This was on the top of the aloe plant as it bloomed. What is it, please???

Aloe mite. Microscopic, resistant to insecticides, highly contagious to other aloes. Cut and remove affected inflorescences, clean your tools carefully afterwards.

That's a pretty bad infection. Act quickly as baja advised and consider isolating the plant away from all other aloes if possible . Watch for any other strange lumps (called galls) these are caused by the mites activity in rhe plant. If the plant has no value to you consider ditching it to prevent spread to others
Good Luck 🤞
Steve

Thanks for the ID. Have been traveling back home, and this is the first chance to check postings.

This was on the aloe plant outside at my dad's house on the east coast of Florida. I will let them know to watch for more and eliminate if possible.

So I noticed the same looking thing on my indoor purple haze aloe after it finished blooming - I assume its the same thing, it looks very similar. Will only aloes be affected by this mite? Or will it attack Haworthia's, Gasteria's, etc... I went on ahead and disposed of the aloe as much as I hated to do that and a few other smaller aloes that were close by because the leaves on them have some strange patches of growth (I thought it may have been damaged from when I got the plant).

How long will it take to start seeing anything on other plants?

Thanks Bill

Aloes are the main target but the other plants in this group are also vulnerable, especially on inflorescences.

The aloe mite may spend months on a plant without causing any symptoms, so you never really can be sure they are actually gone. I guess the main thing is to be vigilant and react quickly when you do see the characteristic signs. Generally I would not assume that amputation of the affected parts has actually cured a plant until you have observed it for at least a year (another round of flowering at least) and seen nothing wrong.

Because the mite cannot be detected by itself (only by the damage it causes when numbers get high ) a plant can go months before it shows signs . By which it could time it could well have infected others already . The only really safe option it to quarantine everything , but most of us just do not have the space to do that. There are specific insecticides called miteicides that can treat them . One set is called avid and forbid (avid kills the mites and forbid the eggs) these chemicals are harmful to potentially you as well as other insects and mammals. If you decide you need to use them , do so with extreme care and use the mimimim amount possible. I guess if you have aloes dotted throughout a wider collection then the risks are much lower . I am really in the worse scenario possible with hundreds of aloes all crammed into relatively tight spaces . Which is why I am so worried about them. There is a emerging threat from red orchid mites which (it the reports are correct ) is causing absolute havoc in some peoples collections. The only thing that really goes in my favour (from a mite point of view anyway ) Is that I don't get a lot of wind indoors which is said to be one of the ways in which they spread .
Steve