Citrus psyllids suck sap from young citrus trees, such as lemons, oranges, and mandarins. An infestation of these bugs will result in weakened buds and flowers, small fruits, sooty mold and honeydew on leaves, and dropping fruits. Given the damage these bugs can do, you must treat your citrus tree early to save it and its fruits.
Here are ten methods you can use to treat psyllid on citrus trees:
- Monitor new shoots on citrus trees.
- Apply 70% neem oil on affected trees and nearby plants.
- Use organic insecticides containing pyrethrins.
- Do not remove wasp nests on your citrus trees.
- Spray insecticidal soap regularly.
- Use foliar pyrethroid insecticide for adult psyllids.
- Spray soil-applied insecticide to kill nymphs.
- Wrap the tree with sticky tape or netting to control ants.
- Prune the trees to improve air circulation.
- Tree removal.
I’ll discuss these treatment methods in detail. Psyllids slowly kill citrus trees, so you need to control their population as soon as you discover their presence in your citrus trees. It takes time to destroy psyllids, so you must regularly apply the treatments.
1. Monitor New Shoots on Citrus Trees
Monitoring your citrus trees is the first step to controlling psyllids. It is the only way to detect the presence of these destructive insects in your trees.
The first place to check should be newly developing leaves because psyllids prefer new shoots to mature leaves. Mature citrus leaves are easier to monitor because they produce new shoots in the spring and fall seasons. Younger trees require more work because they flush periodically, especially in warm weather.
Signs of psyllid presence in citrus trees include:
- Twisted or notched leaves
- Waxy deposits
- Sooty mold
- Adult psyllids (3-4mm long)
- Reduction in shoot length over time
- Stunted tree growth
- HLB disease in mature leaves
You should also use a hand lens to check for small yellow eggs and nymphs. These are usually found on new leaves, so check there first. You can control the psyllid population better by targeting the eggs and nymphs.
When checking for signs of psyllids on citrus trees, you also need to look for Huanglongbing (HLB) disease. If you notice signs of HLB on your citrus trees, chances are psyllids are not far behind.
Psyllids are hosts of the HLB pathogens. They quickly spread it across multiple citrus trees, making it more difficult to control. Not only will you have an HLB disease problem, but the psyllids will be all over your trees, and controlling them will take even more effort, time, and resources.
The downside is HLB disease takes years to reveal its presence. By the time you start noticing symptoms of HLB disease on citrus trees, it would have been incubating in the trees for more than two years.
Signs of HLB disease in citrus trees include:
- Yellow leaves
- Blotchy mottle with hues of yellow and green on leaves
- Thick, leathery leaves
- Shoot dieback
- Fruit drop
- Brown seeds in affected fruits
- Small and lopsided fruits
This video illustrates why and how you should monitor your citrus trees for signs of psyllids. It also shows the signs that confirm the presence of psyllids.
2. Apply 70% Neem Oil on Affected Trees and Nearby Plants
Neem oil targets psyllids in different stages of growth, from eggs to adults. Besides psyllids, neem oil controls powdery mildew and twig blight. It also rids plants of aphids, which is particularly helpful because aphids have a symbiotic relationship with ants (which feed on the honeydew that psyllids produce).
I recommend getting Monterey 70% Neem Oil (available on Amazon.com) to control psyllids and other insects, like spider mites, aphids, and whiteflies. It also kills multiple fungal diseases, including black spot, powdery mildew, and needle rust. It’s ready to use, safe around pets and children, and an organic solution for your psyllid problem.
3. Use Organic Insecticides Containing Pyrethrins
If you prefer to avoid using chemicals on your citrus plants and fruits, opt for organic insecticides with pyrethrins as the active ingredient. Pyrethrin is an extract from pyrethrum and is present in many organic pesticides and insecticides. It’s toxic to insects and is used to control mosquitoes, ants, flies, fleas, psyllids, and other pests.
The Southern Ag Natural Pyrethrin Concentrate (available on Amazon.com) is a perfect choice for anyone looking for an effective organic psyllids control solution. It contains a high concentration of pyrethrins, is easy to use, and offers value for money.
