I can't see the images clearly, but I believe you're witnessing guttation, a physiological process which occurs when the plant's internal water pressure forces sap through tiny openings (often stomata) in leaf and sometimes stem surfaces. It appears that the occurrence is limited here to locations on or at the termination point of secondary leaf veins - but then I can't see if that is consistent. Guttation is common in some plants, a normal part of their physiology, and not as common in other plants. Conditions that limit respiration (closed stomata during the dark cycle, over-watering, humid conditions, cool conditions, low light, defoliation) are all potential causes or contributors. When the water in the sap evaporates, whatever was dissolved in the sap is left behind in a thickened or even crystalline form.

Al

Thank you! It has been unseasonably cold, so that makes total sense. I kept thing some sort of insect, but I can remove these “little bubbles” and very close inspection shows these aren’t eggs sacs or anything of the sort. Your explanation seems correct. 😀

I hoped it would ease your mind in the sense there would be no need to be concerned about insects/diseases. Best luck!

Al

As mentioned, pictures aren’t very clear but sometimes pictures just can’t capture the situation. I sorta see what the previous poster describes, but then a see actual white flecks not sap like....is it under the leaves too? And you said they’re “white” & not milky or clear? Looks like possibly mealy bugs a little to me., esp w the white on the leaf stem too. They don’t look like insects at all but white fuzzy spots, initially very tiny but if not caught quickly, it will develop into small white fuzzy looking mounds sort of & feel a little like thick sticky spider webs. And spreads terribly! If they start getting into the leaf axils & stipules on a pothos or heart leaf Philo, etc, it’s a real horror to get rid of! Really hope the other is right but until you know for sure, isolate it immediately & start checking all nearby plants. If you find it anywhere else, there’s your answer. If you don’t, could still be mealies but at least hasn’t spread & keep separate until treated several times & you’re certain they’re gone. Check others regularly too in the meantime~it’s crazy how they can pop up across the room but not in the neighboring plant. Google it & see what you think. Truly hoping I’m wrong, but took a moment to share my thoughts since it’s such a nightmare~if rather waste a few minutes & be wrong instead of staying quiet & it’s covered in a couple of weeks. Oh, they suck sap thru the plants skin, so they start causing serious damage too, it’s not just a surface nuisance. Good luck~