red milkweed beetle

(Tetraopes tetrophthalmus)

Conservation Status
red milkweed beetle
Photo by Alfredo Colon
  IUCN Red List

not listed


NNR - Unranked


not listed


Red milkweed beetle is one of three eastern milkweed longhorn beetles.

The female is 5 16 to long, slightly larger than the male. The body is robust and has broad shoulders. The head, the plate covering the first segment of the thorax (pronotum), and the hardened wing covers (elytra) are red.

The face is nearly flat. The antennae are ½ to long, about as long as the body. They are all black, not ringed with white or gray. The red base of the antennae is inserted into the black eye, splitting the eye into two parts. Two segmented feeler-like structures (palpi) are attached to the lower jaw-like structures (maxillae). The last segment of each maxillary palp is pointed.

The pronotum has four small black spots and a raised, disk-shaped hump.

Each elytron has five black spots: one in the shoulder region (humerus); a small spot at the base of the elytron near the scutellum; a small antemedial spot neat the suture; a large medial spot near the center; and a small post medial spot near the center.

The legs, including the third segments (femurs), are all black. The forward, middle, and back legs each have 5 end segments (tarsi). They appear as 4 segments because the minute 4th segment is concealed by the enlarged 3rd segment.




Total Length: 5 16 to


Similar Species


Milkweed longhorn beetles are found on one or more species of milkweeds. The plant species on which the beetle is found is an aid to identification of the beetle species.

Red-femured milkweed borer (Tetraopes femoratus), as its name suggests, has red femurs. The antennae are ringed with white. The medial black spots on the elytra are no larger than other spots or are absent. It feeds exclusively on showy milkweed.


Meadows, fields, prairies, roadsides. Anywhere the host plants are found.




May to September






Life Cycle


Adults emerge in May or later, coinciding with the flowering of common milkweed. In early summer the female lays eggs near the base of a common milkweed stem. When the larvae hatch they bore into the stem. They overwinter in the roots.


Larva Food


Roots of common milkweed and possibly one or more other milkweed species.


Adult Food


Leaves and buds of common milkweed and possibly one or more other milkweed species.


Distribution Map



7, 24, 27, 29, 30.







Coleoptera (beetles)  


Polyphaga (water, rove, scarab, longhorn, leaf and snout beetles)  




Chrysomeloidea (long-horned and leaf beetles)  


Cerambycidae (long-horned beetles)  


Lamiinae (flat-faced longhorns)  







Lamia fornator

Lamia tornator

Tetraopes humeralis

Tetraopes tetraophthalmus

Tetraopes tetrophthalmus iowensis

Tetraopes tredecimpunctatus


Common Names


eastern milkweed longhorn beetle

red milkweed beetle









The hardened or leathery forewings on an insect used to protect the fragile hindwings, which are used for flying, in beetles and true bugs.



On insects and arachnids, the third, largest, most robust segment of the leg, coming immediately before the tibia. On humans, the thigh bone.



The saddle-shaped, exoskeletal plate on the upper side of the first segment of the thorax of an insect.



The exoskeletal plate covering the rearward (posterior) part of the middle segment of the thorax in some insects. In Coleoptera, Hemiptera, and Homoptera, the dorsal, often triangular plate behind the pronotum and between the bases of the front wings.



The last two to five sections of an insect’s leg, attached to the tibia; the foot.






Visitor Photos

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    red milkweed beetle   red milkweed beetle  

Susan Gangl

    red milkweed beetle      

Alfredo Colon


Red milkweed beetle, Tetraopes tetrophthalmus

    red milkweed beetle   red milkweed beetle  
    red milkweed beetle   red milkweed beetle  
    red milkweed beetle   red milkweed beetle  
    red milkweed beetle      

Paula Rabine


Loving our milkweed!

    red milkweed beetle      

Lucy M

    red milkweed beetle      

Bill Reynolds


Red Milkweed Beetle crawling all over the Milkweed today.

    red milkweed beetle   red milkweed beetle  
    red milkweed beetle   red milkweed beetle  
    red milkweed beetle   red milkweed beetle  
    red milkweed beetle      



Red Milkweed Beetle
  Red Milkweed Beetle  

Copyright DianesDigitals

Red Milkweed Beetle
Andree Reno Sanborn
  Red Milkweed Beetle  

Tetraopes tetrophthalmus




Visitor Videos

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Other Videos
  Milkweed Beetle

Published on Jul 6, 2013

Tetraopes tetrophthalmus, commonly known as the red milkweed beetle, is a beetle in the family Cerambycidae. The binomial genus and species names are both derived from the Latin for "four eyes." As in many longhorn beetles, the antennae are situated very near the eye - in the red milkweed beetle, this adaptation has been carried to an extreme: the antennal base actually bisects the eye

The milkweed beetle, a herbivore, is given this name because they are generally host specific to milkweed plants (genus Asclepias). It is thought the beetle and its early instars derive a measure of protection from predators by incorporating toxins from the plant into their bodies, thereby becoming distasteful, much as the Monarch butterfly and its larvae do. The red and black coloring are aposematic, advertising the beetles' inedibility. There are many milkweed-eating species of insect that use the toxins contained in the plant as a chemical defense.

  Mating milkweed beetles in the morning, moist
Robert Klips

Uploaded on Jul 24, 2011

The red milkweed beetle, Tetraopes tetrophthalmus (Coleoptera; Cerambycidae) is a common herbivore on milkweed (Asclepias). Note how the antennal base bisects the eye (a trait referred to by both the genus and specific epithet,meaning "four eyes"). Here a pair of them enjoy a summer morning on July 5, 2011 at Killdeer Plains Wildlife Area in Wyandot County, Ohio, USA.

  Feeding Red Milkweed Beetle - Hamilton County, Ohio, USA
William Hull

Uploaded on May 24, 2010

Red Milkweed Beetle feeding on Common Milkweed in my yard in Hamilton County, Ohio, USA. May 24, 2010.

  Courtship in the Red Milkweed Beetle, Tetraopes tetraophthalmus, (Cerambycidae)
David Edwards

Uploaded on Jan 14, 2012

Amorous Milkweed Beetles filmed by David Noel Edwards in Columbia County, New York, at the OOMS Conservation Area at Sutherland Pond (Owned by the Open Space Institute and managed by the Columbia Land Conservancy). "Je T'aime" performed by Serge Gainsbourg and Jane Birkin. Use of this music constitutes fair use because the video is a work of parody.

  Red Milkweed Beetles on wildflowers (Super Macro)

Uploaded on Jul 18, 2009

One of the few insects that can feed safely on milkweed. Caught these two doing their thing in a field near my house. 07/17/09




Visitor Sightings

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  Susan Carlson

Location: Medina next to Baker Park


Location: Brooklyn Park, Mn

red milkweed beetle  
  Susan Gangl

Location: St. Paul, Macalester Groveland / Highland area

red milkweed beetle  
  Alfredo Colon
8/2 - 8/7/2019

Location: Woodbury, Minnesota

red milkweed beetle  

Location: 55416

red milkweed beetle  
  Lucy M

Location: Hennepin County

red milkweed beetle  
  Bill Reynolds

Location: Pennington Co.

Red Milkweed Beetle crawling all over the Milkweed today.

red milkweed beetle  




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