Hard winged flies. Sexy little beasts. They look very cool as larvae, with their translucent wing plates and meaty legs.

Goddard comments in his "Waterside Guide" that "they're of considerable importance to river fly- fishers, particularly in Wales and northern Britain. Elsewhere their value is doubtful." He also, perhaps wrongly if you ask me, states that the nymph is of little value to the fly fisher because it is "all but impossible to imitate". Stonefly wing plate parts are readily available (albeit of poor quality which is leading me to investigate making something better) and various patterns have been developed which are strikingly realistic.

Seven families:

TAENIOPTERYGIDAE

PERLIDAE

PERLODIDAE

CHLOROPERLIDAE

CAPNIIDAE

NEMOURIDAE

LEUTRIDAE

All of the above are relatively small (6-12mm body length) except for the Perlidae (14-33mm body length) and Perlodidae (8.5-28mm body length) families. Of these last two families, Goddard discusses five of the seven species listed by Field Studies Council in their "Guide to the British Sonefly (Plecoptera) families: adults and larvae":

Perla bipunctata Large dark stonefly


Dinocras cephalotes Large pale stonefly


Perlodes microcephalus Orange stripped stonefly


Diura bicaudata Common medium stonefly


Isoperla grammatica Common yellow sally


(These last two are found in still water as well as flowing)

BTW it's amazing how few images Google can find of these on the web...

So here's a few questions:

- do you fish stonefly nymphs in the UK?
- what body lengths do you use?

Nice photo's Steve - do you know how common these are in the UK & Ireland?

__________________
Steve


"There he stands, draped in more equipment than a telephone lineman, trying to outwit an organism with a brain no bigger than a breadcrumb, and getting licked in the process." Paul O'Neil

I see then quite a lot in Scotland. This pair were from Inchnadamph at an elevation of 1300 ft.

Female Stonefly (Perlodes microcephala)



Male Stone Fly (Perlodes microcephala)

__________________
Don't worry, be happy.
Sandy
Carried it in full, then carry it out empty.

Steve, the images aren't mine - I just scanned the web for something to link into the post.

Your question is a good one. I'm as interested in the answer as you are. According to Goddard:

Perla bipunctata "common and abundant except the Midlands, South-East England and most of Ireland. It is on the wing from mid-April to June."

Dinocras cephalotes "fairly common and fairly abundant, it is found in roughly the same areas as p. bipunctata"

Perlodes microcephalus "same areas as [above], but ranges further south and is seen occasionally on the chalk-streams. Adults are on the wing from March to May, and sometimes July."

Diura bicaudata "rather local in distribution, but common and abundant where it does occur, mainly in Scotland, West Wales, the Lake District and parts of Ireland. The adults appear from April to June."

Isoperla grammatica "common and abundant and found all over the British Isles apart from East Anglia and parts of the Midlands. The adults are on the wing from April to August."

I had a day on a tributary to the Test last year in mid September. These things were everywhere. Unfortunately I hadn't invested the time to be able to recognise what they were.

Nice posting Steve . We have no experience in the east midlands. We were told not to consider them in the kick samples as none had been recorded within 10or 20 kms of here.
I thought I had seen one or two on the wing , and had chased one with a net but never proved it and the members were wondering if the levels of substance or alcohol abuse was getting out of hand (vigorously denied!!) .
However one solitary willow fly turned up in a kick sample last summer, to save my reputation. As these spend most of their adult lives scrambling around in the undergrowth we're not likely to see many more for a few years yet.

Leuctra geniculata not present in the east midlands!

Found these adult Dinocras beside a tributary of the river Ayr. The site was high up in the hills.

This one shows a female and the empty nymph skin


Big beasties


The text books say that Dinocras prefers stable surstrate, i.e. big rocks/moss etc and Perla more mobile substrate (gravel etc) and I have always found this to be the case although you will get sites where the two can be found together.

Hf