---

Hi Nigel,

If your specimens are in air-tight boxes and still going mouldy then I think perhaps they haven't been allowed to dry completely after pinning. Either that or the air really is overly damp.

I have never had mould problems when storing my specimens in wooden boxes in a normal, centrally-heated house. Fungal spores exist all around us, and most will survive happily even when it is dry. However, they won't grow until there is enough humidity for them.

I'd suggest putting the open boxes close to (but not on a radiator) in a warm, dry room and allow the flies and boxes to dry completely. Then store them in a warm, dry place. If you are worried about humidity perhaps try pinning small packets of silica-gel inside each box to absorb any humidity. These packets can be taken out regularly and re-dried on a radiator.

It might be that the atmosphere inside you cellar isn't particularly humid, but the cool temperatures caused whatever humidity there was to condense out on the specimens.

Cheers, Chris R.