Assuming system in greenhouse
Greenhouses help us grow plants out of season which every sap sucking B@@@@@d love us for
How are your nitrate levels and general nutrition , plants that are growing quickly are nice and tender for us , and also for the bugs
You say you cant get predator insects , I have never bothered with them
The only spray ive used in the last couple of years is the caterpillar bacteria
I use small lizards and spiders im always catching them and releasing them into a stack of tree branches under my growbeds , where they are safe and dry and can live if they want , they work for free all night.
Firstly know your enemy learn its life cycle what it likes and hates (eg Temperature) aphids for example have an overwinter stage and ants farm them .
Do less sooner if you see one aphid kill it as next week it will have turned into lots the next week you will have a thousand.
Greenhouses shelter the bugs from natures extremes which is why they create so much trouble in them
You will need many approaches to keep on top of this (trapping with sticky traps ect) (calendular will trap them also)
Grow plants they cant resist in pots to attract them (aphids will run through fire to get to a brussel sprout plant)
Take pot away and hose off aphids ect and replace to catch the next lot
Humans have been fighting insects with sprays for a very long time now and havnt won the battle .
The organic type sprays are only a small part of the solution.
