Llanelli Naturalists Newsletter - June 1996
Ian Morgan

The publication, in 1985, of West Wales Dragonflies, containing detailed distribution maps with a brief but very informative text, by S. Coker & A.D. Fox was a milestone in the recording of Odonata in SW Wales. The text drew attention to the importance of seepage-rich pastures on the Preseli Mountains of Pembrokeshire for the Southern Damselfly Coenagrion mercuriale and announced newcomers to the Dyfed fauna (for example the Black-tailed Skimmer Orthetrum cancellatum) and the significant rediscovery of the Club-tailed Dragonfly Gomphus vulgatissimus on the Tywi.

As a decade has now passed since the appearance of the above text, it might be useful to summarise any changes noted in our knowledge of the distribution of Carmarthenshire's species since 1985. Most changes are, perhaps expectedly, due to an improved recording effort, as more previously-unvisited sites have been surveyed. For one or two species only, there appears to have been a genuine, if limited, expansion in range.

The Keeled Skimmer Orthetrum coerulescens would be a good example in the first, larger, category. For this species in Carmarthenshire, Coker & Fox could only offer a "few records", but it has been subsequently recorded from approaching a dozen or more stations - all being flush habitats, primarily in the uplands. An updated map of its known distribution is shown below, and it is anticipated that this species would ultimately (given time and recorder effort) prove to be widespread in the uplands where flushes and mires occur.

The rather capricious Scarce Blue-tailed Damselfly Ischnura pumilio is a nationally-scarce species. Coker & Fox (1985) mention its fondness for base-enriched flushes in Pembrokeshire but recent records from Carmarthenshire suggest that this is a species of peregrine habits, with a marked ability for dispersal in order to find new, often shallow water-bodies at an early successional stage, before such sites vegetate over and presumably become more favourable to other damselflies (Fox, 1987). Cham (1993), referring to a detailed study of this species in southern England, narrates how, "on warm, sunny days with little or no cloud cover, individuals of all age classes and sex were observed flying vertically upwards in a very direct and positive manner...[this]...continued until they were lost from sight, presumably then to be carried along by the prevailing winds".

Post-1985 localities for this species are given below:

1. 2 were observed on a brackish grazing marsh near Commissioners' Bridge, Cydweli 22/408056 (20.7.1987).
2. A female was swept from upper saltmarsh vegetation (with some freshwater seepages) at Morfa-bacas 21/542977 (16.6.1988).  Perhaps this individual dispersed from one of the populations on the commons of Gower?
3. At least 12 were present on a recently expanded pond (on a peaty substrate) at Glyn Tai 22/610131 on 13th June 1988.
4. Llandybie 22/619151 - one turned up on a garden pond (1988, G.W. Hopkins).
5. One was noted over a water-filled deep ditch cut through peat at Carmel 22/589155 (Barry Stewart, June 1992).
6. B.S. also noted "30-plus, including mating pairs" at a newly-excavated pond at the Wildfowl and Wetlands Trust Centre at Penclacwydd 21/530994 (20.6.1989).

Survey work in the last decade has confirmed the importance of the low-lying coastal belt of Carmarthenshire for the Hairy Dragonfly Brachytron pratense. A map of its currently-known distribution in the county is reproduced opposite

An enormous population occupies the ditch/fen complex around the Witchett Pool on Laugharne/Pendine Burrows ("MoD Pendine") (22/20, 22/30), and significant populations also occur in the Lower Gwendraeth Valley, where, for example, they can be observed hunting low down amongst emergent vegetation on the few open ditches or ponds at the Dyfed Wildlife Trust's Ffrwd Fen Nature Reserve (22/418023 and 22/418023) or on lengths of old canals in the Pembrey-Burry Port area. It also occurs on the low-lying coastal flats SE of Llanelli, though here it is absent from several badly polluted "pills" (ditches). In this area, Machynys Ponds 21/512980 is a good site, as is the clean, broad ditch which extends approximately westwards from the new Berwick Roundabout, south of Bynea 21/542987. Proposed new fen/water body creation schemes in the Llanelli area are likely to lead to an increase in populations of this rather specialised fenland dragonfly. There are inland records of one besides the Afon Tâf near Llanddowror 22/240152 (29.5.1991) and there is a seemingly strong population around ditches west of Cors Goch Llanllwch, near Cwmcoch 22/357187 (J. McCallum pers. comm.).

