Gnat attack :(

[TheyCallMeJJay]

Are gnats that bad for plants? I've had infestations and no ill effects in the past. All I ever did was just let the soil dry out (bone dry) at the end of my cycle. I harvested a week later which was actually nice.

I've got billions of them in my yard and veg garden and they never put a dent in that stuff.

 

[TheyCallMeJJay]

Y'all are working to damn hard at getting rid of these gnats...

I'm telling ya this is all ya need and some sticky traps...a lot less work...use once every four weeks and say good bye to the gnats...

Ecological Labs BMC Liquid Mosquito Control-1 oz

http://www.pondworld.com/ecological-...z-st-bmc1.aspx

This is basically a BT designed for mosquito larva, but it does wonders on gnats as well...

I just used those sticky fly traps that you get at the hardware store. Easy Peasy

 

[Photosynthesis]

Interesting concotion Photo, mind naming the supplier?

I had success myself with Dunks, topdressing under mulch and leaving them in the rez for three weeks.



Right.... the suggested repeated application of Bits weekly-biweekly is for just that reasoning.


Well the link you quoted was informing, the Bits work almost exactly like Dunks in media. They should adjust their literature so one does not contradict the other. "Immediate release" doesn't really jive with a one to two week period.

I get it made specifically for me. It's good for about a year. Which is good because of the quantities I have to buy.

 

[magiccannabus]

Do any major retail chains carry a BTI product? I am having a hard time finding a local source...

 

[Jhhnn]

Ace, Home Depot & Lowe's carry the dunks.

Looks like the best deal-

http://www.acehardware.com/product/index.jsp?productId=24850656

 

[magiccannabus]

Awesome thanks! My two NL plants are completely unphased by these gnats, but my mystery plant is having some issues now too. I'm going to clone the NL soon, but I am going to try just cloning directly into chunk DE(Napa 8822) the way many people clone into perlite. We'll see how it goes!

 

[thatonedude]

Do any major retail chains carry a BTI product? I am having a hard time finding a local source...

Walmart carries them as well. they are with the tiki torch fuel and citronella candles

 

[thatonedude]

heck in the summer months I even see them on the counter display at the dollar general

 

[thatonedude]

does anyone know why in the hell im having a green bottle fly infestation in my grow cab? I mean they don't eat plants as far as I know. where are they coming from? im growing organic but everything in my soil mix is well composted

 

[DemonTrich]

I just checked lowes, home depot, kmart, walmart. all only carry the discs, and not the pellets. amazon for the pellets, 30ox container.

walmart on sale for 9.00, everyone else is at 11-15.00 for the discs.

 

[EclipseFour20]

Yep...Amazon was my source for the Bits...got two or bought other stuff to get the free shipping. For those in So Cali, I got Greencoast Hydro to carry the 30 oz jug, which they sell about a buck or two cheaper than Amazon.

 

[thatonedude]

I just checked lowes, home depot, kmart, walmart. all only carry the discs, and not the pellets. amazon for the pellets, 30ox container.

walmart on sale for 9.00, everyone else is at 11-15.00 for the discs.

cant you toss the disks in the blender and make them granular?

if it makes you feel better you can cut it with some sort of buklkibg agent like peat moss and perlite and then grow gnat free plants in it

 

[thatonedude]

sorry sometimes I just have to be a smart ass

 

[thatonedude]

I do have a question though. can the bti dunks be toatally dissolved in water (just enough water to toatally dissolve them) then used to wet just as much perlite as it takes to soak up the solution.

then be mixed into a soil mix as a preventative measure? or does the bacteria die without a host?

 

[OverGrowRefugee]

Thanks for the replies. I worry I won't be able to stop them. I live on the edge of town and there's lots of compost and manure around here.

They don't take over outside. What eats them? I want whatever it is that eats them to come inside too....

"Hypoaspis miles and the similar species, H. aculiefer are soil-dwelling, predatory mites. Hypoaspis mites feed on fungus gnats, springtails, thrips pupae, and other small insects in the soil. The mite is 0.5 mm (1/50 inch) long and light-brown in color. It inhabits the top 1/2 inch layer of soil. Females lay eggs in the soil which hatch into nymphs in 1 to 2 days. Nymphs develop into adults in 5 to 6 days. The lifecycle takes approximately 7 to 11 days. Both nymphs and adults feed on soil-inhabiting pests, consuming up to 5 prey per day. They may survive by feeding on algae and/or plant debris when insects aren't available. Both males and females are present, but males are smaller and rarely seen."

http://en.wikipedia.org/wiki/Hypoaspis_miles

 

[OverGrowRefugee]

There is so many options out there - good luck

http://www.planetnatural.com/product/predatory-mites-spidex/

 

[OverGrowRefugee]

damnit - can't edit post

wrong link - those are for spider mites

here are hypoasis miles for sale - free shipping

http://www.planetnatural.com/product/fungus-gnat-predator-entomite-m/

 

[Ganja Herder]

Sprinkle alight layer of cinnamon powder on top of the soil. They will not go near the stuff and should give your seedlings a bit of time to grow.

 

[magiccannabus]

So I ended up losing all my small and mid-size plants, about a dozen over a couple months here. The two big Northern Lights in the grow bags with mulch and all that never did show any signs of gnat problems, and if anything were feeding too heavily. The other big unknown plant got very sick, despite being in a similar setup. It has recovered amazingly though since putting the centipedes in the mulch. I'm wondering if I already had some predator bugs in the mulch and soil of the Northern Lights, but that perhaps not as many of the predators made it into the other planter. Even one centipede can apparently eat hundreds of bugs a day depending on their size. The only downside is that the centipedes like to be kept moist, and so do the gnats.

