As I mentioned in your other post....
I would suggest removing the plant from the pot & washing off all the soil. (Run it under temperate tap water.) Then soak the plant in fresh water to help gently remove any "soil", moss or "bugs"! (Be sure to dump the water, as it may contain the bugs you are trying to eradicate.)
Then, if you are getting any results killing them with the neem or some other bug killer that isn't too noxious, (I myself usually use something with pyrethrins in it, as I have found it works well & is less harmful to humans*) and douse the plant & its roots/bulb-let with it. Let it sit in a dish of it for a bit to allow it to soak into the nooks & crannies. Then after some time (use your better judgment, but I would assume anywhere from a few minutes up to an hour - but I would likely do about 5 or 10 minutes myself), I would then wash the plant under fresh water again. If you are worried about the "bug killer" harming the plant still, let it soak in clean, fresh water for a while, to dilute & wash off any remaining chemical.
Then get a NEW pot & NEW potting media & re-plant the plant into its new & CLEAN home!
Be absolutely sure to dispose of ALL the old pots & media, and thoroughly clean & wash all surfaces and tools (including your hands!) that came in contact with ANY contaminated pots/media/or plants! You do NOT want to cross contaminate your new pots & mix, and it only takes one small speck of contaminated media to infect your entire new pot.
If you are still worried that there are still bugs hidden in your plant somewhere, then do the "washing/bug-killer/rinsing" procedure a couple times, although I don't think it would in any way be necessary if you do the process right the first time.
There are too many places in your existing pot to provide refuge for the "bugs", as well as their eggs (if they produce any). With this method you will be getting rid of most of the areas that the bugs could inhabit right off the bat, and only treating the plant itself with "bug killer"/chemicals. Less chemical residues, less places for the "bugs" to hide in, and less of a chance that any will be around or survive the process.
Furthermore, washing the plant off when your done will prevent any worry about residual "killer" causing any harm to the plant itself.
This process is like moving into a brand new home, compared to hiring an exterminator to try to take care of your homes problem with ants/termites/roaches/bedbugs/bees/mice & rats! Personally, you want to keep the plant, but who cares about some old plastic pot and bug infested media!
I have done this sort of process ever since I began growing plants, and it is a very common procedure. (I was taught about these basic plant care methods from a professional nurseryman, way back when I was a kid.)
The entire process will stress your plant a lot less than you may think, unless you have never potted up a plant before. And even then, if you haven't... then it is time to learn! Re-potting is a very basic and necessary process to caring for plants, & should not stress most plants at all.
So there is absolutely no need to worry what-so-ever. Currently, the way you are going about this is to treat an entire pot of media & eradicate all the "bugs" that it contains. I am suggesting simply getting rid of the pot and all the media (along with ALL the bugs that they contain), & only worrying about eradicating the bugs (if any) on the plant itself. It is actually safer & more likely of success, as there are a lot less pests residing on the plant than there are in that entire pot full of media!
Besides, at some point down the line, you are going to have to re-pot the plant anyway... so why not now? The plant certainly looks healthy enough still to survive a simple re-potting!
Well, good luck!
Like your other post, I've offered advice/opinions based on what has worked for me. Your results may vary, depending on your situation, expertise & the environment your plants are in. I cannot say with certainty that the "bugs" are what is causing the plants to do what they are doing, but indeed it seems a good place to start.
With the way your plant is yellowing and such, there could be other causes. (Like as was mentioned about lighting & such.) So keep in mind that getting rid of the bugs may not solve the problem. If it doesn't, then it is time to look into the other conditions you have the plant under.
Again, good luck!
*Back when I was young & working in a nursery, we used to sell chlordane dust, nicotine concentrate & other "nasty" stuff that worked great but was highly poisonous! Ah, the good ol' days!
Thank you very much for such a comprehensive reply, I will replant it hopefully in few days.
If these are plant parasitic nematodes and the plants have been infested there isn't a nematicide yet developed that will kill the nematodes without killing the host plant. It is doubtful an insecticide will have much effect if it hasn't already. Some trade names of nematicides are Dowfume (gas), Telone, Vapid, Basamid, Nemafos, Temik and Mocap. Good luck trying to buy these in small quantities.
Why don't you contact the nearest state or federal Department of Agriculture office and see if you can have the nematodes identified. Of course nowadays in this age of austerity socialist free testing and identification may no longer be available but the fees can still be reasonable.
For all you know these may be beneficial nematodes.
