Noticed something strange on one of my larger aloes. Suspecting it might be the start of aloe mite galls. What do you guys think? And is there anything I can do to help this plant?

Sorry for the odd coloring in the photo. I used my flash to pick up details of the patch. I've also isolated the plant. It was close to another larger aloe, and after thoroughly inspecting that plant, I didn't find anything suspicious. The plant of concern has a pup beside it. If I can't save the mother plant, can I potentially save the pup?

Yes, aloe mite. I would toss the plant and the pup.

Aw... well that's disappointing.
Anything in particular that may have caused the problem? Or do they just tend to appear at random?

Well, they come from somewhere. Probably arrived with the plant. It can take a while for a plant with mites to show symptoms. To the extent you have mites on any of your plants (or might have them because for example you kept an offset from an affected plant) that is the biggest potential source of the problem. Zero tolerance is key. Clean the container well (ideally with bleach) after you empty it, and toss the plant in the trash, not the compost.

I don't think stress brings on the mites, to the extent I haven't done any actual experiments. The aloes in the ground here endure pretty serious stress every summer and that doesn't seem to provoke anything particular mite-wise. Some plants are much more susceptible than others to the aloe mite. Some of the more frequent hosts here are arborescens (esp. on the inflorescence), nobilis, spinosissima. Some plants are known mite magnets in cultivation, like longistyla. Some plants are known sources of mites in cultivation, like old tree aloes with affected branches high above the surrounding vegetation. Like this fabulous plant over a Pasadena nursery (can't see the mites in the photo, but they were definitely there):



I wouldn't even think of buying an aloe there. Whenever I see aloe mites in a nursery, I tell the people in charge and make a point of not buying any plants.

More on mites here (under Care):

The Aloes Database

I think Baja gives you the best advice, but if you are willing to invest in some expensive but effective miticides there is probably a way to keep the pup. I have not had many cases of Aloe mite and mostly just thrown affected plants away, but on a different plant website I am a member of there are a number of serious aloe growers who have had success using miticides that we came to learn about because of Agave mite, on Aloe mites.

The most affordable of those is AVID (you can definitely get it on amazon in the US, not sure about Canada). Other miticides are Forbid and Pylon (with the latter you need to make sure you get something that you can spray and is not a one use fogger can that requires an enclosed space and is one use only).

Regular products that are active against spider mites will not do the job, Aloe and Agave mites, different species of the same bug family, are microscopic (I am sure Baja has info in his write up) and live inside the plant.

The protocol would be to isolate the plant and spray it several times in a 2-3 month period and observing new growth.

Another note: Aloe mite will not move into Agaves, and vice versa they are pretty plant family specific.

As to stress bringing them on, I would tend to agree with Baja plant stress does not make the plant get them, but I do think stress can lower the natural defenses that a plant has to the point that an existing Aloe mite population can manifest itself outwardly. This has been observed especially in Agaves, where stressed plants are much more likely to get a bad infestation whereas healthy happy plants appear to have a better chance of overcoming and growing through the infestation. The plant probably came with them, unless you live somewhere where neighbors are also avid Aloe growers as they can be windblown. One thing to remember is that bringing a plant home from a nursery (or getting it shipped to you) is a stressful event as growing conditions tend to change and in the nursery care of the plants may be very different than the care you provide, which can also be a stressor.

In Arizona you can now find Agave mite in wild populations that are extremely remote, so it may be something that has been a feature of Agaves for a long time, but now that we have been in a protracted drought populations are under enough stress that the mites manifest...

If you are worried about introducing these into your collection you will always want inspect new plants carefully, but that is probably not enough as they can be in the plant and not be observable, so people who worry a lot, keep new arrivals isolated for a month or two as they observe new growth and the really serious collectors spray preventatively with one or more of the aforementioned miticides.

Aloe mites are very, very scary.
I agree with Baja that the only certain control is to put the plant in the TRASH.
If you want to save the pup or any others that you might get in the future then investing in a small bottle of Avid is worthwhile.
Avid is specifically for mites and can work on any other mite infestation.
No mater what species.

@Macrocentra
just a case of bad luck there, i have yet to come across the dreaded mites, but i guess its going to happen at some point
Steve

Sounds like they're very discrete at first. I've had the plant since the beginning of the year, and quarantined it for a while before putting it with other plants. No signs of any issues up till this appeared.
Thankfully it hasn't been near any of my aloes except one. Unfortunately, that one it's been near is my favorite in my collection. I hope it ends up okay. It looks okay right now, but it's been living beside it for months now...

Once you've seen them a couple of times, you get better at detecting them sooner.

Aloe mites are very, very scary.
I agree with Baja that the only certain control is to put the plant in the TRASH.
If you want to save the pup or any others that you might get in the future then investing in a small bottle of Avid is worthwhile.
Avid is specifically for mites and can work on any other mite infestation.
No mater what species.