture | Wood fibers | Structural pest |
| Carpet Beetle | Homes, closets, attics | Fabric, keratin, pollen | Household pest |
| Emerald Ash Borer | Ash tree stands | Ash bark and wood | Invasive pest |
| Flower Longhorn Beetle | Meadows, gardens | Pollen, nectar | Beneficial pollinator |
| Larder Beetle | Pantries, animal products | Meat, cheese, hides | Household pest |
| Eastern Beach Tiger Beetle | Coastal sand beaches | Small invertebrates | Protected/beneficial |
| Red Milkweed Beetle | Milkweed patches | Milkweed leaves and stems | Beneficial (mostly harmless) |
| Tooth-necked Longhorn Beetle | Wooded areas, tree roots | Roots, decaying wood | Mostly harmless |
1. Dung Beetle
Dung beetles belong to the scarab family and are best known for their unusual food source: animal droppings. Delaware’s insect records list members of the genus Dichotomius sp. among the beetle species documented across the state, and these beetles typically turn up in pastures, fields, and forest edges where grazing animals or wildlife leave waste behind.
Rather than being a nuisance, dung beetles perform a genuinely useful job. By burying or rolling away dung, they cycle nutrients back into the soil, reduce fly breeding sites, and help control internal parasites that would otherwise reinfect livestock. Their sturdy, shovel-shaped front legs make them efficient diggers, and their glossy, rounded bodies help them push through soil and organic debris with ease.
Pro Tip: If a dung beetle turns up in a garden or pasture, leave it be. Its digging activity aerates soil and speeds up nutrient cycling, which benefits plant roots more than most people realize.
2. Large Rove Beetle
The large rove beetle, represented in Delaware by species such as Platydracus cinnamopterus, looks unusual at first glance because its wing covers are short, leaving most of the abdomen exposed. According to records compiled for the state, this large, black beetle can be found in Delaware during the summer months and lives in moist areas such as under logs and boards, where it can fly and feed on rotting wood and plants.
Identification comes down to a few reliable features. Its most distinguishing characteristic is long, slender antennae about three times the length of its body, paired with an oval-shaped body and elytra that carry a purple, red, or blue sheen depending on the species. Males and females can be told apart by their antennae, since males have hooked antennae while females have notched antennae.
Despite the intimidating appearance, rove beetles are predators of smaller insects and decomposing organic matter rather than a threat to people or homes. Readers curious about how this family compares to beetles in neighboring states can check the beetle species found in Maryland or browse the full Delaware beetle identification database for photo comparisons.
3. Powderpost Beetle
Powderpost beetles are among the more economically troublesome types of beetles in Delaware, largely because homeowners rarely notice them until damage is already underway. These small, cylindrical beetles belong to families that include species like Lyctus planicollis, and their larvae tunnel through seasoned hardwood, leaving behind a fine, powder-like frass that gives the group its name.
Pest control professionals in the region point out that powderpost beetles are often mistaken for termites, not only because they look similar, but because they eat through wood structures, causing costly damage to homes and businesses and structures on properties. Furniture, flooring, and structural beams built from untreated hardwood are the most common targets.
Common Mistake: Many homeowners assume small round exit holes in wood mean termites. Powderpost beetle damage typically shows tiny, perfectly round holes with fine powdery frass nearby, while termite damage tends to hollow out wood along the grain without visible exit holes.
Because both pests thrive in similar conditions, anyone comparing wood-boring insects across the region may also want to review the common black beetle species found in homes and yards.
4. Carpet Beetle
Carpet beetles are tiny, oval-shaped insects that cause outsized frustration indoors. Species such as Anthrenus verbasci, the varied carpet beetle, are mottled with patches of white, brown, and yellow scales that create a mottled camouflage pattern across the wing covers.
Regional beetle guides note that carpet beetle species are harmful indoor pests, and their larvae are the real culprits. These small, bristly grubs feed on wool, silk, fur, feathers, and other keratin-based materials, which puts stored clothing, rugs, and taxidermy at risk. Adults, by contrast, often feed on pollen outdoors and can enter homes through open windows or on cut flowers.
- Look for irregular holes in wool sweaters, blankets, or upholstered furniture.
- Check closets and dark drawers, since larvae prefer undisturbed fabric.
- Watch for shed larval skins, which resemble tiny fuzzy husks near damaged material.
Anyone dealing with recurring indoor pests may find it useful to compare notes with the broader guide to insects people keep and encounter around the home.
5. Emerald Ash Borer Beetle
Few beetles on this list have caused as much ecological damage as the emerald ash borer, scientifically known as Agrilus planipennis. This invasive species has spread through much of the eastern United States, and Delaware is no exception. The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service lists the Emerald Ash Borer among the pests present in Delaware, noting that it attacks ash trees.
Identifying an adult requires a close look, since the beetle is small. Extension entomologists describe adults as bright metallic green wood-boring beetles that are slender, bullet-shaped, and about one-third of an inch long, with females slightly larger than males. Larvae do the real damage, tunneling under bark in winding galleries that cut off a tree’s ability to move water and nutrients.
Important Note: Moving firewood or untreated ash lumber can spread emerald ash borer larvae to new areas. Anyone removing dead or dying ash trees in Delaware should check local guidance before transporting wood off-site.
Pest control specialists in the region confirm that the emerald ash borer can cause serious crop and tree damage in Delaware. Readers tracking the beetle’s spread through neighboring states can compare notes with coverage of beetle species documented in New Jersey, where the same invasive borer has also taken hold.
6. Flower Longhorn Beetle
Flower longhorn beetles bring a welcome dose of color to Delaware meadows and gardens. Species recorded in the state include several in the genus Typocerus, along with related species classified under names like Strangalia luteicornis. State beetle databases list multiple flower longhorn species, including forms cataloged as S. emarginata, S. famelica, S. luteicornis, and Typocerus spp., all documented among Delaware’s beetle fauna.
