Found these tiny white barrel-shaped things neatly lined up on the underside of a leaf. They look like a microscopic drum set. Should I be worried?

leaf, rinse the plant if appropriate, and quarantine it from other plants for about 7 to 10 days while you monitor for any missed eggs or tiny nymphs. I once brought in late-season basil before a cool night and ended up with an accidental insect inspection session at my sink. Since then, every plant gets a full underside-of-the-leaf check before it crosses my back door.

15. The bottom line: worried, but not alarmed

If you found tiny white barrel-shaped eggs neatly lined up under a leaf, you may very well be