Pieris Lace Bug Management – Guide

The Pieris grows into a beautiful flowering woody plant if planted in well-drained and non-acidic soil, but a Pieris lace bug might be its undoing. Other factors like adequate water, enough sunlight, and good weather ensure these plant species mature successfully. However, different types of pests and diseases affect the growth of these plants.

The lace bug and leaf spots are the two common problems affecting the Pieris plants. However, we will discuss the Pieris lace bug management and guide comprehensively.

What Is the Pieris Lace Bug?

The Pieris lace bug, also known as the andromeda lace bug, is a small and stubborn insect that usually damages the foliage of the Pieris plant. These sap-sucking insects can cause upper leaf pale mottling of the Rhododendron woody plant.

A severely affected leaf will look discolored and stippled.

Brief History of the Bug

The Pieris lace bug was first discovered in Japan. There, it did not cause significant damage to plant species until it moved to Britain England. In England, the Pieris lace bug caused uncontrolled damage to plant species, including the Pieris plant.

It was first detected in 1998 in Windsor, England, after damaging the Pieris and rhododendron plant species.

Lace Bug Looks And Appearance

Young lace bugs:

  • Extremely small in size (about 2-3 mm long)
  • Flat body with the brownish appearance
  • Do not have lacey wings. But wings are somewhat transparent
  • Mostly go unnoticed in this stage

Adult lace bugs:

  • Small in size (about 4-5 mm long)
  • Flat body with a black appearance on the thorax
  • Have transparent lacey wings that go all the way to their head
  • In this stage, they can be easily noticed

Nymphs shed their skin six times before becoming mature adults.

How To Tell the Symptoms of an Affected Plant

An affected pieris plant will show both early and late symptoms. Normally, it is hard to detect a leaf being attacked by lace bugs because it won’t show the symptoms immediately.

Here are a few common symptoms of a plant affected by the Pieris sap-sucking lace bug.

  • You should notice the yellow spots and marks on the upper surface of the leaves.
  • After a few days/weeks of continuous feeding and damage, the leaf will look silvery and molted.
  • Notice small and hard vanish-looking dropping on the leaf’s surface.
  • Extremely damaged Pieris leaves drop.
  • You can be able to see the adults and nymphs hiding on the undersurface of the Pieris leaves.

Feeding Pattern and Multiplication

The Pieris lace bugs multiply rapidly during summer. In summer, the weather is relatively warm, which favors pieris bug infestation.

Between March and April, you should be keen to notice the sudden appearance of these stubborn bugs on leaf foliage. They will, however, not be in excess.

From July to September, these lace bugs will be highest and will multiply greatly, causing leaf damage.

The young nymphs often congregate on the underside of the leaves and start sucking sap from the leaves. Also, during these months, you should notice all four generations on the upper and lower side of the leaves: the egg, larvae, nymph, and adults. The nymphs and adult stages are the most destructive of the generation.

Adults and nymphs will suck the plant juices and sap, causing the leaf to struggle, discolor, and slowly die. Eggs are laid on the leaves and are left to hatch.

A severely attacked and neglected plant looks unhealthy.

Close-up of a Pieris lace bug on a leaf, detailed view of its distinctive wing pattern and texture.

Biological Treatment and Control

You should act fast when noticing early symptoms of a Pieris lace bug’s attack on the leaves (foliage developing pale and coarse black/brown blotchy markings on the upper surface).

Most biological treatment methods are cheaper and safer than chemical treatment mechanisms.

What Are the Examples of These Biological Treatment Methods?

Because lace bugs usually feed and damage plants during the warm and dry summer weather conditions (March-April depending on your zone), it is best to deal with them at this time. Prune all the branches and leaves that have been severely affected by the bugs.

This helps control the Pieris lace bugs from spreading to the rest of the shrub. You can also encourage birds and other harmless insects to live in your garden.

Ladybirds and ground beetles are natural predators of not only the pieris lice bugs but other tiny sap-sucking bugs as well.

Each lace bug species feeds only on a particular plant or tree. Say, an oak lace bug only feeds on oak trees, not Pieris woody plants. Since this is the case, it helps if you are planting various plant species in your garden or yard to keep these lace bugs from quickly spreading from one tree to the next.

How to encourage birds in your garden: There are five ways to encourage birds to nest.

  • Always provide foods like grains, cereals, and water.
  • Provide shelter – Install handmade birdhouses and bird boxes on tree branches.
  • Ensure nesting materials like chicken feathers and soft dry grass are around your garden.

