water beetle larvae?

diggleken · #1 (**permalink**) 12-07-2011, 06:38 PM

Hi all,
grateful for help with this - is it a water beetle larva or Caddis etc larva?
I cant find my charts and its a puzzle, previous threads with the same looking species didnt come to any full conclusion. (if poss!)
There seems to be little on the web about water life larvae...........

Cheers
Ken

2dogs2000 · #2 (**permalink**) 12-07-2011, 06:50 PM

The caddis fly larva usually encases itself in debris. I think this is water beetle larva. I am a long, long way from being an expert on this.

diggleken · #3 (**permalink**) 12-07-2011, 07:00 PM

Quote:

Originally Posted by 2dogs2000

The caddis fly larva usually encases itself in debris. I think this is water beetle larva. I am a long, long way from being an expert on this.

Thanks 2dogs - I think its beetle too, looks a little wrong for Dytiscus, but otherwise no idea!
we were doing a pond dip and the kids found this, may have been dislodged from the case.........................

So I'm hedging my bets.
Anyone else?
Cheers
Ken

Ukwildlifeo · #4 (**permalink**) 12-07-2011, 07:04 PM

Looks more caddis fly larva than anything else. Looks like 2 hooks at the tip of the abdomen certainly suggest caddisfly larvae, and the head looks the right shape. I think I can make out gills along the abdomen.

Was this in a pond? Most, if not all, caseless caddisfly are found in flowing water to my knowledge, but the hooks do suggest this is a case builder but it is minus its case for some reason.

Added this pic showing the head shape of a caddis

As for the lack of pond stuff on the net, that may change soon...

2dogs2000 · #5 (**permalink**) 12-07-2011, 07:12 PM

Well I have learnt something today. I didn't know you could get caseless caddis fly larvae.

diggleken · #6 (**permalink**) 12-07-2011, 07:18 PM

Quote:

Originally Posted by Ukwildlifeo

Looks more caddis fly larva than anything else. Looks like 2 hooks at the tip of the abdomen certainly suggest caddisfly larvae, and the head looks the right shape. I think I can make out gills along the abdomen.

Was this in a pond? Most, if not all, caseless caddisfly are found in flowing water to my knowledge, but the hooks do suggest this is a case builder but it is minus its case for some reason.

Added this pic showing the head shape of a caddis

As for the lack of pond stuff on the net, that may change soon...

Ah, now were getting somewhere!
Brilliant ukw, this was a moorland stream, quite acidic, there are caddis using gritstone for cases, but as I say, kids dipping may well have dislodged and broken a case by the time it got to me.
Need an ID for a bioblitz if thats poss, even genus will help!
Cheers
Ken
Cracking shot by the way!

Ukwildlifeo · #7 (**permalink**) 12-07-2011, 07:22 PM

Quote:

Originally Posted by diggleken

Ah, now were getting somewhere!
Brilliant ukw, this was a moorland stream, quite acidic, there are caddis using gritstone for cases, but as I say, kids dipping may well have dislodged and broken a case by the time it got to me.
Need an ID for a bioblitz if thats poss, even genus will help!
Cheers
Ken
Cracking shot by the way!

Im afriad my 'expertise' runs short there. Caddis larvae are pretty hard to ID and I wouldnt know where to start with one minus the case.

diggleken · #8 (**permalink**) 12-07-2011, 07:46 PM

thanks again ukw - caseless Caddis Fly (Hydropsychidae family) I got from a previous post, thats it for this one I suspect, photo not too great anyway.

Thanks for your help!
Cheers
Ken

lovecrawlies · #9 (**permalink**) 29-07-2011, 07:08 PM

Had a look in the wonderful 'A key to the major groups of British Freshwater Invertebrates'. Based on the photo, I followed the keys assuming it hadn't originally been in a case, and that it did have gills along the sides of the abdomen. This seemed to narrow down to caddis fly larvae of the family Rhyacophilidae. Some of the images for this on-line look similar to your specimen. The nearest alternative was Hydropsychidae, which have gills positioned more underneath the abdomen. Most apparrent difference is in swimming technique, Rhy. swim with an up and down movement, Hydr with 'exagerrated side to side movements of the back-end'. Hope this is helpful!

The 'Key to...', by the way, is more enchanting than its title or function would suggest. Who could want more from a book than the description of an ostracod swimming as 'this activity resembles the bumbling of a distraught runner bean seed'.