Skip to content

Have you seen a March brown in Wester Ross?

Posted: Thursday 4 March, 2010 @ 10:06:34

March brown (Rithrogena germanica) Photo copyright Craig Macadam

Here’s a survey that you may be interested in taking part in.  


For anglers, the March brown (Rhithrogena germanica) is one of the most iconic mayfly species. R. germanica is under threat across Europe and it is thought that the UK may be a stronghold for this species. The Ephemeroptera recording scheme needs your help to discover where the March brown is found in the UK. To find out more please visit the March brown survey page on the Buglife website


The relatively large R. germanica (13-15mm) adults typically emerge en-masse from rivers around lunch time in March and April.


There are two closely related species: Rithrogena germanica (March Brown) and R. semicolorata (Olive Upright). In 2007 we collected larvae of the latter species from a number of streams around Gairloch [the flat headed larvae with the spot in the middle of the femur for those who were there . . . ]. 'Larvae of both species can be found in medium to large watercourses where they crawl amongst the stony substratum,  . . large specimens collected in March and April will be R. germanica, while mature specimens collected in May or June will be R. semicolorata . . . but  there are no reliable characteristics to allow the safe separation' [quote from Macadam, 2006, A pictorial guide to the larvae of the British Ephemeroptera (Mayflies)].


So: do we have March Browns in Wester Ross rivers? Please click here to download a recording form and how to identify a march brown. In addition to the mottled wings, the diagnostic feature is the spot on the upper leg, so you’ll need a hand lens to be sure of identification. If you would like to borrow a pooter (magnifying pot), use a micro-scope (we have two basic ‘scopes here) or borrow a book or id chart, let me know! Look out for dippers, grey wagtails and the first swallows or martens . . . I’ll by a drink for the first authenticated record from Wester Ross for this year . . . (probably need a specimen for that!).


If you see a hatch of these distinctive insects please send details to Craig at the address below. Please copy records to WRFT as well as Craig Macadam, Ephemeroptera Recording Scheme c/o Buglife Scotland, Balallan House, 24 Allan Park, Stirling, FK8 2QG.