Eliminating Strawberry Aphids – A Complete Guide

As a strawberry grower, few things are more frustrating than walking outside to find your strawberry plants covered in tiny, sap-sucking aphids. While aphids pose little threat to your health, they can ravage a strawberry planting if left unchecked. Getting rid of strawberry aphids requires diligence and a multi-pronged approach. With the right techniques though, you can protect your strawberries and reclaim your bountiful harvest.

What Are Strawberry Aphids?

Aphids are soft-bodied, pear-shaped insects that feed by sucking nutritious sap from plants. Of the nearly 5000 known aphid species, the strawberry aphid (Chaetosiphon fragaefolii) specifically targets strawberries and other members of the rose family. They are commonly referred to as “greenfly”.

No bigger than a pinhead, strawberry aphids can appear green, yellow, grey, black, or white in color. They tend to gather in large groups 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 quickly.

Excessive sap-sucking stresses the plant while aphids secrete a sticky residue called honeydew that encourages mold growth. Heavily infested runners and fruits often become disfigured. Left uncontrolled entire crops can be devastated.

Recognizing Strawberry Aphid Damage

Keep an eye out for these common signs of strawberry aphid infestation

• Visible colonies of green, yellow, black, grey, or white specks on the undersides of leaves

• Leaves becoming puckered, twisted, or curled downward.

• Yellow spots or stippling on leaf surfaces.

• White mold/fungus growing on leaves coated in honeydew secretions.

• Deformed and stunted fruits covered in honeydew.

• Black sooty mold developing on fruits.

• Wilting, weak plants despite adequate watering.

• Ant trails present around plants as they feed on honeydew.

Catching infestations early allows for quicker control before exponential population growth. Inspect the undersides of random leaves weekly. Pay extra attention after warm winters which favor aphid survival.

Why Getting Rid of Aphids is Crucial

More than just a nuisance, strawberry aphids can completely destroy your crop if not controlled. Here’s why it’s so important to eliminate them:

• Sucking away plant sap stresses the plant and inhibits fruit development.

• Toxic honeydew secretions promote growth of harmful molds that damage fruits/foliage.

• Flowers and fruits become disfigured, preventing proper pollination.

• Viruses are spread from infected to healthy plants via aphid feeding.

• Aphids’ rapid reproduction leads to out-of-control infestations.

• Ants that feed on honeydew will actively protect and spread aphid populations.

To save your strawberry crop, implement control tactics at the first sign of aphids before irreparable harm is done.

Organic Ways to Get Rid of Strawberry Aphids

Getting rid of strawberry aphids doesn’t necessarily require dousing your plants in harmful pesticides. There are several organic and non-toxic remedies that can be highly effective against heavy aphid populations.

Insecticidal Soap

Insecticidal soaps made from potassium salts of fatty acids disrupt cell membranes on contact, killing aphids while leaving no chemical residue. Use on both tops and undersides of leaves, avoiding blooms. Repeat applications may be needed.

Neem Oil

Derived from the neem tree, this oil smothers aphids while providing residual protection. Mix according to label directions and spray weekly. It’s safe for pollinators!

Horticultural Oils

Lightweight summer oils like canola oil also smother aphids on contact when mixed with water and applied liberally to foliage. Avoid blooms and apply during cool conditions.

Pyrethrin Sprays

Pyrethrin insecticides are plant-derived and break down quickly in sunlight with minimal toxicity. Direct contact is key for effectiveness. Avoid using near harvest.

Insecticidal Dusts

Powdered diatomaceous earth (DE) cuts through an aphid’s waxy coating causing dehydration. Dust plants, taking care to reach the undersides of leaves where aphids hide. Reapply after rain.

Strong Water Streams

Blast plants with water to simply knock aphid populations off of leaves and down into soapy water traps below. Focus on the undersides.

Organic Sprays

Various organic/non-toxic aphid sprays utilize plant oils and acids to kill on contact. Look for active ingredients like clove oil, citric acid, or sodium lauryl sulfate. Thorough coverage is important.

Vinegar Solutions

A vinegar/water mixture of 1 part vinegar to 3 parts water helps lower pH levels and dissolve aphid exoskeletons when sprayed on infested plants. Avoid blooms and rinse plants after an hour.

Soap Sprays

Basic dish soap mixed with water (1-2 tsp per gallon) breaks down aphids’ protective waxy coating. For mild infestations, spray leaves thoroughly covering undersides.

