If you would have answered the above question would have helped so now we will have to assume what stage and size the plants are. You can dunk them in a neem soapy water bath. Turn the plants upside down and dunk in a buckets.You can also buy preditor mites if your just starting to veg or if your in flower insects wont be fast enough. You can use 3 cans of Doktor Doom pyrithum bug bombs.You set one off then wait 2 days as the originals started to die they laid eggs which hatch in 2 days.Then the second can goes off on that 2nd day killing all the new immature mites. Then wait 2 more days and hit it with the 3rd to mop up any leftovers. Can be used up to a day before harvest. You can also try neem soap foliage sprays, things like einstein oil or liquid pyrthium sprays that stick to the leaves