Red Milkweed Beetle

Tetraopes tetrophthalmus · Order: Coleoptera · Family: Cerambycidae

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.
Red Milkweed Beetle
Photo: Katja Schulz, CC BY

Red milkweed beetles are brightly colored red and black, warning predators that they are not edible. They live on common milkweed, feeding on its leaves, flowers, and roots, and lay eggs inside the plant stem in mid-summer.

Source: Wikipedia

How to recognize it

The beetle’s red and black colors serve as a warning that it is inedible.

Source: Wikipedia

Where it lives

They feed by opening veins in milkweed, which reduces exposure to the plant’s latex-like sap.

Source: Wikipedia

What it eats

Adults eat milkweed foliage and flowers; larvae eat the plant’s roots.

Source: Wikipedia

Life cycle

Females lay clutches of eggs inside the base of the milkweed stem in mid-summer.

Source: Wikipedia

When you see it

Egg-clutch laying occurs in mid-summer.

Source: Wikipedia

Where it is found in the US

Recorded in 38 of 51 states and DC. Most records: Illinois, Pennsylvania, New York, Ohio, Massachusetts, Maryland, Michigan, Wisconsin.

Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Status: native in North America; native in Canada; native in United States. Source: iNaturalist

Months it is reported in the US

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Source: GBIF

More photos

Red Milkweed Beetle photo 3
Photo: Katja Schulz, CC BY
Red Milkweed Beetle photo 4
Photo: Judy Gallagher, CC BY-SA
Red Milkweed Beetle photo 5
Photo: unknown, CC0
Red Milkweed Beetle photo 6
Photo: Bill Keim, CC BY

Same family (Cerambycidae)

House LonghornHouse LonghornHylotrupes bajulusCan damage your homeAsian Longhorned BeetleAsian Longhorned BeetleAnoplophora glabripennisDamages trees, gardens or cropsWhite-spotted SawyerWhite-spotted SawyerMonochamus scutellatusCan damage your homeRed Pine Longhorn BeetleRed Pine Longhorn BeetleStictoleptura rubraSpotted Longhorn BeetleSpotted Longhorn BeetleRutpela maculataDamages trees, gardens or cropsLocust BorerLocust BorerMegacyllene robiniae

Sources

  • Wikipedia: https://en.wikipedia.org/wiki/Tetraopes_tetrophthalmus

Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia

Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.

How this page works

This is one bug's fact sheet. The colored box at the top says whether it is dangerous. Sections below cover how to recognize it, whether it is a pest, and how to deal with it. The US map shows which states have records; tap a state to see other bugs there.

Every fact on Bug FAQ comes from a named source (university extension sites, government agencies, GBIF, iNaturalist, Wikipedia). The source is linked next to each section. If we have no source for something, we leave it out.