The Great Algae Fly Experiment

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What does one do on a wet Saturday afternoon? Well, if you are me, then you sit smearing golden syrup on bits of cardboard. Why was I doing that? – I hear you cry…..

Well, recently I’ve had a problem with little white worms or grubs attacking my seedlings in the greenhouse. I posted a question on GoY and Owdboggy very kindly identified the critters as the larva of Algae Flys. Algae flys are those tiny little flys that live on the surface of compost in pots. They are completely harmless in themselves, but they lay their eggs on the surface of the compost and the larve hatch out and eat the green algae which grows there in moist humid conditions. All well and good, but they are also partial to the root hairs of seedlings :-(
This photo shows Aquilegia seedlings that have been damaged by them.

I have also lost a lot of my Echinacea seedlings (4 remain out of the 12 seeds I sowed).

So, I had a bit of a surf and found the following organic remedies:-

1. Allow the soil surface to dry out as the grubs are susceptable to desication.
2. Have little pots of cidar vinigar, which the flys drop into and drown.
3. Use sticky yellow cards, which the flys are attracted to and get stuck to.

Thus…..

I gathered together a few materials! Didn’t quite know whether vasaline or golden syrup would be best, so used both to compair in the name of science!

And I stuck them in the greenhouse.

QUIZ TIME – would anyone like to have a guess at how many flies I catch? :-)
Sarah.

20 Apr, 2008
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Comments

Irish

are they tiny ? prob catch hundreds if they are. good idea that, the sticky paper.

20 Apr, 2008

Janette

I will have a try at 78 Hope your experiment work well I am going to give this a try myself I have little flys in the greenhouse ,but luckly nothing has been eaten ,exept for my Dahlias but I found the culprid a tiny little caterpillar who was quickly evicted into the nearby hedge lol

20 Apr, 2008

Sid

I'm worried the golden syrup will attract wasps! (Didn't think of that at the time....oh, well). Hope I don't catch hundreds as I will need to count them all! :-D

20 Apr, 2008

Janette

I think I will wait an see just what you trap first before I try lol

20 Apr, 2008

Sid

Quick update - I think it may be back to the drawing board with this one - the golden syrup has either dried out or run off, because when I went to check this afternoon how many flies I'd caught, the card was no longer sticky :-( I've given them another coat, but maybe using double sided sticky tape would be a better solution?

20 Apr, 2008

Janette

Oh no Sahra hard luck with your experiment maybe the double sided tape will work better Good luck

20 Apr, 2008

Marksbegonias

I wouldn't know how to go about creating a DIY version. But i always use yellow sticky traps in the greenhouses - and blue sticky traps, as the blue ones are supposed to attract "Thrips" which i have had problems with. The yellow ones are in garden centres, the blue ones i found at garden direct, through the post.

21 Apr, 2008

Sid

Thanks, Mark. I could buy some, but I'm such a miser! ha ha ...

21 Apr, 2008

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