Anyone with even the remotest interest in the natural history of Cornwall can’t have failed to notice the huge influx of Painted Lady Butterflies – Cynthia cardui sweeping across our peninsula. It is one of the biggest events of it’s kind that the county has witnessed in over a decade.
During the second week of April 2009 I was staying in the Sierra Grazalema Natural Park, Andalucia, Spain, where hundreds of Painted Ladies (plus a handful of Clouded Yellows – Colias croceus) could be seen nectaring and presumably laying eggs everywhere we went.
It is thought this wave of immigrants into the Iberian peninsula originated from the Atlas Mountains of Morocco where heavy rains during the winter produced a carpet of lush vegetation that provided ample food for the caterpillars, which in turn produced huge numbers of adult Painted Ladies.
The Painted Lady can complete it’s lifecyle in roughly a month, hence the offspring of the Spanish invasion are probably those which are with us now in Cornwall. Given that weather conditions have been favourable to allow such a movement, it might be expected that other species would be arriving here. Sure enough on the 29th May 2009, along with circa 200 nectaring Painted Ladies, I noted large numbers of Silver Y moths – Autographa gamma and a couple of Hummingbird Hawkmoths – Macroglossum stellatarum along the Carleon/Poltesco Valley on the Lizard peninsula.
So if various species of Lepidoptera are reaching our shores then why not a dragonfly or two, after all true dragonflies are generally stronger flyers than butterflies & moths. Mature male Red-veined Darters – Sympetrum fonscolombei were certainly on the wing in Andalucia on the 7th April 2009. So it comes as no surprise that there are indeed Red-veined Darters arriving with the Painted Ladies in Cornwall. The British Dragonfly Society’s website (http://www.dragonflysoc.org.uk/hotnews.asp) reports that Christine Moore has recently recorded the following:
1 male & 1 female Red-Veined Darter seen in tandem & ovipositing at Boscathnoe SWLT on the 31st May.
10+ male Red-Veined Darters were observed at Windmill Farm Nature Reserve on the Lizard Peninsula on the 2nd June.
54 male Red Veined Darters (inc 5 pairs in tandem ovipositing) along the west bank of Drift Reservoir on the 2nd June.
25+ male Red Veined Darters (inc 2 pairs in tandem) were seen on Penzance model boat pool on the 3rd June.
Meanwhile Leon Truscott reported a single male Red-veined Darter at Penlee Point near Torpoint on Monday 1st June.
On Monday 5th June Roger Lane spotted a single fast moving teneral, or female Red-veined Darter on the cliff top at Charlestown (SX0451), while Henry Cook recorded a male Red-veined Darter on the eastern side on Carminow Creek at Loe Pool near Helston on the 6th June.
Adrian Parr, of the BDS Migrant Dragonfly Project has forwarded the following Red-veined Darter records :
30/05/2009 One male at Caerthillian Cove, Lizard. (per Mark Tunmore)
30/05/2009 One male at Lands End. (J. Foster)
31/05/2009 One male at Lloyd’s Lane, Lizard village. (T. Blundon)
01/06/2009 4+ at Lands End with a pair ovipositing at a nearby farm pond. (J. Foster)
05/06/2009 18 along strandline & footpaths, (recently arrived?) at Godrevy Cove. (M. Tunmore)
05/06/2009 Two near North Predannack Downs, Lizard peninsula. (Mark Tunmore)
Not quite as spectacular as the Painted Lady influx but a notable event by dragonfly standards.
On Sunday the 14th June 2009 I visited Windmill Farm on the Lizard peninsula where there were 6 males holding territories around the margins of the two northern scrapes. Although there were also lots of teneral Common Darters - Sympetrum striolatum making their maiden flights, there were no mature males to make identification of the darters a challenge.
The Red-veined Darter is a highly migratory species which is resident in the Mediterranean countries of Europe, arriving in Cornwall pretty much annually as an immigrant, although last year was a poor one. Indeed the species has successfully bred here on a number of occasions but the resident populations have seldom been sustained.
The successful years include 1997 when I recorded Red-veined Darters at a site on the Lizard peninsula in every month from May to November inclusive. Exuviae (the cast larval skins left behind after an adult emerges), were collected in August, September & October with the last teneral Red-Veined Darter being observed with it’s exuvia on the 1st November. If breeding does take place at any of the Cornish sites involved in this latest influx we could be seeing an emergence of Red-Veined Darters here later in the year during September & October.
If you have any further sightings of Red-veined Darters in the county and would like to share them do let me know via the “contact steve option” of the website.