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How to get rid of aphids?
Getting rid of aphids requires multiple tactics, depending upon the species and the plant or crop which is under threat.
From spotting the symptoms to understanding which crops are most at risk, as well as tips for control, here’s everything you need to know about keeping your harvests protected from aphid damage.
Spotting aphids is the essential first step to keeping ahead of the damage they can cause.
Aphids are small, soft-bodied, pear-shaped insects that feed on plant phloem sap using piercing-sucking mouthparts. Their color varies by species, ranging from green and yellow to black, gray or even pink.
What are the most common aphids?
There are more than 4,000 different aphid species recorded, with several hundreds of species considered to be major agricultural and horticultural pests. Several species, such as the green peach aphid (Myzus persicae), the cotton aphid (Aphis gossypii), and the black bean aphid (Aphis fabae), are among the most commonly occurring and widely studied. They feed on many plant species and are remarkably adaptable.
A few aphids rarely cause visible harm - but populations can multiply every few days under favourable conditions.
Green peach aphid
Myzus persicae
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Cotton aphid
Aphis gossypii
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Black bean aphid
Aphis fabae
How do I identify aphid infestations on my plants quickly?
Aphids cause both direct damage (from feeding on plant sap) and indirect damage (through byproducts and disease transmission).
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Direct damage
Aphids use their needle-like mouthparts (stylets) to pierce plant tissues and withdraw plant sap, effectively siphoning off the plant's supply of sugars, amino acids, and water. Additionally, aphid saliva is toxic, causing deformation damage to plant tissues.
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Some visible signs of plant damage include:
- Leaf curling and distortion - particularly on young, actively growing tissues where aphids prefer to feed
- Stunted growth - shoots fail to extend and canopies remain undersized
- Chlorosis (yellowing) - nutrient depletion manifests as pale or yellowing foliage
- Deformed buds, flowers, and fruits
- Wilting despite adequate soil moisture, reduced vigour, and eventual plant death in severe, sustained infestations
Indirect damage
Indirect damage often causes far greater crop losses and plant health impacts than direct feeding damage alone.
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Some of the key indirect effects include:
- Viral disease transmission – the most serious damage aphids inflict on crops. Aphids vector multiple plant viruses, including:
- Barley Yellow Dwarf Virus (BYDV) in cereal and grain crops
- Potato Virus Y (PVY) and Potato Leafroll Virus (PLRV) in potatoes and solanaceous crops
- Cucumber Mosaic Virus (CMV) in cucurbits, tomatoes and peppers
- Turnip Yellows Virus (TuYV) in oilseed rape
Symptoms for these viral diseases vary but can include mosaic patterning on leaves, mottling, leaf rolling, stunting, and significant yield collapse. Just a few aphids can transmit viruses-often before visible colonies are detected.
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Honeydew and Sooty Mould
Aphids excrete excess sugars as honeydew, a sticky, shiny residue that coats leaf surfaces and fruit. This creates multiple issues:
- Sooty mould development – Honeydew provides an ideal substrate for black sooty mould fungi, which physically blocks sunlight from reaching leaves, reducing photosynthetic capacity and plant vigour
- Pest attraction – Honeydew attracts secondary pests such as ants and nuisance flies, compounding crop damage
- Market downgrading – The sticky residue reduces produce quality, downgrading marketability of fruit, vegetables, and ornamentals. The combination of reduced plant health and economic loss makes honeydew accumulation a serious concern, particularly in high-value fresh produce and ornamental crops.
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Exoskeleton contamination
Aphids moult regularly as they develop, leaving whitish exoskeletons that accumulate in crop canopies and on produce. This creates visible contamination-a significant concern for salad crops and fresh produce.
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There are hundreds of crops that can be vulnerable to aphid infestation, with damage having impacts on both plant health and operational profitability.
Aphids are cosmopolitan, occurring on every continent except Antarctica. Even though some species only feed on one crop (specialists), there are others that can and will feed on multiple plants, vegetables or flowers (generalists).
The following shouldn’t be considered a comprehensive list but outlines some of the biggest threats to a range of different crops. For more tailored advice contact a local agronomist or Syngenta representative.
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Brassicas
The key pests here include Cabbage aphid (Brevicoryne brassicae) and the green peach aphid (Myzus persicae). Dense colonies can lodge deep within heads and florets and can be nearly impossible to reach with contact sprays once established. As a result, aphid contamination of harvested produce is a major commercial issue.
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Leafy salads
The key pest is the currant-lettuce aphid (Nasonovia ribisnigri). Lettuce has low tolerance for aphid pressure because contamination renders a product essentially unmarketable with even small colonies having a major economic impact.
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Cucurbits
Courgettes, cucumbers, melons, squash are vulnerable to the cotton aphid (Aphis gossypii) and green peach aphid with virus vectoring being a major concern.
