Kaya666answered grow question 6 years ago High there! Yeah, I'm afraid those buggers ARE after your plants & can cause big problems if allowed to multiply. First things first: how are they getting into your growspace? Try to figure that out so all your eradication efforts aren't in vain. Close any windows that are open near your grow room, keep pets out & do a top to bottom cleaning (vacuum, dust, etc) before every new grow. Take off shoes & coats and other outerwear when you come inside too. If you want to be extra careful, you can bake your soil in the oven for about 7 minutes on a piece of aluminum foil before using it. Sometimes soil is left outdoors by manufacturers or stores & bugs get in the small holes in the bags.
Once that's addressed, check out GrowWeedEasy.com for tips on how to deal with white flies specifically. If you're not entirely sure what pest you're dealing with, that website can also help you identify exactly what you're up against as they have pics of every bug, virus & fungus known to infect marijuana. Here's the White Fly page:
https://www.growweedeasy.com/cannabis-white-flies