Scale Insects: 11 way to kill scale insect (Updated for 2023)

Most scales are small and discreet insects that may have size up to ½ inch while their body color, multiple shapes are along with texture and other features may vary with the climate and species. The soft scale on plants may produce a thin, soft cottony or powdery layer and sometimes a wax molting covering their bodies that forms the part of their bodies and secrete copious amount of honeydew while armored scales have hard shield covers composed of wax and molted skin that can be separated from the body of insects. Honeydew comprises of sugars that make the plants’ foliage sweet & sticky, an attraction for ants, flies, and bees. Scale insects feeding is associated with sap sucking behavior that lead to yellowing and wilting of leaves by sucking sap from fruit-bearing plants and shrubs through piercing-sucking mouthparts. Sap feeding by scale insects may cause leaves to turn yellow and wilted, stunted & ugly looking, and finally death of parts of plants or entire plants on the heavy infestation. Plants lose their vigor and are prone to diseases like powdery mildew, sooty molds, sucking pests and borers.

Considering their widespread damages and diseases associated with their infestation, a careful selection of remedies will lead to knowing how to get rid of scale insects on your gardening plants.

What are scale insects?

Adult females and nymphs of most species may be circular or ovate, without wings, without a separate head or other easily recognizable parts of their bodies. Some species change their appearance as they grow to become adults while in some other species males and females may differ in shape, size, and color. Adult males are tiny and delicate that don’t survive longer having a pair of wings & antennae while Some other scale species don’t have males and reproduce without mating.

How to get rid of scale insects?

#1 Garden Safe-Neem Oil Extract Concentrate (Chemical – Editors’ Choice)

Plant scale treatment easy formula for organic gardening lovers that provides coverage against all 3 stages of insect development i.e. Eggs, Nymph, and adults. The formulation contains 70% neem oil that serves as an effective control against a variety of scales, chewing and sucking insects along with control on fungal diseases whereas it can be used till the time of harvests.
How to get rid of scale on plants is so simple. Just add 3-4 tablespoon of Neem oil into 1 gallon of water and start spraying at the first appearance of any scales in your garden. For better results, repeat after every 7 days till the time of harvests without fears of residual effects being an organic solution for the entire edible greens in your garden.

#2 Green Lacewing 1000 Eggs (Natural – Editors’ Choice)

1000 live eggs of Green Lacewing species (Chrysoperia rufilabris) are predators for the variety of soft-bodied insect & pests that damage your edible, flowering and fruit trees in the garden including mealy bugs, aphids, spider mites, and other scale insects doing harm to your edible greens. They are capable of performing in the varying degrees of changing temperature and humidities along with their usage on gardens, greenhouses, indoor plants and decorative plants
In the garden, 1000 Green Chrysopa eggs are sufficient for 200-250 square meters. Larva hatched from eggs will live for 2-3 weeks in the garden to become an adult that will further survive for 2 months to prey on California red scales including mealybugs and other scale insects in your garden. If all soft-bodied insects are gone, they will live on pollens only and wouldn’t harm your edible plants.

#3 Good Bugs-Ladybugs (naturally Control)

These are 1500 live predatory ladybugs that perform the best during the temperature ranges between 30 to 80 ℉  and are the first choice of organic gardeners for their edible greens whereas they are non-selective as well to feed on both larval and adult stages of all types of scale on plants. You definitely need to recognize them after they are released into your organic garden as they lay yellow and orange eggs in clusters of 50 or more, the larva is black crawling with orange spots and adults as beetles with black markings with yellow and reddish-orange in color.
Besides praying on plant scales, they look for all slow-moving insects on your edible greens including aphid, leafhoppers and thrip and the most devastating strain of scales i.e mealy bugs. Release good bugs soon after sunset after watering your plants. 1500 live bugs are sufficient for 90-100 square meters area.

#4 Bonide All Seasons Horticultural Oil Spray

Bonide Horticultural oil spray contains petroleum distillates up to 98% that stay longer on the surface of the leaves if you are interested in how to kill scale insects in your garden using less toxic compounds with minimum or no residual effects at all. Normally, scale insects have shielded bodies while only those products perform well that stay longer on their bodies and that’s what Horticultural oil contains for the smooth killing of scales, leafminers, and other soft-bodied insects on your edible greens. It controls scales along with their eggs during all stages of plant growth without any harm or side effects.
Add 2 -2.5 ounces of Horticultural Oil Spray in 1 gallon of water and spray on the entire plant foliage using a hand-held mist sprayer. Water your plants before or immediately after spraying.

#5 Monterey Horticultural Oil

Another product having mineral oil in its active ingredients up to 80% that can be used easily due to it’s ready to use containers. Again, it possesses features similar to oils that stick to the surface for the leaves for effective control of scales due to immotile position on plants. It can successfully be used on vegetables, fruits, small trees and ornamentals in your garden. Generally, products containing horticultural oils are recommended for outdoor gardening on the plants that take longer to mature. Short tenure vegetables and microgreens must be avoided as you can’t harvest immediately after its use.
Just connect the bottle with the garden hose, turn it on and start spraying on your garden plants to kill scales and all other soft-bodied insects. If the plants are limited, then add 2.5-5 ounces of Horticultural oil in 1 gallon of water and spray plants using a high-pressure hand-help sprayer.

