Strawberry aphids are a common pest that can wreak havoc on strawberry plants. As sap-sucking insects, they stunt plant growth and spread disease. Left uncontrolled, entire crops can be devastated. Getting rid of strawberry aphids requires diligence and a multi-pronged approach. But with the right techniques, you can protect your strawberries and enjoy a bountiful harvest.
What Are Strawberry Aphids?
Strawberry aphids are small, soft-bodied insects that feed on the sap from strawberry plants and other members of the rose family Their scientific name is Chaetosiphon fragaefolii No bigger than a pinhead, they can appear green, yellow, grey, black, or white. Strawberry aphids tend to cluster on the undersides of leaves and along stems where they form dense colonies. A single female can produce up to 20 offspring per day, allowing populations to explode exponentially.
Excessive sap-sucking stresses the plant while their sticky honeydew secretions promote mold growth Heavily infested runners and fruits often become disfigured and damaged. Left uncontrolled, entire strawberry crops can be devastated by these tiny pests
Recognizing Strawberry Aphid Infestations
Be on the lookout for these common signs of a strawberry aphid infestation
- Visible colonies of green, yellow, black, grey, or white insects on the undersides of leaves
- Curled, twisted, or puckered leaves
- Yellow stippling damage on leaf surfaces
- White fungal growth on leaves coated in honeydew
- Deformed and stunted fruits covered in honeydew
- Plants wilting despite adequate water
- Ant trails around plants feeding on honeydew
Catching infestations early allows for quicker control before populations explode. Inspect the undersides of random leaves weekly, especially after warm winters when aphid survival is higher.
Why Eliminating Aphids is Crucial
More than just a nuisance, strawberry aphids can completely decimate crops if left unchecked. Here’s why it’s critical to get rid of them:
- Sucking sap stresses plants and inhibits fruit development.
- Toxic honeydew secretions breed harmful molds on fruits and foliage.
- Flowers and fruits become disfigured, impeding pollination.
- Viruses spread from infected to healthy plants via feeding.
- Rapid reproduction leads to uncontrolled infestations.
- Ants protecting aphid colonies spread infestations further.
To save your strawberry crop, control aphids early before irreparable damage is done.
Organic Ways to Eliminate Strawberry Aphids
Getting rid of strawberry aphids doesn’t necessarily require harmful pesticides. There are several organic and non-toxic remedies that can effectively control heavy aphid populations.
Insecticidal Soaps
Insecticidal soaps made from potassium salts of fatty acids kill on contact by disrupting cell membranes. Spray tops and undersides of leaves, avoiding blooms. Repeat applications may be needed.
Neem Oil
Derived from the neem tree, neem oil smothers aphids while providing residual protection. Mix according to label directions and apply weekly. It’s safe for pollinators!
Horticultural Oils
Lightweight summer oils like canola oil smother aphids when mixed with water and liberally applied to foliage. Avoid blooms and apply during cool conditions.
Pyrethrin Sprays
Derived from chrysanthemum flowers, pyrethrin insecticides provide fast knockdown of aphids. Direct contact is key for effectiveness. Avoid use near harvest.
Diatomaceous Earth
The sharp edges of this powdered mineral cut through the waxy coating of aphids, causing dehydration. Dust undersides of leaves where aphids hide. Reapply after rain.
Strong Water Sprays
Simply blasting plants with water can knock aphid populations off leaves and into soapy traps below. Focus on undersides of leaves.
Organic Aphid Sprays
Various OMRI-listed aphid sprays utilize plant oils and acids like clove, citric, and sodium lauryl sulfate to kill on contact. Thorough coverage is important.
Soap Sprays
Basic dish soap diluted in water breaks down aphids’ protective coating. For small infestations, spray leaves, especially undersides.
Row Covers
Floating row covers form a barrier that keeps winged aphids from reaching plants. Use early in the season to exclude migrating aphids.
Sticky Traps
Yellow and blue sticky traps lure and capture winged adult aphids before they can infest plants. Place several around beds.
Using Beneficial Insects
In addition to sprays, certain beneficial insects provide natural aphid control:
-
Ladybeetles – Both larvae and adults voraciously consume aphids. Attract them with companion plants like dill and cilantro.
-
Lacewings – Lacewing larvae (aphid lions) feed on aphids. Adults eat pollen and nectar.
-
Aphid Midges – Tiny fly larvae that devour aphids from the inside out.
-
Hoverflies – Eggs laid near colonies produce maggots that feast on aphids.
-
Parasitic Wasps – Wasps like Aphidius colemani lay eggs inside aphids, killing them as larvae emerge.
-
Green Lacewings – Eggs hatch into larvae that can eat hundreds of aphids during development.
Consider purchasing and releasing beneficials or planting companion plants to attract existing populations.
Cultural Practices That Deter Aphids
Certain cultural techniques make conditions less favorable for strawberry aphids:
-
Use drip irrigation which keeps foliage dry, deterring aphids. Overhead watering spreads them.
-
Reflective plastic mulch disorients winged aphids and disguises plants.
-
Remove overwintering weed hosts near beds that could harbor aphids.
-
Increase airflow with trellising or raised beds.
-
Carefully manage nitrogen to avoid excess which encourages reproduction.
-
Remove and destroy severely infested leaves and runners to contain spread.
By limiting habitat and comfort, these practices restrict aphid reproduction and infestation levels.
Spot-Treating Heavily Infested Areas
When dealing with large, heavily infested sections, spot treatments allow you to target just problem areas:
-
Mix higher strength solutions of organic pesticides for focused application.
-
Remove and destroy badly infested runners before spot treating remaining plants.
-
Apply thick layers of diatomaceous earth to seriously affected patches.
