A part of the bougainvillea’s appeal is that they are relatively disease and pest-free plants. If you follow BGI’s Rules for Care and fertilize with Bougain®, which has a lot of micronutrients that are important for healthy, blooming bougainvillea, these pests and diseases are NOT likely to affect your plant. This page contains most (but not all) common pests/diseases that may affect your bougainvillea.
If your bougainvillea does get pests or diseases, which happens very rarely, always try the least harmful way to get rid of them first. If you use chemical pesticides to control insect pests, you will also kill natural predators. If you choose a chemical control, be sure to carefully follow the instructions and rules. Also, make sure you always wear safety gear and protective clothing, such as a long-sleeved shirt, long pants, neoprene gloves, goggles, and a respirator. Chemical pesticides are not recommended for use inside the home.
Known also as greenfly, blackfly or plant lice, aphids are minute plant-feeding insects. Important natural enemies include the predatory ladybugs/ladybirds/ladybeetles, and lacewings. Aphids are tiny, pear-shaped, sap-sucking pests, appearing in the spring to feast on your plants’ tender new leaves. They leave behind a secretion that attracts ants and promotes mold growth. Not to fear; you don’t have to resort to toxic chemicals to save your bougainvillea.
Small reddish-brown spots on the leaves, which usually show up on younger plants and make them look “rusty,” are the first signs. These enlarge into circular or irregular dark necrotic spots. When environmental conditions are drier and less favorable, leaf spots are slower to develop. Lesions have a tan center with a dark reddish-brown edge, and sometimes they have a chlorotic halo around the edge. In time, leaf edges may become ragged as the necrotic tissue turns dry and papery. When it rains a lot or is very humid, the sores appear quickly and are usually black with clear vein lines. Infection of developing leaves and bracts results in puckered, distorted growth.
Natural Control Maintaining dry foliage is the primary control measure. Cut branches back and away from each other, or if the tree is just starting to grow, leave a lot of space between them. Branches that are overlapping can’t dry quickly and become more susceptible to leaf spot disease. Remove infected leaves and/or plants from the growing area. Dispose of them immediately to reduce the spreading of infection.
Chemical Control Spray fungicide in the spring if necessary. It will not cure infection that is already there, but it can control the spread of it. In frost-free climates where bougainvillea is perennial, disease incidence drops during cool and/or dry weather.
Seeing yellow or tan spots on older leaves could mean that the plant needs more magnesium (which happens a lot with yellow bougainvilleas) or that it has been watered too much.
Plants that are over-watered or subjected to water logged conditions can develop root or stem rot. You can easily avoid it by being careful and using a broad-spectrum fungicide drench when transplanting or planting in the landscape.
Bougainvillea are beautiful tropical vines that add bursts of color to gardens. However, these plants can fall victim to several common insect pests. Learning how to identify and control bougainvillea bugs will help you keep your plants looking their best. This article will cover the most common bougainvillea pests and provide organic and chemical control options.
Common Bougainvillea Bugs
Here are some of the most prevalent insects that enjoy munching on bougainvillea:
Aphids
These small soft-bodied insects pierce stems leaves, and tender plant tissues to suck out fluids. Heavy aphid populations cause yellowed, curled, and stunted growth. They also secrete sticky honeydew that can grow black sooty mold.
Leaf Miners
The larvae of these small moths create meandering tunnels between the leaf surfaces. This damage causes curling and distortion. Adults are hard to spot, but larval trails are very noticeable.
Armored and Soft Scales
Both armored and soft scales suck nutrients from phloem tissues. They secrete honeydew and can cause leaf yellowing and premature dropping. Soft scales appear cottony or waxy.
Spider Mites
Too small to see individually, spider mites look like moving dots on colony-infested leaves. They suck cell contents causing stippling and bronze discoloration. Leaves may be covered in webs.
Thrips
Tiny insects that cause scarring, stippling, and stunting. They prefer rapidly growing tissues.
Loopers
Green caterpillars with white stripes that eat irregular holes in leaves. They blend extremely well into stems and feed at night.
Snails and Slugs
Not insects, these gastropods chew holes in leaves and tissues. They leave behind silvery slime trails where they glide along.
Organic Bougainvillea Bug Control
Maintainvigor
Keep plants healthy with proper sunlight, water, fertilization and pruning. Vigorous growth helps withstand pest damage.
Hosing
Knock off pests with a strong spray from the hose. Focus on undersides of leaves.
Traps
Set up sticky traps for adult insects like thrips, leaf miners, and flies. Pitfall traps catch slugs and snails.
Row Covers
Temporary lightweight fabric can exclude pests until plants establish.
Natural Predators
Attract beneficial insects like ladybugs, lacewings, and syrphid flies which eat pests.
Neem Oil
Derived from the neem tree, this oil disrupts insects’ reproduction and metamorphosis. It smothers soft-bodied insects.
Insecticidal Soap
Potassium salts of fatty acids disrupt soft bodied insects’ cell membranes. Avoid applying during hot sun.
Bacillus thuringiensis
This bacterial disease kills caterpillars like loopers when ingested. It must be reapplied frequently.
Diatomaceous Earth
The sharp edges of this powdered fossilized algae damages insects’ exoskeletons and causes dehydration. Avoid breathing in the dust.
Sluggo
Iron phosphate bait is safe for pets and wildlife. It causes slugs and snails to stop feeding.
Chemical Bougainvillea Bug Treatments
If organic options have not resolved an infestation, targeted chemical insecticides may be warranted.