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Potatoes
With potatoes the key threats are green peach aphid and potato aphid (Macrosiphum euphorbiae) both of which vector potato virus Y and potato leafroll virus.
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Tomatoes and Peppers
Aphids such as the green peach aphid transmit viruses (particularly Cucumber mosaic virus), produce honeydew, and promote sooty mould growth-substantially reducing produce quality and creating significant economic losses.
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Peas
The key pest here is the Pea aphid (Acyrthosiphon pisum) which targets growing points and pea pods.
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Beans
Black bean aphid (Aphis fabae) forms dense, conspicuous colonies on stems and growing tips.
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Apples
Woolly apple aphid (Eriosoma lanigerum) can attack roots and aerial wood; Rosy apple aphid (Dysaphis plantaginae) curls leaves and deforms fruitlets.
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Peaches and plums
The green peach aphid overwinters on stone fruits as they make an exceelnt egg host.
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Soft fruit
Strawberry aphids are a concern as they act as a vector for virus transmission which can drive down harvest quality and impact overall plant health.
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Roses
Can be targeted by multiple different species but most common is the rose aphid (Macrosiphum rosae). Vectoring of Rose Mosaic Virus is a concern, but roses are almost a universal indicator species for aphid pressure.
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Mint
Mint is at risk from key pests like the green peach aphid (Myzus persicae), and mint aphid (Ovatus crataegarius). Mint's commercial value is often in oil quality - aphid feeding and honeydew deposition can alter leaf surface chemistry and reduce essential oil concentrations.
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Basil
Key pests are the green peach aphid (Myzus persicae), and the cotton (melon) aphid (Aphis gossypii). Basil leaves are thin and delicate - even light feeding causes visible distortion and yellowing that renders produce unsalable. Honeydew on basil is particularly problematic because the leaf surface holds moisture, promoting rapid sooty mould development.
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Parsley
At risk from key aphid species like the Willow-carrot aphid (Cavariella aegopodii) and green peach aphid (Myzus persicae). These pests can spread carrot motley dwarf virus complex to parsley, causing reddening, stunting, and leaf distortion.
What causes aphid infestation?
Aphid infestations are caused by multiple factors, influenced by plant growth stage, weather, aphid behaviour and other environmental factors.
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When plants are young and growing, they are most vulnerable to aphid infestation. Winged aphids will land on the plant and leave behind wingless young called nymphs who immediately start feeding. Maturation is rapid and the nymphs are ready to reproduce live young in 7 to 10 days. The University of Kentucky suggests that each aphid can produce around 40-60 offspring.
This explosive growth is most pronounced during warm spring and summer months with long daylight hours. Aphids reproduce asexually through parthenogenesis, where unfertilized eggs develop into live, genetically identical females.
Adding to this advantage, aphids experience telescoping generations: pregnant females carry offspring that are already pregnant with the next generation. These compounding factors enable populations to expand exponentially until the host plant becomes so stressed it can no longer support them. Winged aphids then disperse to find new hosts, restarting the cycle.
Aphid season can vary depending on the species and the region of the world they are present within.
Generally, aphid seasons run from early spring through late summer, with activity and general population peaking between May and July. Aphids thrive in warm, dry weather and can multiply rapidly. The rapid spread means that they can appear on garden plants, roses, fruits and vegetables before their natural predators (like ladybird, green lacewing and hoverfly larvae) become active in sufficient numbers.
The aphid lifecycle is dictated by seasonal changes, daylight length, and temperature. Activity patterns shift throughout the year in response to these environmental cues.
The aphid lifecycle is complex and driven by seasonal changes, daylight length, and temperature. Reproduction occurs through two main strategies: some species alternate between woody winter hosts and herbaceous summer hosts, while others remain on the same host year-round.
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Overwintering stage (egg)
In temperate climates, the cycle typically begins with fertilized eggs laid in fall on bark, crevices, or stems of woody hosts (trees, shrubs, or perennial plants). Eggs remain dormant through winter, gradually darkening from green to black as they mature.
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Spring hatch and stem mothers
When spring arrives, eggs hatch into wingless female aphids called stem mothers. These females do not require mating to reproduce-a critical advantage for rapid population growth.
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Asexual summer generations (parthenogenesis and vivipary)
Throughout spring and summer, populations multiply exponentially through parthenogenesis (asexual reproduction) and vivipary (live birth). This creates three compounding advantages:
- Genetic clones – Stem mothers produce genetically identical daughters
- Telescoping generations (the “Russian Doll” effect) – unborn nymphs inside mothers are already pregnant with their own offspring, accelerating population growth
- Winged dispersal – When host plants become overcrowded or nutritionally depleted, mothers produce winged females (alates) that disperse to new, softer hosts (vegetables, herbaceous plants) to establish new colonies.