-
Inject insecticidal soap or horticultural oil solutions into the base of heavily infested plants.
-
Physically wipe or disturb isolated infested plants before spraying.
-
Cover and dispose of small heavily infested areas of beds, then replant with clean plants.
Spot treatments let you eliminate the worst areas without damaging the entire crop.
Prevention Between Growing Seasons
To avoid recurring issues, implement preventative measures after harvest:
-
Remove and destroy all old crop debris, eliminating overwintering sites.
-
Work compost and organic fertilizer into beds to strengthen plants.
-
Plant cover crops to improve soil health and attract beneficial insects.
-
Scout regularly and treat early signs of aphids before damaging populations establish.
-
Control weeds that could act as alternate hosts.
-
Rotate crop placement year to year to disrupt aphid cycles.
With diligent prevention, plants will be less susceptible once the new growing season starts.
When to Call a Professional Exterminator
For severe recurring infestations, a professional pest control operator may be needed. They can utilize stronger insecticides and detect hidden colonies. Consider professional help if:
-
Home remedies consistently fail to control aphids.
-
Damage is rapidly spreading crop-wide.
-
Large colonies are found in root systems.
-
You lack time for adequate control measures.
For best results, combine their treatments with cultural practices to deter future infestations after elimination.
Be Vigilant Against Strawberry Aphids
Uncontrolled strawberry aphids can lay waste to prized berries. But by regularly scouting for early signs and swiftly employing organic remedies, you can protect your crop. Integrate multiple tactics like beneficial insects, sprays, and cultural practices to knock back infestations before plants become overwhelmed. With persistence and vigilance, you can enjoy abundant strawberry harvests aphid-free.
Description of the Pest
Strawberry aphid is pale green to yellow. Both adults and nymphs have transverse striations (horizontal lines) across the abdomen and are covered with knobbed hairs that are readily seen with a hand lens. These striations and hairs are not found on any of the other aphid species infesting strawberry.
Melon aphid is small, globular, and color varies from yellowish green to greenish black. This species is often the first to migrate into the strawberry fields each season and is the most difficult aphid species to control with insecticides.
Green peach aphid and potato aphid are less common in strawberries than the other species. The green peach aphid is green to greenish yellow and is more streamlined than the rounded melon aphid. Winged adults typically have a black spot on the top of the abdomen that is easy to see with a hand lens.
The potato aphid is much larger than the other species and has both a pink form and a green form in California. The long legs on this species give it a characteristic spiderlike appearance.
Aphid numbers usually peak during late March in Central and Southern California and undergo a natural decline to economically insignificant levels during May and June. In high-elevation nurseries, numbers peak in mid- to late summer. Numbers may continue to increase to damaging levels when spring temperatures are moderate and humidity is high.
In California strawberry production fields, aphids rarely reach damaging levels but occasionally cause yield losses because of honeydew contamination. Honeydew deposition on fruit causes sooty molds to develop and the white skins shed by aphid nymphs to stick to the fruit. This contamination renders the fruit unmarketable as fresh fruit.
Aphids transmit several viruses that can cause significant economic losses in strawberries if the planting remains in the field for several years. While not a serious problem in annual production plantings, aphid transmission of viruses is a major concern for nursery production.
While biological control can help to keep aphid numbers low, insecticide applications may be necessary in Southern California, and occasionally in Central Coast fields, if spring weather is conducive to their development. Insecticides are also applied in strawberry nurseries to prevent aphid buildup and virus spread. In other strawberry fruit production areas, aphids rarely reach damaging numbers and are not treated.
A complex of at least seven species of primary parasites have been reared from aphids infesting strawberry plants. However, the parasites themselves are attacked by a large number of hyperparasite species (parasites of the parasites) that limit the buildup of primary parasites.
Generalist predators such as syrphid fly or green lacewing larvae often provide a greater level of control. Lacewings can be purchased and released to help control aphids, but research is lacking on the efficacy of augmentative releases against aphids. Naturally occurring biological controls can keep aphid numbers below economically damaging levels, such as with the case of the melon aphid in Southern California strawberry-growing regions, so consider parasite and predator numbers before any treatment decision is made.
- Control dust (e.g., with water sprays on driveways or with cereal crops at ends of beds) to facilitate parasite and predator activity.
- Avoid excess nitrogen fertilizer, as aphid numbers tend to be especially high in plants that receive too much nitrogen.
- Some row covers (plastic tunnels or Remay-type enclosures) reduce aphid numbers to below economic levels, but the costs can be a limiting factor for large- or even small-scale plantings.
Use cultural and biological controls and sprays of insecticidal soap, azadirachtin (Neemix), neem oil (Trilogy), and pyrethrin (PyGanic) on organically certified strawberries.
Dealing with Aphids on Strawberries
FAQ
How do I get rid of aphids permanently?
- Place Sticky Traps. …
- Encourage Beneficial Bugs. …
- Use Organic Pesticides. …
- Maintain Garden Regularly. …
- Try Companion Planting. …
- Encourage Soil Health and Biodiversity. …
- Spray Oils. …
- Sprinkle Diatomaceous Earth.
Can you spray soapy water on strawberry plants?
Aphids. Soapy water sprayed directly on the bugs will kill them, without harm to the strawberries, and no residual effect on other insects. New aphids will replace them, so you’ll need to spray them every few days. Just fill a clean spray bottle with water and add a squirt of dish soap.
What can I spray on my strawberries for bugs naturally?
Try organic methods of pest control when protecting strawberries from insects and other pests. Organic methods for keeping pests away from strawberries might involve hot pepper spray, rotten eggs, blood meal, castor oil, orange peels, soap, and human hair.