Beetles in Montana

Some of the several beetle species inhabiting Montana occur seasonally, while a few appear year-round. The mountain pine beetle is a common pest here to pine species like the ponderosa and lodgepole, active between July and August. The state also has a lot of blister beetles mainly dwelling in alfalfa fields, alongside soybean, sugarbeet, and potato plantations.

Beetles in Montana (MT)

The pine sawyer beetle, about 2 inches long occupying pine and fir forests, is Montana’s largest beetle.

Biggest Beetles: Pine Sawyer Beetle, Ten-lined June Beetle, Asian Lady Beetle

Smallest Beetles: Black Carpet Beetle, Black Blister Beetle

Most Common Beetles: Mountain Pine Beetle, Black Blister Beetle, Spotted Blister Beetle

Scarab Beetles

  • Ten-lined June Beetle (Polyphylla decemlineata)
  • Hairy Flower Scarab Beetle (Trichiotinus assimilis)

Lady Beetles

  • Asian Lady Beetle (Harmonia axyridis)
  • Convergent Lady Beetle (Hippodamia convergens)
  • Seven-spot Ladybird Beetle (Coccinella septempunctata)
  • Twice-stabbed Ladybug Beetle (Chilocorus stigma)

Longhorn Beetles

  • Red-femured Milkweed Borer Beetle (Tetraopes femoratus)
  • Ponderosa Pine Bark Borer Beetle (Acanthocinus princeps)
  • Red-shouldered Pine Borer Beetle (Stictoleptura canadensis)
  • Ponderous Borer Beetle (Trichocnemis spiculatus)
  • White-spotted Sawyer Beetle (Monochamus scutellatus)
  • Yellow Douglas Fir Borer Beetle (Centrodera spurca)
  • Yellow Velvet Flower Beetle (Cosmosalia chrysocoma)
  • Pine Sawyer Beetle (Monochamus galloprovincialis)
  • California Prionus Beetle (Prionus californicus)
  • Asian Long-horned Beetle (Anoplophora glabripennis)

True Weevils

  • Knapweed Root Weevil (Cyphocleonus achates)
  • Elegant Weevil Beetle (Pachyrhinus elegans)
  • Mountain Pine Beetle (Dendroctonus ponderosae)

Water Scavenger Beetles

  • Giant Black Water Beetle (Hydrophilus triangular)

Carrion Beetles

  • Garden Carrion Beetle (Heterosilpha ramosa)

Jewel Beetles

  • Golden Jewel Beetle (Buprestis aurulenta)
  • Western Sculptured Pine Borer Beetle (Chalcophora angulicollis)

Leaf Beetles

Net-winged Beetles

  • Golden Net-wing Beetle (Dictyoptera aurora)

Ground Beetles

  • Cow Path Tiger Beetle (Cicindela purpurea)
  • European Ground Beetle (Carabus nemoralis)
  • Western Tiger Beetle (Cicindela oregona)
  • Boreal Long-lipped Tiger Beetle (Cicindela longilabris)

Rove Beetles

  • Gold-and-brown Rove Beetle (Ontholestes cingulatus)

Click Beetles

  • Western Eyed Click Beetle (Alaus melanops)

Blister Beetles

  • Ashgray Blister Beetle (Epicauta fabricii)
  • Spotted Blister Beetle (Epicauta maculata)
  • Black Blister Beetle (Epicuata pensylvanica)
  • Dark Blister Beetle (Epicuata murina)
  • Black Meloe (Meloe niger)

Skin Beetles

  • Black Carpet Beetle (Attagenus unicolor)