Looks like mealy bugs to me, other members will advise you how to get rid of them, watch for them on any other plants you have

Your critters look like wax scale but they are elongated, not round as mine are. Let someone else here give you a second opinion on if it's wax scale.

You can wipe out wax scale fairly easily with a horticultural oil treatment. You can buy it commercially or you can make your own from water, vegetable oil, and a very mild biodegradable detergent. There are a lot of different recipes out there. Some include other ingredients and some use alcohol instead of water. I like a fairly light vegetable oil like safflower oil so it will be less likely to clog the stomata (air pores in leaves). Put 1 tablespoon of oil in a gallon of water and add a few drops of biodegradable dish washing detergent. Mix well and pour into a spray bottle. Spray the entire plant, making sure to mist the tops and bottoms of the leaves and even the stem. Repeat the treatment four weeks later. The treatment is best done during cool weather in spring and fall. It looks like you have your plants indoors so they should be fine. I would be careful treating in-ground trees after temps get up in the 80s. The wax scale will still be on your plants but the animal inside should be dead...suffocated from the oil sealing up his breathing holes.

Ah, so you have another ID suggestion already. I think the horticultural oil treatment will also take care of mealy bugs.

yes what Johnmerr said and same treatment as John recommended, or neem oil

I agree with the scale diagnosis.