Similar to chironomids.. but not

dbk

Active Member
#1
I was fishing some spring fed ponds yesterday and encountered an emergence that triggered a feeding response similar to that which I have observed when chironomid pupae are emerging.. there was lots of feeding near the surface (boils) and some in the surface film feeding with an odd "eat" of something on top of the surface... and (because of the water clarity and depth) I could see trout on the "hunt" eating something subsurface as they were cruising... they would just open their mouths and eat something about midway between the surface and bottom of the pond...

On the surface I discovered an olive colored adult insect (18-20) with a wing configuration similar to a an adult chironomid and in a throat sample I took there were what appeared to be chironomid pupae but no white gills.. and these pupae moved or behaved differently.... in the vial they would "coil and re-coil".. convulsing in place if you will before pausing momentarily before starting again.. it was a very "spastic" motion that did not resemble the movement of chironomid pupae I have obtained through such samples.. I also took in the sample some of what appeared to be more "worm-like" in appearance- thicker and little to no taper in its body profile. .. assumed maybe it was the larval form of this bug... I have seen it show up in samples from time to time when fishing stillwaters, but the selectivity induced during the emergence of this bug has captured my interest. Any ideas on what it could be?
 

jamma

Active Member
#5
I was fishing some spring fed ponds yesterday and encountered an emergence that triggered a feeding response similar to that which I have observed when chironomid pupae are emerging.. there was lots of feeding near the surface (boils) and some in the surface film feeding with an odd "eat" of something on top of the surface... and (because of the water clarity and depth) I could see trout on the "hunt" eating something subsurface as they were cruising... they would just open their mouths and eat something about midway between the surface and bottom of the pond...

On the surface I discovered an olive colored adult insect (18-20) with a wing configuration similar to a an adult chironomid and in a throat sample I took there were what appeared to be chironomid pupae but no white gills.. and these pupae moved or behaved differently.... in the vial they would "coil and re-coil".. convulsing in place if you will before pausing momentarily before starting again.. it was a very "spastic" motion that did not resemble the movement of chironomid pupae I have obtained through such samples.. I also took in the sample some of what appeared to be more "worm-like" in appearance- thicker and little to no taper in its body profile. .. assumed maybe it was the larval form of this bug... I have seen it show up in samples from time to time when fishing stillwaters, but the selectivity induced during the emergence of this bug has captured my interest. Any ideas on what it could be?
Phil Rowley's book Stillwater Selections identifies this as Chaoborus pupae.They start out clear and gradually turn apple green.Also mentions the lack of gills and says they develop 2 horn like appendages on their head.
 

Taxon

Moderator
Staff member
#6
I was fishing some spring fed ponds yesterday and encountered an emergence that triggered a feeding response similar to that which I have observed when chironomid pupae are emerging.. there was lots of feeding near the surface (boils) and some in the surface film feeding with an odd "eat" of something on top of the surface... and (because of the water clarity and depth) I could see trout on the "hunt" eating something subsurface as they were cruising... they would just open their mouths and eat something about midway between the surface and bottom of the pond...

On the surface I discovered an olive colored adult insect (18-20) with a wing configuration similar to a an adult chironomid and in a throat sample I took there were what appeared to be chironomid pupae but no white gills.. and these pupae moved or behaved differently.... in the vial they would "coil and re-coil".. convulsing in place if you will before pausing momentarily before starting again.. it was a very "spastic" motion that did not resemble the movement of chironomid pupae I have obtained through such samples.. I also took in the sample some of what appeared to be more "worm-like" in appearance- thicker and little to no taper in its body profile. .. assumed maybe it was the larval form of this bug... I have seen it show up in samples from time to time when fishing stillwaters, but the selectivity induced during the emergence of this bug has captured my interest. Any ideas on what it could be?
A photo is worth more than a thousand words. ;)
 

jamma

Active Member
#9
Chaoborus as mentioned above are glassworms. Sounds like a good candidate, but pics help a lot.
Stilly nailed it,glassworms are the larva.Ran into a hatch of these one day at Dry Falls by the shoreline reeds where the bay opens out into the lake proper.Had never heard of them before but had a midge tied up with photo-luminescent(glows when exposed to light)floss like material.Don't know if the glow helped any but the pale green color of the floss was a good match.Me and another guy stationed up and for the next hour or so we were just reeling them in.Too much fun.
 
#10
Stilly nailed it,glassworms are the larva.Ran into a hatch of these one day at Dry Falls by the shoreline reeds where the bay opens out into the lake proper.Had never heard of them before but had a midge tied up with photo-luminescent(glows when exposed to light)floss like material.Don't know if the glow helped any but the pale green color of the floss was a good match.Me and another guy stationed up and for the next hour or so we were just reeling them in.Too much fun.
To be fair, I wasnt the one who suggested it, just paired the common name to the latin name.
Could be any number of things in that group of diptera though, without a pic its muy diffacil, verdad?
 

jamma

Active Member
#11
To be fair, I wasnt the one who suggested it, just paired the common name to the latin name.
Could be any number of things in that group of diptera though, without a pic its muy diffacil, verdad?
In all fairness,yeah,a picture would be good,a preserved specimen even better.But allow me to throw one more log on the fire and that will be all I have to offer on the subject.The source I am referring to comes from the expertise of Brian Chan and Phil Rowley,two of the best(if not THE two best)stillwater experts.I quote verbatim from the text,"The pupae are very active,moving up and down in the water column using a vigorous head to tail lashing motion,seldom staying still for more than a second."Doesn't this sound exactly like the gentleman described it?I am 99.9% sure this is the insect the gentleman saw but I appreciate your skepticism,it is the sign of a keen mind.
 
#12
In all fairness,yeah,a picture would be good,a preserved specimen even better.But allow me to throw one more log on the fire and that will be all I have to offer on the subject.The source I am referring to comes from the expertise of Brian Chan and Phil Rowley,two of the best(if not THE two best)stillwater experts.I quote verbatim from the text,"The pupae are very active,moving up and down in the water column using a vigorous head to tail lashing motion,seldom staying still for more than a second."Doesn't this sound exactly like the gentleman described it?I am 99.9% sure this is the insect the gentleman saw but I appreciate your skepticism,it is the sign of a keen mind.
Yeah, I would agree. I just always like pics to go along with it, as I am far from an expert on Stillwater insects
 

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