Systemic Insecticides
Applied as drenches, injections, or granules, systemic insecticides are taken up by plants’ vascular systems. This provides extended control as pests ingest the poisons while feeding. Neonicotinoids like imidacloprid are common choices. These should be used only when necessary because they can negatively impact bee populations.
Contact Insecticides
These insecticides must directly coat the insects’ bodies to be effective. Sprays and dusts work for short term control of surface pests like aphids and scales. However, frequent applications are needed. Malathion, carbaryl, pyrethroids like bifenthrin, and horticultural oils can be used. Always follow label directions.
Growth Regulators
These chemicals mimic insect molting hormones. When ingested, they cause lethal incomplete molting. Options for bougainvillea include azadirachtin, pyriproxyfen, and kinoprene. Multiple applications are required.
Combination Products
Many commercial insecticides combine multiple modes of action for greater effectiveness. For example, products may contain both pyrethroids and neonicotinoids. Seek targeted rather than broad spectrum products when possible to preserve beneficial insects.
Integrated Bougainvillea Pest Management
The best approach combines multiple tactics:
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Inspect plants frequently to catch problems early before they escalate.
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Remove heavily infested leaves and prune away dense growth to reduce hiding places.
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Use a strong stream of water to wash off pests.
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Apply insecticidal soaps or oils for mild infestations.
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Release natural predators if available.
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Apply biorational insecticides like Bt for loopers and neem oil on small plants.
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Spot treat isolated pest hot spots with contact insecticides.
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Consider systemic insecticides only if other options have failed.
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Rotate between insecticide classes to prevent resistance.
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After treatment, continue monitoring and reapply only as needed.
With vigilance and integrated pest management, you can keep your bougainvillea thriving and minimize the use of harsher chemicals. Consistent inspection and prompt targeted action when problems arise is key to success. Don’t let bugs get you or your bougainvilleas down!
Scalloped Leaves a.k.a. “Help, Something’s Eating My Bougainvillea!”
See “Snails & Slugs” and “Bougainvillea Looper Caterpillar”
Caterpillars; namely the Bougainvillea Looper Caterpillar
The bougainvillea looper is a green or brown caterpillar about 1 inch long. It is also called inchworm or measuring worm. The looper larva is very good at looking like stems and branches, and it mostly feeds at night. This is why you might see damage to the plant but not be able to find the culprit. The adult is a moth, a very fast flyer with a wingspan of about 1 inch. The moth does not feed on the foliage. To be like the larva, it only comes out at night to lay its eggs on the underside of bougainvillea leaves. Go out scouting very early in the morning or at night if you have a good strong flashlight. The bougainvillea looper feeds from the edges of the leaves, which results in severe scalloping of the foliage. Attacks begin on the young tender shoots and leaves before progressing down the stem. The bug will do a lot of damage to the bougainvillea plants’ looks, but it doesn’t seem to kill the plants.
Chemical Control
Biological insecticides based on neem and Bacillus thuringiensis (BT, or Dipel®) should work well against loopers without hurting other insects that may naturally control them. Insectical oils and soaps will not control caterpillars such as the looper. Most synthetic insecticides that say they can be used on landscape ornamentals to kill caterpillars, like carbaryl (Sevin®), will probably also kill the bougainvillea looper. However, these chemicals often kill beneficial insects as well. Spraying insecticides late in the evening is recommended. This is when the bougainvillea looper caterpillars and adult moths are active. These are also the times when the good bugs are not likely to be active.
Common Bougainvillea Problems
FAQ
How do you get rid of bougainvillea pests?
What is a homemade bug spray for bougainvillea?
What is the best pesticide for bougainvillea?
What are the bugs eating my bougainvillea leaves?
How do I get rid of pests on my bougainvillea?
There are a number of ways to get rid of pests and diseases on your bougainvillea, including: Hand-picking: This is the most effective way to get rid of small pests, such as aphids and mealybugs. Simply pick them off the leaves and stems of plants and dispose of them.
What bugs eat Bougainvillea plants?
Aphids, mealybugs, scale insects, and whiteflies are all common pests of bougainvillea plants. Powdery mildew, rust, and botrytis blight are all common diseases of bougainvillea plants. The best way to control pests and diseases is to practice good cultural care, such as watering and fertilizing your plants properly and pruning them regularly.
How can I Keep my Bougainvillea plants healthy and beautiful?
By identifying the problem early and taking steps to control it, you can help keep your bougainvillea plants healthy and beautiful. Here are some key takeaways to remember: Aphids, mealybugs, scale insects, and whiteflies are all common pests of bougainvillea plants.
How to kill beetles on Bougainvillea?
Follow the packaging instructions carefully. Apply Bacillus thuringiensis, better known as BT, to your bougainvillea for killing aphids, caterpillars and some beetle species. These bacterial diseases won’t affect you, your pets, most natural predators or the environment but they are deadly to specific insects.
Does Horticultural oil kill Bugs on Bougainvillea?
Using insecticidal soap or horticultural oil Insecticidal soap and horticultural oil are both effective at killing a variety of pests on bougainvillea. Insecticidal soap is a mild soap that is designed to suffocate insects. Horticultural oil is a type of oil that coats the insects and prevents them from breathing.
How to get rid of ladybugs in Bougainvillea?
Introduce beneficial predators to your garden. These include green lacewings and different species of ladybugs. Follow the packaging instructions carefully. Apply Bacillus thuringiensis, better known as BT, to your bougainvillea for killing aphids, caterpillars and some beetle species.