Get em early, cheap.
Faicuk Yellow Dual-Sided Sticky Fly Traps for Plant Insect Like Aphids, Fungus Gnats, Leaf Miners and White Flies (30 Pack)
https://www.amazon.com/dp/B01IMTVAI6/ref=cm_sw_r_awdo_19NNKHN62G2ZZ7JC9PC6
Love these, waterproof, work fantastic, inexpensive. Several different types, these are 'non-toxic' although I don't think the other ones are toxic. I usually put them out twice, once early, then again when in flower. I think these and Zerotol are my main plan for the season.
Ps I do have some BT, from two years ago, the "GOOD" stuff, haven't opened it but once to fill a wand sprayer. I'm surprised how many people think BT is a be all, end all, it is only good for caterpillars and worm type bugs, nothing else. So I don't really use it. Instead, along with the stickies, I constantly monitor the girls for any wiggles. Or eggs. Or a anything.
Last note, around here, we can only order lady bugs early, into late spring I think.
Thinking of raising a few for incremental releases.
Peace all.