How to Get Rid of Azalea Caterpillar: Effective Methods Explained

Azalea caterpillars can be a real nuisance for gardeners and homeowners alike.

These pests are known for their voracious appetite and can quickly defoliate azalea plants, causing stress and reduced flowering.

In this article, we will explore effective methods to get rid of azalea caterpillars and protect your plants from future infestations.

How to Get Rid of Azalea Caterpillar
Azalea Caterpillars

Native to the southeastern United States, azalea caterpillars start as small green worms that eventually grow into larger, black and yellow-striped caterpillars with reddish heads and prolegs.

They are commonly found on azaleas, but also known to infest blueberry bushes. Early detection and intervention are crucial to prevent significant damage to your plants.

Identifying Azalea Caterpillars

Description and Life Cycle

The azalea caterpillar (Datana major) is a common pest found on azalea plants.

Young azalea caterpillars are small green worms that eventually grow into medium purple worms, and finally into large black and yellow-striped worms with reddish heads and prolegs.

Adult caterpillars develop into Datana major moths.

Damage to Azaleas

Azalea caterpillars can cause significant damage to azalea plants by defoliating them.

Although they generally don’t kill the plants they feed on, the stress caused by defoliation might reduce the plant’s ability to flower.

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Datana Major moth. Source:
Natasha Wright
CC BY 3.0, via Wikimedia Commons

Datana Major Moth

The Datana major moth is the adult stage of the azalea caterpillar. It lays eggs on azalea plants, which then hatch into larvae.

The larvae are initially small green caterpillars that grow into the large, colorful azalea caterpillars.

Comparison Table: Azalea Caterpillar and Datana Major Moth

FeatureAzalea CaterpillarDatana Major Moth
Size2 inchesSmaller
ColorBlack, yellow-striped with red headBrown to gray with wavy lines
Life stageLarval stage of Datana majorAdult stage of azalea caterpillar
Feeding habitsDefoliate azaleasDoes not feed on azaleas

How to Get Rid of Azalea Caterpillar?

Monitoring and Detection

Staying vigilant and inspecting your azalea bushes can help you detect azalea caterpillars early, while they are still small and easier to manage.

Maintaining Plant Health

  • Ensure proper plant care (watering, fertilizing, pruning)
  • Keep plants well-drained and free of debris
  • Avoid over-stressing plants with excessive pruning or harsh chemicals

Healthy azalea plants are better equipped to resist pests, including azalea caterpillars. Stress-free plants are less likely to attract infestations.

Natural Predators and Pollinators

  • Encourage natural predators like parasitic wasps, lacewings, ladybirds, and spiders
  • Attract pollinators like bees, butterflies, and hummingbirds to your landscape
  • Avoid using broad-spectrum pesticides that harm beneficial insects

Natural predators and pollinators help maintain a balanced ecosystem and can assist in controlling azalea caterpillars.

For example, parasitic wasps are known to prey on some caterpillar species, reducing their population and helping to protect your plants.

Comparison Table

MethodProsCons
Monitoring and DetectionEarly detection, no cost, no negative impact on the environmentTime-consuming, depends on individual vigilance
Maintaining Plant HealthNo additional cost, overall health benefits for plants, less pest attractionRequires consistent and proper plant care
Natural PredatorsEnvironmentally friendly, supports balanced ecosystemTakes time, indirect control

Controlling and Treating Azalea Caterpillars

Manual Removal Methods

  • Hand-picking: Wearing gloves, remove caterpillars from plants
  • Squish or discard: Caterpillars can be squished or discarded after removal
    • Frequent inspection: Regularly check azaleas for eggs and caterpillars

When dealing with azalea caterpillars, one option for control is through manual removal methods.

Wearing gloves, you can hand-pick the caterpillars from your azalea plants. Once removed, you can either squish the caterpillars or discard them in another location.

Be sure to inspect your azaleas frequently for eggs and caterpillars to prevent infestations.

Chemical Control Options

ChemicalProsCons
AcephateBroad-spectrum controlToxic for humans and beneficial insects
MalathionRelatively low toxicityPotential environmental effects
CyfluthrinLow acute toxicityPotential effects on non-target insects
PermethrinEffective on caterpillarsToxic to bees and aquatic life
BifenthrinLong residual controlHarm to non-target insects
SevinBroad-spectrum controlToxic to bees
Bacillus Thuringiensis (BT)Organic, safe for beneficial insectsShort residual effect, requires multiple applications

Chemical control options include products like acephate, malathion, cyfluthrin, permethrin, bifenthrin, and Sevin.

These synthetic chemicals can be effective in controlling azalea caterpillars but can have negative impacts on human health, the environment, and beneficial insects.

