Milkweed bugs can be a nuisance in gardens where milkweed plants grow. While they don’t usually cause significant damage, their presence may be unwanted. Here are some effective ways to get rid of milkweed bugs from your garden organically without harming other pollinators like butterflies.
Identify Milkweed Bugs
Milkweed bugs are insects that get their nutrients from milkweed plants. There are two common species – the large milkweed bug and the small milkweed bug.
Adult large milkweed bugs are about 3/4 inch long and have a reddish-orange body with black stripes and markings. Nymphs are smaller and mostly red and black.
Small milkweed bugs are only about 1/2 inch long. They are orange with black spots and stripes. Nymphs are mostly yellow and black.
Both large and small milkweed bugs tend to cluster in groups on milkweed leaves and stems where they feed. They don’t cause major plant damage, but may be considered a nuisance.
Remove Milkweed Bugs by Hand
One easy organic method for controlling milkweed bugs is to simply remove them by hand. Here’s how:
- Wear garden gloves to protect yourself from bug secretions or sap.
- Check under leaves and on stems where milkweed bugs tend to gather.
- Gently brush off any clusters of bugs into a container.
- Drop the bugs into a bucket of soapy water to kill them. You can also crush them.
- Repeat daily or as needed until population is under control. Be sure to get the nymphs too.
This physical removal is safe for other beneficial insects and doesn’t use any chemical pesticides. Just be patient and consistent.
Apply Diatomaceous Earth
Diatomaceous earth is an organic powder made from fossilized algae that can help control milkweed bugs. Here’s how to apply it:
- Buy food-grade diatomaceous earth, available at garden centers.
- Lightly dust it onto leaves, stems, and the soil around milkweed plants.
- The powder abrades the waxy coating on insect bodies, causing them to dehydrate.
- Reapply after rain or watering. Use a duster for easier application.
- Diatomaceous earth is non-toxic to people and pets but can also kill beneficial insects. Use carefully and directly on infested plants only.
Introduce Natural Predators
Encouraging natural predators in your garden can help reduce milkweed bug populations. Beneficial predator insects include:
- Ladybugs – Both adults and larvae eat milkweed bug eggs and nymphs. Attract them with flowering plants.
- Green lacewings – The larvae eat small insects like nymphs. Adults eat nectar and pollen.
- Parasitoid wasps – They lay eggs inside milkweed bugs, killing them from the inside out. Allow native species to thrive.
- Praying mantis – Will eat both young and adult milkweed bugs they can capture. Don’t kill them!
A diverse garden with pollinator-friendly native plants will attract these predators and help control milkweed pests.
Use Organic Insecticidal Soap
Insecticidal soap sprays made with potassium salts of fatty acids can control milkweed bugs. Here’s how to use this organic option:
- Buy pre-mixed insecticidal soap or make your own soap spray.
- Shake well and apply directly onto milkweed bugs and nymphs.
- Thoroughly coat leaves, stems, and bugs on the undersides too.
- The soap disrupts cell membranes on soft-bodied insects causing them to desiccate.
- Repeat applications may be needed. Don’t rinse the plants after application.
- Insecticidal soaps can harm monarch caterpillars. Use carefully only on infested plants.
Apply Neem Oil Spray
Extracts of the neem tree have long been used as organic insecticides. Here’s how neem oil can help control milkweed bugs:
- Look for 100% cold-pressed neem oil and mix with water.
- Add a small amount of mild soap to help it stick to plants.
- Thoroughly spray leaves, stems, and underleaf areas where bugs hide.
- Neem oil can disrupt the molting process and egg laying ability of insects.
- Repeat weekly applications for a few weeks until the infestation is gone. Reapply after rain.
- Neem oil can also harm pollinators and monarch larvae. Only use directly on infested plants.
Cover Young Milkweed Shoots
If milkweed bugs consistently appear when your plants first emerge each year, try covering the tender shoots.
- When new growth first appears in spring, place lightweight row cover over plants. Secure the edges well.
- Leave the cover on for about 2-3 weeks until plants are larger and less vulnerable.
- Check under periodically and remove any bugs that got in.
- This prevents milkweed bugs from colonizing the young shoots early in the season.
Remove Milkweed in Fall
Since milkweed bugs overwinter as adults in plant debris, cleaning up thoroughly in fall can reduce their numbers the next season.
- After frost kills back your milkweed plants, cut all the dead foliage to ground level.
- Pull out any remaining root crowns and stems.
- Dispose of all plant debris in sealed bags with the trash, not the compost.
- Eliminating their winter shelter exposes bugs to predators and weather.
- Consider not replacing milkweed in infested areas for a season or two.
A combination of manual, organic, and habitat modification techniques can reduce milkweed bug populations without using any harmful pesticides. Be vigilant, and get them before they multiply. Protecting monarch caterpillars and other pollinators should be a priority as well. With some persistence, you can eliminate annoying milkweed bugs from your garden.
Frequently Asked Questions
What plants do milkweed bugs infest?
Milkweed bugs feed almost exclusively on milkweed plants (Asclepias species). They rely on milkweed for nutrients and nourishment, so are really only problematic where milkweed is grown.
How do milkweed bugs damage plants?
Milkweed bugs don’t usually inflict major damage on established plants. The adults and nymphs suck sap from leaves, shoots, and seed pods. This can stunt plants and reduce flowering and seed production. Mostly they are just a nuisance.
Do milkweed bugs bite or sting?
Milkweed bugs don’t bite humans or pets. While they can produce a mild toxic secretion if threatened, they are harmless to handle. The secretions are mainly a defense against predators.
Should milkweed bugs be manually killed?
It’s preferable to simply flicking milkweed bugs off plants into a bucket of soapy water rather than crushing them. They don’t cause enough damage to warrant killing them. The soapy water will dispatch them quickly without harming other beneficial insects.
How long do milkweed bugs live for?
The adult milkweed bugs that overwinter each year live for several months. After becoming active in spring, they mate, lay eggs on milkweed plants, then die by summer. The resulting nymphs form a new generation of adults that continues the cycle.
What attracts milkweed bugs?
Milkweed bugs are mainly attracted by the presence of milkweed plants (Asclepias) which they rely on for food and breeding habitat. They detect the plants through chemical cues. Planting milkweed will ensure milkweed bugs pay your garden a visit.
Conclusion
While milkweed bugs are more of a nuisance than a real threat to your garden, controlling their populations on prized milkweed plants may be desired. Thankfully, there are many organic and eco-friendly methods to effectively get rid of milkweed bugs or reduce their presence without using harmful pesticides. Be patient, consistent and willing to hand remove these insects as part of maintaining your garden if you choose to grow milkweed. And be sure to avoid damaging monarch caterpillars and other beneficial pollinating insects in the process. With some persistence, your garden can be relatively free of annoying milkweed bugs.