Shucks

[Paul Arden]

Can anyone tell me what are these please? There must have been many hundred in a tight wind lane. Very localised which throws me a bit since I haven’t seen them before.

Thanks, Paul

[Viking Lars]

I say they are mayfly nymph shucks. How big are they?

Lars

[Paul Arden]

About an inch long. Slightly more maybe. Mayfly huh? Damn missed a batch. The mayflies are weird here. Out of proportion. The wings are small

[Viking Lars]

Did you read my msg above? *Nymph* shucks. Nymphs don't have wings :-). None the less, I'm 99% sure they are schucks from mayfly nymphs, but I've been unable to find out anything about mayfly species in Malaysia.
Comparing them to species I know (looks and size) they could live on/in the lake, but since that's a flooded lake (as far as I remember you telling me), maybe it's more likely they come from a nearby stream. Any streams?

Lars

[Paul Arden]

Over the entire lake in one small wind lane I find a few hundred shucks clustered together. Nowhere else - and I cover 5km of bank or more. I doubt they came from a river. There are some feeder streams so it IS possible they got flushed out together and congregated in a wind lane...

The other possibility it’s something landing locally en masse like termites. Termites eventually lose their wings and sink to the bottom - so you find wings. The thing about them is that they have localised landings.

It’s why I’m very confused. I’ve never seen a shuck like this here before and then to encounter rather a lot in one place and nowhere else...

I know wind and currents do strange things and it’s probable that it was a wide emergence. But still!!

[piffilus]

Paul, didn't you meet with someone doing research on mayflies around your whereabouts? I remember you posted a couple of pics of one with two very long tails before I came last time, when we were having the "tying the best dragonfly comp". I tied a couple of not so very good ones before I came and never tried. They were probably much too big anyway, I reckon...

[t.z.]

These shucks look somewhat like the ones the Ephemera Vulgata (green drake) leaves behind. Your "version" is a bit more "bushy" ...

However, strong short legs and bushy breathers (tails) indicates a burrower type mayfly. I'd suspect a rather muddy / grassy area in the lake where those hatch. At Skålestrømmen we have those hatching from June 20 to the first week of July. A flock of seagulls visits every year. I suppose the come from far (around 200km distance) to feed on these bugs. Have you observed flocks of birds? It can be so many of these big mayflies that the seagulls get so full that they have to sit on the water after 2 hours feeding in mid air.

[Paul Arden]

No there is a surprising lack of bird life here. Well waterfowl anyway. No sea gulls either. I don’t know how far they travel but I’m inland about 280Km to either coast and while only 260m above sea level I am contained within some fairly high hills/mountains.

Anyway I’m surprised about burrowers indeed I’m just surprised about the whole thing. I’ve seen “mayfly” on the lake but I’m very small numbers as in like 1-2. To find this number of shucks, albeit in one very localised location is a mystery.

Even water levels make life a bit complicated for these flies because between the beginning and end of the Wet Season there is usually a ~8m rise in water levels.

Furthermore I’ve been living on the lake for about 8 years now and this is the first time I’ve encountered it.

So all in all it’s just one big mystery.

Cheers, Paul