The Society for the study of flies (Diptera)

Hi Judy,
I have just cleared out some shelves in my shed, specifically for rearing Diptera, or anything else that emerges. I've never really tried before. So far I just have a few bits of dry dead wood (for coleoptera mainly), an old wasp nest (from my attic) and some leaf/general litter from the garden. I think I'll go out tomorrow in search of suitable wet dead wood to bring home - it's so cold there will not be much else to do in the field!.

I was going to suggest that the forum runs a workshop on finding and rearing diptera larvae. But I never got round to suggesting it when we were at Preston Montford. Would anyone else  vote for a rearing workshop?

Nigel Jones

Last edited by conopid (2008-04-07 15:58:33)

Nigel, if you are going for dead wood, the best sort is often still with bark on.  Or it's good if you can remove some of the under bark layer and rear from that (Lonchaeids). Even small branchlets can be quite productive -I once reared Choerades marginatus from a rotting oak branchlet.  If you are putting the wood in the shed, you will have to be patient - it will not be any faster than outside.  Checking it daily is the difficult thing, which is why I bring mine indoors!  Also you must keep it moist, or fly pupae cannot hatch properly.  If you find a hollow tree, the decomposing stuff at the very bottom can be good.  If you find beetle bored wood, you may get good flies associated with the beetle tunnels.   A rearing workshop would be great, but the March time when the DF workshop usually happens is not good for fungi (November better) or (I presume) good for many carrion flies, but it would be good for deadwood and flies of other habitats like marsh/bog/fen that come out in May/June.  When would be possible for carrion flies, Andy?

It's the Rearing News: the waterlogged dead wood with obvious frass extrusions collected last week is going great guns - Lipsothrix craneflies emerging (all yellow so prob. remota) though I must modify my technique.  Managed to drown some of the maturing pupae by putting the wood the wrong way up in water in my rearing pot.  Wood must go in exactly the same way it was in the stream and with the same amount out of the water.  Another rotting log with obvious syrphid larvae has produced what I think is Chalcosyrphus nemorum and several Sphegina individuals.  In the book (Stubbs and Falk) it says these species breed in dead wood in damp situations but does not mention semi-submerged wood.  Perhaps my rotting log acquired its syrphids on the bank, then fell in the water and acquired Lipsothrix larvae as well.  Other rearing pots with water logged fen moss mat are producing small black hoverflies which I think are Orthonevra species - here the method is take a chunk of mat (with permission, of course) place in the pot the right way up with minimal disturbance and add rainwater to the level that mimics the fen level. Found one of the empty puparia, but very difficult to see them in the moss as they don't seem to crawl up and out.  Stratiomyid Vanoyia tenuicornis came out last week - easy to see the empty puparia because they climb out on top of the moss or even up on stalks, above the water level before fixing themselves by one end to the substrate.  Watch this space as I'm going out for wood mould from ancient hollow apple trees next week!

Last edited by Judy Webb (2008-04-28 02:08:33)

Hi Judy,
How much moss-matt, soaking wet log do you collect? I have collected an 18 inch section of moss covered log, that was partly submerged in a small running streamlet. So far I have had a single Phoridae and two other flies of indeterminate (by me) family. I have the log in a plastic aquarium, keeping the water level up with rainwater. I've had the log a week now, so I am hoping for lots more to come.

Is there any chance that you could post a photo of rotting wood with "obvious frass extrusions" so I can be sure what this looks like. I am visiting a likely site for this next week.

Last week I also collected some "gloop" from a rothole in a sycamore and some rotting twigs from a log jam. I collected dry and quite hard through to wet and crumbling twigs from log jams in streams. These were all out of the water, but suspended in the log jams, above the stream. Looking forward to seeing what emerges.

Would you believe this? After a flurry of emergences of small, rather boring looking flies, I had not found anything emerging from my mossy log for about six days, and wondered why. Today as I was inspecting for flies I discovered a small toad in the tank. It must have been living in the mossy log! I am left wondering how many delicious (and very interesting) flies it may have consumed.....

I re-housed the toad in my neighbours pond.

Last edited by conopid (2008-05-15 00:23:19)

Success from the sedge litter - just posted photos of puparia and adult of Thaumastoptera calceata in the gallery.  This is  a small yellow cranefly which has a larva that lives in a case, rather like a caddis fly larva.  I would not have guessed these cases were Dipteran!

With all this rain, this has the makings of the most amazing year for fungi for a long time.  It is easy to rear Diptera from fungi - just bring a cap or bracket home and place on about 3-5cm deep of damp coir fibre or compost in a plastic pot covered by a white net.  Check on it daily for the next few weeks.  Fungus gnats should emerge first in a flurry, sometimes within a week, then followed by maybe Platypezids, Muscids, Heleomyzids, Drosophilids, Sphaerocerids, Phorids....sometimes even Ula craneflies and Cheilosia hoverflies.  Even pristine caps will usually produce something - you do not even have to see larvae present.  It is quite important to identify the fungus as far as you can before setting it to rear, so get the latest copy of  a reasonable guide like Roger Phillips 'Mushrooms' which has good photos.  If you are still not sure, take some photographs of the fresh fungus (both topside and underside to show gills or pores, post them in this  forum and I'll have a go at the identification.  I should be able to suggest genus, at least. Good luck!

Hi Judy

You say use a "white net", it this colour important?

I had a whole bunch of fungus gnats all emerge in one day from one fungus. Then nothing else for days, so far. I have pickled a few for some one to determine some time. Will bring to the AGM. Also a couple of Drosophila from Boletus and a horde of Muscina levida from Boletus edulis.

I now have quite a few containers of fungi. I use horticultural fleece to cover mine - this has a very fine weave that nothing can get through, and it's very cheap (and white).

Hoping for more things to emerge soon. Would like some Platypezidae, Heleomyzidae and Cheilosias especially.....

For pootering flies out from under the net I find David Henshaw's simple pooter (usually used for spiders) very good - it is made of two pieces of flexible clear plastic tubing stuck into each other with a piece of net between them. You suck the flies into it and have to keep sucking to hold them in (or block with your finger) until you blow them into a glass tube with some tissue to let them harden.

Nigel, the FenEntScan key for Drosophila works really good - I could bring it to the AGM (please remind me three days before!) so you could have a go? We will be there from Friday until Sunday.

as a bit of an aside i just got a book out from the uni library "hand book of insect rearing vol. II" which has a rather good section on diptera (although is all the diptera that is demed economically important!)

'Handbook of Insect Rearing', Vols. 1 and 2, edited by P. Singh and R.F. Moore, Publisher is  Elsevier, Amsterdam, 1985, ISBN = 0444424660. seems to be out of print?