We brought my split-leaf philodendron outside for the summer and it's about time to bring it back inside, so I just gave it a careful once-over to avoid bringing in guests I don't want. We had a fungus gnat problem w the plants I brought in last winter that has left me slightly scarred and this plant was the only one I brought outside this year because of that. Anyway, sure enough there are bugs underneath the leaves. But they're unlike any of the bugs that come up when I do a google search for common houseplant pests.

They are tiny-- about an 1/8th of an inch long-- and grayish in color. They don't appear to be mobile and a little flick gets them right off. Most leaves have one or two underneath, save the one pictured that had a whole bunch. I cut that entire leaf off and discarded it; the rest I just wiped clean and gave a little spray of Safer to.

Anyone know what they are? And any advice on further steps before I bring this guy inside? Whenever I do bring it in, I'll be keeping it separate from my others for a couple months to be safe...

Thanks in advance!