National Biodiversity Data Centre, WIT west campus, Carriganore, Waterford
Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht, Dublin, Ireland.
Cover photos: From top: Heptagenia sulphurea – photo: Jan‐Robert Baars; Siphlonurus lacustris –
photo: Jan‐Robert Baars; Ephemera danica – photo: Robert Thompson; Ameletus inopinatus ‐
photo: Stuart Crofts; Baetis fuscatus – photo: Stuart Crofts.
Ireland Red List Series Editors: N. Kingston & F. Marnell
Nomenclature & Checklist
Regionally determined settings
Based on almost 14,000 records for Ireland, the 33 species of Irish mayflies (Ephemeroptera) are
evaluated for their conservation status using International Union for the Conservation of
Nature (IUCN) criteria and guidelines (IUCN, 2001; 2003; 2010). Six (18%) of the Irish species
are assessed as Threatened, two species as Near Threatened and two species as data deficient.
The six Threatened species are:
Siphlonurus armatus (Northern Summer Mayfly) – Critically Endangered
Baetis atrebatinus (Dark Olive) ‐ Endangered
Ephemerella notata (Yellow Hawk) ‐ Endangered
Rhithrogena germanica (March Brown) ‐ Vulnerable
Procloeon bifidum (Pale Evening Dun) ‐ Vulnerable
Leptophlebia marginata (Sepia Dun) – Vulnerable
The two Near Threatened species are:
Kageronia fuscogrisea (Brown May Dun)
Ameletus inopinatus (Upland Summer Mayfly)
The two data deficient species are:
Baetis fuscatus (Pale Watery)
Ecdyonurus torrentis (Large Brook Dun)
records used in this assessment have been largely based on collections of nymphs.
poses a problem for species which are only reliably confirmed from adult material and has been
considered in the assessment. Interestingly, most of the Threatened species inhabit rivers,
although some also occur in lakes, and their status possibly reflects a longer and more
widespread history of pollution pressure on rivers. The
Threatened species are also those that
have restricted distributions and so are particularly vulnerable to impact. A number of other
species (Caenis macrura, Ecdyonurus torrentis and Siphlonurus alternatus) have restricted
distributions but have not been listed because no significant change has occurred between the
two time periods (pre‐1990 and 1990‐2011). Water pollution is the key threat to the species
listed. The implementation of the objectives of the Water Framework Directive should bring
about improvement in water quality which should help stem losses in aquatic biodiversity. In
the interim the aforementioned species should be prioritised for monitoring together with the
two Threatened and two data deficient species with sampling focussed particularly on the
adults. It is also essential that knowledge gaps on the autecological requirements and pollution
sensitivity of these species be addressed so as to inform conservation measures. Finally, it is
crucial that we identify and protect species‐rich refugia in catchments throughout the country
that will become important source areas for ephemeropteran and other pollution‐sensitive
species as impacted systems recover in the future.
The authors would like to thank the many scientists and naturalists who have contributed
ephemeropteran records to the National Biodiversity Data Centre, in particular the
Environmental Protection Agency, post‐graduate students in the School of Biology and
Environmental Science, University College Dublin, and Imelda O’Neill at the Northern Ireland
Environment Agency who have made large databases available for this analysis. We are very
grateful to the staff and students at these organisations who helped with the data collection
including Hugh Feeley, Pamela Maher, Gary Free, Ruth Little, Deirdre Tierney, and Imelda
O’Neill. Thanks are also due to Dr Naomi Kingston and Dr Brian Nelson, NPWS, for their
assistance with the red listing and to John Lucey and Craig McAdam who were the external
reviewers of this publication.
The Ephemeroptera, commonly known as mayflies, is an ancient order of insects dating from
the Carboniferous and Permian periods, and the oldest of the extant winged insects. There are
over 3,000 species from 42 different families (Barber‐James et al. 2008). They are totally reliant
on aquatic habitats where they live most of their life as juveniles, emerging solely to reproduce.
They have colonised a range of aquatic habitats including streams, rivers, ponds and lakes. The
greatest number of species are associated with running water where some have adapted to
particular flow and substrate conditions, while other are not so restricted, e.g. Baetis rhodani.
Most species are considered herbivorous and are categorised as grazers but some species are
also gatherers feeding on fine particulate organic matter in addition to plant material. Few
species are considered to be predators. In fact, many species have a fairly plastic diet
capitalizing on seasonally abundant food sources. Mayflies do not feed during their short‐
lived adult stage. They are unique in that they have two adult phases, the sub‐imago or dun
which usually moults within 24 hours, and the imago or spinner which is the final reproductive
stage. Life history strategies vary in that some complete their life cycle within two years while
others can produce several generations each year.
In Ireland, the Ephemeroptera are species‐poor compared to Britain and mainland Europe
(represented by only 33 species) and this is due in large part to our glacial history and isolation
from mainland Europe. Despite this they represent a key component of our freshwater
biodiversity. In running water they can constitute a high proportion, both numerically and in
terms of biomass, of the total macroinvertebrate fauna, except where conditions are highly
acidic, and they also make a significant contribution to the diet of salmonid fishes. Their
emergence is important in terms of the energy returned to terrestrial ecosystems. The adults are
consumed by a variety of animals from birds to spiders.