Multiple generations can occur throughout a single summer, with each generation living 20–40 days.
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Sexual autumn generation (mating and overwintering eggs)
As daylight decreases and temperatures drop in fall, environmental cues trigger production of both male and female aphids. These winged forms fly back to their woody overwintering hosts, mate, and females deposit eggs to restart the cycle.
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Year-round exceptions
In warmer climates or indoors, aphids may bypass the egg stage entirely, remaining active year-round as live-bearing females reproducing clonally without males or eggs.
What is the best way to prevent aphids?
The correct management strategy depends on the severity of the population, the crops, plants or flowers at risk and the species of aphid in question.
However, the following steps should be considered when developing a management plan.
- Alternate chemistry: Create a planned rotation across different chemical classes and modes of action. The Insecticide Resistance Action Committee (IRAC) tracks the development of resistance in different aphid species, and taking this into account is crucial to ensure effective application and treatment.
- Scouting and thresholds: Plants should be carefully monitored for early colonies before they become established. Only spray when local economic thresholds of damage have been met.
- Biological Controls: Integrating natural predators such as parasitic wasps, lacewings or other insects can help keep aphid populations under control.
- Sanitation: Remove weeds and volunteer crops that can serve either as overwintering locations or bridging hosts for aphids.
What are effective natural remedies for aphids?
Integrated approaches include cultural practices (removing infested plant parts), biological controls (predatory insects like ladybugs, lacewing larvae and certain wasp species that feed on aphids), and direct measures like insecticidal soaps and horticultural oils (e.g., neem oil).
However, when infestations escalate and these methods prove insufficient, growers often turn to chemical controls.
While chemical insecticides can effectively suppress aphid populations, they can harm beneficial insects that naturally control aphids, potentially reducing long-term integrated pest management effectiveness.
What insects eat aphids?
A good example of the benefits that can come from encouraging beneficial insects can be found in the use of flower strips for commercial apple orchards.
Dr Charlotte Howard, lead author of the study, explains: "Flowers attract helpful insects that work hard to keep pests under control. Farmers could save money while boosting biodiversity and letting nature do some of the heavy lifting in looking after their crops.”
Dr Howard and the wider team modeled three different scenarios to predict the most beneficial location for the flower strips – either at the center of the orchard, on land at the end of rows of trees, or as a border to the orchard. In years with high aphid activity, conventional commercial orchards with flower strips saw a lower percentage of apple trees with aphid fruit damage, dropping significantly from 80 percent to 48 percent. In fact, a wildflower strip in the center of an orchard could put insects closer to aphids and potentially benefit farmers by as much as £2,997, or around $4,000, per hectare, per year.
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How to get rid of aphids at different life cycle stages
| Aphid life cycle | Season | Challenges to control | Approach |
| Overwinter eggs | Winter | Hard to spot, resistant to cold temperatures | Horticultural oil or hose down the plant with water |
| Crawling Nymphs & Wingless Adults | Spring | Rapid population expansion and plant damage | Neem oil or water. Small colonies can be crushed by hand. Encourage beneficial insects and natural predators |
| Winged Adults | Summer | Migratory and vectors of plant disease | Physical barriers or fine insect netting can be effective to protect vulnerable crops. Chemical control options or beneficial insects should also be used as necessary. |
There are thousands of different kinds of aphid and many of them are recurrent threats to a vast range of flowers, ornamentals, fruit, vegetables and other crops.
However, with careful monitoring, a healthy ecosystem of beneficial biodiversity, natural and chemical control methods, pest pressure can be kept under control.
FAQ
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What aphids eat?
Aphids feed almost exclusively on plant phloem - the vascular tissue that transports dissolved sugars (sucrose), amino acids, and other organic compounds from photosynthesizing leaves to the rest of the plant.
However, phloem sap is sugar-rich but protein-poor. Aphids need amino acids to build tissues and reproduce, but sap provides them in low concentrations. As a solution to this problem, aphids ingest enormous quantities of sap relative to their body size, extracting the amino acids and then excreting the excess sugar as honeydew. Given the amount they consume, a single aphid can produce several times its own body weight in honeydew per day.
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Do coffee grounds get rid of aphids?
This is widely believed but there is no compelling scientific evidence that points to this being effective as a means of controlling aphids.
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Which plants are aphid resistant?
Aphid-resistant plants deploy a combination of physical barriers, chemical deterrents, and molecular immune responses to prevent phloem-feeding insects from colonizing. There are some plants which aphids will generally not target. Plants with strong odours like onion, garlic, dill and rosemary all have organic compounds which aphids don’t enjoy.
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Will aphid spray hurt ladybugs?
This is dependent on the control method used. Always read the label carefully and follow the instructions exactly as provided.
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