4. Do Not Remove Wasp Nests on Your Citrus Trees
Wasps feed on psyllids, so they can be a long-term solution to your psyllid problem. The best part is that wasps are naturally attracted to citrus trees, especially when they are flowering. They feed on the nectar; some even set up camp on the trees.
Wasps feed on aphids and psyllids. If you have an infestation of either of these two insects on your citrus trees, wasps will build a nest and make the affected trees their home. That’s why many people often assume they have a wasp problem when the reality is that there is an aphid or psyllids problem.
So next time you notice wasps around your garden, let them hang out for a while. You want to maintain this food chain until you entirely eradicate the psyllids in your citrus trees.
5. Spray Insecticidal Soap Regularly
Insecticidal soap is effective in controlling tiny, soft-bodied pests like psyllid. However, you should spray your citrus trees regularly to boost its effectiveness. Insecticidal soap eradicates psyllids in different stages of growth. It will destroy the eggs, nymphs, and even adult psyllids.
Insecticidal soap also controls opportunistic insects, like aphids. Ants often follow aphids, but also protect psyllids (possibly because they provide honeydew for the ants).
Garden Safe Insecticidal Soap (available on Amazon.com) is an organic solution for psyllids, leafhoppers, aphids, mealybugs, and other insects. It’s ideal for indoor and outdoor plants, including fruit trees, vegetables, shrubs, and flowers. It’s a ready-to-use spray, so no preparation is required.
6. Use Foliar Pyrethroid Insecticide for Adult Psyllids
Adult psyllids are not as easy to control as eggs and nymphs. So if the invasion of your citrus trees is extensive, you may need a more robust solution than organic soap and neem oil.
Foliar pyrethroid insecticide is effective on adult psyllids. But since it has chemicals, you need to be cautious regarding the timing and frequency of use because you don’t want to destroy other insects, such as pollinators.
7. Spray Soil-Applied Insecticide To Kill Nymphs
The soil-applied insecticide is effective on young citrus trees under attack by nymph psyllids. If you use insecticides for the leaves and fruits, you should also opt for a soil-applied insecticide. It will systematically target the psyllids in and around the soil.
The long-term use of soil-applied insecticide will eventually protect the entire citrus tree. It will take months for insects to attack citrus trees again. This is unlike the foliar-applied insecticides, whose protection lasts 2-3 weeks.
8. Wrap the Tree With Sticky Tape or Netting To Control Ants
One of the telltale signs of psyllids on citrus trees is the presence of ants on leaves. If you look closely, you’ll discover nymph psyllids are at the base of the leaves. Ants feed on the honeydew that psyllid nymphs produce. To protect their food source, ants guard the psyllids against predators, like wasps.
To keep ants away from the psyllids, wrap the tree with sticky tape or netting. Remove the sticky tape every 1 – 2 weeks. You can also place liquid baits or ant stakes at the base of the tree to keep the ants away from the tree.
9. Prune the Trees To Improve Air Circulation
Pruning will improve air circulation throughout the citrus tree and help reduce the presence of ants in the citrus tree. But before pruning, you must first treat any psyllids on the citrus tree using one of the methods we’ve reviewed above. Otherwise, the phyllids will spread when new shoots start to grow.
10. Tree Removal
If the damage to the tree is extensive, it’s best to cut down the tree and dispose of it safely. Citrus trees badly damaged by psyllids should be destroyed to prevent the further spread of these destructive insects. Local authorities in states like Florida and California are often involved in the disposal process to contain the spread of these pests to other citrus trees in the area.
Psyllids will not only destroy your citrus trees, but they will affect other plants. They spread extensively and if you’re not keen, you may not notice them until the trees show signs of decline.
You need to monitor your citrus trees regularly to spot psyllids early. The treatment of eggs and nymphs is easier and sometimes more effective, but you may be better off trying a multifaceted approach to deal with psyllids of all growth stages.