Hi George
I was able to buy perlite in 100ltr bags from Gargen City Plastics in Melbourne They had it in 3 grades fine medium & corse and it was very cheap by comparison with local 5ltr bags. I get most of my Garden supplies from them now as I can research on line and make up an order or have small items sent.
In regard to the"worms" in your germinating medium I have had visual grubs (about 3mm) in mine which I think were fungas knats.
At the first sign of insects now I use “Chlorpyrifos” sold as Hortico Lawn Beetle and Slater Killer It is used comercially to clear up grubs and worms in root crops and seems to work for me.
Russ
Looking on internet for fungus gnat larvae, I found some nice pictures by entomologists. the first one of yours, with the reddish background shows the same thing. The key is the black head and yellow tail. Eelworms, or nematodes, are usually much smaller creatures than what you showed on the tape measure. They lack the distinctive black head.
Various control measures are described on one site. Physical treatments are those previously mentioned, plus your boiling water trick may work. The boiling water may not get all the eggs or pupae unless you can get all the medium really hot. It also leaches out nutrients if drained. Lacking a pressure cooker, you could use a steamer (or colander suspended in a pot) for half an hour. That too will leach some nutrients. Chemical treatments are all the various nasties, such as chlorpyrifos, if its not banned over there.
For future work, keeping the new, unused potting medium dry generally discourages the fungus gnats, though there might be eggs or pupae in it that might survive. I don’t know, though I’ve never seen them in dry medium I’ve used. They are a plague in our growth chambers if we can’t break the breeding cycle, once the medium is moistened. A few lingering adults can quickly colonize clean new medium.
The great advantage of perlite is that it is not food for gnats. And it doesn’t support the fungus they love. But it is really hard to keep moist as discussed. If you can get fine vermiculite and blend equal parts with the perlite you get a lot better moisture control. Either way you’ll have to use a liquid fertilizer. Be very cautious to not use urea-based nitrogen sources in these sterile media. Plants have a really hard time handling urea, or the ammonium that it breaks down to. In normal soil nitrifying bacteria converts it to nitrate first. But in the U.S., ammonium nitrate, the best source, is no longer available. Nitrochalk if you can find it is a good substitute.
cocnut coir, if you can find some that is both pH neutral and salt-free, is helpful to use as a medium for gnats. I like it better than peat moss by far, but the key is to find a neutral source for it since it is often processed in areas high in salts, which is deadly to seedlings.
lol I remember when ammonium nitrate became illegal. Idiots were making bombs and drugs with it. The bright side to it was that it was one of the cheap products that turned soil into salt mines, but companies now just use urea.
Hi Larry D… thanks for confirming that this is a fungus gnat!! One of them had burried deep holes in another embryo I found, diving in from the cotyledon end and tunelling through real deep into where the meristem tissues would be…it sorta broke my heart to look at it 
As for fertilizer, I have been using a commercial soluble one (N15-P4-K26) at 10% of full strength as soon as seedlings emerge…it works great guns for me!
Thanks Russ and Michael for sharing you ideas also…I’ll take them all into consideration.
Looking back now, two super fast germinating diploid embryos popped up as delicate seedlings one day, and the next morning were still up but minus their cotyledons and meristem…they were topped, and were like two sticks poking up from the soil and this was despite snail baits already around the pot and no slimy snail tracks…it had left me scratching my head…it was like some joke…Now I am suspicious maybe these fungus gnat larvae have attacked the tops of some real delicate seedlings, as well!!!
I am soooo sad about this…I have lost hundreds of real valuable embryo/seedlings to these horrid things, and it’s too late!!!
Watch out for that fertilizer because even if it worked in soil previously, it may not in a sterile system. It’s sort of like getting an aquarium into balance. You have to supply a specific culture to handle the ammonia.
I had for the first time decided to use wooden toothpicks to mark where I had sown each of these hundreds of embryos, which in hind sight is the best thing I could have done, as it has assisted me in monitoring the progress / troubleshoot the non-germinators, to try and understand the WEC results better, rather than just guess that failures are due to bad embryos or the hot weather or whatever other great excuse randomly popped into my head.
