Mosquito Dunks for Fungus Gnats

[Carl_B]

Does anyone use Mosquito Dunks for Fungus Gnats? I have been using a product here in the UK which contains Bacillus thunbergii var. israelensis but it works quite expensive for only 4-5 treatments of my collection I've since purchased 20 Summit Mosquito Dunks from Amazon.com as they aren't available really here in Europe at a reasonable price and I plan to use them in my 210 Litre Water Butt (That's a Rain Barrel to those in the US) and I was wondering how much of a dunk to use? the label states that each dunk is able to treat 100ft of surface area regardless of depth but obviously I assumed this is for mosquito larvae which tend to congregate just below the surface...

[greenknight]

Mosquito larvae come to the surface to breathe, BT infects them when they eat it - the bacteria from the dunks spreads across the surface. then sinks, so it's all through the water. I would think a quarter of one dunk would be more than enough.

I another idea for using them when I searched the Web - instead of putting it in the water, you can crumble up a disk and sprinkle about a quarter teaspoon on the surface of each pot.

[Carl_B]

Mosquito larvae come to the surface to breathe, BT infects them when they eat it - the bacteria from the dunks spreads across the surface. then sinks, so it's all through the water. I would think a quarter of one dunk would be more than enough.

I another idea for using them when I searched the Web - instead of putting it in the water, you can crumble up a disk and sprinkle about a quarter teaspoon on the surface of each pot.

Thanks greenknight, I thought that it would be enough just to put them in the water butt, however I did consider crushing half a dunk and mixing it into my cuttings compost or onto un-bagged seedlings as that's where they are doing the most damage little sods.

[greenknight]

I'm sure putting it in the water butt would work, too. I think you might get quicker results by crumbling some up and applying it directly. The dunks are designed to slowly release the bacteria for 3 months or more, hard to say how long it would take to get enough in the water to be effective. I think it would be a good idea to apply some directly to any pots that are currently infested, then put a piece in the water for continuing protection.