These beetles are easy to spot on blooming plants during warmer months. Elongated bodies, long antennae, and a habit of resting motionless on flower heads while feeding on pollen and nectar set them apart from other longhorn beetles that bore into wood. Because they spend so much time on flowers, they also double as minor pollinators, brushing pollen from bloom to bloom as they feed.
Gardeners who want to attract more of these beneficial visitors can plant native flowering species and avoid broad-spectrum insecticides during bloom periods. For a broader look at how longhorn beetles compare across regions, the Delaware beetle listing database catalogs dozens of related species, and the beetle species found in South Carolina offers a useful Southeast comparison.
7. Larder Beetle
The larder beetle, Dermestes lardarius, is a household beetle with a long history of coexisting with people. Records describing the species note that it is one of the most common types of beetles in Delaware, with larvae and adults feeding on various animal products such as meats, cheese, cured fish, woolen goods, and animal skins, and adults well adapted to human environments such as pantries and pet food containers. The species is old news to science as well, since Linnaeus first described this beetle in 1758.
Adults measure roughly a third of an inch long, with a dark brown body crossed by a pale yellow band dotted with black spots near the front of the wing covers. Larvae are bristly and brownish, and they tend to wander away from the food source to pupate, sometimes boring into wood or packaging in the process.
Because larder beetles thrive wherever stored animal products sit unchecked, sealing pet food containers and rotating pantry stock go a long way toward prevention. Those interested in other pantry and household insects can browse the wider guide to different types of insects people commonly encounter indoors.
8. Eastern Beach Tiger Beetle
Few beetles in Delaware carry as much conservation weight as the eastern beach tiger beetle, Habroscelimorpha dorsalis (formerly classified as Cicindela dorsalis). This species is found in Central America and North America, with a body length of 13 to 15 millimeters, making it one of the larger tiger beetles along the Atlantic coast.
The northeastern subspecies has had a difficult history. It formerly occurred on ocean beaches from Cape Cod, Massachusetts, south to the Chesapeake Bay, but today occurs at only a handful of sites, including locations along the eastern and western shores of the Chesapeake Bay in Maryland and Virginia. In 1990, the northeastern beach tiger beetle was listed as threatened under the Endangered Species Act due to massive population declines throughout its range.
Habitat loss is the primary driver behind this decline. Beach development, destruction of habitat by vehicles, and stabilization of beaches with artificial jetties, bulkheads, groins, and riprap have resulted in the near extirpation of the species in the northeast. Adults are diurnal hunters, and researchers note that this beetle serves as an important part of the delicate coastal food web and can act as an indicator of beach integrity and quality.
Key Insight: Because tiger beetles depend on undisturbed sand for burrowing and larval development, beach walkers can help by staying off roped-off dune areas and keeping vehicles away from posted beach nesting zones.
For details on the species’ federal status and range, the U.S. Fish and Wildlife Service species profile offers current information, and the beetle’s shared range with Maryland is covered in the guide to Maryland’s beetle species.
9. Red Milkweed Beetle
The red milkweed beetle, Tetraopes tetrophthalmus, is one of the easiest beetles on this list to identify simply by location. Field guides covering the region note that to find red milkweed beetles in Delaware, a person needs to find milkweed, since they are almost always near their host plant, the common milkweed.
Physically, the species stands out with a bright orange-red body dotted with black spots, a color scheme that mirrors the warning coloration of monarch butterflies, which also depend on milkweed. The beetle is narrow and elongated, with unridged antennae that bisect its eyes, a feature that helps separate it from other red-and-black beetles found in gardens.
Key Insight: Like monarch caterpillars, red milkweed beetles absorb toxic compounds from milkweed sap. This makes them unpalatable to most predators, which is why their bold coloring works as a warning rather than camouflage.
Because the beetle’s survival is tied directly to milkweed availability, planting native milkweed species supports this beetle alongside monarchs and other pollinators. Readers building a pollinator-friendly yard might also check the guide to harmless insect species safe around gardens for more low-risk backyard visitors.
10. Tooth-necked Longhorn Beetle
The tooth-necked longhorn beetle refers to members of the subfamily Prioninae, a group named for the small tooth-like projections running along the sides of the pronotum, just behind the head. Species in this group, including root borers in the genus Prionus, rank among the largest longhorn beetles found in the eastern United States.
These beetles spend most of their life underground as larvae, feeding on the roots of hardwood trees for one to several years before emerging as adults. Adults are typically dark brown to black, heavy-bodied, and most active at dusk or after dark, which means most people only encounter them when one is drawn to porch lights on warm summer nights.
Because larvae feed on roots rather than structural wood, tooth-necked longhorn beetles rarely threaten homes the way powderpost beetles do, though heavy infestations can stress young or already weakened trees. Anyone curious how many beetle families exist worldwide, and where this group fits in, can start with the overview of how many types of beetles exist.
Delaware’s beetle diversity reflects the state’s mix of coastal beaches, wetlands, farmland, and forest, and the ten species covered here represent only a small slice of what actually lives there. Some, like the dung beetle and flower longhorn beetle, quietly support healthy ecosystems. Others, including the emerald ash borer and powderpost beetle, demand more caution given the economic and ecological damage they can cause.
Learning to tell these species apart takes practice, but paying attention to habitat, size, coloring, and antennae shape covers most identification needs in the field. Readers who want to keep exploring beetle diversity beyond Delaware’s borders can compare findings with related guides covering beetle species in Missouri, insects found in New York, or the wider world of insects living in the Amazon rainforest.