BROWSE HOW TOs

How to Control Scale Insects on Outdoor Plants

By eHow Home & Garden Editor

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Scale insects are sucking insects that weaken plants by sucking the sap from the tender plant tissues. Leaves yellow and drop and eventually the plant will die if not controlled. Here's how to treat scale on your outdoor plants.

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Instructions

Difficulty: Moderately Easy

Things You’ll Need:

Chilocorus Nigritus
Lindorus Lophanthae
Coreopsis Plants
Dill Seeds
Garden Shears
Horticultural Oils
Pyrethrin
Sponges
Fennel Seeds
Insecticidal Soaps

Step1

Know what you're looking for. Scale insects resemble round or oval 1/10- to 1/5-inch bumps without legs. They are hard to spot unless you look very closely.

Step2

Look for scale insects on the undersides of leaves year-round. They gather in clusters near leaf joints and on leaves and soft stems. The scale secrete a large amount of honeydew onto the foliage, which causes sooty mold, a black fungus, to grow. Black leaves and stems are also an indication of scale insect infestation.

Step3

Prune and dispose of infested branches and twigs.

Step4

Attract predatory beetles, such as soldier beetles and ladybugs, to your garden by planting coreopsis, dill, fennel and nectar plants such as salvia.

Step5

Remove scale insects from plants using a soft cloth or sponge dipped in insecticidal soap. Rinse with plenty of fresh water after washing the plant.

Step6

Purchase and release Chilocorus nigritus or Lindorus lophanthae beetles or Metaphycus helvolus, a parasitic wasp.

Step7

Spray a mixture of insecticidal soap and horticultural oil to control scale insects. The oil smothers the slow-moving insects.

Step8

Spray pyrethrin as a final resort. Pyrethrin is an organic pesticide made from a chrysanthemum. There are also chemical pesticides available.

Tips & Warnings

Always try the least toxic method of pest control as your first step.
If you use chemical pesticides in your garden, you will also kill the natural predators of scale insects.
If you choose to use a chemical method of control, always wear protective clothing and safety gear, including a long-sleeved shirt, long pants, neoprene gloves, goggles and a respirator.

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Comments

SunflowerOcity said

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on 10/19/2007 Good Stuff! See also: http://www.ehow.com/how_2094685_control-garden-pests-naturally.html

Anonymous said

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on 11/22/2005 If the plant is a tree or large bush, put a product called Tanglefoot around the base of the trunk. It keeps ants from climbing up, and ants often spread scale.