Small caterpillars and earwigs are the usual suspects when butterfly bush leaves show ragged edges. If you are wondering what is eating my butterfly bush, the answer usually involves a few specific insects that find the foliage as tasty as you find the blooms beautiful.
Butterfly bushes (Buddleja) are tough, fast-growing shrubs. They resist most diseases and deer tend to leave them alone. However, a handful of pests can turn the leaves into lace or chew them down to the stem. Let’s look at the most common culprits and how to stop them.
Common Pests That Eat Butterfly Bushes
You don’t need a magnifying glass to find most of these pests. You just need to know when to look. Some feed at night, others during the day. Here are the usual offenders.
Caterpillars And Butterfly Larvae
It is ironic that a plant named for butterflies gets eaten by their babies. Several moth and butterfly caterpillars will feed on the leaves. You might see green caterpillars, black and yellow striped ones, or fuzzy brown ones.
- Signs: Large, irregular holes in the middle of leaves. Dark green or black droppings (frass) on the leaves below.
- Timing: Late summer and early fall are peak times.
- Control: Pick them off by hand in the evening. Or spray with Bacillus thuringiensis (Bt), a natural bacteria that kills caterpillars but is safe for other insects.
Earwigs
Earwigs are nocturnal scavengers. They hide in dark, damp places during the day. At night, they climb up and chew ragged holes in the leaves. They are the number one suspect if the damage appears overnight.
- Signs: Ragged, irregular holes. Leaves that look like they were shredded, not cleanly cut.
- Check: Look under the pot, in mulch, or inside rolled-up leaves during the day.
- Control: Set a trap. Fill a small container with soy sauce and a little oil. Sink it into the soil so the rim is level with the ground. They will fall in and drown.
Japanese Beetles
These metallic green and bronze beetles are hard to miss. They feed in groups, usually in the middle of summer. They are more common in the eastern United States.
- Signs: Skeletonized leaves. The veins remain, but the soft tissue between them is gone.
- Timing: They are active for about 6-8 weeks in June and July.
- Control: Knock them into a bucket of soapy water in the morning when they are sluggish. Avoid beetle traps, as they often attract more beetles to your yard.
Spider Mites
Spider mites are tiny, almost invisible pests. They are not insects but arachnids. They suck the sap from the leaves, causing stippling and discoloration. They thrive in hot, dry, dusty conditions.
- Signs: Yellow or bronze speckling on leaves. Fine webbing on the underside of leaves and between stems.
- Check: Hold a white piece of paper under a leaf and tap it. If you see tiny moving specks, you have mites.
- Control: Blast them off with a strong jet of water. Repeat every few days. For severe infestations, use insecticidal soap.
Whiteflies
Whiteflies are tiny, white, moth-like insects. They cluster on the undersides of leaves. When you shake the plant, a cloud of them flies up. They suck sap and excrete sticky honeydew, which can lead to sooty mold.
- Signs: Sticky leaves. Yellowing or wilting foliage. Black sooty mold on the leaves.
- Control: Use yellow sticky traps. Spray with neem oil or insecticidal soap, making sure to coat the undersides of the leaves.
What Is Eating My Butterfly Bush At Night
If the damage appears overnight, you are dealing with nocturnal feeders. Earwigs are the top suspect. However, slugs and snails can also be the problem, especially in damp, shady gardens.
Slugs and snails leave a slime trail behind. They chew irregular holes in the leaves, but they prefer to feed on lower leaves and young growth. They are most active after rain or heavy watering.
How To Identify Night Feeders
Go out to your garden with a flashlight after dark. Wait about 30 minutes after sunset. Check the leaves and the soil around the base of the plant. You will likely catch the culprit in the act.
- Shine the light on the underside of the leaves.
- Check the soil surface for slime trails.
- Look for earwigs hiding in the leaf axils.
- Look for slugs or snails near the base of the stem.
If you see earwigs, use the soy sauce trap. If you see slugs, sprinkle diatomaceous earth around the base of the plant. It is sharp and cuts their soft bodies, but it is safe for pets and humans.
Why Are There Holes In My Butterfly Bush Leaves
Not all holes are caused by insects. Sometimes, the damage is from physical or environmental factors. Before you spray pesticides, rule out these non-insect causes.
Hail Damage
Hail can shred leaves in minutes. The damage looks like torn, ragged holes. It usually affects the top leaves and new growth. There are no insects to find. The plant will recover on its own.
Wind Damage
Strong winds can cause leaves to rub against each other or against structures. This creates brown, scuffed areas that can tear. It is more common on exposed plants.
Chemical Burn
If you sprayed fertilizer or herbicide on a hot day, the leaves might burn. This looks like brown spots or holes in the center of the leaves. It is not caused by chewing. The damage is usually uniform across the plant.
How To Stop Pests From Eating Butterfly Bush
Once you identify the pest, you can take action. The best approach is to start with the least toxic method first. Chemical pesticides can kill beneficial insects like bees and ladybugs that visit the flowers.
