Hypoaspis mites

Lorri D · November 20, 2012

I brought some plants in from outside (stupid) they had fungus gnats and I didn't know it. I now have fungus gnats in my seedlings. I have been using neem, but the seedlings aren't taking it very well. I killed a few of them so far using it.

My seedlings are too far along for me to just toss, but I can't keep applying neem either. I have been looking for alternatives and found hypoaspis mites on the net.

I'd like to hear if you have experience with these preditory mites and if you liked them or if anyone has another method of getting rid of the fungus gnats. I have been watering from below and letting the top layer dry out, but they still survive. I even shake them every hr or two and suck the gnats up as they fly up with a vacuum. Everytime I think they are gone for good, more come back in a few days.

Thanks so much everyone! Lorri D

Cole_Robbie · November 20, 2012

If you get a mosquito dunk tablet for ponds and soak that in your water for about a day or so before giving it to the plant, that will kill the fungus gnats.

mcsee · November 21, 2012

We use them where I work and they are very effective in controlling Fungus Gnats, but you can't just rely on one release to correct the problem. I'm not sure how easily available they are to you, but whatever way you decide, remember that the lifecycle of the Hypoaspis is roughly 10 days, but can vary up to 30 depending mainly on temperature. Eggs laid in the medium will hatch into larvae in 1-3 days, so at the very minimum get two releases to cover 3 weeks minimum.

Heritage · November 21, 2012

Bacillus thuringiensis, subspecies israelensis is my preferred organic method for controlling fungus gnats. This is the species of BT used in mosquito dunks as mentioned above by Cole Robbie. It is also available as Gnatrol in a form easy to apply:
http://www.amazon.com/Valent-Gnatrol.../dp/B003E7BGTU

Steve

Rgold1963 · November 22, 2012

Hi Lorri. I have been using them for years in my growing medium with great results. Depending on what you are growing in and how extensive the population of gnats are, you will need to make appropriate release amounts of hypoaspis. Atheta have also worked really well and I use both in my greenhouse.

It may take them several weeks to catch up but once established, you should not have any more issues with the gnats.

Here is a link to my supplier who is in Oregon. Hope it's ok to post this. I have known John (the owner) since 1993 and can highly recommend his products as they have worked really well for me over the years. http://store.evergreengrowers.com/pr...Gnat+Predators

Let me know if you have any questions about any types of biological control. I would be happy to answer.

Ron

November 20, 2012	#1
Lorri D Tomatovillian™ Join Date: Jan 2012 Location: NorthWest Posts: 267	Hypoaspis mites I brought some plants in from outside (stupid) they had fungus gnats and I didn't know it. I now have fungus gnats in my seedlings. I have been using neem, but the seedlings aren't taking it very well. I killed a few of them so far using it. My seedlings are too far along for me to just toss, but I can't keep applying neem either. I have been looking for alternatives and found hypoaspis mites on the net. I'd like to hear if you have experience with these preditory mites and if you liked them or if anyone has another method of getting rid of the fungus gnats. I have been watering from below and letting the top layer dry out, but they still survive. I even shake them every hr or two and suck the gnats up as they fly up with a vacuum. Everytime I think they are gone for good, more come back in a few days. Thanks so much everyone! Lorri D

November 20, 2012	#2
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	If you get a mosquito dunk tablet for ponds and soak that in your water for about a day or so before giving it to the plant, that will kill the fungus gnats.

November 21, 2012	#3
mcsee Tomatovillian™ Join Date: Aug 2007 Location: Victoria. Australia Posts: 543	We use them where I work and they are very effective in controlling Fungus Gnats, but you can't just rely on one release to correct the problem. I'm not sure how easily available they are to you, but whatever way you decide, remember that the lifecycle of the Hypoaspis is roughly 10 days, but can vary up to 30 depending mainly on temperature. Eggs laid in the medium will hatch into larvae in 1-3 days, so at the very minimum get two releases to cover 3 weeks minimum.

November 21, 2012	#4
Heritage Tomatovillian™ Join Date: Nov 2010 Location: San Diego Posts: 1,255	Bacillus thuringiensis, subspecies israelensis is my preferred organic method for controlling fungus gnats. This is the species of BT used in mosquito dunks as mentioned above by Cole Robbie. It is also available as Gnatrol in a form easy to apply: http://www.amazon.com/Valent-Gnatrol.../dp/B003E7BGTU Steve

November 22, 2012	#5
Rgold1963 Tomatovillian™ Join Date: Nov 2012 Location: PNW Posts: 44	Hi Lorri. I have been using them for years in my growing medium with great results. Depending on what you are growing in and how extensive the population of gnats are, you will need to make appropriate release amounts of hypoaspis. Atheta have also worked really well and I use both in my greenhouse. It may take them several weeks to catch up but once established, you should not have any more issues with the gnats. Here is a link to my supplier who is in Oregon. Hope it's ok to post this. I have known John (the owner) since 1993 and can highly recommend his products as they have worked really well for me over the years. http://store.evergreengrowers.com/pr...Gnat+Predators Let me know if you have any questions about any types of biological control. I would be happy to answer. Ron