Although Milkweed contains toxic chemicals that protect it from many animals, they are some insects that have evolved to feed on Milkweed. Unfortunately, these specialized insects are the reason why milkweed plants get damaged and eventually die.
Most Common Milkweed Pest
Cobalt Blue Beetle
It is a metallic cobalt-blue or blue-green beetle about 6 to 9mm. The adult beetles feed on foliage and cause leaf defoliation. The larvae also feed on the roots.
Red Milkweed Beetle
It is a red to red-orange colored beetle about 8 to 15 mm large with black spots and long black antennae. The Adults feed on the leaves and the larvae on the milkweed roots.
Large and Small Milkweed Bugs
These bugs are orange-red and black in coloration. The small ones are about 10mm big and the big ones up to18 mm large. They are forming small colonies on the stems, foliage, and seed pods and feeding on them.
Oleander Aphid
A bright yellow to orange colored aphid with black legs and antennae. Comes in winged or non-winged forms—about 2mm large and feeding on stems, foliage, flowers, and pods.
What you can do!
Four Pest Prevention Strategies
1. Crop Scouting is the best practice to get rid of harmful bugs and beetles. Scout your Milkweed Plants and remove any of these insects by hand.
2. Plant other wildflowers and native grasses with your milkweed plants to enhance the habitat for predatory insects that feed on the milkweed pest.
For example, the Oleander Aphid is preyed upon by many beneficial insects, including lady beetles, hoverflies, and wasps.
3. Take out dead grass and Milkweed stems to reduce the number of potential egg-laying sites. Red milkweed beetles deposit their eggs in the hollow stem of dead grasses and other flowers.
4. Using pesticides is not recommended, considering that your Monarch Caterpillars will also be damaged. You can use some organic products, like horticultural oils, insecticidal soaps, and plant-derived oils.
