What Happens To Aphids When They Don’t Have Plants?
Aphids are a common pest found in the garden and yard. These little insects love to feed on your vegetable plants, ornamental flowers, and even young shoots on trees, but what happens when aphids don’t have access to a food source?
When aphids don’t have plants, they will either produce winged offspring and migrate to a new host or they will perish. Aphids live for approximately one month and must feed daily to survive and reproduce. Without plants, aphids cannot feed or reproduce and populations will eventually dwindle.
Below, we’ll go over what happens to aphids when they don’t have a plant host to feed on. We’ll also give you some tips on how how to get rid of aphids!
Why Are Aphids On My Plants?
Before we get into what happens to aphids when they don’t have plants, let’s talk a little bit about why aphids are on your plants in the first place.
There are four main reasons why aphids are crawling all over your favorite vegetable plants or ornamentals:
These soft-bodied insects do not normally pose a serious risk to established plants, but they can wreak havoc on new plants and seedlings. For this reason, it’s important to find these scuttling pests before they do any real damage.
If you’re specifically wondering about your indoor plants, I highly recommend bookmarking our piece on why you have aphids on your houseplants.
Aphids Feed On Plant Sap
Who doesn’t enjoy a good meal? For some, that means steak and potatoes, for others a decadent salad or salmon.
For aphids, their food choice is pretty simple: plant sap. Aphids use needle-like mouthparts to pierce plant leaves and suck out the sap.
Plants are an aphid’s only food source as they do not feed on anything else. If there are aphids on your plants, it’s because they use them as a food source.
If you’re noticing aphids in your garden, you can read more about the common vegetables that aphids love to eat here.
Aphids Use Plants For Safety And Shelter
Have you ever seen a curled leaf and wondered why it looks like that? Surprisingly, the answer is probably aphids!
When aphids feed, they will inject chemicals into the leaf, causing it to curl over on itself. This, in turn, helps shelter and protect the aphid from hungry predators like ladybeetles and wasps.
Not all aphids can cause leaf curl. Some must resort to simply sticking to the underside of the leaf.
These two tactics make it difficult to get rid of aphids because they are so well protected. The leaves also help shelter aphids from heavy rain that could otherwise knock them off their host plant.
Aphids Might Be On Your Plant Because They Migrated
An aphid migration may not be as impressive as elk or buffalo, but the how and why are pretty interesting.
The aphid lifecycle is built for survival. In the summer, females do not have to mate to reproduce and instead give birth to live young. Specifically, the young are all wingless females.
However, if the aphid population becomes too large and food becomes scarce, aphids will start producing winged females. These aphids then use their gift of flight to find another host plant where they start producing wingless females again.
The cycle continues like this all spring and summer, with aphid migrations here and there when the population gets too high.
If you only see one aphid on your plant, it may be because it just migrated there and is planning on starting the cycle over. This is a great time to use a spray bottle or garden hose to spray it off!
Aphids Numbers Are Highest In Spring
Spring can be a wonderful time: snow is melting, buds are forming, and life is revived from long winter dormancy.
Another oh-so-wonderful thing that spring brings is insects!
Aphids are the most active and do the most damage in late spring. The temperatures are warm but not too hot and tender new plants provide plenty of food.
If you have aphids on your plants, it might be because it is the perfect time of year for aphid populations to explode in size.
How Long Do Aphids Live When They Don’t Have Plants?
Plants are as important to aphids as oxygen is to us. They simply can’t live without them! If you’ve removed an aphid’s source of food, you may be wondering how long they can survive before you can replace your plants and get on with your life.
The good news is, aphids can’t last very long without plants. In general, you will only have to wait about a week for aphids to kick the bucket without plants.
Aphids Need To Eat Daily
Aphids are fast-paced insects that need to eat daily to keep up their extremely fast metabolism. They love to feed on sap-rich parts of the plant such as new leaves and buds.
To get enough protein to satisfy their hungry bellies, aphids need to eat quite a bit of sap! Most of the sap consists of sugar with a very small amount of protein.
Aphids combat this imbalance by excreting most of what they ingest as honeydew; a sticky, sugary substance that leaves a residue on leaves. If it drops from a tree it can also leave a sticky residue on your car or buildings!
According to the University of Wisconsin-Madison, aphids may take up to 24 hours to get one meal. The reason is that their mouthparts are very delicate and must be pushed into the leaves slowly to avoid damage.
Such a long feeding time means that aphids feed for most of the day. Without a plant host, aphids will not be able to satisfy their nutritional needs.
