You have scale, Remove all the dead, drying leaves, & throw them away immediately, no use treating them. I would recommend a spray bottle with 1/3 rubbing alcohol, 2/3 water with a couple drops of glycerine or dish soap to make it stick, spray it all over the plant and keep it out of the sun while it dries. I'm not sure if agave leaves will burn if you use rubbing alcohol, so I would test it on the underside of a leaf first.

Do not touch another plant without washing your hands afterward.

Wow, this is a bummer. Mentha's solution will work, but If you want a longer lasting treatment, try Bayer tree and shrub insect control concetrate. It is imidacloprid 1.47%. Ignore the instructions for trees, and dilute at 1 oz/gallon. This will produce a solution of imidicloprid 115 ppm. Drench the soil. The plant will absorb it, and it will be protected from any sucking insect for about 3 months.

I agree, your Agave has scale. The one and only time I bought a plant that was infested w/scale, I used Fish Emulsion. 1 cap per 16ox mister of water.

Whatever you use, make sure you spray the entire plant. Upper and bottom leaves, stems.
Hand-pick some to start, and destroy..Don't leave them lying around where they cand find other plants.
Speaking of other plants, inspect Agaves neighboring plants. Good luck, Toni

It is scale !!! I have never had that on anything !!!Thank you Mentha and thanks to Paracelsus and Toniso for all your help. I really like the idea of the bayer stuff and have never heard of it.

What I did do yeaserday was break off the dead stuff and bag that up...next I wiped each stalk off with baby wipes and put the plant out on the front porch for sone air....but no sun......it lookes better already.

I also had a tiny bit on a blue agave that was in the same general area. Now I need to check my basement stock to see if I have any problems down there.
Again.....thank you so much !!!!!

Jean

Jean, yes, inspect ALL your plants..
It's the crawlers, (babies) that are hard to find.. That's the reason it's important to spray all parts of your Agave/s. Leaves/stems, etc.

I think Baby Wipes contain Rubbing Alcohol, right? It's been a long time, lol. If it does, alcohol will help somewhat, but Jean, to rid those suckers, literal suckers, you better get to work.
Clean and inspect daily until you get hold of Bayer or whatever you choose to use.
They multiply fast. Are these guys hard-shelled? Yuck, plant bugs are gross looking, especially when magnified.

I read an article that explained how eggs are in waiting, during winter months, then when climate is 'just right' they come out of hiding. Hatch.

As much as I dislike Scale, IMO, they're easier to rid than Mealy..
I purchased an Olive tree from an online nursery. I ordered from this place several times, and never ever found insects, but there's always that first time, you know?
The olive tree arrived. I set it beside a group of citrus and other tropicals. (BTW, it was winter, days cloudy, and my eyes aren't what they used to be.)
I can't recall how many days later, while misting, I spotted a brown lump on a leaf..then another and another. Jean, I wanted to cry..there were hundreds of scales..truly that many and more.
Then, I looked at citrus neighboring the olive..all branches growing nearest the Olive had loaded..which is one advantage..scale move slower than say, mites.
What do you do with a hundred scale? Hand-pick each? What?

Earlier in that summer I spoke with a woman in Fl who owns a citrus nursery. She's the person who told me they use Fish Emulsion as a scale preventative and insecticide.
I phoned her, explained the situation, asked the portion of FE to water. She gave me the recepie, and it worked! Talk about grateful.
One thing that bothered and still troubles me to this day. The olive was delivered in winter. It was very cold outside. Yet, the cold didn't bother or kill the scale. This was pre-heat-pack days..the cold didn't bother the tree either, so I don't have an answer.
The olive is alive and well to this day. So are the citrus.
So, IMO, scale aren't terribly destructive IF something is done, but if left to live, bye-bye plant.Good luck, Jean, Toni

Thank you again to everone who came to my rescue and especially for a correct identification.

I am still cleaning and checking.....my light is not great in the basement and that scale is hard to see.

Also I don't have a lot of space to seperate the plants.

Jean