Red Milkweed Beetle

Common Name: Red Milkweed Beetle.

Scientific Name: Tetraopes Tetrophthalmus.

What to look for?  A distinctively red, elongated winged insect with numerous black dots. The Red Milkweed Beetle has a red head and body. The pronotum, or first segment of the thorax, has four small black spots. This beetle has hardened wing covers, or elytra, that are also red and have five black spots. And on their flat face is what has been described as a red “mask”. They two long, black, horn-like antennae. The red base of the antennae is inserted into the black eye, splitting the eye into two parts – they have four eyes! And they have six, black legs.

Where can they be found at Carillon Stonegate Pond? For only a month or so during the summer, the Red Milkweed Beetle may be found on some of the milkweed plants that grow around Carillon Stonegate Pond, over at Stonegate Park, or anywhere there are milkweeds.

How big are they? The Red Milkweed Beetle averages approximately one-half of one inch in length.

What are their flight patterns? As fliers, Red Milkweed Beetles are able to easily move around, but only within a patch of their host milkweed plants. They are not known for their distance flying.

How else do they behave? Behaviors to deal with predators are somewhat moot. With their reddish coloration serving as a warning, Red Milkweed Beetles are poisonous due to the toxic cardiac glycosides in the milkweed that they eat. Predators quickly develop a strong avoidance reaction to Red Milkweed Beetles.

What’s for dinner? Red Milkweed Beetles feed primarily on the leaves, stems, and flowers of their host plant, Common Milkweeds. Larvae feed on roots.

Where do they take up residence? The Red Milkweed Beetle lives primarily in the Great Plains states, Midwestern states, and Northeastern states. They reside in any habitat that supports milkweed plants.

When and where do they breed and nest? In early summer, a female Red Milkweed Beetle lays her eggs at the base of a milkweed stem, sometimes inserting them into the stem. Females select larger males for mating over the smaller males. Newly-hatched larvae locate the roots of milkweeds and burrow through the soil. They will dwell in the soil, feeding on milkweed root through early fall. They overwinter in the root and may resume feeding briefly in spring before pupating. The larvae create earthen chambers to pupate in and emerge in a month as adults. By fall, the adult Red Milkweed Beetle will die.

Where do they migrate? The Red Milkweed Beetle does not migrate. Larvae overwinter in the ground near their host milkweed plants.

Do they make any interesting sounds? No. Red Milkweed Beetles mostly communicate through pheromones, using visual, tactile, and chemical senses of perception.

Interesting Facts About the Red Milkweed Beetle:

  • Red Milkweed Beetle and Milkweed Bugs: Red Milkweed Beetle is a beetle whereas the Milkweed bug is a true bug. Bugs and insects, which includes beetles, are similar in several respects: six legs, three body parts (head, thorax, and abdomen), and two antennae. But true bugs (order Hemiptera) do not have mouths for biting and chewing food; instead, they have a tube-like beak for sucking fluid. The Red Milkweed Beetle has a mouth.

  • The scientific name, ‘Tetraopes Tetrophthalmus’, is redundant with both the genus and the species name meaning “four eyes” and refers to the way the socket of an antenna divides each compound eye in two, resulting in a lower eye and an upper eye.

  • There are only the few things that can eat the toxin-containing plants of the milkweed genus, Asclepias: Monarch butterflies, Large Milkweed Bugs, Small Milkweed Bugs and Red Milkweed Beetles.

For more information on the Red Milkweed Beetle and sources of information used in this blog (these are the several of the sources that I am using to learn as I blog), please visit The University of Michigan Animal Diversity Web, Maryland Biodiversity Project, University of Wisconsin Milwaukee Field Station – The Bug Lady, Urban Wildlife Guide, and Iowa State University Bug Guide.

The Carillon at Stonegate community is very fortunate to have a variety of wetland, forest and prairie environments conducive to a variety of birds and other wildlife, insects and plants. Our community and the Kane County Forest Preserve do an exceptional job in maintaining this natural environment – both for the benefit of the birds and wildlife and for our residents to enjoy.


Take a hike and see what you can find – and identify!