Bacillus Thuringiensis (BT), a natural bacteria, is an organic control option that is safe for beneficial insects but might require multiple applications.

Organic and Homemade Solutions

  • Insecticidal soaps: Control caterpillars with soapy water or insecticidal soap

  • Homemade recipes
    • Molasses solution: Mix 1 cup of molasses with 1 liter of water and spray on plants
    • Garlic solution: Blend 3 cloves of garlic with 1 liter of water and spray on plants
    • Vegetable oil: Mix 1 tablespoon of vegetable oil with 1 liter of water and spray on plants

Organic and homemade solutions can also be effective in controlling azalea caterpillars.

Insecticidal soaps, made from soapy water or specialized insecticidal soap, control caterpillars while remaining environmentally friendly.

Organic products containing Dipel and spinosad are also available. Homemade recipes include molasses, garlic, and vegetable oil solutions for spraying on plants.

Conclusion

Azalea caterpillars can cause wide scale defoliation if they occur in large numbers. They can be controlled by hand-picking, pruning, or using biological or chemical pesticides.

We have shared some effective techniques to remove these caterpillars from your gardens in the article above.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about azalea caterpillars. Scroll down to have a look at some of them.

Letter 1 – Prominent Moth Caterpillar: Azalea Caterpillar

Can you identify this photo for me?
I live in Columbia, South Carolina and found this caterpillar on an azalea bush this morning. My sister says it devours all the leaves on azaleas. When I went back to find it later, it was nowhere to be seen. What is it, please? Thanks.
Lane Bowden

Hi Lane,
This is a Prominent Moth Caterpillar in the genus Datana. The posture is quite distinctive. According to BugGuide, the species is Datana major, the Azalea Caterpillar.

Letter 2 – Datana Caterpillar Aggregation

caterpillar id and behavior explanation
Hello. I was in a swampy woods in northwest Indiana when I came across a group of caterpillars in a very strange arrangement. There were approximately 20 in the group, and they were all congregated together, but more interestingly their arrangement was exactly symmetrical.

I’ve attached a photo. Can you tell me what these caterpillars are and what they’re doing? The closest I can come using a caterpillar ID book is Gulf Fritillary, but I think I may be a bit out of their range. Thanks,
Scott

Hi Scott,
This behavior is consistant with caterpillars in the genus Datana, but there are no images on BugGuide that exactly match this coloration. Identifying the food plant might help with an identification.

Thanks for getting back to me. The caterpillars that I saw were on Vaccinium corymbosum (highbush blueberry). I’m guessing Datana ministra?
Scott.

Letter 3 – Snowbush Spanworms, NOT Azalea Caterpillars

Caterpillars
May 2, 2010
My niece found these in her garden and I would like to know what kind of caterpillars they are and if they are harmful.
Amy
Miami, Florida

Handfull of (possibly) Azalea Caterpillars

Hi Amy,
These look like they might be Azalea Caterpillars, Datana major, but it is impossible to tell from this photo which obscures many details.  It would also be helpful to know what plant they were found eating upon. 

According to BugGuide, “larvae present July to October” and “larvae feed mainly on leaves of azalea (Rhododendron spp.) but have also been recorded on apple, blueberry, Red Oak, and Bog Rosemary (Andromeda polifoloa).” 

Would it be possible to get a more detailed image and/or information on the plant they were eating?

Correction:  March 18, 2012
Snowbush Spanworms
Thanks to a comment we just received from Nikki that correctly identified these as Snowbush Spanworms, we are able to link to the BugGuide information page on the species that states:  “larvae feed on plants in the spurge family (Euphorbiaceae) such as Breynia and Phyllanthus species.”

Letter 4 – Datana Caterpillar

Can u help id
August 11, 2011 3:18 PM (13 hours ago)
Any idea what these are?
Thanks
Kim Carlen

Prominent Moth Caterpillars from the genus Datana

Ed. Note:  Though we appreciate the brevity of texting and the capacity for using cellular telephones for all communications, we created a submission form so we would not have to keep asking the same questions, like the location where the image was taken.  We have written back requesting the location on this image.

Caterpillar id
Location: NE Pa
August 12, 2011 3:08 pm
Can you please help id these caterpillars. They were on a blueberry bush in NE PA. Thanks for your help.
Signature: Kim Carlen

Thanks for resending Kim.  We don’t want to waste time searching North American species if the submission is from Australia, for example.  These are Prominent Moth caterpillars in the genus Datana. 

Based on your location, we believe the likeliest candidate is Datana drexelii, and BugGuide indicates that Blueberry is a food plant.  The list of food plants is:  “Birch, blueberry, linden, sassafras, sourwood, and witch-hazel.”

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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