Most Aphids Won’t Last More Than A Few Days Without Plants!
Aphids rely on plants for more than just food. In their short lifespan, aphids rarely migrate to different plants unless there is a high population and not enough food.
It’s common for aphids to live their entire lives on a single plant.
Besides the obvious source of food that plants provide, plants also give aphids a few necessities for survival:
- Shelter: Aphids use the underside of leaves to protect them from inclement weather such as a heavy thunderstorm. Without this, aphids would be easily swept away by the rain.
- Protection: Plants and their leaves provide aphids with the ability to hide from predators.
Aphids won’t last long without food, shelter, and protection provided by their host plant. Most aphids cannot last more than a few days without eating.
Aphids Need Plants To Reproduce
In addition to their need for food, shelter, and protection, aphids also need plants to reproduce.
Aphids mostly give birth to live young by asexual reproduction, meaning the daughters are identical to the mother and are more or less clones. However, if there is no food source, aphid reproduction slows down rapidly.
Since aphids do not reproduce without a host plant, this can be an effective way to manage aphid populations.
More on that later – but one of the most common reasons that aphids keep coming back is that they’re literally born to reproduce!
Plants Shelter Aphid Eggs Throughout Winter
Aphids will be hesitant to produce new offspring when no plants are around. They’ll also be hesitant to lay eggs without a proper plant host.
As temperatures drop in the fall, aphids will stop producing live offspring and switch over to laying eggs. Aphids will look for a nice cozy spot on their host plant to deposit the eggs. These eggs will need the host plant to survive the winter.
Without a host plant, aphids have nowhere to lay their eggs. This is an excellent way to break the cycle and have fewer aphids in the spring.
All in all, aphids do not last long without a plant host. They need the plant for food, shelter, protection, and reproduction.
Another reason why aphids do not last very long without host plants is the fact that they are slow-moving insects. If they are knocked off a plant or the plant is removed, they have a hard time finding a new plant host.
If you’d like to know if YOUR garden plants are attracting aphids, take a peak at our list of 9 flowers that aphids tend to love!
Best Ways To Remove Aphids If They ARE On Your Plants
Whether you’re bringing your plants inside or have seen aphid damage on your outdoor plants, you may be wondering about the best ways to remove these little pests.
Luckily, aphids are pretty easy to remove from your plants and you have a few different ways to go about doing it.
#1 Use Your Garden Hose
One of the easiest ways to remove aphids from your precious plants is to simply knock them off with water.
Check your plants weekly to identify whether or not you have an aphid infestation. Be sure to look on the underside of the leaves for these sneaky pests.
Once you’ve identified an aphid problem, arm yourself with your garden hose and spray the infested plants. Again, be sure to spray the underside of the leaves as well.
An adapter like the VIKING High Pressure Adjustable Hose Nozzle can make it more comfortable to spray for long periods of time. It can also help you save water by targeting just the plants you want to spray!
The best time to check for an aphid infestation is late spring. Aphids like warm temperatures but not TOO warm such as in the middle of summer.
#2 Encourage Natural Predators
There are tons of creatures that prey on aphids and help keep their population in check. We can use this to our advantage to minimize aphid outbreaks.
Some of the most important predators of aphids include:
- Parasitoid wasps
- Ladybugs (lady beetles)
- Lacewing larvae
- Syrphid fly larvae
- Soldier beetles
- Aphid midge
- Minute pirate bugs
These predators specialize in aphids, but there are many other generalist predators like spiders and earwigs that will snack on aphids if the opportunity arises.
There are a few things you can do to encourage natural enemies to take care of your aphid problem:
- Plant flowers that bloom at different times: Flowers can attract a host of predators that feed on aphids without attracting aphids themselves. Providing flowers that bloom in spring, summer, and fall can help keep aphid populations in check for the entire growing season.
- Avoid insecticides: It may be tempting to use insecticides to get rid of aphids, but this can do more harm than good. Insecticides will reduce natural predators and because aphids reproduce so rapidly, aphid populations will recover quickly while predators will not.
In addition to harming beneficial predators, insecticides have been used so heavily in the past that studies such as the one reported in the Journal of Agronomy for Sustainable Development found that aphids are becoming resistant to insecticides.
#3 Release The Lady Beetles!
Ladybugs are one of the top predators of aphids and can help keep these pests in check. The difference between lady beetles and some of the other predators is that lady beetles are mass-produced and can be purchased online.
NaturesGoodGuys 1500 Live Ladybugs can be used in your garden or flowerbed to get rid of aphids.
