The Moths of Dawlish Warren

Dawlish Warren is a well-known site in south Devon for many naturalists, with a national reputation and indeed international designations for some of its plants and birds. Other species groups however have not been overlooked with more than 4100 species recorded on site, including 668 moths. This latter total includes 47 Nationally Scarce species (recorded in fewer than 100 GB 10km squares).

For those that are unfamiliar with the Warren, the recording area is only 210ha in size so this is clearly an exceptional site, even more so when you consider terrestrial habitats only account for around 75ha. It is the diversity of habitats squeezed into a small space that delivers this abundance of life.

The south-west corner of the recording area is marked by Langstone Rock, a 15m high red sandstone headland with habitat very distinct from the Warren. Heading north-east, the base of the spit has largely suffered from tourism development and ‘hard-engineered’ sea defences and offers little special habitat for Lepidoptera, excepting the mines of Phyllocnistis xenia on the introduced White Poplars, but the abundance of Red Valerian does mean this is a favoured area for nectaring Humming-bird Hawk-moth Macroglossum stellatarum and Jersey Tiger Euplagia quadripunctaria.

The remainder of the spit is semi-natural. The depressed central area of the spit becomes flooded in winter, supporting willow-birch-alder scrub with ponds, small areas of flower rich dune slack and marshy grassland. The scrub held the first Devon colony of Cream-bordered Green Pea Earias clorana, whilst Puss Moth Cerura vinula caterpillars are regularly found and Lunar Hornet Moth Sesia bembeciformis and Red-tipped Clearwing Synanthedon formicaeformis have also been recorded. This area is also a good source of leafminers and case-bearers with scarcer species such as Stigmella prunetorum & Coleophora coracipennella on Blackthorn and C. binderella on Alder.

Red-tipped Clearwing at Dawlish Warren (Alan Keatley)

Red-tipped Clearwing at Dawlish Warren (Alan Keatley)

The ponds and associated reeds host a good selection of wainscots with Fen Arenostola phragmitidis, Obscure Leucania obsoleta and Twin-spot Lenisa geminipuncta notable and three species of China-mark also recorded.

The grasslands are often full of Six-spot Burnet Zygaena filipendula and Yellow Belle Aspitates ochrearia, with Prochoreutis myllerana, P. sehestediana and Red Sword-grass Xylena vetusta also present.

The majority of the Outer Warren is a mix of semi-fixed dune grassland and bramble scrub with a mobile dune ridge, with areas of embryo dune now largely restricted to Warren Point. It is these areas that hold most of the rarer species including Anerastia lotella and Bryotropha umbrosella both at their only VC3 location. Other range restricted species can often be numerous including Synaphe punctalis and Pediasia contaminella.

Anerastia lotella (Patrick Clement)

Anerastia lotella (Patrick Clement)

The fixed grassland on Warren Point holds the bulk of the site’s remaining populations of Cinnabar Tyria jacobaeae and Brown-tail Euproctis chrysorrhoea. Caterpillars of the latter species can appear in large numbers and often attach themselves to humans when searching for new areas to defoliate. This rather irritating habit led the Dawlish Warren Recording Group to sponsor this species in the recent national atlas!

The dunes hold specialised species such as Beautiful Gothic Leucochlaena oditis, Shore Wainscot Mythimna litoralis, Sand Dart Agrotis ripae, Archer’s Dart A. vestigialis and Crescent Dart A. trux, whilst areas of Pellitory-of-the-wall hold both Cosmopterix pulchrimella and Bloxworth Snout Hypena obsitalis. Stands of Prickly Saltwort on the foredunes host the only Devon population of Gymnancyla canella.

Gymnancyla canella (Patrick Clement)

Gymnancyla canella (Patrick Clement)

The Inner Warren (no public access) has been a golf course for over 100 years and historically has been stable, supporting fixed-dune grassland with strips of rare dune heathland. The estuarine side of the spit supports an area of saltmarsh and thereafter expanses of estuarine mudflats. The Golf Course roughs support a similar range of species noted above, as well as populations of Opostega salaciella and Aroga velocella, the latter at its only site in Devon. The saltmarsh also has a range of specialist species including Plain Pug Eupithecia simpliciata, Coleophora maritimella, Phalonidia affinitana and Ancylosis oblitella.

In addition to the wealth of resident species, Dawlish Warren is also well placed to receive migrants and in the right conditions large numbers of Plutella xylostella, Nomophila noctuella and Silver Y Autographa gamma can be flushed during the day. Other migrants such as Humming-bird Hawk-moth and Convolvulus Hawk-moth Agrius convolvuli, Small Marbled Eublemma parva and Tebenna micalis have been recorded breeding.

More infrequent migrants include Ni Moth Trichoplusia ni, Vestal Rhodometra sacraria, Scarce Bordered Straw Helicoverpa armigera and Striped Hawk-moth Hyles livornica, with rarer species still including Diasemiopsis ramburialis, Spurge Hawk-moth Hyles euphorbiae and Crimson Speckled Utetheisa pulchella. Other visitors may or may not have travelled as far with Scarce Merveille du Jour Moma alpium, Double Line Mythimna turca, White Satin Moth Leucoma salicis and Water Ermine Spilosoma urticae all recorded, along with the first Devon record of Rosy Wave Scopula emutaria and the third of Elegia similella.

Despite all this there is still much to discover on site with new species recorded every year. In 2019, these included Stigmella anomalella, Phyllonorycter messaniella, P. rajella, Zelotherses paleana, Acentria ephemerella and Muslin Moth Diaphora mendica all presumably overlooked residents. Even with the relative lack of trapping in 2020, six further species have been found, including Red-tipped Clearwing, Agonopterix ocellana and Pammene aurana.

Many thanks to all those who have submitted records and photos over the years. The full species list can be found on the Dawlish Warren Recording Group website. If anyone has Dawlish Warren photos of species to illustrate the website please get in touch via [email protected]. Permission to run a light trap or pheromone lure on the Warren must first be sought from Teignbridge District Council or Dawlish Warren Golf Course.

Kevin Rylands, Dawlish Warren Recording Group

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