Spotting Citrus Gall Wasp Infestations: Signs and Symptoms to Watch For

Citrus trees are an awesome addition to any garden, bringing juicy fruits and a vibrant aesthetic. But, these beloved trees can fall victim to pesky pests like the notorious citrus gall wasp.

It’s super important to spot the signs of citrus gall wasp infestations early on to effectively manage and keep your citrus trees healthy. In this guide, we’ll check out the telltale signs and symptoms to watch for, so you can protect your citrus trees from these annoying invaders.

Understanding Citrus Gall Wasps

Photograph of lemon tree showing a citrus gall with exit holes.

Image source: Agriculture Victoria

Citrus gall wasps (Bruchophagus fellis) are tiny insects that belong to the family of gall wasps. These pests target citrus trees, laying their eggs within the tree’s branches, causing abnormal growths known as galls.

Lifecycle: The lifecycle of citrus gall wasps typically involves multiple stages, including egg-laying, larval development within galls, pupation, and emergence of adult wasps.

Host Trees: Citrus gall wasps primarily infest citrus trees, with lemon, orange, lime, and mandarin trees being common hosts.

Damage: Infestations by citrus gall wasps can lead to stunted growth, reduced fruit yield, and overall decline in tree health if left untreated.

Signs of Citrus Gall Wasp Infestations

1. Gall Formation

Galls are abnormal growths or swellings on the branches of citrus trees. They are typically round, woody structures ranging in size from a few millimetres to several centimetres.

Look for knobby protrusions along the branches, often with a woody texture and a slightly different colour compared to the surrounding bark. These galls may also have small exit holes where adult wasps emerged.

2. Leaf Distortion and Yellowing

Infestations by citrus gall wasps can cause distortion and discolouration of leaves, leading to a noticeable yellowing or wilting.

Check for abnormal leaf shapes, curling, or drooping, particularly in the vicinity of gall formations.

3. Stunted Growth and Reduced Fruit Yield

Citrus gall wasp infestations can hinder the tree’s overall growth and development, resulting in stunted branches and diminished fruit production.

Monitor the tree for signs of slowed growth, fewer blossoms, and reduced fruit set compared to healthy trees.

Seasonal Considerations

Citrus gall wasp activity tends to peak during certain times of the year, often coinciding with warmer months.

Be vigilant during peak activity periods, such as spring and early summer, to detect infestations early on.

Other Indicators and Secondary Symptoms

1. Presence of Wasps or Larvae

Adult citrus gall wasps and their larvae may be visible near gall formations or on affected branches. Look for small wasps or larvae emerging from galls or congregating on the tree’s surface.

2. Bark Splits and Lesions

Severe infestations can lead to bark damage, including splits, lesions, or oozing sap. Inspect the tree’s trunk and branches for any signs of bark abnormalities or wounds.

Get Our Citrus Gall Wasp Products

Don’t let citrus gall wasps wreak havoc on your beloved citrus trees! At Gardening Direct, we offer effective citrus gall wasp prevention and treatment products to help you combat these pests and protect your citrus orchard.

Citrus Gall Wasp Prevention Pack

Safeguard your citrus trees from gall wasp damage with our intuitively designed ‘Citrus Gall Wasp Prevention Pack’. Loaded with essential tools, such as our Citrus Protectant Spray and Citrus Gall Wasp Trap, this pack offers a comprehensive approach to keeping your trees healthy and pest-free.

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Citrus Gall Wasp Trap (with cage)

Our latest ‘Citrus Gall Wasp & Insect Trap’ proactively targets a variety of pests including Citrus Gall Wasps, Fruit Flies, Whiteflies, Aphids, and Thrips. Designed with an effective glue field, it captures these insects without the risk of ensnaring non-target animals, thanks to the innovative enclosure cage. To optimise protection, we suggest using one trap per citrus tree.

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For our full range of gardening supplies and tools, browse today.

Act Fast to Save Your Citrus Trees!

Untreated citrus gall wasp infestations can lead to severe damage, including weakened trees and reduced fruit quality.

Early detection and prompt management are key to mitigating the impact of citrus gall wasps and preserving tree health.


By familiarising yourself with the signs and symptoms of citrus gall wasp infestations, you can take proactive measures to protect your citrus trees and maintain a thriving orchard. Keep a close eye on your trees year-round, especially during peak activity periods, and be prepared to intervene as needed.

If you need any further guidance or assistance, don’t hesitate to contact us and we’d be glad to help.

Frequently Asked Questions (FAQs)

How do citrus gall wasps damage citrus trees?

Citrus gall wasps lay their eggs within the branches of citrus trees, leading to the formation of abnormal growths called galls. These galls disrupt the flow of nutrients and water within the tree, resulting in stunted growth, reduced fruit yield, and overall decline in tree health.

Are all citrus tree varieties susceptible to citrus gall wasp infestations?

While citrus gall wasps primarily target citrus trees, susceptibility can vary among different citrus varieties. Lemon, orange, lime, and mandarin trees are commonly affected, but some varieties may show greater resistance to infestations.

Can citrus gall wasp infestations be prevented?

While complete prevention may be challenging, there are steps you can take to minimise the risk of citrus gall wasp infestations. These include promoting overall tree health through proper irrigation, fertilisation, and pruning practises, as well as implementing early intervention measures when signs of infestation are detected.

How can I effectively monitor my citrus trees for citrus gall wasp infestations?

Regular monitoring of your citrus trees is key to early detection of citrus gall wasp infestations. Inspect the branches and foliage for signs of galls, leaf distortion, yellowing, or unusual growth patterns. Additionally, keep an eye out for adult wasps or larvae near gall formations.

Is it safe to use citrus gall wasp spray on my citrus trees?

Yes, citrus gall wasp sprays are formulated to target citrus gall wasps specifically and are generally safe for use on citrus trees when applied according to the manufacturer’s instructions. However, it’s important to choose a product labelled for use on citrus trees and to follow all safety precautions outlined on the product label.

When is the best time to apply citrus gall wasp spray?

The timing of citrus gall wasp spray application can vary depending on the product and the specific recommendations provided by the manufacturer. In general, it’s advisable to apply the spray during periods of peak citrus gall wasp activity, typically in the spring or early summer months, to target emerging adults and prevent egg-laying. Be sure to follow the application instructions carefully for optimal effectiveness.