How To Get Rid Of Stink Bugs On Citrus Trees

Almost every backyard in Australia has a citrus tree of some sort and unfortunately, they’re not immune to pests and diseases.

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Having a lemon or lime tree in your garden means that you might face the problem of stink bugs (also known as bronze orange bugs).

You want to get rid of these as quickly as possible. Not only do these pests release a very unpleasant odour when they’re disturbed, but they’ll also suck the sap out of any new growth.

In turn, you’ll find that this causes flowering and fruiting buds to drop and your fruit harvest will be greatly diminished.

Follow our guide below for getting rid of stink bugs on your citrus trees.

Take precautions before attempting to remove the stink bugs

Before you try any of the methods below, make sure that you take precautions to protect yourself from the bug’s secretions.

The stinky liquid that the bronze orange bug expels is highly caustic and can cause irritation to your skin and eyes.

Therefore, remember to wear goggles, long rubber gloves, and protective clothing before you attempt to remove them.

The best time to get rid of these pests is in winter before they’ve had time to multiply their numbers. 

During winter, you’re likely to only see the nymphs which are around 6mm long, flat, and lime green.

As these mature, they’ll take on the bronze and orange colour of the adult bugs and can reach a length of around 25 mm.

The most effective method for removing stink bugs is physical removal:

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Hose or vacuum them off

If your citrus tree is relatively small and you don’t have a huge infestation, you can use a garden hose to blast the bronze orange bugs off your tree.

Be sure to collect them in a plastic bag and squash them before placing the bag in the rubbish bin.

If you’re a bit squeamish about squashing them, then just drop them into a bucket of methylated spirits to kill them.

Similarly, you can use a vacuum cleaner to suck the bugs off your tree. Make sure that you empty the contents of the vacuum into a sealable plastic bag and place it in the rubbish bin.

Use detergent and water to physically remove the bugs

For this physical method of bronze orange bug control, you’ll need a bucket filled with water and dishwashing liquid.

Here’s what to do:

  • Make sure you wear goggles and long rubber gloves before attempting this. Remember, the spray from these bugs can cause irritation to your skin and eyes.
  • Take the bucket of soapy water out to your citrus tree.
  • Either shake the stink bugs off the branches into the bucket or dunk each branch into the bucket to remove the bugs. You could also use something like a small paint brush to brush the bugs off and into the bucket.
  • As the bugs fall into the bucket, the detergent will kill them.
  • As an alternative, you can put the soapy liquid into a spray bottle and liberally spray the entire tree. Make sure you don’t do this on a hot day because it may damage an already stressed tree.

With this manual removal method, you’ll need to keep an eye on your tree for a number of days and remove any extra bugs that you may have missed.

Make sure that you also look out for stink bug eggs during the warmer months. You will usually find them on the undersides of the leaves.

If you notice a collection of eggs on a leaf, just take the leaf off the tree and place it in the bin. 

If you’re vigilant in doing this, it will disrupt the life cycle of the bronze orange bugs and their numbers will be greatly reduced.

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How to control an infestation of stink bugs on larger trees

If your trees are quite large or you have a heavy infestation, you may want to spray your trees with an insecticide.

One option is to use a natural product like pyrethrum, neem oil, or another organic spray formula such as eco-oil which may work on eggs and small nymphs but not adults.

You can also use a systemic insecticide that contains Imidacloprid. However, this can have negative impacts on beneficial insects like bees. Also, many people will want to avoid using insecticide on their fruit trees.

Make sure that you spray your trees every 10 to 14 days to not only kill the adult bugs but also the young nymphs before they turn into adult beetles.

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Keep your citrus tree healthy to avoid further infestations

Quite often, if you have a heavy pest infestation on your citrus tree, it means that the tree may be under stress.

To remedy this, make sure your tree is receiving enough water and apply some citrus fertiliser to promote strong and healthy growth.

Photo of author

Annette Hird

Annette Hird has an Associate Diploma of Applied Science in Horticulture. She has worked in a variety of production nurseries, primarily as a propagator. She also had the responsibility of a large homestead garden that included lawn care, fruit trees, roses and many other ornamental plants. More recently, Annette has concentrated on improving the garden landscape of the homes that she has lived in and focused a lot of energy on growing edible plants as well. She now enjoys sharing her experience and knowledge with others by writing articles about all facets of gardening and growing plants.