How to encourage ladybeetles and other Pieris lace bug predators to nest in your garden:

  • Make it easy for them to find food and water.
  • Have flowering plants ladybirds like.
  • Regularly water the plants and encourage the ladybirds to nest in your garden.

Chemical Treatment

Although chemical treatment is the most common practice most people use to get rid of the Pieris lace bug, it should be done correctly. Wrongly treated plants and incorrectly chemical diagnosed plants can die from excess chemical absorption.

Most insecticides and bug killers eradicate bugs in the nymph or earlier stages. The recommended insecticides vary in terms of strength and level of plant damage.

  • Time of application: You should apply chemical insecticides in early summer because, during summer, all four generations of the Pieris bugs will be present.
  • Recommended insecticides: choose an insecticide according to the level of plant damage and degree of lace bug infestation.
  • Dosage use: Read more on the dosage used on the label of your insecticide.

Different Types Of Recommended Insecticides

There are different kinds and classifications of insecticides in the market today. The most common insecticides are systemic, ingested, and contact. These can either be natural (organic) or human-made (synthetic).

Other kinds are formula preparations, which are also used to kill pests and unwanted insects. Organic sprays that contain natural pyrethrum ingredients kill the pieris lace bugs without affecting the plant’s tissues.

The synthetic insecticide containing synthetic pyrethroids has chemicals that kill all four pieris generations.

The three classifications of insecticides include:

  • Ingested insecticides: Pests and unwanted insects will ingest the insecticides when spraying.
  • Contact: When the insecticide is sprayed, direct contact with the insecticide causes the integrated pest to die.
  • Systemic insecticide: These insecticides are introduced and applied to the soil. A plant absorbs the insecticide through its roots and moves to the leaves and other external areas. The plant then forms a protective layer that acts as a poison to any unsuspecting pest that intends to feed on the plant.


Most insecticides pose a danger to pollinators and harmless insects. Ensure that you don’t use a broad spectrum of insecticides that also kills Pieris lace bug predators. Because if you unintentionally killed them, too, you would lose the protection this Pieris lace bug predators offer. And you may not like the next wave of Pieris lace bug’s attack.

Preventing the Pieris Lace Bugs and Other Harmful Pests From Accessing Your Garden

You can use different ways to control the pieris bugs from accessing your garden.

Here are 8 ways you can try at home.

1. Boosting Healthy Soil

Nutrient-rich and well-fertilized soil boosts the growth of plants. In addition, a healthy plant is usually immune to pest management and diseases.

2. Plant Correctly

Planting correctly means getting enough water, sunlight, and other essentials needed for growth. If your plant gets all the necessary growth ingredients, it will not succumb to pests like the pieris lace bugs.

3. Planting Strong-scented Pest Resistant Shrubs

Identify pest-resistant shrubs and plant them close to your pieris plants. The strong scent from the shrubs will repel harmful insects that want to nest in your garden.

4. Use of Floating Row Covers (FRC)

A floating row cover is a non-woven fabric that is light and allows sufficient light to reach the plant. In summer, when young pieris plants are vulnerable to the Pieris lace bug, you can cover them with this fabric until they are mature and tolerant.

5. Handle and Control the Outbreak Early

Once you notice an outbreak of pests, you must take drastic measures and solve the issue. A severely infested plant that can’t recover should be cut or removed completely. Removing the plant ensures that the pests do not spread to the other plants.

6. Do Not React. Be Proactive

Let the encounter be a learning lesson. If you have previously dealt with the Pierisak lace bug outbreak, ensure you learned a few tips and tricks for a healthy tomorrow.

7. Only Use Safe and the Correct Mulch

Do not use mulch that is formed from the dropped leaves of the lace bug-infested plant. Most of these leaves will still contain the eggs, nymph, and adult pieris bugs.

8. Pruning

Identify the infested and damaged foliage, cut them, then burn them. This ensures the death of what remains of the Pieris lace bugs and keeps them from spreading. An alternative you can do is to throw the foliage you cut. However, you must ensure that you dispose of it properly to discourage their growth and spread.

Final Thoughts

It takes time to have a bug-free outdoor environment with attractive Pieris and Rhododendron woody plants. Having the correct advice and products meaningfully helps in achieving successful outcomes. The above-discussed points should help you completely deal with these small and stubborn pests.

If the bugs persist, even after you attempt the above approaches, you should consult with your local garden store for a closer look or guidance on what to do next.

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