So I have photos of when I first noticed the root aphid issue, not the best but thought to post them for anyone who stumbled upon this thread later on. May help them identify the issue, although pretty easy to tell if something is on your roots.
You get some which are light in colour and some which are dark in colour, based on my research the ones darker in colour are a big issue and far more difficult to kill and seem to be resistant to more pesticides. They may also change colour as they grow, not 100% sure on this.
I saw reports where Orthene was not working as well against these darker root aphids experienced in some tobacco fields.
To date I have spent over R2000 on pesticides trying to get rid of these root aphids.
The following is what I have tried:
Bio-Insek Powder (beauvaria Bassiana & Metarhizium) - also contains diatomaceous earth along with the spores. Applied as a soil drench only.
Eco-Insect Control (Spinosad) - applied as both a soil drench and foliar. Even tried doses upto 1.6ml per L
Bio-Neem (Azadirachtin) - Applied as a soil drench at the recommended dose of 5ml per L and applied as a foliar as well (same dose)
I then thought I might be winning the battle and continued to drench with the above mentioned products as a pre-caution. I even filled the bottom of my rooting tray with the mixture I used as a soil drench to help my new set of cuttings make it without these darn root aphids... End of last week however I took a peak into my clone dome only to notice roots, but one cutting which had rooted had root aphids, the other cuttings looked fine. I tossed the cutting which contained the root aphids in the bin along with all cuttings of that strain, sprayed some doom into the bin and took the bag outside... Very disappointed and frustrated, felt as if all the money I had spent, all the time and effort on applying these drenches was all for nothing.
I even went as far as to soak the glue plugs in the soil drench solution with the above 3 mentioned products before putting the cuttings into the clone dome and I cleaned out the clone dome (top and bottom) with a heavy JIK (bleach) solution to ensure it was as clean as could be. Of course the dome went into the veg tent, which at the time I thought and hoped was root aphid free - they just took a short vacation, chilling in the coco it would seem.
My plants in my veg tent did not look happy, the most purple stems I have ever seen and such light, pale, yellow leaves. It's shocking and very disappointing. Growth is extremely slow as well.
After further research and more reading, it become clear to me that based on my experiences and the experiences of many other growers out there - using these organic pesticides is more of a money pit and quite frankly a waste of time. The fact that even some systemic pesticides such as Orthene are not effective against these root aphids was also a clear indication that I have a big issue on my hands.
I read a comment someone had made somewhere stating that they took multiple pesticides (I think 10 in total, of which 2 were systemic) and mixed them at higher doses and put them into a small cup each. This person then proceeded to break off pieces of roots which were covered in root aphids from his cuttings and leave it in the cup with the pesticides and he wait a week only to find that majority were not very effective and the root aphids were swimming around having a pool party in the pesticides. The Imidacloprid was the one pesticide which stood out and was different and had killed all of the root aphids. How true this is, I cannot say - it is just some comment I found on the internet although it is a comment I can relate to.
As mentioned previously in this thread, I kept the rooted cuttings in my clone dome initially and then used that as a way to test the pesticides. I dunked the cuttings into solutions of the pesticides and then monitored to see whether they were actually working on not.
From what I saw, it took a few days but there was a reduction in root aphids most appeared to be dead but it did not happen over night despite the direct contact (full submersion) into the pesticide solution which contained the above 3 mentioned pesticides. I suspect the Bio-Insek did work as well as I saw some fungus on some areas of the glue plugs after a week or so, at this point I thought I was winning the war against the root aphids. I potted up the cuttings after getting rid of the root aphid carcasses, I dunked each cutting into the pesticide solution again (it was a fresh solution each time, I never let the solution sit for a period of time) - glue plug and plant and then put them into some fresh coco in fresh fabric pots which were either brand new and just unpacked from the box or which had been through a washing machine cycle.
So fast forward back to me noticing root aphids on the new, 2nd batch of cuttings after I had thought I was winning the war... I then inspected some of the plants which were in smaller plastic pots which needed to be potted up. Upon very very close inspection of the roots coming out from the bottom of the pots with a torch, I noticed those mother fucking root aphids again. So it was clear to me that my attempt at getting rid of these root aphids had failed and the money I had spent was a waste and at best took out a small percentage of the root aphid population.
I potted up the plants, the weird thing being that once the plant was removed from the pot, I could not see the root aphids anymore. Closely inspecting the roots of these plants, I could not find the root aphids (the coco was a bit wet, so it fell apart when removing form the small plastic pots and was put into the larger 20L fabric pots). So even when inspecting roots when transplanting, they are not easy to see. They can easily be missed, especially if one is not looking for them - this just makes it that much more difficult to notice you have these pests.
