by Trey Lamkins, Landscape Operations, Kimmel Education and Research Center
If you’ve walked past a patch of Common Milkweed (Asclepias syriaca) recently, you may have noticed more than just its sweet-smelling flowers and tall, sturdy stems. Look a little closer, and you’ll find that milkweed isn’t just a plant—it’s a community. From hungry caterpillars to busy ants and colorful beetles, milkweed hosts an entire ecosystem of insects and fungi.
So, what exactly is growing (or crawling!) on your milkweed? Let’s take a look:
Monarch Caterpillar
Perhaps the most famous milkweed resident, the Monarch butterfly (Danaus plexippus) lays its eggs exclusively on milkweed plants. The striped caterpillars that emerge feed on the leaves, storing the plant’s natural toxins that help protect them from predators. Spotting a Monarch caterpillar is always a reason to celebrate—it means your milkweed is doing its job in the life cycle of this iconic and at-risk species.
Oleander Aphids
These tiny, bright orange insects are often found in clusters on milkweed stems and buds. While they may look alarming, Oleander Aphids (Aphis nerii) are a common (though non-native) guest. They suck sap from the plant and excrete sticky honeydew, which can attract ants and cause sooty mold to form. In small numbers, they’re not a serious threat—but if left unchecked, they can stress the plant and inhibit growth.
Ants
Attracted by the honeydew produced by aphids, ants often act as uninvited bodyguards. They’ll defend aphid colonies from predators like lady beetles in exchange for this sugary reward. While ants themselves don’t harm the milkweed, their presence is often a sign of an aphid infestation.
Asian Lady Beetle (Adult and Larva)
Not all insects on your milkweed are pests! The Asian Lady Beetle (Harmonia axyridis)—both as a black-and-orange-spotted adult and its spiky black larval stage—is a voracious predator of aphids. While this non-native species can sometimes be a nuisance indoors in the fall, out in the garden it plays a helpful role in natural pest control.
Longhorn Milkweed Beetles
With their striking red bodies and black antennae, Longhorn Milkweed Beetles (Tetraopes tetrophthalmus) are a native species that feeds on milkweed foliage, stems, and flowers. While they can cause minor damage, they’re part of the natural biodiversity of milkweed ecosystems and play a role in native food webs.
Powdery Mildew
If you notice a white, powdery substance on milkweed leaves, you're likely seeing powdery mildew—a fungal disease that thrives in warm, humid conditions. While not typically fatal, it can reduce the plant’s vigor and photosynthesis. Increasing airflow around plants and removing heavily infected leaves can help manage the spread.
Final Thoughts
Common Milkweed is more than a plant—it’s a microhabitat. By growing it, you’re supporting a dynamic community of insects (and fungi!) that contribute to our broader ecosystems. Some of these visitors are beneficial, some are just passing through, and a few may need managing—but together, they tell the story of milkweed’s vital ecological role.
Next time you spot a bug or blemish on your milkweed, take a moment to observe and learn. You might just be witnessing a small but powerful part of Nebraska’s native landscape in action.
Get Involved: Join Us This July!
Pollinator Workshop | July 16th | 9:00 AM - 12:00 PM | Kimmel Orchard & Vineyard
Join us to learn how to support pollinators, select native plants, and create thriving habitat in your own backyard. The workshop will feature educational sessions, youth activities, and a UNL Bee tour. Perfect for families, educators, gardeners, and anyone who care about conservation.
Register here: Pollinator Workshop RSVP