Got different types of aphids on plants in your garden? Are they pests? Or could they actually be a beneficial bug buffet?
Aphid insects clustered to the bottom of a leaf
Our Texas summers are well known for scorching heat. While rising temperatures can bring out the best in sun-loving plants, they also invite pests such as aphids.
What should you do when you find aphids on plants?
These uninvited guests can wreak havoc on plants you’ve put in the ground, but with a bit of knowledge and well-considered preparation, you can protect your garden from their most destructive tendencies.
Today we’re going to talk about aphids, where you’re likely to find them, ants and the surprising role they play in farming aphids, and the role of aphids within the larger food chain of a healthy garden.
We’ll also cover some of the most common short-sighted common gardening advice you’ll probably want to avoid, and why.
Where You’re Likely to Find Different Types of Aphids on Plants
These tiny, often plant-specific insects will cluster on the underside of leaves. Some aphids types are loyal to one plant and one plant only. Other varieties can feed on a number of different plants, or switch host plants on a seasonal basis.
You will find the aphid insect everywhere from crape myrtle trees, to roses and ornamental plants, to vegetables. Depending on the location and climate, the location of the aphid insect will vary. Once you know their general form and habits, it will be easy for you to spot them.
Most aphid insects suck sap and excrete a clear sticky substance known as “honeydew.” This honeydew can be a precursor to a black fungus that can block sunlight from the leaves. Honeydew is also harvested by certain kinds of ants that actually farm the aphids for the convenience of being able to harvest the honeydew as a food source. Some bees even collect the aphid honeydew and use it to make something called forest honey!
Common gardening advice? Eradicate the aphids!
The aphid insect can potentially be prolific and when the conditions are ripe for them, they can quickly infest and kill the plants in your garden.
A quick google search will tell you to remove aphids in the garden by using innocuous-sounding methods such as spraying the plants with pressurized water, spraying with insecticidal soaps, or spraying with organic repellents such as neem-oil or other essential oils.
What about introducing natural predators? Will that work?
You may have seen advice to buy a batch of ladybugs, then release them in your garden to eat the aphids on your plants. But ladybugs you buy from a local garden store or online source might NOT be the right ones to eat the aphids in your garden. They might not even be local to your state!
It’s also quite likely that grown ladybugs are simply going to fly away as soon as you release them, having a minimal effect on the aphid population in your backyard.
As we’ll discuss later in this post – it can be far more effective to wait and attract local ladybugs to lay their eggs in your garden. These eggs will hatch ladybug nymphs that will be hungry for your specific aphids, and the wingless nymphs will stick around to eat the aphids as they mature.
While natural oils and predators are more conscientious methods than spraying your garden with conventional pesticides, they’re still based on a “kill the enemy” mentality that pervades even organic gardening methods.
What if you could find a way to not only kill the aphids, but instead learn how you might be able to coexist with them in a mutually beneficial way.
A permaculture perspective: Turn your liabilities into assets.
With a permaculture perspective, “extermination” is not an acceptable way of dealing with bugs.
All life is interconnected, and the more we focus on killing off the “bad bugs,” the more unstable we make the entire system. Aphids have evolved to have a role and be a part of the living ecosystem and they’re here in some ways to be our teachers.
When you start to look at things systemically, the questions become – What are these bugs here to teach us? How can we learn from them to make the whole garden healthier? What role do they play in the local food chain, and how can you use that to your advantage?
Holistic, or integrated pest management is the science of seeing the big picture of your garden ecosystem, and working with nature instead of trying to control it.
Aphids were my first real test of holistic pest management, and it took me several years of squishing them to be brave enough to try it. We finally decided one spring to stop fighting the aphids and plant flowers to attract ladybugs instead (calendula, geranium, alyssum—we already had parsley, cilantro, dill, mint, and some others). Between the flowers and the banquet of aphids we were finally leaving available to them, the ladybugs showed up and stayed. Which meant we suddenly had a lot less work to do. A very satisfying proof of permaculture ideas all around.
The three main aphid types you’ll see here in Texas are the green peach aphid, the crape myrtle aphid, and the oleander aphid. Each of these aphid types has a different appearance as well as a different set of host plants.
The green peach aphidis tiny – with a body length less than ⅛ of an inch, red eyes, long antennae, and color variations that might include pink, green, or stripey. This aphid has the widest range of host plants including (not surprisingly) peaches, tomatoes and peppers, along with roses, and chrysanthemums.
The crape myrtle aphid is another Texas local. These little beasties are even smaller than their green peach cousins, measuring in with a body length about 1/16 of an inch. Color variations in this variety range include pale yellow and pale green, with black spots on the abdomen, dark tipped antennae, wings and two two-tipped humps on their backs. They also infest ONLY the crape myrtle – though this plant may host other aphids types as well.
