Best Earthworm Friendly Fungus Gnat Solutions (Pun Intended)

[Eleutherios]

So I have recycled, living soil. My soil has an extremely robust earthworm population in it. However, like clockwork, fungus gnats have shown up, this time of year, for the last two years. I have some success with nematodes for sure, but I have trouble finding the brand, that used to use most often. The alternatives are pricey, and I am not completely satisfied with the results. Any tips on brands, that you guys would vouch for, would be appreciated.

The other option, that I considered is a non-fruiting, Cordyceps-type fungus, that I have seen mentioned in research articles. My head hurts too much to go on a deep dive for species info right now, but later, I will try to post that. Again, any 1st hand experience as well as reputable sources would be valued.

The other things, that I am considering, are along the lines of a dunk with neem, spinosad, eo's (cedar, thyme, & lemon grass,) and/or Dr Brauner's. Mostly I see folks talking about misquito dunks. I feel like some combination of the above could do the trick. I'm just looking for anyone's thoughts on concentration and maybe if I can do this and spare my hard working earthworm friends. Thank you.

 

[Eleutherios]

So I saw that no one had any ideas, but it seemed like other people found the idea interesting. So having gone back and looked for some articles, I figured that I'd post what I found so far.

Long story short, it would seem that most E.O.'s used at the values tested, spinosad, and neem, at the concentrations recomended, all had minimal or no effect on earthworm populations. They do seem to cause a more rapid biodegradation of spinosad though. So consider that, in terms of frequency of application, with soil drenches for fungus gnats or whatever else.

Concerning E.O.'s

https://www.sciencedirect.com/science/article/abs/pii/S1878818119310965 -full text

https://onlinelibrary.wiley.com/doi/abs/10.1002/ps.424 -abstract only

https://www.schweizerbart.de/papers...lic_monoterpene_rich_essential_oils_from_Apia -abstract only

Concerning spinosad

https://www.sciencedirect.com/science/article/pii/S2666765722000606 -full text

https://onlinelibrary.wiley.com/doi/abs/10.1002/ps.424 -abstract only

Concerning neem

https://www.hindawi.com/journals/aess/2011/925950/ -full article


My head hurts too much to do more than that right now, but wanted to share what I found. I will be doing a combined treatment and it will be pretty clear as to the outcome, in so much as my standard nursery pots all actually excrete worm castings out of the holes in the bottoms. I have to sweep it up at least once a week. So if that continues. The worms are happy. Anyways, I will look for the name of that fungus species later. I know that I already have some papers on it. When half of my file names are a random, nonsensical, alphanumeric strings, it makes it a little hard to pin down. Then when you go to organize... there goes an afternoon... Anyways, I just thought that someone else might find this useful.

 

[Three Berries]

BT doesn't harm the little wigglers they say. I use Mosquito Bits in every other watering.

 

[midwestkid]

I was going to recommend B.T. as well.

 

[Hammerhead]

I recommend a stick about 8" long LMAO. Gnats are the easiest pest to get rid of using nothing but a Stick. All you need to do is fluff the top 2-3" of any Soil/soilless medium after you water/feed. This will cause the top layer to dry fast. Gnats need moisture. If your medium has a dry top layer gnats will never be a problem. Ive been doing this for a decade now. Test it yourself on 1 plant and you will see gnats will ignore that medium.

This method works best in small batches. The more plants you have the more of a PITA it is to do ..

 

[Bmac1]

Hypoaspis miles. Once they are established, gnats don't have a chance. I am growing in living soil beds/totes. When I used pots, a layer of sand on top and watering from the bottom got rid of them.

 

[exploziv]

I have heard the BT does wonders without killing earthworms, so if you can get that.. its probably the easiest way.

 

[Greenheart]

Been there. I love ROLS. I was running an indoor bed with lady beetles , reds, and euros.

BTI dunks are effective. I used nematodes and predator mites as well. In my case flyers were never eliminated but it helped control the population significantly without going all out nuclear and defeating the purpose of organic gardening.