If they are indeed plant parasitic nematodes and your plants are infested (worms in tissue) there is usually little alternative other than destroying the plants and dumping everything and starting over again. Nematicides are preventatives at best.
If the plants are continuing to decline then you have little to lose by cleaning and repotting the plants. Provided you take care to lessen the chances of reinfesting your new media and quarantine and isolate your current plants from any new acquisitions.
Then again this is going on the assumption that the nematodes (or whatever) are the cause of your problems. Yellowing leaves could be a sign that the roots dried out (almost always fatal).
Grand Hotel... always the same. People come, people go. Nothing ever happens.
I just had to re-pot my big VFT because he was potted using Schultz brand peat moss, and there were little osmocote bb's in it that they didn't feel the need to mention on the bag. Each leaf he put out was smaller and more squiggly and the traps were stunted.
Well I decided that yesterday was as good of a day as ever to re-pot it. I had some 50:50 peat:sand mix (washed and sterilised using 1% peroxide solution for 24 hours) left from other re-pottings and some new pots that came in recently.
The plants were removed from their pots and rinsed under tap water until squeaky clean. I then I gave them a bath in pyrethrin containing insecticide for approximately 10 minutes. Following that plants were again washed with tap water and submerged in distilled water for 4 hours. Before replanting them into pots I inspected the distilled water and found two nematodes alive and well swimming. That I suspect is not good. Both pots are now isolated from each other and from the rest of the plants an will remain this way.
Below are the pictures.
Second Plant (notice more developed root system):
The dark long roots were present on the plants when they were first separated and repotted from a small pot that they came in. Surprisingly, even though at some point both plants produced a lot of leaves, the roots on both plants seem underdeveloped. Have they rotted away?
Indeed you look to have done a good job & put in a good effort!
So you know (in case you don't), any of the black roots that seem to have "skinny" portions (thin like a fat hair) are likely dead, however the black roots that have the small white/yellowish growing tip on them & a decent amount of thickness throughout their length are alive and growing!
You can safely cut off the dead roots with no harm to the plant. In fact it is one less place for rot or "uninvited guests" to hide & reside.
If indeed you saw more 'bugs" in the water, another wash & dose of some insecticide could have been repeated, but from the sound of it you have done a decent job and now time will tell how things go from here.
I often dust with a rooting/fungicide mix when planting back up, but VFT's are so hardy that this is pretty much overkill. I also encourage trimming off black/dead leaves & remains. (Not every portion needs to be removed, but I like to make it clean looking and remove the obvious "spent" portions. They aren't going to return back to life anyway, but one needs to use reasonable care when doing this.
Many people use "transplanting" time to break the bub-lets apart to propagate more plants, however I like my plants large so I only divide them when they produce small "side-cars" of smaller plantlets. When left on, the plants often grow & pack so close upon themselves that there is no room for decent growth anyway, & so it allows me to propagate new plants without taking away much energy from the main plant in allowing it to get large.
From the look of your plants, they are decently healthy and growing quite well. I don't know how long you have had them, but they apparently have liked where they were growing at some point.... at least before the bug attack!
Do keep us posted on the progress of the plants. If the "bug killer" you used doesn't do the trick, then indeed something stronger will be needed. I do hope that won't be necessary, but you never know.
Keep in mind that you have now greatly decreased the nematode/bug population by "thinning out the herd", which alone may be enough to give your plant the upper-hand once again.
I myself have occasionally used stronger things like malathion, diazinon and other such nasties, however with overuse, incorrect handling & people who don't know what they are doing (nor able to respect the potency of such materials), it seems that anything that works really well is being taken off the market.
(And in view of the damage that people have done with these things, I guess removing them from the hands of the general public was a prudent solution.) But indeed, it can be hard to find something that may work well.
Again, time will tell if the infestation returns, but you've done a great job of addressing the situation head-on! Nice pics by the way!
I already tried to use three different insecticides to address the problem with no improvement: first it was neem oil extract, then imidocloprid ( I spraed so much that the soil seemed drenched), then when no improvement was seen I bought AzaMax, sprayed the pant and drenched the soil with 1% suspension.
One of the crazy ideas I had and wanted to try as part of an experiment is to use over the counter cat roundworm medicine to try and kill the nematodes that were washed out first and then use it on the plant itself. I know it sounds crazy and I did not try it but both types of parasites are essentially the same thing and what works for one should work for another But I have no idea how something like piperazine dihydrochloride will affect the plant so I did not try it.
Have you had any experience with predatory nematodes? I can't seem to find much information about using them against plant nematodes around here.