I wouldn't put that plant anywhere near my others.
Isolation sounds like is in order until you get to the root of the problem.

Either its another plant that was just above it that dripped onto that one, or your plant has a severe pest problem, and they are hiding very well from you.

I would use a magnifying glass and look for mites, aphids, or mealie.

A good general rule of thumb before you bring it in is to prepare for its arrival into your home to make sure your plants are clean.
I would cut it way back, leaving you less coverage to worry about and less coverage for pest to eat or hide. It also makes getting to all the pests easier.

I would then wash the whole plant and pot off with a good stream of water rubbing as most of the leaves as you can between your fingers. Make sure to wash the pot and the lips on the rim of the outside of the pot.

Then use a good Fish Emuslion or some kind of horticultural soap or oil and spray the entire tree over, under the leaves and all over your pots, and the top of your mix.
Make sure there are no weeds or anything growing on the top of your mix. Make sure its clean

I would repeat this treatment every week for 3 weeks and then once a month with a good natural soapy water through the winter to prevent another infestation.

These kind of preventitive actions routine will just about kill any pest sucking on your plant now and for the future, whether you see them or not.

I hope this helps

Mike

Rose, the white spot could be Mealybug.

Like Mike suggested, inspect and isolate your new plants bought last month.

Mealybug are very slow movers. As adults, it seems they remain in one spot..they're highly contageous which is the reason they need isolation.

I'd wash the entire plant with soapy water..'dish-soap.' Then spray with Rubbing Alcohol. 2 Tablespoons per 10-15oz of water..if you see another white, fuzzy bug, it can be removed by dipping a Q-Tip or cotton ball in Rubbing Alcohol, then wiping it off..Usually, when swiping Mealy, cotton will have red/brown coloring.

I hope your plant/s don't have Mealy..They're hard to kill. Scale, mites and whitefly are nothing compared to mealy..

As a last resort, you can either return plants or use chemical sprays/systemic. Only after you ID the pest, and if impossible ridding.
I don't care to use chemicals, Rose. Good luck.

And believe when I tell you, Toni has lots of experience with keeping bugs at bay!

Toni, was it ANTS you can't stand or the SPIDERS, next to MEALY?lol

Mike:-)

Mike though I can't stand ants, especially mounds, SPIDERS are the WORSE! They've got to go! Where, to another country or the moon, but not here on earth, especially in my house and plants...YUCK

Mealy is the worse plant bug..Difficult killing both adults and nymphs. To top it off, mealy attract ants! Sheesh. What's this world coming to? lol.

Toni...What would you do if SPIDERS served a purpose, like ate MEALY bugs? Would you like them then, let them loose in your house..? Remember the ladybug thing? lol

I had to have a good laugh today! It's good to see you staying busy and helping here. Proud of you.

Mike

Does mealy bug cause sticky leaves? My plant is still relatively tiny - I rinsed off all the leaves last night and the stem, and edge of the pot ... and the stickiness is gone. the mealy smushed away yesterday morning - doesn't seem to be there... and I don't see any bugs...

I'll do the soapy water and alcohol routine for any return visitors. the plant looks healthy. I have a ponytail plant that has mealy (never knew what those white things were called) - confined solo in another room (a wall, door and about 10 feet away from my gardenia and light set-up). Now that I know what it is and how to treat - this weekend will be an event of fighting those invaders. I guess I can't ignore that ponytail plant any longer...

Oh noooooooooooooooooooo....Not on your pony tail palm!

Make sure you really soak that plant too because they can lay eggs and hide in places that you could never reach. Too many hiding spots in a pony tail palm. Keep a close eye on it....I hate to say this, but even in a seprate room, somehow Mealy seem to spread from one to another.
Don't wait to long to treat that one and make sure to wash all surrounding walls, floor, and such.

By the way, have you ever thought of systemic products, works like a charm if you don't mind the toxins. I usually treat mine outside if I get any issues on a plant I can't bare to throw away.

If you don't have a room to store an infected plant in, I use one of those bags from the cleaners, a large plastic see through bag and prop it over the plant with sticks in the pop like a pop up tent.

Mike

I guess this means it's time to give that ponytail a significant 'haircut' too.

Mike, you know how much I love plants, right? BUT, even if spiders killed Mealy and every other HP pest around, I'd have to side with mealy..

Do you believe me when I say I hate spiders? LOL

Ladybugs..lol

Mealybug squish easily enough. Touching mealy w/Q-Tip and RA usually shrivels them up.

Ponytail's rarely acquire insects, but when they do, the most common is Mealy...Mealy are usually seen on the crown, top center foliage.

Mike is so right about mealy finding homes on plants in other rooms..I think, touching a plant w/insects, then a different pest-free plant, starts an infestation.

3-yrs ago I discard 30-something African Violets. Right in the trash. They were together, but soon after my Clivias got Mealy. Four rooms apart. Believe me, I inspect plants daily, and Clivia were mealy-free..Mealy attacked Clivias after handling AV's.
I should have known, when I purchased an AV locally..I liked its flowers, but the leaves looked odd..Sometimes, insects cause deformity to foliage. That's how it started.

Hopefully, this winter, there's no mealy attack. Ants work with mealy...they're friends. lol. Mealy supplies honeydew ants eat..ants keep plant-friendly pests away. Pain in the butts, they are.

Hopefully, what you saw was nothing more than Perlite..Toni

I'm not seeing any other white spots. even on the ponytail plant - which had them before back in the summer - I looked at it over the weekend, and there's no white spots... so I don't know if that means that the apartment is now to cool in the hallway, and whatever 'bugs' will be in hibernation for the winter?

that being said, the sticky leaves are quickly returning - there's 2 of them on that gardenia, and the rest of the plants don't seem affected. I am thinking that I should pull those two leaves off? since the washing was such a short 'fix'...(less than a week).

Ok, so after the 3 sticky leaves off of the gardenia - there's been no more stickiness returning. I took a closer look at the PT - and while it didn't have any white clumps on it - the residual white was still on many of the leaves. (So, here is the before picture) and I'll post the follow ups of what I've done to her. She's also EXTREMELY roOT bound (I hadn't watered her for a few weeks and she slid right out of the pot... - she won't be able to wait until april - I will have to get her into a bigger pot this weekend.

and this is the after picture - I peeled off all the leaves that had any sign of white residue. (most of which was at the base of the leaves)

The 3 bulbs are looking quite reduced in size without half their foliage. (I threw the leaves out the window) ... didn't even want to tempt fate by having them in my garbage. the leaves must look quite interesting in the bare dirt of my very shaded back yard.

and this the current state of the bulbs themselves.

I haven't a clue how I'm going to separate these babies enough to repot them. I will probably go up 2 sizes and use a 12"? pot? ... keep the bulbs together? suggestions would be greatly appreciated...