Over the weekend and after more research and debate with myself, I decided fuck it and pulled the trigger and purchase some ProTek Complete 350 SC (Imidacloprid). A mere R170 for a 50ml bottle.
Read the pamphlet, mixed it at 1ml per L and as I was about to dose the plants (I was actually wearing gloves while doing this, but upon further research it seems that is actually not needed. Not absorbed very well via topical application and the doses to cause any harm seem to be extreme doses. Like the entire bottle in concentrate form per KG of body mass. It is used as a spot on for animals, we all know animals lick and groom themselves - heck some of us may have even used it on our own animals without knowing) I saw a root aphid chilling on top of the one fabric pot, I picked it up and put it into a droplet on my gloves of the solution and as soon as it touched the solution it stopped moving. I think it died immediately, maybe not. I stared at it for quite a while waiting to see if it would move again and it did not. I then put the fucker into the solution just incase. I wanted it to die a slow, painful death and wanted to make sure it was dead.
I continued to dose the plants in my tent with the solution of Imidacloprid. Now I know, some of you reading this will be shocked, horrified and disgusted that I have dared to use a systemic pesticide on my cannabis plants - fuck, not just any systemic pesticide but a neonicotinoid, Imidacloprid! Oh my goodness, the possibilities and potential health risks. Well shit, the decision did not come easily... but more on that later*.
I got to one plant in my tent, which just so happened to have a piece of grass growing inside of the pot as well (random I know, not sure where it came from but whatever), I ran out of solution. I had started applying a bit over the portion with the grass. I needed to meet up with a friend so quickly stepped out, upon my return I noticed 3 root aphids chilling on the piece of grass, dead! I blew and they just fall down, lifeless. Man oh man, did this make me excited! I mixed more solution and then noticed the plant was a male (regular seeds), so it got the cut. I did drench the coco and leave it in the tent to ensure any and all root aphids inside that pot die as well. The plant which got the cut went into a bag and into the bin outside straight away.
So it has now been a few days since I dosed the plants, there has been no sign whatsoever of root aphids and the plants are starting to perk up and are already starting to get some colour back in their leaves! This shit is legit, it really seems to work! It is still early days, I know but from the reports I have read, people have gotten rid of their root aphids with a single application of this Imidacloprid. It is systemic and travels up the plant and continues to travel up the plant as they grow. So any root aphids which may survive or eggs which did not die on contact for whatever reason, should die shortly after sinking their mouthes / teeth / whatever into the flesh of my plants. I will continue to monitor these plants, but at this point in time I feel as if I may have actually, eventually, managed to get rid of these root aphids and am pretty confident I have.
*Back to the possible risks of Imidacloprid with cannabis. I will be honest, my thinking was that if it is used on tobacco which is also smoked and if it is not very toxic when ingested, it does make me feel a bit more at ease using this particular systemic pesticide on cannabis. I understand that cannabis and tobacco are different, so it could be a danger in cannabis and not so much in tobacco. We all know that smoking is not good for us, period. Chances are we may have already consumed cannabis which has been dosed with Imidacloprid prior to us growing our own. Difference is, at least I know what is in mine and I can take precautious and it is my choice as to whether I decide to consume the cannabis or not (still undecided) and I can even send the bud to a lab to be tested.
My grow is indoors only, so bees are safe. I will need to make sure I dispose of the coco responsibly as well to avoid contamination in nature as I understand this pesticide is a big issue for bees and fish as it can get into water supplies easily. I would not dose outdoor plants with this. Not that I typically allow my pets into my grow area, however if they did get in and chomped on my plants I feel safe that it would not cause much if any harm to them. I do not plan on continuing to use this pesticide either, it is a temporary effort to get rid of the pests.
Only the plants in my veg tent were dosed, the ones in flower still have root aphids and will not be dosed with Imidacloprid.
So that is a bit of an update and where I stand at the moment. I feel that if I were to let these plants veg, take cuttings and then flower those cuttings it would be safe to consume the bud from those plants as it would be over 3 months before those cuttings went into flower and I do not believe the systemic pesticide would be in very high quantities, if at all, in the plant still and do not think it would transfer to the bud. I do want to look at sending bud in to be tested to see what the results are for interest sake - bud from the plants which were dosed. I feel I could have probably gotten away with a lower dose of 0.5ml per L based on the pamphlet and the results I have seen so far. Even if the dose is not high enough to kill the root aphids, at lower doses it can disorientate them and cause them to wander and stop eating.
I will provide further feedback after a bit of time. I documenting this for anyone who may run into this pest in the future and hope that it can help them out.