Baetis rhodani, Kingmoor Nature Reserve, 29 October 19 (3 of 3)
Baetis rhodani mayfly (male) found on a wooden post in the Kingmoor South Nature Reserve, Carlisle, 29 October 19.
This is the first mayfly I've seen for several months, and so I thought it might be worth collecting so I could run it through my Ephemeroptera key. I'm not sure it was really worth the effort (see below) as the species turned out to be extremely common and widespread throughout the UK with NBN Atlas currently holding over 44,000 records!
All photos were taken using the integral camera on my SX10D microscope at various magnifications. Photo 1 shows the full insect but with the tip of its one remaining caudal filament off screen; Photo 2 shows a fore wing, an in situ close-up of its rear wings and one of its rear tarsi; Photo 3 shows the forceps and eyes.
Note on identification: The specimen was identified from Photos 1 and 2 as belonging to the Baetidae family using the Ref 1 key (hind wings present with only a few main veins, two long caudal filaments (one missing), hind tarsus with three free segments). It was further identified as belonging to the Baetis genus as the fore wing intercalary veins are paired (Photo 2). After a lengthy session with the microscope it was eventually confirmed as being either B. rhodani (B. rhodani/atlanticus) or B. buceratus, for the following reasons: The presence of a "costal process" (ie the thorn-like feature) near the base of the hind wing (Photo 2); the presence of three longitudinal veins (one of which is not visible on the photo) on this wing, with no forking; no toothlike processes on the inner margins of the forceps, including the basal segment (Photo 3, top). The forceps for these two species are illustrated as Figures 18c and 18d in the key, and the former would appear to be the better match. Also it can be seen from Photo 1 that the forceps are not pointing downwards to the ventral surface which is characteristic of the latter species.
The sighting was actually reported to iRecord as Baetis rhodani/atlanticus, as B. atlanticus is a recently discovered species which is apparently very similar to B. rhodani.
Ref 1: A key to the Adults of the British Ephemeroptera, J M Elliot and U H Humpesch, Freshwater Biological Association, Scientific Publication No 47, 1983.
Baetis rhodani, Kingmoor Nature Reserve, 29 October 19 (3 of 3)
Baetis rhodani mayfly (male) found on a wooden post in the Kingmoor South Nature Reserve, Carlisle, 29 October 19.
This is the first mayfly I've seen for several months, and so I thought it might be worth collecting so I could run it through my Ephemeroptera key. I'm not sure it was really worth the effort (see below) as the species turned out to be extremely common and widespread throughout the UK with NBN Atlas currently holding over 44,000 records!
All photos were taken using the integral camera on my SX10D microscope at various magnifications. Photo 1 shows the full insect but with the tip of its one remaining caudal filament off screen; Photo 2 shows a fore wing, an in situ close-up of its rear wings and one of its rear tarsi; Photo 3 shows the forceps and eyes.
Note on identification: The specimen was identified from Photos 1 and 2 as belonging to the Baetidae family using the Ref 1 key (hind wings present with only a few main veins, two long caudal filaments (one missing), hind tarsus with three free segments). It was further identified as belonging to the Baetis genus as the fore wing intercalary veins are paired (Photo 2). After a lengthy session with the microscope it was eventually confirmed as being either B. rhodani (B. rhodani/atlanticus) or B. buceratus, for the following reasons: The presence of a "costal process" (ie the thorn-like feature) near the base of the hind wing (Photo 2); the presence of three longitudinal veins (one of which is not visible on the photo) on this wing, with no forking; no toothlike processes on the inner margins of the forceps, including the basal segment (Photo 3, top). The forceps for these two species are illustrated as Figures 18c and 18d in the key, and the former would appear to be the better match. Also it can be seen from Photo 1 that the forceps are not pointing downwards to the ventral surface which is characteristic of the latter species.
The sighting was actually reported to iRecord as Baetis rhodani/atlanticus, as B. atlanticus is a recently discovered species which is apparently very similar to B. rhodani.
Ref 1: A key to the Adults of the British Ephemeroptera, J M Elliot and U H Humpesch, Freshwater Biological Association, Scientific Publication No 47, 1983.