Step-By-Step Treatment Plan
Follow these steps to get the problem under control.
- Inspect: Look at the leaves, stems, and soil. Identify the pest before treating.
- Remove: Hand-pick large insects like caterpillars and Japanese beetles. Drop them in soapy water.
- Wash: Spray the plant with a strong stream of water to dislodge mites and whiteflies.
- Trap: Set out earwig traps or yellow sticky traps for whiteflies.
- Spray: Use insecticidal soap or neem oil for soft-bodied pests. Apply in the early morning or evening to avoid harming bees.
- Repeat: Most treatments need to be repeated every 5-7 days for a few weeks.
Preventive Measures For Next Year
Prevention is easier than cure. Here are some ways to make your butterfly bush less appealing to pests.
- Water at the base: Avoid overhead watering. Wet leaves attract slugs and promote fungal diseases.
- Clean up debris: Remove fallen leaves and dead branches in the fall. This removes overwintering eggs and hiding spots.
- Encourage predators: Birds eat caterpillars and beetles. Ladybugs eat mites. Plant dill, fennel, and yarrow nearby to attract them.
- Do not over-fertilize: Too much nitrogen creates soft, succulent growth that pests love. Use a slow-release fertilizer in spring.
Does The Butterfly Bush Have Natural Defenses
Butterfly bushes are generally resistant to most pests. They have a strong scent and slightly fuzzy leaves that deter some insects. However, stressed plants are more vulnerable. A plant that is not getting enough sun or water is more likely to be attacked.
Ensure your butterfly bush gets at least 6 hours of full sun a day. They are drought-tolerant once established, but they need regular water during their first year. A healthy plant can outgrow minor pest damage quickly.
When To Use Chemical Pesticides
Chemical pesticides should be a last resort. If natural methods fail, you can use a systemic insecticide. These are absorbed by the plant and kill insects that feed on it. However, they can also kill bees that drink the nectar.
If you must use a chemical, apply it in the evening when bees are not active. Do not spray the flowers. Read the label carefully and follow the instructions. It is often better to prune back the damaged growth and let the plant regrow.
Frequently Asked Questions
Here are some common questions gardeners have about butterfly bush pests.
Will A Butterfly Bush Recover From Being Eaten
Yes. Butterfly bushes are very resilient. They can lose a lot of foliage and still survive. If the plant is completely defoliated, cut it back to about 12 inches from the ground. It will regrow quickly. Do not do this late in the fall, as it can stimulate new growth that will be killed by frost.
Do Rabbits Eat Butterfly Bushes
Rabbits will occasionally nibble on young, tender shoots. However, they usually avoid mature plants. If rabbits are a problem, protect the base of the plant with a wire cage in the early spring. Deer also avoid butterfly bushes because of the strong scent.
Are There Any Plants That Repel Pests From Butterfly Bushes
Planting garlic, chives, or marigolds near your butterfly bush can help deter some pests. These plants have strong scents that mask the smell of the butterfly bush. However, they will not completely eliminate the problem. They are best used as part of an integrated pest management plan.
Why Are The Leaves Turning Yellow And Falling Off
Yellow leaves are usually a sign of overwatering or poor drainage. Butterfly bushes do not like wet feet. If the soil is soggy, the roots will rot. This can also attract fungus gnats and other soil pests. Let the soil dry out between waterings. If the plant is in a pot, make sure it has drainage holes.
Is It Normal For The Bottom Leaves To Look Bad
Yes. The lower leaves on a butterfly bush often look rough. They are shaded by the upper growth and may not get enough light. They are also more exposed to soil-borne pests and splashing water. If the lower leaves are damaged, prune them off. This improves air circulation and reduces the risk of disease.
Identifying the pest is the first step. Once you know what is eating my butterfly bush, you can choose the right treatment. Most of the time, a simple hand-picking or a soap spray will solve the problem. The plant is tough and will bounce back with new growth in a few weeks.
Check your plant every few days. Look at the underside of the leaves and the base of the stem. Early detection makes treatment much easier. Do not panic if you see some damage. A few holes are normal. It only becomes a problem when the plant is losing more leaves than it is growing.
Remember that butterfly bushes are meant to be enjoyed. They are one of the best plants for attracting pollinators. A little bit of pest damage is a small price to pay for the butterflies, bees, and hummingbirds they bring. Focus on keeping the plant healthy, and it will handle most minor pest issues on its own.
If you have tried everything and the pest persists, consider replacing the plant. Some varieties are more resistant to pests than others. Look for compact varieties like ‘Blue Chip’ or ‘Pugster’ series. They are bred for better disease resistance and may have fewer pest problems.
Keep an eye on the weather. Hot, dry summers lead to more spider mites. Cool, wet springs lead to more slugs and snails. Adjust your watering and monitoring schedule accordingly. A little attention goes a long way in keeping your butterfly bush healthy and beautiful all season long.