Cactus Cultivars

Author Topic: Sciara flies /Fungus gnats  (Read 5584 times)

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Offline robinast

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Sciara flies /Fungus gnats
« on: Sunday, 29 September 2013 - 08:15:23 »
A small fungus gnat population have been always present in my greenhouse. Usually, they do not cause much trouble - unless they lay into young seedlings pots. Occasiaonally I've experienced very painful losts due to them...
It is possible to get rid of them by using some insecticide - but if to be honest, I'm not just very eager to use them (though I do use, if absolutely necessary). Luckily, I accidentally found a good way to get rid of them without use of any insecticides.
Generally, I keep my sowings at +30...+35 C daytime and around +25 nightly. Nevertheless, it happened so that in one of my seedling boxes, the temperature raised well above +40 and remained so during several nights. And to my greatest surprise, after that I saw several dead Sciara worms between the seedlings on the ground while seedlings themselves do not seem to have any damages.
Just recently I had noticed some Sciaras flying around and I had started to worry about what damage they could cause. Now it seems that I have no reason to worry any more! :) Of course, I still will keep my eye on the seedling boxes as previously. Nevertheless, I think I can say to myself "No worries, mate!" now.
Some pictures from my collection:
http://e-aiand.com/kollektsioon/index.php

Offline fanecchissimo

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Re: Sciara flies /Fungus gnats
« Reply #1 on: Sunday, 29 September 2013 - 12:37:49 »
you are right. sciara flies disappeared after my greenhouse went above 50°C.  they are more sensible than cacti to heat!

Offline fanecchissimo

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Re: Sciara flies /Fungus gnats
« Reply #2 on: Sunday, 29 September 2013 - 12:41:23 »
if i can add, you should catch some spiders outside and place them inside the greenhouse. wonderful work for free

Offline Simon

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Re: Sciara flies /Fungus gnats
« Reply #3 on: Sunday, 29 September 2013 - 22:43:51 »
I top dress all my pots with a layer of gravel, no more fungus gnats, and also less soil splash so less problems with fungal disease too.

Offline andrea.a

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Re: Sciara flies /Fungus gnats
« Reply #4 on: Sunday, 29 September 2013 - 22:58:07 »
Interesting topic!
To prevent sciara attack i use to put a small fan near the seedlings (pc cooling fan), it prevents adult sciara flies to "land" on the pots and deposit eggs (or larvae, i don't know), it also helps with fungal infections.
Andrea.

Offline fanecchissimo

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Re: Sciara flies /Fungus gnats
« Reply #5 on: Monday, 30 September 2013 - 11:09:28 »
fans are great all year long apart from frozen days, they cool off more the plant!

Offline danskibsted

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Re: Sciara flies /Fungus gnats
« Reply #6 on: Tuesday, 01 October 2013 - 11:55:16 »
I have had problems with sciara flies also. When I place my newly made pereskiopsis grafts inside the humid boxes, I see many sciara flies after 1 week. They eat the grafted seedlings :(
Any good tips on how to get rid of this problem? I can not raise the temperature, and a fan is not possible inside the boxes. Maybe there is a good insecticide?
Any help is apreciated!
Dan

Offline robinast

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Re: Sciara flies /Fungus gnats
« Reply #7 on: Tuesday, 01 October 2013 - 19:27:24 »
Dan, did you say that the fungus gnats eat the grafted seedlings on top of the Pereskiopsis stock?!  :o
Their larvae live in soil and feed on the young seedlings (among other organic matter) and the adults do not feed at all...
http://www.ext.colostate.edu/pubs/insect/05584.html
Sometimes I have used Vertimec, and insecticide and acaricide, mainly to control spider mites - but it should be effective against sciarids as well
http://www.syngenta.com/global/corporate/en/products-and-innovation/product-brands/crop-protection/insecticides/pages/vertimec.aspx
Some pictures from my collection:
http://e-aiand.com/kollektsioon/index.php

Offline Farel

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Re: Sciara flies /Fungus gnats
« Reply #8 on: Tuesday, 01 October 2013 - 21:52:18 »
This is my 1 post so hi everyone! Greetings from Poland!

To cope with sciara flies is use very eco friendly method - Drosera plant. It catches all adult specimens.


Offline robinast

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Re: Sciara flies /Fungus gnats
« Reply #9 on: Wednesday, 02 October 2013 - 06:29:20 »
Drosera? Fine! Sounds like a pefect solution!  :)
Some pictures from my collection:
http://e-aiand.com/kollektsioon/index.php

Offline Onzuka

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Re: Sciara flies /Fungus gnats
« Reply #10 on: Wednesday, 02 October 2013 - 09:17:44 »
Here in the UK you can buy a big aerosol can of household fly killer for £0.99 and it kills the adult sciaras in minutes!  Sprayed into the atmosphere, as it is supposed to be used, it has no effect on the cacti.

Steve

Offline Simon

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Re: Sciara flies /Fungus gnats
« Reply #11 on: Wednesday, 02 October 2013 - 09:43:09 »
I love the Sundew idea! Welcome Farel!
I have used sticky traps in the past but it looks like the sundew does a better job so I reckon I might try some in the propagator next winter, they grow wild by the thousands in the bushlands around where I live!

Offline danskibsted

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Re: Sciara flies /Fungus gnats
« Reply #12 on: Wednesday, 02 October 2013 - 17:53:01 »
Dan, did you say that the fungus gnats eat the grafted seedlings on top of the Pereskiopsis stock?!  :o


It seems like it. The boxes with sciara flies has alot of dead seedlings (30-50%!), and the boxes with no sciara flies has only very few dead seedlings (0-5%).
I guess there must be some sort of relation.

Offline robinast

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Re: Sciara flies /Fungus gnats
« Reply #13 on: Wednesday, 02 October 2013 - 19:50:47 »
Hmmm... the explanation could be that they carry fungus spores or hyphae onto the cut surface and then the tender grafts just rot. Of course, I dont' know - but as the adults don't feed, this seems quite logical explanation. I myself have never had such a problem with grafts. Yes, sometimes larvae have damaged young seedlings - and that's all.
Some pictures from my collection:
http://e-aiand.com/kollektsioon/index.php

Offline Simon

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Re: Sciara flies /Fungus gnats
« Reply #14 on: Wednesday, 02 October 2013 - 23:19:50 »
Could it be something else that is hard to see like thrips or mites?
A photo of native sundews and terrestrial orchids near our home...
<a href="http://www.flickr.com/photos/36369542@N04/10061394504/" title="Sundews and terrestrial orchids. by The Living Rock, on Flickr"
« Last Edit: Thursday, 03 October 2013 - 02:35:25 by Simon »

 

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