How to get rid of mealybugs on tomatoes

What mealybugs look like on tomatoes

White cottony mealybug clusters in tomato leaf axils, on lower stems, and on the root collar. Honeydew, sooty mould, and stunted top growth.

For the full set of mealybugs damage symptoms across host crops, see our Mealybugs identification page.

Why tomatoes attracts mealybugs

Several mealybug species (Planococcus citri, P. ficus, Phenacoccus solenopsis) are documented on greenhouse tomatoes, particularly long-cycle crops with overlapping pest pressure from other Solanaceae.

Severity for this combo: Moderate — monitor closely. When to act: Greenhouse tomatoes year-round; outdoor tomatoes during warm sheltered late summer.

Step-by-step control protocol

This is the integrated-pest-management protocol — non-chemical control first, biological and organic options second, conventional sprays only as a labelled last resort. Total cycle: about three weeks for most home cases.

1. Confirm the pest. Inspect the plant — look for white cottony tufts in leaf axils, leaf undersides, and stem joints. If unsure, photograph the affected area and open Growli for instant species ID.
2. Isolate where possible. Move container-grown tomatoes away from healthy plants. For outdoor beds, mark the affected row so you can monitor it daily.
3. Apply non-chemical control first. Dab visible adults with a cotton swab dipped in 70 percent isopropyl alcohol
4. Add biological or organic spray. Insecticidal soap or horticultural oil weekly during crawler activity. Prune out the worst-affected stems. Release Cryptolaemus montrouzieri larvae in commercial greenhouses.
5. Repeat on schedule. Most mealybugs protocols need repeating every 5-7 days for three weeks to catch each new hatch. A female lays 300-600 eggs in a cottony ovisac. Crawler-stage nymphs hatch wax-free and mobile — this is the only stage when contact sprays really work. Adults are protected by their wax coat.
6. Monitor and prevent recurrence. Inspect tomatoes weekly for the rest of the season. Quarantine new plant arrivals for 3 weeks before mixing with your collection

Best biological control for mealybugs on tomatoes

For greenhouse, polytunnel, conservatory, and indoor production on tomatoes, biological control gives long-term suppression without the residue or pollinator harm of synthetic sprays:

• Cryptolaemus montrouzieri (mealybug destroyer) — release larvae rather than adults for indoor use; adults disperse
• Leptomastix dactylopii — parasitoid wasp specific to citrus mealybug
• Chrysoperla carnea (green lacewing) larvae — generalist predator that eats mealybug crawlers

Organic spray options

Horticultural oil and insecticidal soap work best during the crawler stage, when nymphs have not yet built their wax shield — apply every 5-7 days to catch successive hatches. Neem oil disrupts moulting. Systemic insecticides are sometimes used in commercial nursery production but are not appropriate for edibles or indoor herbs.

Prevention going forward

• Dab visible adults with a cotton swab dipped in 70 percent isopropyl alcohol
• Quarantine new plant arrivals for 3 weeks before mixing with your collection
• Wash leaves and stems under lukewarm water in a sink or shower
• Prune out and bin the worst-affected stems
• Unpot suspect plants and inspect roots for white waxy root mealybug colonies

Common mistakes when treating mealybugs on tomatoes

• Spraying once and walking away. A female lays 300-600 eggs in a cottony ovisac. Crawler-stage nymphs hatch wax-free and mobile — this is the only stage when contact sprays really work. Adults are protected by their wax coat. A single spray misses everything that hatches afterwards — plan a 3-week protocol.
• Confusing the species. Tomatoes hosts several similar-looking pests. Confirm before treating; the wrong protocol wastes weeks. Open Growli for a confirmed ID.
• Spraying in midday heat. Insecticidal soap and horticultural oil burn leaves above 30 degC and on drought-stressed plants. Apply at dawn or dusk.
• Mixing biological control with broad-spectrum sprays. Pyrethroids and neonicotinoids wipe out predator releases. Use one strategy at a time.

Frequently asked questions

How do I get rid of mealybugs on tomatoes?

Insecticidal soap or horticultural oil weekly during crawler activity. Prune out the worst-affected stems. Release Cryptolaemus montrouzieri larvae in commercial greenhouses. A female lays 300-600 eggs in a cottony ovisac. Crawler-stage nymphs hatch wax-free and mobile — this is the only stage when contact sprays really work. Adults are protected by their wax coat.

What do mealybugs look like on tomatoes?

White cottony mealybug clusters in tomato leaf axils, on lower stems, and on the root collar. Honeydew, sooty mould, and stunted top growth.

When should I treat mealybugs on tomatoes?

Greenhouse tomatoes year-round; outdoor tomatoes during warm sheltered late summer.

Why are mealybugs attracted to tomatoes?

Several mealybug species (Planococcus citri, P. ficus, Phenacoccus solenopsis) are documented on greenhouse tomatoes, particularly long-cycle crops with overlapping pest pressure from other Solanaceae.

What is the best biological control for mealybugs on tomatoes?

Cryptolaemus montrouzieri (mealybug destroyer) — release larvae rather than adults for indoor use; adults disperse. Insecticidal soap or horticultural oil weekly during crawler activity. Prune out the worst-affected stems. Release Cryptolaemus montrouzieri larvae in commercial greenhouses.

Will mealybugs on tomatoes spread to other plants?

Yes. Mealybugs from tomatoes typically migrate to nearby susceptible hosts — see the affected-crops list on the main mealybugs page. Quarantine, sticky traps, and weekly inspections of neighbouring plants are essential.

Are pesticides safe to use on tomatoes?

Insecticidal soap, horticultural oil, neem oil, and Bti are the safest options for edible and indoor tomatoes. Always read the product label and follow manufacturer's PPE, dosage, and re-entry guidance. Pesticide approvals change — confirm via the UK HSE pesticide register or US EPA before use.

Sources

Combo-specific guidance sourced from US Cooperative Extension publications (UC IPM, NC State, UMD, UMN, Penn State, CSU, UF/IFAS EDIS), Clemson HGIC fact sheets, Royal Horticultural Society guidance, and Cornell NYS IPM Biocontrol fact sheets. Reviewed by the Growli editorial team in May 2026.

Keep going

• All crops affected by mealybugs
• Mealybugs — full kill protocol (article)
• How to grow tomatoes — full guide
• Tomatoes plant-care reference
• Tomatoes companion plants
• All 8 garden pests covered in this guide
• Garden pest identification — complete article