Aphids are one of the most common plant pests in the world so finding aphids on plumeria is as inevitable as the sun setting in the evening. At some point in your plumeria growing journey, these common plumeria pests are going to affect your plumeria, and sadly, it’s more likely on healthy plumeria plants.
Even if you do everything right, aphids will find plumeria stems and quickly build populations on frangipani at all stages of life. In this article, we’ll teach you everything you need to know about these plumeria bugs, and how to keep them off plumeria trees.
What are Aphids?
Aphids are a vast insect family, covering over 200 species of tiny white, black and green flies, but the most common are the white, sap-sucking aphids you often find on new growth in the garden.
Aphids eat chlorophyll in the form of sap, so are attracted to new growth, particularly from highly scented plants with high sugar content.
What is the aphid lifecycle?
While frustrating, aphids are fascinating creatures, with the ability to transform their bodies, self-clone, and can lay up to 80 eggs through their 25-day lifecycle.
Because aphids are so common it’s impossible to completely eradicate them from a garden, but you can discourage them by planting more attractive, sacrificial plants, and can diminish populations throughout the growing season.
To really get to grips with aphids on plumeria you need to know how they develop, overwinter, and multiply:
The aphid lifecycle:
- Aphid eggs: Mature aphids lay their eggs in autumn across the soil surface. They are quickly covered by leaf litter, before overwintering through freezing temperatures and hatching in early spring when the ground thaws and plants begin to produce fresh shoots.
- Aphid ‘stem mothers’: The earliest aphids you see in spring are called stem mothers. Stem mothers have no wings and stay on a single plant. They hatch and take a few days to develop through the larval stage, then climb up the stems of plants to begin feeding on new growth. At this stage, the population is small as does not affect your plants. After 4-7 days they are ready to reproduce.
- 2nd generation – Spring aphids: Spring aphis come in two categories; winged, and wingless. The winged aphids are emigrants, flying off to find new plants, and reproduce when they find somewhere that can sustain a new population. the wingless aphids will stay on pants that have enough sap and healthy new growth to sustain a growing population. Both are direct clones of the mother, born through osmosis, not eggs.
- Spring and summer clones: The clones of these aphids continue to expand populations by either travelling to new healthy shoots, or overwhelming plants that are high in chlorophyll (like plumeria). Until late summer, the cloning process continues, with both flying and wingless aphids reproducing up to 8- times over the 25-day lifespan.
- Final generation – Late season aphids: The last generation of aphids are cloned in late summer when the day lengths begin to shorten and plants stop producing new shoots. When flowers are finished and fruit begins to develop, they can no longer flourish. The late summer clones, lay eggs, which hatch quickly into a mix of winged females, and winged males. This selective laying at the right time of year means males use their short lifetime flying from plant to plant, widening the gene pool, and strengthening the population.
- Eggs: Male aphids die after mating and the females lay eggs on the soil surface. These then lay dormant until spring.
Even more fascinating than the aphid’s ability to select gender is that they are regularly farmed by ants. Ants get much of their energy in summer by eating sugary aphid secretions called honeydew. As ants are well-coordinated and keep track of plant health around your garden, they pick up wingless aphids and move them to new plants with better chlorophyll.
How Aphids Affect Plumeria
There are many articles online that perpetuate the myth that aphids are attracted to unhealthy plumeria plants. This is not true. Aphids are attracted to healthy, vigorous growth, and are often farmed by ants who actively move them to healthier parts of the plant.
Because plumeria produces such fleshy growth tips, they are rich in sap and can cope fairly well with aphid infestations, but if the population gets too much it completely prevents leaves from emerging and can cause foliage discoloration on late-season growth.
Plumeria leaves puckering: Why is my Plumeria wrinkled?
The biggest negative effect of aphids is that they, essentially, intercept nutrients from growing tips, flowers, and leaves, which restricts overall plant health. This causes leaves to wrinkle and pucker as they are either shrouded in honeydew, the secretions of aphids, or have no access to nutrients or moisture.