I just went out and literally picked several of these things around some unpsrouted embryo markers…it looks as though these have had a good dinner and are fattening up now!!!
So is this also a fungus gnat larva, with food in tummy, or is it a different predator??
Scale: 1 gap = 1/16 inch
Since there are literally about 200 or so embryos that are still sown in various pots in this heavily infested mix, which are expected to germinate soon (or which should have germinated by now), I think what I might do is go out right now, and immediately pick out all of the embryos against every marker that are alive, put them in a glass of water, and heat-treat the mix in the mean time, then re-sow the embryo/seedlings when the mix has cooled down… I cannot bear to just sit there now and watch the demise continue, knowing what is causing the trouble, and knowing how valuable these embryo/seedlings actually are to me.
urrrrgh!!!
George
I understand how you feel as I have been through disasters with seeds and germination but I would highly recommend using the Chlorpyrifos on at least 1 pot. Just spread on surface & water it in.
I think that the stress of moving will be very hard on the embryo/seedlings and may do as much damage as the gnats.
Just trying to help as I love reading your posts.
Russ.
I just removed three seedlings and two live (diploid) embryos from one pot, which was all that I could find that had not been eaten alive or else disintegrated out of about 30 markers in that particular WEC run!!! And there are eight other runs to go through now. Ughhhhh!!
This is the scale of the devastation.
If I had not investigated, I could easily have blamed the enitre WEC procedure, or the embryos themselves from having come out of ultra dried achenes. Although I cannot be certain if any of these other factors are also to blame, previous runs have never had such bad germinations, and some “smoking gun” evidence does seem to be staring me in the face here, I dare say.
Obviously there are so many other variables I should be considering and preventing, in order to optimize my WEC germinations. Live and learn.
In a way, I am so glad I took the time to look… I can still hear the words of an old professor-teacher of mine ringing in my ears:
“…more is missed by not looking than by not knowing…”
ENJOY THE PIX (and thanks for listening/reading this, it helps me some):
\
Hi Russ. Thanks for your kind words and support, you are a great rose friend!!
Don’t worry I am very used to transferring these embryos and embryo/seedlings, I have just removed half of all of them, and there have been no breakages. They are currently floating (+/- submerged) in baby food jars filled with water, and in a few hours they’ll be back in their homes, after the boiling water has cooled down all the seed raising mixes in the original pots.
I hear what you say about the chemical treatment…however the truth is, I would just rather try the boiling water thing as it is so easy, and if it does work I’ll surely soon enough know…it is not a perfect solution, however I have a gut feeling it might just be “good eough”, and that would be grand!!
I would rather use dark seed raising mix, it is so much easier to sow white (embryo) against black (germinating medium), if you know what I mean.
Let’s wait and see.
Job done!!
crosses fingers
As I was doing this job, I clicked a few pictures just to break the monotony of the whole ordeal LOL.
Here is the moth eaten / chewed appearance of one embryo I found:
Here is another embryo in the process of being devoured:
Here are some things I am doing for myself… maybe you may find these ideas useful to think about, or perhaps comment on:
*I am finding that embryos derived from freshly harvested achenes which are immediately processed, with EE + WEC, give far superior germination results compared to embryos derived from ultra-dried achenes undergoing EE + WEC.
*These days, I am either running the WEC the day the hips are harvested, or else if there are too many hips for the WEC, I am cold storing the harvested hips in plastic baggies in the fridge, and then shelling each hip only on the day of its WEC run.
*In conjunction with the 48-72 hour WEC water soaking, I have recently learnt to also deliberately look out for any molding embryos. The minute I spot any molded ones, I now go ahead and sow the whole group soaking in that glass of water, rather than wait the full 72 hours of water soaking.
You may find it interesting to know that so far I have only seen these molded / drowned embryos in batches derived from ultra-dried seed, and at least so far, I have never seen this happen in embryos extracted from fresh healthy hips!!!