Net-winged beetles (family Lycidae) are soft-bodied insects recognized by their ridged wing covers that resemble a net-like pattern. While often mistaken for harmful beetles, most species are harmless and even beneficial.
They are commonly found in wooded areas, gardens, and near decaying organic matter.
The Toxic Mimic: Net-Winged Beetles
The Net-Winged Beetle (Family Lycidae) is a distinctive group of beetles found throughout the United States, particularly in moist, wooded environments. While they are often mistaken for pests due to their bright “warning” colors, they are actually beneficial or neutral members of the ecosystem. In the U.S., they are most famous for their role as the “models” in complex mimicry rings involving moths, flies, and other beetles.
Identification: The “Sculpted” Wing
Net-winged beetles are named for the intricate, raised network of ridges on their soft wing covers (elytra). These ridges create a “net-like” appearance that is unique among North American beetles. Most species, such as the common End Banded Net-Winged Beetle (Calopteron reticulatum), feature bold orange and black patterns.
- Aposematic Coloration: Their bright colors serve as a warning to predators (birds and lizards) that the beetle is highly toxic. When disturbed, they excrete a foul-smelling, bitter-tasting fluid from their leg joints.
- Flattened Shape: They typically have a broad, flattened body and antennae that are long, serrated (saw-toothed), and prominent.
- Mimicry: Several harmless insects, including some species of moths and even the Black-and-Yellow Longhorn Beetle, have evolved to look like Net-Winged Beetles to trick predators into thinking they are also toxic.
Larval Life: The “Trilobite” Look-Alike
The larvae of Net-Winged Beetles are just as fascinating as the adults. They are often found under rotting logs or in leaf litter across the Eastern and Pacific Northwest forests. These larvae are heavily armored and flattened, bearing a striking resemblance to ancient Trilobites. Contrary to some myths, they are not wood-borers; instead, they are believed to feed on slime molds, fungi, or the liquids produced by decaying organic matter.
U.S. Ecological Significance
From a “Pestipedia” perspective, Net-Winged Beetles are non-pests. They do not damage crops, timber, or ornamental plants. In fact, the adults are often found on wildflowers like Goldenrod and Milkweed, where they act as minor pollinators while feeding on nectar. Their presence in a garden or woodlot is usually a sign of a healthy, moisture-rich environment with plenty of decaying organic material to support their unique lifecycle.
Managing “False Alarms”
Homeowners often worry when they see a “swarm” of these bright beetles on a tree trunk or fence in mid-summer. In the U.S., this is typically a mating aggregation. Because they are chemically protected and do not bite or sting, there is no need for chemical control. In fact, spraying them may inadvertently kill the beneficial mimics that share their habitat. If they become a nuisance near doorways, they can simply be swept away with a soft broom.
Identification
They are typically orange, red, or black with soft bodies and distinct wing patterns.
Lifecycle
Larvae develop in moist environments and feed on fungi or decaying material.
Impact
They are not harmful to plants and may aid decomposition.
Control
No control needed—these beetles are beneficial or neutral.