Early signs of aphid damage like this are pale foliage discoloration and chewed leaves. The chewed leaves are not caused by aphids, but by the ants that benefit from their secretions.
This distorted growth should be removed, and ideally, you should remove badly infected leaves – particularly if the wrinkled leaves start to turn brown or yellow, which is a sign of fungal infection caused by the humidity from honeydew, getting into minute bites from the aphids across leaves and stems.
How to Spot Aphids on Plumeria
The first sign of aphids in spring will be one of two tiny insects sitting around growing tips. If you remove these early season aphids as soon as you see them, it will have a big impact on population growth.
Once populations grow, you’ll notice clumps of white insects sitting fairly still at all times of day on heavily infested areas, either just under leaves or at the tops of stems. Beyond that, aphid populations begin to overtake leaves and look almost like clumping molds.
Other plumeria pests you might mistake for aphids
Mealybug and spider mites are often mistaken for aphids despite being different sizes and colors. Severe spider mite infestations will include clumps of a white fluffy mess that at first glance look like clumps of aphids at the base of each leaf. These are in fact spider mite eggs, covered in silk webs.
Mealybugs, however, cover themselves in white mucus to prevent ladybugs from eating them. Their relatively similar size means they are often mistaken for whitefly. Still, they typically live across the underside of leaves, and the first symptom will be yellow spots on the surface of leaves, caused by excess humidity on the base.
How to Treat Aphids on Plumeria Plants
Unlike spider mites and mealybug, you should never simply spray aphids off your plants, as they will just find their way back, and can clone flying versions of themselves which actually increases the population. To get rid of aphids you need to treat your plant with the best aphid treatments possible.
Once you have treated the population with your chosen chemical (preferably an organic insecticide) you can then spray them from the plant stem. Once treated, these common plumeria plant pests are unlikely to return to the same plant.
Best Treatments for Aphids on Plumeria
1. Ladybugs
Once the ladybugs have done their work, simply open the windows, and they will fly out. Ladybugs don’t like being indoors, and releasing them into your garden has all sorts of benefits from other garden plants, and wildlife too.
Pros
- Organic
- Non-invasive
- Safe for other pollinators
- Safe for kids and pets
- Great for wildlife
Cons
- Messy
- Expensive
2. Neem Oil
While neem oil might seem like a magic bullet in the garden it should always be used with caution. Just because something is organic doesn’t mean it’s safe. Arsenic is a naturally occurring substance and is obviously harmful. Neem oil is very bad for pollinators, and should never be sprayed outdoors until the plants are covered and protected until the spray has dried.
Pros
- Kills aphids
- Organic
- Safe for kids and pets
- Cheap
Cons
- Not safe for pollinators & other insects
- Needs diluting
3. Horticultural Soap
It might sound cruel, but with proper applications, horticultural soap kills pests instantly. Just be sure you don’t spray it onto plants that are in flower as you can accidentally spray bees, wasps and hoverflies, or even ladybugs – which are already doing the job for you!
Pros
- Kills aphids
- Cheap
- Long-lasting
- Safe for wildlife when dry
Cons
- Not safe for pollinators if sprayed direct
- Needs diluting
4. Castile Soap
If you use liquid castile soap and neem oil in equal portions, diluted in water (1:1:8) you can create your own budget horticultural soap too. The only downside is that castile soap tends to set so needs heating, or scraping from the bottle. Don’t worry though, it will still work after setting, provided it’s mixed up with water again.
For a non-organic alternative, you can use liquid dish soap, but it can contain chemicals that are bad for plumeria, so check the label.
Pros
- Organic
- Safe for wildlife when dry
- Safe for kids and pets
Cons
- Goes off relatively quickly
- Not safe for pollinators if sprayed direct
- Needs diluting
5. Mighty Mint 32oz Plant Protection
Insecticidal soaps, dishwashing detergent, and even a mild solution of pesticides can be enough to put some gardens off using most treatments, so sticking to organic preventions can be very effective instead.
