White bug ...
at first I thought that it was the dreaded (GH) white fly...
I had some very bad experience with that little critter.
So far I learned NOT to introduce in my GH by not bringing
in plants TOO-early, and then spraying with a "systemic" spray.
[E: beleive me, once established - a real nightmare to just control]
As far as (them) mealy bugs, they were never a problem
on my property. However, each year I do rent a small
(9 sq ft) in our town community GH. Invariably my clean plants
do get infected with mealy bugs from the adjacent spot.
After some explaining, some (naive) people even thought that
they were "some" flower buds???!!!! [Arrrh...]
Mealy bugs are easy to control. A spray with malathion goes them in.