The oleander aphid is a bright yellow specimen with black legs, black antennae, and a black tip on its abdomen that grow to be about ⅛ of an inch long. This bug likes to hang out on milkweed, butterfly weed, and oleander.
Ants & Aphid Farming
There are different versions of ant/aphid symbiosis, including ants that farm aphids and dairying ants that “milk” the aphids for their honeydew. In each of these cases, the ants protect and nurture the aphids, and in turn, the aphids adapt their honeydew production to better feed the ants.
Symbiosis can be defined as an interaction between two different organisms living in close physical association, typically to the advantage of both. It can also be a mutually beneficial relationship between different groups.Wikipedia
When you go down the rabbit hole of tiny-interactions and expand your research beyond aphids and ants, you’ll find some parasitic relationships too. These include things like caterpillars that disguise themselves with ant pheromones in order to get into the ants nest and get better access to the honeydew of ant-farmed aphids. There are even aphids types that mimic the ant-cosplay game and use insect subterfuge to gain access to baby ant larvae – upping the game for their own benefit.
Just like in the world of bigger people – these interrelationships can be complex and multilayered. But risk and reward sit right next to each other, managed somewhat by the luck of the draw.
Why Aphids Show Up In Your Garden
If you let an unchecked population of aphids run wild and unchecked in your garden, you will start to see stunted plant growth, discolored, curled, or deformed leaf development, or galls forming on leaves, stems or roots. That’s not a great plan if you want to actually harvest anything you grow.
But with the proper checks and balances provided by adequate and healthy biodiversity, these problems tend to be small or non-existent. The system as a whole is what you’re trying to keep healthy – not just any one individual plant.
Aphids tend to target plants that are weakened by poor soil, deficient in nutrients, or planted in isolation, away from any aphid-discouraging symbiotes. So by listening to your aphid teacher – you might find a deeper deficiency or lack that you can address to the benefit of your garden as a whole!
Are They Really Pests? Or Are They a Beneficial Bug Buffet?
In our studies of permaculture here at Symbiosis TX, we have learned that what might first appear as a liability can later prove to be an asset.
While most gardeners see aphids as pests, it may come as a surprise that they may also serve a positive purpose in your garden. So long as you don’t have too many of them, (a good metric is roughly less than 12 aphids per square inch) they can actually serve as a food source for many of the beneficial bugs you want to attract to your garden.
The more beneficial bugs you can attract, the more biodiverse your garden ecosystem will become. A few aphids might actually benefit your garden more than they will harm it.
The Do’s and Don’ts of Aphid Treatment
You will absolutely want to observe any aphids types you may find in your garden or yard. You will also want to take action if the population grows to the size that can cause damage to your plants and prevent you from harvesting the food and flowers you’ve put energy and effort into raising.
But you DON’T necessarily want to eradicate or kill all the aphids you see. Despite common internet advice to spray with water, soap, or neem oil – this is a symptom-treatment-approach that fails to take the bigger picture of your garden’s ecosystem into account. If you have aphids, they are there to tell you something about your garden and your environment. Take some time and attention to listen to what they have to teach.
“Like what?!” I can hear you asking the question as you shake your head in disbelief.
Maybe they’re giving you a clue that your soil is lacking in the nutrients that will strengthen your plants to the point where they are healthy and able to resist the negative results of aphids. Or maybe they’re letting you know this would be a good time to plant the flowers and companion plants that will improve the biodiversity of your garden ecosystem.
List of Do’s
Do watch the aphids to see if their numbers increase
Do look at the same kind of plants located in different parts of your garden to compare their overall health
Do employ your sleuthing ability – see if you can determine why certain types of aphids are one place, but not another
Do balance patience and observation to see if natural predators show up in a reasonable timeframe
Do plant things like marigolds and other protector/companion plants – from seed if possible
Do research locally effective tools of IPM (Integrated Pest Management)
List of Don’ts
Don’t freak out.
Don’t spray them off with high pressure water
Don’t spray them with insecticide chemicals, or even neem oil
Don’t immediately go out and get a batch of predators to release into your garden
Don’t look at one plant at a time – but instead consider the bigger picture of your garden’s ecosystem
Building Resilience by Working With the Big Picture
Treating the presence of aphids as the problem can be a shallow and disconnected approach to your whole garden health. Understanding why different types aphids show up, what the aphids are doing, how they might be symptomatic of a deeper imbalance, and digging into the root cause of the negative impact of their presence is more of a holistic root cause analysis.
When you treat the root cause – both the symptoms and the underlying imbalances will eventually resolve themselves.
Nature is magical like that. All you have to do is remember, and work from that understanding. Aphids are not just garden pests to be controlled. They are living bits of data that can tell you a lot about the overall health of your garden.
