I too thought I was battling gnats for the last 6 months or so. Could not defeat them with BT, diatomaceous earth, no-pest strips, neem. I noticed the crawly ones only recently, thinking they were a different pest. I've had mag deficiency, yellowing, crispy leaves, low yields, low vigor on at least 25% of my plants. Yet didn't think they were related to what I thought was relatively harmless nuisance...
I gave up hope on defeating them, just contain them, I thought, winning is impossible.
I killed my mothers and started over from seed, sterilized everything, yet they returned. They haven't completely infested yet... do not want to go there again. Knocking dead bodies and shit specks off of buds with a bamboo skewer is not my idea of fun.
Thanks to spleebale
for this thread and super thanks to FoCo
! Yesterday morning I applied Spectracide
@ 7.5ml/gal(per FoCo's suggestion) to ph'd water and applied as a soil drench to my dried-out coco hempy buckets. Instant death motherfuckers!!!
Flyers, crawlers, they touch this stuff and it's over fast. At 7.5ml/gal it works and there is almost no smell, Spectracide undiluted has a very strong paint thinner type smell.
Within a few hours all of the plants looked noticeably happier, more perky and not just because I had let the coco dry. Today they are even happier, taller, perkier. The two most sickly plants are the most improved.
This shit works and it's $10 at Lowe's. I'm really happy I didn't try some of the $50-$150 pesticides that others are recommending that may or may not work.
By the way, if you have lots of fliers, I've had great success trapping them with masking/cello/transparent packing tape wrapped around the base of the hood. This works well around the top edge of pots too and keeps those fuckers from sticking to the buds.