Agave Disease Wildfire - mites or necrotising?

[agavetreat]

Hello everyone -- I had the opportunity to review and get myself familiar with the list of diseases and pests agaves can face. I have a few agaves I have planted outdoors, and I have noticed some rather odd characteristics. The agaves were planted outside in a row. I want to get your thoughts on what is affecting them. I believe its grease mites. If so, what treatments would you recommend. Please consider I am in CA and can not purchase some of the options.

This is what originally my agave nickelsiae and agave victoria looked like when received.

agave nickelsiae when first received.

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nickelsiae and victoria first received

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For the agave nickelsiae I noticed the core of it has "blackened" with ugly orange like streaks that resemble those of agave mite damage. Searching online, I have not yet seen mites attack nickelsiae, however I am wondering if this is what the "grease" marks look like on nickelsiae when affected with agave mites. Thoughts?

agave nickelsiae core with orange lesions and black core

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agave nickelsiae close up of the blackened core

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agave nickelsiae closeup of orange lesion part 1

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agave nickelsiae closeup of orange lesion part 2

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My agave victoria is exhibiting similar yet slightly different traits. It instead had its foliage change to a light green color. The base appears to be developing red purple spots. It has ugly orange lesions, especially on the bottom near the core.

agave victoria with large lesion at the bottom

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agave victoria top view

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agave victoria discoloring and circle blight

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agave victoria close up view of base

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[agavetreat]

Next to them I did notice the altman parryi (artichoke agave) that I bought show a lot of grease stains. Its likely this is what may have spread it to the surrounding plants.

artichoke with mild orange lesion and grease stain

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artichoke close up grease stain with orange lesion

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artichoke grease stain

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The artichoke seems to me to have clear symptoms of mites, which is leading me to believe the king and queen agave are suffering some form of it. Thoughts, opinions and solutions?

[Gee.S]

A. parry is definitely harboring mites, not so sure about the others, tho agave mite does manifest in unusual ways at times. I would treat them all without a doubt, along with anything else in the vicinity.

[agavetreat]

A. parry is definitely harboring mites, not so sure about the others, tho agave mite does manifest in unusual ways at times. I would treat them all without a doubt, along with anything else in the vicinity.

Thank you Gee. Any suggestions on a miticide I can apply? I assume spray every 4 weeks? The links on the forum that i tried were expired or not allowed in CA.

[Gee.S]

Abamectin is the least expensive translaminar miticide. You would need to spray once per week. Other miticides are monthly, but far more costly.

[agavetreat]

Abamectin is the least expensive translaminar miticide. You would need to spray once per week. Other miticides are monthly, but far more costly.

Looks like its banned from being shipped in california. Will visit local homedepot to find something. There was organic miticide advertised that uses peppermint oil, and rosemary oil. Not sure if you have had success with those?

Also, how do you know the application of the miticide is working? Do the grease stains disappear or they harden? Thanks

[Gee.S]

You won't find anything at HD. It isn't enough to be rated for mites, it must be rated for eriophyid mites. Look for "Forbid miticide" online. If miticides aren't available in CA, you may need to destroy the plants.

Nothing will reverse damage done. Just look for new healthy, symptom free growth. It may take a while.

[Azuleja]

You need a drench or spray with the active ingredient bifenthrin, spiromesifen, spirotetramat, carbaryl or abamectin. Forbid 4F and Avid are two trade names that are a little more common. No, these are not sold for home use in CA. They require a pest control applicators license because of the toxicity to people and wildlife, especially amphibians, birds (hummingbirds) and insect pollinators. If you search enough online stores, including Amazon and eBay you will eventually find someone who will ship to you. Read or look up the actual label thoroughly before using. Because of the mite life cycle, multiple treatments are needed.

No, organic treatments with herb oils absolutely are not going to be effective with this pest. The nickelsiae doesn't really looks like mites to me, but they have now been exposed by your parryi and all your agaves should be treated. The way you know the treatment has been effective is when new growth is consistently clean. The previous stains and lesions remain until they grow out completely. It's a slow process.

Altman's is kind of notorious for selling infected plants as are big box stores and many nurseries that sell agaves and aloes. It's frustrating since the problem gets passed to home owners who don't recognize the symptoms when buying and don't have easy access to effective treatments. But all of us who love agaves eventually learn how to deal with this pest.

@Gee.S as a side note some aloe growers are using acephate/orthene as a systemic drench for aloe specific eriophyid mites (along with excising any galls) and swearing that it clears them in one treatment. It's a water soluble powder that isn't rated for eriophyids specifically but is listed for treatment of galls and all kinds of nasties, sometimes referenced in the same breath as bifenthrin, carbaryl and other heavy hitters. It is affordable and sold in smaller quantities so I ordered some for scale, which it's supposed to be very effective at eradicating. I don't have any eriophyid infected agaves but have been wondering about it since it's more accessible.

[Fairview]

@Azuleja I wonder if Fipronil would work? Active ingredient in Frontline for fleas and ticks. It is not labeled for mites but I used it on my show chickens. One app and it kept them mite free for over a year.

It is also the active ingredient in many pesticides to control fire ants and mole crickets in the lawn and landscape.

[Azuleja]

@Azuleja I wonder if Fipronil would work? Active ingredient in Frontline for fleas and ticks. It is not labeled for mites but I used it on my show chickens. One app and it kept them mite free for over a year.

It is also the active ingredient in many pesticides to control fire ants and mole crickets in the lawn and landscape.

Fire ants, mole crickets, fleas, ticks and poultry mites are not at all analogous to eriophyid mites so I'm going to say no.