Have had a horrendous year with whitefly on my tomato plants, nearly as bad last year as well.
Once I had run out of proper insecticides, which are now banned they multiplied out of control!
I have a pall who has a 10 foot and a 20 foot long greenhouses and never has any problem with fly!
Not me, over the years I have tried yellow pads(loads) Pravada (totally useless) soap spray, and nicotine spray, seedweed spray, derris spray and this year home made garlic spray,all totally useless, (no I did not over use any of them!)
Have grown tagetes, marigolds,and basil plants again totally useless, the basil plants were covered with them!
All that is left is to stand with one foot in a basin of cold water with one foot and the other with my trouser leg rolled up to my knee!
>:(