hanzo385answered grow question 5 years ago Water. They drown in water. If youre in coco or soil, its even easier to hose them off. You can tip the plants to the side, put your thumb over the hose tip, or use a nozzle and spray them off good. especially the undersides of the leaves. Do that about 3 or 4 times every 3 days. It wont kill eggs, so if eggs hatch, the repeated sprays with kill the newly hatched bastards before they lay new eggs. After a few times, you should be good. While theyre out of the grow area, it would prob be a good idea to clean that area too.