The Ephemeroptera are particularly important as indicators of water quality and form the core
of many biotic indices including the Irish EPA Q‐value system. In the Irish index only Baetis
as a whole particularly vulnerable to species loss. Kelly‐Quinn and Bracken (2000) expressed
concern about the apparent loss of species richness in many river systems throughout Ireland.
The records of Ephemeroptera in Ireland date as far back as the late 1800s and all of our 33
species were first recorded in Ireland within 100 years of this first record (Figure 1). The work of
Kelly‐Quinn and Bracken (2000) brought together the extensive records that existed for the
group. This database was updated by Mary Kelly‐Quinn and the National Biodiversity Data
Centre in 2012 with data from university research projects and from river biologists at the
Environmental Protection Agency and the Northern Ireland Environment Agency. The primary
data repository is the National Biodiversity Data Centre with all records verified by Mary Kelly‐
Quinn. This database was used for the red list analysis. It is now also available online through
Biodiversity Maps (https://maps.biodiversityireland.ie/).
At the time of writing (May 2012) no ephemeropteran species are legally protected in Ireland.
The mayfly list is the seventh in a series of regional red lists for the island of Ireland being
developed by the National Parks and Wildlife Service and the Northern Ireland Environment
Agency in conjunction with the National Biodiversity Data Centre and the Northern Ireland
biological records centre, CEDaR. The International Union for the Conservation of Nature
(IUCN) provides guidelines for using the red list categories at a regional level (IUCN, 2003).
This guidance was used alongside the current IUCN categories and criteria (IUCN, 2001), and
guidelines for their use (IUCN, 2010; see Appendix 1) in the production of this red list.
Nomenclature & Checklist
Nomenclature and checklist follows O’Connor and Nelson (2012). Nomenclature for common
names follows MacAdam and Bennett (2010).
Of the five IUCN criteria only A, B and D2 were used in the absence of any population level
data for the species under consideration (Table 2) (see Appendix 1).
Regionally determined settings
The time frame for assessing change was set at 1990‐2011 and pre‐1990. The number and
distribution of records in the Ephemeroptera of Ireland database from 1850 to 2011 are shown in
Figures 1 and 2. There are more records for the period 1990‐2011 which implies that any decline
in distribution shown in the maps is conservative and the real decline may actually be greater
than the maps show. However, it also needs to be taken into account that a large proportion of
the 1990‐2011 records come from the EPA River Biologists’s data which holds records of only
six ephemeropteran species. A species was considered extinct if it had not been recorded in over
100 years. Two species were considered data deficient, i.e. little or no information on the
abundance and distribution of the species. The IUCN advise that red lists are re‐evaluated
every five years where possible, or at least every ten years. The next red list assessment for Irish
Ephemeroptera should therefore take place no later than 2022. The assessment was carried out
on an all‐Ireland basis. The IUCN regional guidelines recommend that regional assessments
should be carried out in a two‐step process (IUCN 2003). Step one is the initial assessment of the
regional population. Step two can be applied if there are any conspecific populations outside
the region that may affect the risk of extinction within the region. This was determined not to
apply to the Irish mayfly populations and the Red List Categories defined by the criteria were
records are from the EPA River Biologist’s data from 2005 to 2009).
validated record (795), (B) hectads with records before the end of 1989 (282), and (C) hectads with records
since the start of 1990 (776). The island of Ireland has just over 1000 hectads containing some land.
A total of 33 species were assessed (Table 1), which includes all of the ephemeropteran species
considered to occur in Ireland. The assessment included Baetis fuscatus which is indicated as
unconfirmed on the current Irish checklist. Its presence in Ireland requires confirmation with
adult male voucher material as previous records are based on females and nymphs (O’Connor
and Nelson 2012). All taxa were assessed at the species level in accordance with the IUCN
guidelines (IUCN 2001; 2003).
The assessment was undertaken on the 14
of May 2012 by a panel comprising Mary Kelly‐
external assessors: Craig Macadam (Ephemeroptera Recording Scheme, Great Britain) and John
Lucey (Environmental Protection Agency, Ireland).
Brief species accounts are given with the information derived from Kelly‐Quinn and Bracken
(2000). Additional ecological information is taken from Buffagni et al. (2009). Information on
pollution sensitivity is largely derived from the EPA Q‐value sensitivity classification
(McGarrigle et al. 2002). Sensitivity to deposited sediment (hereafter referred to as siltation) is
taken from Extence et al. (2011). Maps are provided for the Threatened and Near Threatened
Table 1: Red list of Irish Ephemeroptera (Mayflies). CR = Critically Endangered, EN = Endangered, VU =
Vulnerable, NT = Near Threatened, lc = least concern.
Alainites (Baetis) muticus