Pros
- Effective aphid prevention
- Organic
- Safe for kids and pets
- Safe for pollinators and wildlife
- Good value
- Ready-mixed
Cons
- Doesn’t remove existing aphid populations
How to Prevent Aphids
Aphids will only stay on healthy, well-watered plants. Providing good ventilation, allowing their natural predators in, and finding the right balance of plant food early in the season will help to reduce the chances of an aphid infestation.
As well as treatments, like insecticidal soap and light horticultural oil spray, there are three important factors to prevent aphids from finding and settling on plumeria.
- Watering
- Ventilation
- Feeding
Overwatered Plumeria
We always say to stop watering entirely overwinter as plumeria need a period of dormancy to thrive the following year, but what we don’t talk about enough is how to bring plumeria out of dormancy effectively.
Rather than completely dousing plumeria plants in spring at the first signs of growth, begin reintroducing water gradually. The first water in spring will need to be thorough, to revive the soil structure, so do make sure to water until it runs through the bottom of the pot once in early spring. The next time you water, add a well-balanced fertilizer so your plant doesn’t end tod rink as much to get its nutrients.
By watering less until summer, you’re encouraging sturdier shoots, but with less moisture content. This makes plumerias less attractive to aphids.
Organic aphid prevention
As well as watering less generously in spring while the aphids choose their home for the start of the year, it’s also important to consider organic controls, like ladybugs, and carnivorous thrips. Aphids have loads of natural predators, including hoverflies and wasps too, so for plumeria in the greenhouse, ensuring your space is well ventilated will dramatically reduce aphid populations.
Ladybugs, thrips, and wasps prefer to be outside, so if you find small populations, you can release them indoors for a few days, and then open the windows. They will gladly fly out after a big meal of aphids.
Remove aphid eggs over winter
Aphid eggs lie dormant in the soil for up to four months, and can even freeze and thaw in spring without being damaged at all. Thankfully, you can destroy overwintering eggs from the soil easily, and it is unlikely to damage your plant.
We always remove the surface layer of soil from our plumeria in late winter while the plant is dormant, and mulch with organic compost in spring.
Because aphid eggs are usually less than 10mm deep in the soil, all you have to do is remove last year’s mulch, and replace it. Be sure to discard the spent mulch as it can contain eggs and larvae from all sorts of plumeria pests.
Plumeria Aphids FAQs
How do I treat aphids on my plumeria?
There are a few effective ways to treat aphid infestations on plumeria plants. The most common treatment is horticultural soap, including neem oil, and castile soap, but for more organic options than don’t risk harming bees or pollinators, consider sourcing natural aphid predators like ladybugs.
How to clean plumeria leaves?
To clean plumeria leaves, use a dilute mix of castile soap, neem oil, and water (1:1:8), and wipe each leaf gently with a microfibre cloth. This helps to remove honeydew, and remnants of aphid infestations and kills early fungal infections before they take hold. The other benefit of regularly cleaning plumeria leaves is that they hold a beautiful shine.
Can I spray neem oil on plumeria?
Neem oil is the most effective organic pesticide for indoor plants. While neem oil is never advised for outdoor use due to its general insecticidal properties, is it a great organic option for managing pests and insects inside your home and has no negative effects on plumeria leaves.
Conclusion
I have to admit, I do quite admire the tenacity of aphids. Of all of the creatures to have evolved on this green plant, they have the most advanced and adaptable reproductive systems of any creatures, and no matter what we do to get rid of them, they will always return.
But, and it’s an important ‘but’, aphids wreak havoc in our gardens, and while our job as gardeners is to look after our patch of earth, it’s also to manage it, cultivate and ensure it provides us with as much joy as possible. Quite where aphids fit with the ‘joy’ part of that is unclear.