#6 Safer-Insect Killing Soap Concentrate

This insect-killing soap contains potassium salts of fatty acids that are derived from the natural sources like plant extracts and seriously effective against mealybugs, aphids and other scales on your edible plants. They trigger dehydration on coming in contact with the bodies of scales including soft and hard-bodied scales. It is able to penetrate into the waxy layers of scales and turns them dead on contact leaving no harm on the gardening plants.
Insect Killing Soap is OMRI registered, approved for organic farming and can be sprayed on the gardening plants including all edible greens and leafy vegetables during all stages of growth until harvested. Add 2.5-3 ounces of this concentrate in a gallon of water and spray the entire plants using a mist sprayer so that the upper foliage of the plants become fully wet.

#7 Southern Ag-Natural Pyrethrin Concentrate (Chemical Control)

Its active ingredient is pyrethrin (0.96%) while it contains piperonyl Butoxide up to 9.6%. Piperonyl butoxide is not an insecticide but a surfactant that increases the efficacy of insecticide when sprayed on the surface of the leaves by sticking them for longer. Since plant scale treatment is a bit tricky than other pests that cause damage to your plants due to their adhering nature while most the insecticides used are spilled over waxy layers on their bodies and don’t kill them. It enables the insecticides to penetrate into the bodies of scales deeply and kills them on contact.
Add 1-2 teaspoon of Southern pyrethrin into 1 gallon of water to spray your entire plants thoroughly in the evening. It kills the entire range of scales including mealybugs, Carolina red scales and cottony cushion scales in your edible garden.

#8 Bonide- Insect Control Systemic Granules, 0.22% Imidacloprid (naturally Control)

Recognizing scale insects and the damage they cause on your ornamental plants, shrubs and trees can be corrected with the quick application of systemic insecticides like Imidacloprid 0.22% formulation that absorb into the roots and transported to the plant’s foliage to make them poisoned for the scales and other damaging pests. These granules are meant to be used on any of the edible greens whether they are vegetables, fruits or herbs in your garden.
Long-lasting control makes your ornamentals pests free for 8 weeks after application. Simple to use as well. Just incorporate granules into the garden soil after earthing up beneath the trees or plants and water them immediately so that they would absorb it for transporting it to plant foliage.

#9 Tanglefoot Tree Care Kit (naturally Control)

Tanglefoot works by preventing ants and pests from crawling up the tree stem from the soil to the leaves and fruit and tender shoots. Its application along the tree stem stops the movement of all crawling insects that bring soil-borne diseases to the plant foliage. You need to cover the trunk with the paper before applying Tanglefoot on the stem.
Try to band your tree trunk at 2-3 different sites keeping some distance so that low flying insects are also captured. You can also hang yellow cardboards near the trunk where you applied Tanglefoot.

#10 Rubbing Alcohol (naturally Control)

Rubbing alcohol works well when infestations are low on limited branches or plants. You may use a cotton swab to dip into alcohol and clean the infested stuff. Alcohol dissolves their skin and dies of dehydration in this process.
Keep it repeating till you notice any type of scales on your edible plants in the garden. You can also make a 50% solution, put into the garden sprayer and spray on the infested leaves.

#11 Sevin Insectkil 32oz Rts (Systemic Control)

Get rid of scale on plants if they are in the limited ratio. This quick remedy contains Zeta Cypermethrin in very limited quantity ( 0.35%) and is considered the best for ornamental plants including all indoor. Avoid using on vegetable or microgreens due to its residual effects but it performs best to tackle all sorts of scales including mealybugs.
The product is best to protect small plants and seedling if they are not edible. It is ready to use formulation that you can buy and spray to kill scales instantly.

Life Cycle of scale insects

Scales hatching takes place from eggs and they develop through nymph & larva to an adult. Once matured, females produce eggs that are habitually covered under their bodies, although some species lay eggs under prominent waxy covers. Eggs are usually in the clusters of 50 or more undersides of the leaves. Eggs hatch into crawlers that settle upon getting the suitable host to make fresh colonies apart from the parent flocks. Their feeding starts typically within 1 to 2 days after they were hatched. The existence of all of their life stages may widespread during the entire growing conditions.

How to Control Scale Insects?

Cultural practices are always preferred for preventing and controlling scale insects in any organic garden. These practices would never let scales infest your garden until overruled;

• Provide your plants proper air circulation so that the air crosses the plant foliage and reduce humidity.
• Increase plant in the way that foliage of one plant doesn’t intermingle with others.
• Water your plants regularly and keep underneath soil well-drained.
• Remove plant debris and undecomposed matter away from your garden space.
• Feed your plants with suitable nutrients especially avoid excessive nitrogen application.
• Prune branches and twigs that are heavily infested with scales if on limited branches otherwise remove infested plants entirely.
• Remove weeds and other green covers underneath your garden plants.

How to get rid of scale on plants, naturally?

Break scales and ants symbiosis as ants feed on the predators & parasites of scapes. Upon noticing an increase in the ant’s population be sure that they are being attracted to the waxy layers & secretions of scales. Sticky traps will help you stop ants climbing up your gardening plants.