TastyLandscape Growing fruit trees at home in Southern California
Treatment reminder:
Leaf miner season has begun; time to treat your citrus leaves.
White leafminer trails and yellow leafminer larva.
What is it again?
“Citrus leafminer” is a leaf deforming disease that will impact just about every untreated citrus tree in the US (and elsewhere). It causes a lot of damage and can be devastating to young trees. The disease is caused by the larva of a tiny month that eats its way through the under-surface of a leaf. The bug came to the US relatively recently and is now widespread.
New untreated flush attacked by leaf miners. Compared to older protected-treated leaves in background which are not damaged. This damage taught me the lesson to spray with spinosid until November.
Earlier each year:
The disease hits in the warmer months and the leafminer season seems to be happening earlier each year. I am not sure if I am just noticing it occurring earlier or if global warming is causing it to happen earlier each year. Regardless, the disease has begun last month (May) and this short post is just a reminder that it is time to start treating your trees again.
Leaf uncurled to show white leafminer trails and yellow leaf miner larvae
More info:
I have written a complete article about leafminer a few years ago. It covers everything from diagnosis, cause and treatment options. That article is up-to-date. For more info, you can get to that Citrus Leafminer: Diagnosis and Treatment article via the hypertext link. I always use the organic spray mix that is detailed in the article. It works great for me, but there are other treatment options.
Happy gardening!
Hi Doc.
Many of your photos do not open on Goole’s web review
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Hey Steve.
Thanks for the heads up.
I was not able to see your .png.
However, ill look into it.
Any additional info appreciated.
Thanks,
Tom
Hello Dr:
I found your article when looking for organic control for citrus leafminer and I love it! The complete and authentic info and the lifelike pictures are awesome. I live in the Sacramento metropolitan area (USDA Zone 9B). My problem is still in an early stage. can I follow the regimen you’ve recommended for SoCal and start treating now until mid-Nov? Thanks and sincere appreciation for sharing such precious information and your valuable experience.
Nani
Hi Nani
Thanks for the great feedback.
Awesome to hear that I could be of help.
You are very welcome.
The treatment should be effective for any geographic region.
With the exception that in the warmer areas such as the tropics, people have to treat all year long.
The leaf miner treatment will kill the larva and prevent further harm but it wont reverse damage that has already occurred.
Thanks again and best of luck.
Tom
I read your article about leaf miners from 2013. Thank you for all of the excellent information and the product recommendations. I recently bought a new container of Neem Oil after reading extensively about leaf miners online. What is your opinion of Neem oil? I used one application on the leaves a few weeks ago but Im still concerned over the possible burning effect it may have on the leaves on hot days here in Southern California. If you think its a good product, is it possible to substitute Neem for the All Season Mineral Oil in combination with the Spinosad since I have so much of it now? Also, have you heard of the leaf miner season starting as early as April in SoCal. Im seeing a lot of white flying bugs around right now.
Thanks for the info.
Hi Shay
Great question.
Neem oil is great for superficial bugs, but it wont penetrate under the leaf surface to get to the leaf miner larva. I have not personally seen leaf burn as a result of using neem oil. However, I use the concentrations on the label, spray in the spring, and the evening. I suppose in theory, you could substitute neem oil for mineral oil… however, I dont have personal experience trying this and I would check with an authority (such as manufacture) before mixing them.
Best,
Tom
Hi Dr. Osborne
I’m hoping you are still responding to comment on this blog. I’m growing a few citrus tree at my house. 1 lime, 1 lemon, 1 tangerine, and 1 blood orange. As of now, only the lime tree is looking healthy. All the other trees look sickly, yellowish leaves. All are showing sign of nutrient deficient micro & macro. Do you think is it still the right time feed them right now by giving them some liquid soluble fertilizer with all the NPK and micro-nutrients?
-James
Hi James
Thanks for your question.
Yellow leaves can happen as a result of a many different things… However, the most common reasons are 1. poor fertilization/poor soil, 2. over watering resulting in root damage, and 3. bug infestation that drains the nutrients from a plant. (but in my experience that is less common).
Regarding the fertilization; as you noted there are many types of nutrients. Different nutrient deficiencies result in specific yellowing patterns on leaves. However, if you have more than one deficiency, it can result in a mixed pattern which can be difficult to figure out.
Best,
Tom
From my observation, it is a nutrient deficient for sure because the leaves are yellow but the veins are green. Should I give some fertilizer right now even though it is in late december? I’m located in San Diego near mission valley. It never get below freezing in my area.
Hi James
Agree, nutrient deficiency is likely the issue… but be sure to investigate other potential causes.
Below are a few other sites that have some leaf – nutrient diagnostic guides (note, I am just adding for reference, I am not affiliated with them)
From U of Florida: https://edis.ifas.ufl.edu/ch142
From U of California http://acmg.ucanr.edu/files/204721.pdf
From another website: https://deepgreenpermaculture.com/2018/07/08/citrus-nutrient-deficiency-yellow-leaf-with-green-veins/
Best,
Tom
With best regards I found it useful but you have written it as a disease while it is a pest.
Thanks Latif
Appreciate your insight. Great point.
Best,
Tom