Now, you don’t want to just open the bag and shake the ladybugs out into your garden. There is a very specific way these lady beetles should be released to truly control aphid populations.
Follow these steps to ensure your lady beetles don’t just fly away as soon as you release them:
- Step 1: Before releasing, gently mist the ladybugs
- Step 2: Mist the plants you are releasing the lady beetles near.
- Step 3: Only release ladybugs after dusk
- Step 4: Release them at the bottom of infested plants and trees
1500 lady beetles may seem like a lot, right? Surprisingly, this number is needed just to control a single plant! A study reported in the Journal of Biological Control found that a release of 1400-1750 beetles is enough to clear aphids from a single rose bush.
Even though it may seem like a lot, you may need to purchase two or three bags of ladybugs to control a severe aphid infestation.
The great thing about using ladybugs is that it is a natural way to remove aphids from your garden and yard.
No chemicals, no-nonsense, just a couple (thousand) of nice lady beetles attacking the heck out of the aphid population!
#4 Lure Aphids Away With Crop Traps
There are thousands of different species of aphids out in the world, with around 1,300 calling the United States their home.
Not all aphids are the same, and most have a preference for the type of plant they infest and feed on. For example, cabbage aphids feed exclusively on cruciferous plants while green peach aphids feed on almost anything.
One way to deal with such a variety of different species is to lure them away from your prized zucchini and tomatoes by providing especially attractive plants nearby (but not too close!).
Some of the best trap crops to plant for aphids include:
Plant these lures a little bit away from your garden plants or ornamentals. This strategy is only effective if you plant them before an aphid infestation occurs.
Once the aphids are infesting these plants instead of your garden veggies, you can implement some of the other strategies to get rid of the aphids.
Additionally, you can use scents that aphids hate in areas away from these trap plants to further deter them from your prized foliage.
#5 Destroy Plants After The Growing Season
Aphids have the amazing ability to both produce live offspring and lay eggs depending on what is needed for survival.
In the fall, aphids will begin laying eggs instead of live offspring to give the next generation a chance to survive the winter. These eggs are typically deposited on a host plant and bundled up to stay cozy and safe.
In the garden, this could mean your spent vegetable plants that are done growing for the season but still remain in the garden.
Instead of letting those plants decay in the garden over winter, consider disposing of them in the fall by physically pulling them, tilling them, or other means of destroying the plants.
This will help destroy most of this year’s aphid eggs so that next year’s generation starts out small.
You can read our guide on the most common fruits that aphids love to learn more about what plants you’ll be likely to find aphids on!
Wrapping Things Up
Aphids are an annoying pest to have in the garden and on your houseplants. They’re small, hard to see, and hide on the underside of leaves where we can’t get to them.
Luckily, aphids won’t last long without plants and will typically only stick around for a few days before they either perish or migrate to a different area.
Aphids use plants for food, protection, shelter, and to reproduce and lay their eggs.
Taking away their host plant is an effective way to get rid of aphids. You can also try planting crop traps, using your garden hose, encouraging natural enemies, and releasing lady beetles to remove aphids from your plants.
If aphids are really destroying your crops and you can’t seem to get rid of them, you can always reach out to a professional near you through our nationwide pest control finder.
Flint, M. L., & Dreistadt, S. H. (2005). Interactions among convergent lady beetle (Hippodamia convergens) releases, aphid populations, and rose cultivar. Biological Control, 34(1), 38-46.
Peccoud, J., Simon, J., von Dohlen, C., Coeur d’acier, A., Plantegenest, M., Vanlerberghe-Masutti, F., & Jousselin, E. (2010). Evolutionary history of aphid-plant associations and their role in aphid diversification. Comptes Rendus Biologies, 333(6-7), 474-487.
Rousselin, A., Bevacqua, D., Sauge, MH. et al. Harnessing the aphid life cycle to reduce insecticide reliance in apple and peach orchards. A review. Agron. Sustain. Dev. 37, 38 (2017).
Smith, C.M. and Boyko, E.V. (2007), The molecular bases of plant resistance and defense responses to aphid feeding: current status. Entomologia Experimentalis et Applicata, 122: 1-16.
Zack is a Nature & Wildlife specialist based in Upstate, NY, and is the founder of his Tree Journey and Pest Pointers brands. He has a vast experience with nature while living and growing up on 50+ acres of fields, woodlands, and a freshwater bass pond. Zack has encountered many pest situations over the years and has spent his time maintaining and planting over 35 species of trees since his youth with his family on their property.
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