Neem under standard use can be beneficial for earthworms Reference 1996 study in Oregeon:

"ECOLOGICAL EFFECTS

• Effects on Birds: No significant effects on other wildlife were reported (238).
• Effects on Aquatic Organisms: The formulated product Azatin-EC is not expected to kill fish at recommended rates. The LC50 for rainbow trout exposed to azadirachtin is 0.48 ppm (241). It may cause significant fish kill if large concentrations reach waterways. It breaks down rapidly (in 50-100 hours) in water or light, and is not likely to accumulate or cause long-term effects (238, 241).
• Effects on Other Animals (Nontarget species): Azadirachtin is relatively harmless to spiders, butterflies, and insects such as bees that pollinate crops and trees, ladybugs that consume aphids, and wasps that act as parasites on various crop pests. This is because neem products must be ingested to be effective. Thus, insects that feed on plant tissue succumb, while those that feed on nectar or other insects rarely contact significant concentrations of neem products. Another study found that only after repeated spraying of highly concentrated neem products onto plants in flower were worker bees at all affected. Under these extreme conditions, the workers carried contaminated pollen or nectar to the hives and fed it to the brood. Small hives then showed insect-growth-regulating effects; however, medium-sized and large bee populations were unaffected (234). A study of neem products and their effect on mortality, growth and reproduction of earthworms in soils was conducted. Positive effects on weight and survival were found in soil treated with ground neem leaves and ground seed kernals under greenhouse conditions. Reproduction was slightly favored over a period of 13 weeks in a neem-enriched substrate in rearing cages. Various neem products were incorporated in the upper 10-cm soil layer of tomato plots. None of the materials had negative side effects on seven species of earthworms (240). No significant effects on other wildlife were reported (238)."

 

[Eleutherios]

Been there. I love ROLS. I was running an indoor bed with lady beetles , reds, and euros.

BTI dunks are effective. I used nematodes and predator mites as well. In my case flyers were never eliminated but it helped control the population significantly without going all out nuclear and defeating the purpose of organic gardening.

Neem under standard use can be beneficial for earthworms Reference 1996 study in Oregeon:

"ECOLOGICAL EFFECTS

• Effects on Birds: No significant effects on other wildlife were reported (238).
• Effects on Aquatic Organisms: The formulated product Azatin-EC is not expected to kill fish at recommended rates. The LC50 for rainbow trout exposed to azadirachtin is 0.48 ppm (241). It may cause significant fish kill if large concentrations reach waterways. It breaks down rapidly (in 50-100 hours) in water or light, and is not likely to accumulate or cause long-term effects (238, 241).
• Effects on Other Animals (Nontarget species): Azadirachtin is relatively harmless to spiders, butterflies, and insects such as bees that pollinate crops and trees, ladybugs that consume aphids, and wasps that act as parasites on various crop pests. This is because neem products must be ingested to be effective. Thus, insects that feed on plant tissue succumb, while those that feed on nectar or other insects rarely contact significant concentrations of neem products. Another study found that only after repeated spraying of highly concentrated neem products onto plants in flower were worker bees at all affected. Under these extreme conditions, the workers carried contaminated pollen or nectar to the hives and fed it to the brood. Small hives then showed insect-growth-regulating effects; however, medium-sized and large bee populations were unaffected (234). A study of neem products and their effect on mortality, growth and reproduction of earthworms in soils was conducted. Positive effects on weight and survival were found in soil treated with ground neem leaves and ground seed kernals under greenhouse conditions. Reproduction was slightly favored over a period of 13 weeks in a neem-enriched substrate in rearing cages. Various neem products were incorporated in the upper 10-cm soil layer of tomato plots. None of the materials had negative side effects on seven species of earthworms (240). No significant effects on other wildlife were reported (238)."

I ended up using a cocktail of 120mL spinosid, 60mL neem, and 30 mL Citronella EO per gallon (with a little Dr Brauner's) as a surface spray and it has reduced their population by 99.5% after a single application. It has been a minute and they haven't really rebounded, but I will do another application here soon.