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I have got to replace the polythene on 3 large polytunnels this winter but my problem is i have a large number of these pupa attached to the inside of the tunnels, i counted 30 and i was not even trying, can i take them off and overwinter them somehow?, any advice would be great.

Hi,

Take a look here - http://www.ukbutterflies.co.uk/phpBB2/v ... nel#p17337

Somewhere in the thread I gave my thoughts.

Cheers,

- Pete

Thanks Pete, i missed that post, good to know that they should survive.

I've decided to leave the Pupa where they are, the dirt when I had a good look is actually on the outside but I don't think I'll grow brassicas any more, I sow some flowers instead. I have an idea that I could possible do damage to them if I tried to remove them, I did encourage them to the garden after all, I'll leave them in peace

Thinking more on this i have decided the best think to do is cut out the pupa whilst leaving it still stuck to the polythene, should lessen the chance of damage.

Shirley Roulston wrote:but I don't think I'll grow brassicas any more,

I grow around 20 a year as a late crop in my tunnels specifically for Caterpillars, i enjoy watching them and following their lifecycles. Steve

I'll grow a late crop just for the butterflies. ok.

I grow nasturtiums for my whites.

Thanks Susie, that's a good idea I have saved the seeds from this summer's flowers so I can sow some in the poly tunnel so the butterflies have a nice surprise when they hatch and then the cabbages come later. Shirley

It is possible to remove them without harm. You'll need some small scissors to cut the silk girdle around the abdomen ... VERY carefully. Then, working behind the final segment of the pupa where the cremaster ( lots of little hooks ) is embedded in a small pad of silk, again VERY carefully, rub up the pad of silk until it is free of the polytunnel plastic.

Professional butterfly breeders use polytunnels for their large breeding programmes and are faced with similar problems when time comes to harvest their livestock.

You can use Uhu glue to affix these pupae to a flat sheet of card board ~ a small blob to embed the cremaster into and allow to set. Place them all in the same direction. A day later when the glue is fully set, you can hang them all in the same direction on the cardboard and keep them somewhere cool ~ out of sunlight throughout the winter and early spring ~ an unheated garden shed is ideal ~ and when you see the first butterfly against the window come spring, time to leave a window open to allow the rest to escape once they've hydraulically expanded their wings and allowed them to harden off ~ that can take up to 24 hours depending on conditions so do not disturb until they decide they are ready for flight.

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