The Black Darter Sympetrum danae is a probably under-recorded (though still localised) species of acidic mires, often in the uplands. It flies late, normally from mid-July to early October. "New" localities for this species are: Cors Bryn Mawr (22/672501), A.P. Fowles (20.8.1987); Allt y Garn 22/587155 and Cors Carmel 22/594156 (both September 1991); "Cors Helyg" near Cefn Bryn Brain 22/740136 (August 1991); on seepages and pools on old spoil tips at Rhandirmwyn 22/782435, (late August 1993). A thriving population has also become established on ponds formed by the blocking up of ditches on the western end 22/366185 of the DWT's Cors Goch Llanllwch reserve near Carmarthen - the only lowland site for this species in the county. For the naturalist who prefers not having to trudge over the uplands or through difficult bog terrain to see this species, a late August or early September stroll along the new boardwalk at Llyn Llech Owain Country Park remains the best option (eg at 22/567150 or 569153). The present writer would, however, prefer if local enthusiasts would search out new sites!

The Southern Hawker Aeshna mixta was confirmed as a breeding species as early as 30th August 1979, when Owain D. Hughes discovered (and photographed) tenereal specimens at the Upper Trebeddrod Reservoir ("Furnace Pond") 22/50-02-. It was subsequently found (there being no work done on Odonata in Carmarthenshire. in the intervening period) during the mid-1980's at a number of coastal ponds such as Machynys Pond and Old Castle Pond (22/500004) at Llanelli and the "Ashpits Pond" (22/462012) just east of Burry Port. A. mixta is regarded as a probable breeder at WWT Penclacwydd (B. Stewart, pers. comm.). This late-flying hawker is also known to occur commonly at the Witchett Pool, 22/28-07-.

Ten years after the discovery of A. mixta in Carmarthenshire, the Black-tailed Skimmer Orthetrum cancellatum was added to the county list by Barry Stewart who confirmed breeding at WWT Penclacwydd by observing adults emerging from exuviae on 9th June 1989. It has subsequently been proven to breed at the main Machynys Pond 21/578990 and at Dafen Pond, Llanelli 22/531041 (both June 1989). As has been many times noted elsewhere, this species prefers ponds with bare margins and individuals often return repeatedly to the same "perch". The preference for unvegetated pond edges is noticeable at Machynys and Dafen and it is likely that other new water bodies in the Llanelli area  should prove attractive to this species. Indeed, it has already colonised "Penrhyngwyn Pond" 21/516974, presumably from populations already established at the nearby Machynys Ponds or WWT Penclacwydd, and has recently (1995) been recorded at Sandy Water Park, Llanelli 22/497004.

The Ruddy Darter Sympetrum sanguineum is believed to breed at WWT Penclacwydd (B. Stewart, pers. comm.) but is only sporadic at a couple of other coastal sites (such as the small, well-vegetated easternmost of the ponds at Machynys, 21/513979), and there is a 1995 record from Bevan's Pond on the Cydweli Flats (22/413046, A Lucas).  Perhaps it is overlooked, but the distinctive intense red of the males suggests not.

The Variable Damselfly Coenagrion pulchellum is likewise a rather enigmatic species in the county. It was recorded in 1984 by Coker (1985) from a pond at Ddôl 22/226233, and the present writer has taken specimens of Coenagrion with "wine-glass" markings on the second abdominal segment at the thickly-vegetated Typha-pond at Glynea, (Bynea, 21/553989) and also the small eastern Machynys Pond. J.R. Ellis very interestingly reports a capture of a singleton from the towpath at Ffrwd Fen 22/419028 on 13th June 1993. I suspect that this species is certainly overlooked, lost in "a sea" of the commoner blue damselflies (in particular Coenagrion puella). The impression of a slightly darker abdomen and the species' preference for really well-vegetated sites may be useful pointers to future detection. The low-lying coastal belt probably offers the best chance of discovery of C. pulchellum.

References

Cham, S.  (1993).   Further observations on generation time and maturation of I. pumilio with notes on the use of a mark-recaptive programme.  J. Br. Dragonfly Soc. .9, 40-46.

Coker, S. & Fox, A.D.  (1985).  West Wales Dragonflies.  Mountain Books, Haverfordwest.

Fox, A.D.  (1987).  Ischnura pumilio (Charpentier) in Wales: a preliminary review.  J. Br Dragonfly Soc. 3:32-36.