After losing my next wave of plants, I got frustrated and tried to design a better way to do things. I settled on trying to put chunk DE(Napa 8822) in the bottom quarter of the starting pots(party cups in this case) so the drain holes were covered generously. Then I put a layer of coir that fills about half the total volume of the cup. Then I put a thick layer of the diatomaceous earth on the top of the coir, and thoroughly soak the material. I start with a spray bottle usually because the 8822 puts off some dust when you hit it with water for some odd reason, so the sprayer knocks that dust out of the air before it can really spread. I am guessing perlite might work for this but it may not stay put well, and probably wouldn't stop the bugs as well. After I got all that ready I put two cuttings from each of my Northern Lights in color-coded cups. I prepped the cuttings with honey and rooting hormone. They've been in there over a week so far and they have not yellowed or shown much else in the way of stress. One cutting of each sort of started to flop over at one point, but I watered the cups and it stopped, so I think the mix was just getting too dry.

The important point to all that is NO GNATS SO FAR! I know they like coir, but there's very little in the way of nitrates in there so I don't think they'll be too drawn to it. The layers above and below of chunk DE will definitely make larvae trapped in the soil with only a gauntlet of razors between them and the surface. I'm starting to wonder if I should be starting my seeds in this mix......

 

[Mikell]

You're gunna love this. Copied from an email I got from a wicked resourceful local grower.

Author: "mikeg"

The soil-dwelling Hypoaspis miles mite is one of my favorite wee beasties. Commercial potting soil is dense enough that they can only occupy the top 1cm of soil.

Habitat:

When i raised them, i used hydroponic store expanded-clay pellets as a media, with a sphagnum wick throughout as a water/humidity source. Use unmilled fibrous sphagnum -- the coarse woolly stuff from deep woods. The best quality sphagnum is that which you pick yourself. Drench it with boiling water to oust potential pests, rinse thoroughly.
Assembly: take a 1-gallon pot , hold a narrow (5cm) wad of moss in the center of the pot against the pot's "floor". Backfill all around with pre-rinsed, still-wet clay pellets. Hold another wad against the top of the first one, backfill again. Continue to within 5cm of pot rim. In a potful of pellets, you now have a narrow vertical core of moss.
Set within a tray holding 3cm water. Tray must be wide enough that it doesn't touch the pot's sides. Not only do you now have a water source to wick moisture (or at least humidity -- Hypoaspis drown readily in too much free water) thru the media... you also have a "moat" to contain them.
You need a dark cabinet or ventilated box -- they are photophobic.

Food

I used "micro-worms" (Anguillula silusiae --not to be confused with "white worms"), as they are known in the aquarium trade. These 1mm long nematodes are an intermediate-sized live food used for fish fry. No pet store in this area carries them. Befriend someone in an aquarium club if your local pet merchants also fail to.
Raising them always seems to raise a pervasive sour stench, like a sourdough culture that spoilt 2 weeks ago, and this is absolutely unnecessary. It never smells nice, but the odor can be greatly reduced.
All the aquarium hobbyists use a substrate (grain-based) at least 3 cm deep, with all the attendant anaerobic putrescence. Thus, only the top 5mm are habitable, and the culture senesces because of toxin buildup, not because the food supply attenuates.
A 5-10mm layer in the bottom of a 500ml yogurt container will not go foul. It will last as long as the other method (best changed every week, though, to maintain vigor). It WILL dehydrate quicker, and 100% humidity is better for them anyway. Place the yogurt container in an ice cream tub with 1-3 cm water, cover with fine mesh (fruit flies and other insects' larvae will otherwise contaminate it).
Quick-cooking oatmeal is the easiest substrate to provide. Use extra water to produce a thin porridge or thick soup consistency.
Pour or smear a thin layer of your starter culture on the porridge. Depending on temperature, you can begin using the culture in 1-3 days.

Feeding

I used pieces of unbleached coffee filter paper as "dinner platters" to feed the mites. Just snip them into one-sixth-of-a-pie wedges, and, using tweezers, touch one side to the nematode culture. If porridge tends to stick, then first mist culture's surface with water.
Lay paper, wormy-side down, on the clay pellets. Next feeding (1-3days later, depending on temperature and mite population), lay the next piece of paper beside the first.

Note that eggs are frequently laid as they eat, thus are all over that paper. Thus, whenever you need to remove a paper scrap to make room for a fresh serving, you should pin it to the soil surface of a potted pepper (or whatever) as an innoculum. Leave it for 1-2 days ( their eggs' incubation period). Covering it with a light sprinkling of damp potting media should help prevent dehydration. NOTE: grab that paper scrap the instant light strikes the mites' habitat so they don't escape.

I believe that this system has a flaw: it will selectively breed for a weaker mite. A metaphor: keep a kennel of wolves, feed and rear 'em like poodles. In a few hundred to a few thousand generations you have large scruffy grey poodles. Poodles are ineffective predators of, say, caribou. Anguilula silusiae is the equivalent of poodle food. I always meant to isolate one of the smaller species of, say, springtails, as a food organism. They're pretty much a caribou in this metaphor.

Breed your own beneficials! Share with your friends! Almost cooler than pet rocks!

The caveat at the end is interesting, and I wonder if there is a better food source/method for the Hypoaspis. I haven't really researched this or any variations yet, and am a ways away from trying it out, but it's good enough to share as is.