Orange-striped Stonefly Survey

Perlodes female

Keep your eyes peeled for the Orange-striped stonefly

The Orange-striped stonefly, Perlodes microcephalus, is widespread in Europe. However due to differences between British and other European populations, the British Orange-striped stonefly has now been classified as a separate species, Perlodes mortoni.

The most recognisable difference is that in Britain the adult males are flightless with wings reduced to a stub, whereas elsewhere they have a variety of wing length, some having fully formed wings. Note – the adult females in all populations have fully formed wings. Your records of the British Orange-striped stonefly are important.

By sending specimens to the Riverfly Recording Schemes you will be contributing to research on the species status and informing conservation action. Download the flier for more information.

Orange-striped stonefly survey flier –PDF-File, 989.2 KB

What does the Orange-striped stonefly look like?

The adult Orange-striped stonefly is relatively large (males 13-18mm and females 16-23mm long) and is easily recognised by the presence of a clear orange stripe running along the top of the head and prothorax (the body section behind the head).

Perlodes female

How do I find the Orange-striped stonefly?

The adults may be found on the banks of stony rivers and streams – sheltering under rocks or crevices, or under structures e.g. bridge abutments – mainly between March and May, sometimes as late as July.

What should I do when I find the Orange-striped stonefly?

The Riverfly Recording Schemes are interested in receiving specimens of adult Orange-striped stoneflies (male and female). Specimens should be collected and stored in a small vial or tube, noting the precise location, date and by whom the specimen was found. To preserve specimens fill the tube with spirits (at least 40% abv: gin, vodka, etc.), seal and send to the Riverfly Recording Schemes at the address below, as rapidly as possible, for identification and preservation.

For more information and to request specimen tubes contact

Send your Orange-striped stonefly specimens with the completed flier, to:

Riverfly Recording Schemes

Buglife - The Invertebrate Conservation Trust

Balallan House, 24 Allan Park, Stirling FK8 2QG

Thank you for your participation. The Riverfly Recording Schemes will report findings at and in The Riverfly Partnership newsletter.

For reference: Zwick, P. 2011. Polymorphism and taxonomic problems in the Perlodes microcephalus group (Plecoptera: Perlodidae); Perlodes mortoni removed from synonymy. Illiesia, 7(26):291-296.