North­ern Fe­bru­ary red stonef ly

Trout & Salmon (UK) - - FIRST CAST - By Craig Macadam, co­or­di­na­tor of the River­fly Record­ing Scheme.

The North­ern Fe­bru­ary red stone­fly (Brachyptera pu­tata) is a spe­cial species. First found in the River Clyde in 1838, it now mainly oc­curs in north­ern Scot­land, par­tic­u­larly the north-east and Cairn­gorms. Out­side of Scot­land, it has only been found on the Usk in Wales and Wye, and nowhere else in the world. Nymphs are found in the mid­dle to lower reaches of larger rivers, with good wa­ter qual­ity and clean grav­els. Win­ter sun­shine is es­sen­tial so they tend to avoid stretches of river that are heav­ily shaded by bank­side trees. They seem to pre­fer deeper ar­eas of flow­ing wa­ter where they live among large stones. It’s thought that they feed by gath­er­ing tiny frag­ments of or­ganic mat­ter from the bed of the river. The nymphs emerge from their eggs in au­tumn and grow rapidly through win­ter. They are sturdy with long an­ten­nae and tails. As the end of win­ter ap­proaches in Fe­bru­ary the nymphs ready them­selves to emerge from the wa­ter. The ma­ture nymph climbs out of the wa­ter on to a rock, tree, or bank­side struc­ture such as a bridge sup­port in the evening. Nymphs have been ob­served climb­ing up to two me­tres up a bank­side tree, and their cast nymphal skins can be found above head height on bank­side walls and bridges. Adults can be seen from Fe­bru­ary to April and they are often en­coun­tered as they bask in the sun on fence posts by the river. They have also been found un­der stones along the river side or rest­ing on snow patches where they may be gain­ing warmth from sun­light re­flected off the snow. Males have red­dish wings, which are fore-short­ened mean­ing they can­not fly. Fe­males have fully-formed grey­ish wings with four black bands.

Can you help?

The last na­tional sur­vey for this species was in 2003. We des­per­ately need to know where it now oc­curs. Win­ter is the per­fect time to spot adult stone­flies as they bask on fence posts along­side rivers. It’s easy to get in­volved – take a pic­ture of the stone­fly and send it to scot­[email protected] buglife.org.uk or tweet it to @buglifescot­land with your name, pic­ture, date, the river and lo­ca­tion.

The Fe­bru­ary Red is 8-10mm long.

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