Row Covers

Floating row covers provide a physical barrier preventing aphids from reaching plants. Use in early season to exclude winged aphids migrating in.

Sticky Traps

Yellow and blue sticky traps lure winged adult aphids preventing them from landing and reproducing on plants. Position several around strawberry beds.

Using Beneficial Insects Against Aphids

In addition to sprays and barriers, certain beneficial predatory insects provide natural aphid control:

Lady Beetles – Both adults and larvae voraciously consume aphids. Attract them with companion plants like dill and cilantro.

Lacewings – Lacewing larvae feed on strawberry aphids. Adults eat pollen and nectar.

Aphid Midges – Tiny flies that lay eggs in aphid colonies. The larvae then devour aphids from the inside out.

Hoverflies – Eggs laid near aphid colonies hatch into larvae that feasts on aphids. Avoid harming beneficial maggots.

Parasitic Wasps – Wasps like the aphidius wasp lay eggs inside aphids, killing them as larvae emerge. Let wasps thrive.

Green Lacewings – Lacewing larvae known as “aphid lions” are fierce aphid predators. They eat hundreds of aphids in their development.

Releasing purchased ladybugs or lacewings can supplement naturally occurring populations. Provide diverse pollen and nectar sources to attract and maintain beneficial insects in your garden ecosystem.

Cultural Ways to Deter Aphids

Certain cultural practices make conditions less favorable for Strawberry aphids:

• Use drip irrigation which keeps foliage dry, deterring aphids. Overhead watering spreads them.

• Reflective plastic mulch disorients aphids and makes plants less appealing.

• Remove any overwintering weed hosts near beds that could harbor aphids.

• Use trellising or raised beds which increase airflow around plants.

• Manage nitrogen carefully, avoiding excess which stimulates aphid reproduction.

• Remove and destroy severely infested leaves/plants to prevent spread.

By limiting their comfort and habitat, you create an environment unfavorable for prolific aphid reproduction.

Spot-Treating Badly Infested Areas

When dealing with large, heavily infested areas of your strawberry patch, spot treatments allow you to target problem areas without exposing the entire planting:

• Mix higher concentration solutions of recommended organic insecticides for focused application.

• Remove and bag badly infested runners to destroy aphid colonies before spot treating remaining plants.

• Use thick sprays of insecticidal dusts like diatomaceous earth on seriously effected patches.

• Inject insecticidal soap or horticultural oil solutions directly into the base of severely infested plants.

• Physically wipe, hose, or otherwise disturb aphids on isolated plants before applying insecticides.

• If practical, cover and dispose of small infested sections of beds, then replant with clean plants.

Spot treatments give you a chance to eliminate heavily infested areas without damaging your entire crop.

Prevention Between Harvests

To avoid recurring issues, it’s crucial you implement prevention tactics between seasons:

• Remove and destroy all crop debris after final harvest. This eliminates overwintering sites.

• Work organic fertilizer and compost into beds which strengthens plants against future infestations.

• Establish cover crops to restore soil health and attract beneficial insects.

• Inspect beds periodically and treat any early signs of aphids.

• Keep nearby weeds under control, eliminating alternative aphid hosts.

• Rotate crop placements, making it harder for aphids to find host plants.

With diligent prevention, your plants will be much less susceptible once the next growing season arrives.

When to Call in a Professional Exterminator

In cases of severe, recurring infestations, it may be worthwhile to have a professional pest control operator assess your situation. They have access to stronger insecticides and can detect hidden colonies you may have missed. Professional exterminators also know the most vulnerable stages in an aphid’s life cycle to target.

Signs you may need professional help:

• Aphid populations persist despite using multiple home remedies.

• Damage is rapidly spreading from isolated areas to the remainder of the crop.

• You are finding large aphid colonies in the root systems and crowns.

• Other priorities prevent you from implementing adequate control measures yourself.

For the best results, combine their treatments with cultural practices to deter future infestations after the current aphids are eliminated.

Be Vigilant To Safeguard Your Strawberry Crop

Left unchecked, strawberry aphids can devastate your prized berries. But by diligently scouting for early signs and swiftly implementing organic control measures, you can protect plants and preserve your harvest. Integrate multiple tactics like beneficials, sprays, and cultural practices to knock back infestations before they overwhelm your crop. With persistence and vigilance, you can enjoy aphid-free strawberries.