Atropos migrant insect review – May 2010

The undoubted highlight of the month was the Bath White Pontia daplidice recorded in a Wembury, Devon, garden on 22nd (R. Billington). Nowadays a very rare visitor to our shores, it arrived during a spell of hot and sunny weather following southerly winds. The more regular migrant butterflies were in short supply although Clouded Yellow Colias croceus were noted from Portland, Dorset, on 12th and 24th. Numbers of Red Admiral Vanessa atalanta and Painted Lady V. cardui picked up during the last week of the month, particularly in the south-west of England with the latter obviously in far lower numbers than the spectacular 2009 invasion!

The most exciting immigrant moth captures were single Striped Hawk-moth Hyles livornica at Sholing, Southampton, Hants, on the 5th (A. Collins) and at Cury, Cornwall, on 26th (F. Johns).

The Portland Ribbon Wave Idaea degeneraria caught at Ventnor, Isle of Wight, (R. Wilson) was an interesting record and may possibly have been an immigrant. It was one of the few highlights of a rather cold National Moth Night on 15th.

The regular immigrants were generally in short supply, although did include a sprinkling of Diamond-back Moth Plutella xylostella, Rush Veneer Nomophila noctuella, Rusty-dot Pearl Udea ferrugalis, Humming-bird Hawk-moth Macroglossum stellatarum and Pearly Underwing Peridroma saucia (noted on the Isles of Scilly and on Portland, Dorset).

Dark Sword-grass Agrotis ipsilon were widely recorded with multiple counts during the last week of the month from Dorset and Cornwall. Silver Y Autographa gamma were noted throughout the month with a definite arrival in the last week, with for example, 100+ noted at Falmouth, Cornwall, by day on 25th.

Looking ahead, June is traditionally a good month to look for migrant Odonata such as Lesser Emperor Anax parthenope and Red-veined Darter Sympetrum fonscolombei. These two species have been increasingly reported in recent years from suitable water bodies.

Further reports of Clouded Yellow Colias croceus, Red Admiral V. atalanta and Painted Lady V. cardui are likely in June with the possibility of something rarer like a continental Swallowtail Papilio machaon gorganus which occasionally migrates to southern England.

Regular immigrant moths in June usually include Vestal Rhodometra sacraria, Gem Orthonama obstipata and Bordered Straw Heliothis peltigera with further records likely of Striped Hawk-moth H. livornica (particularly in the south-west of England). For those very lucky, maybe even a Spurge Hawk-moth H. euphorbiae could be on the cards – records of which have been increasing in recent years. June is a good month for Small Marbled Eublemma parva and towards the end of the month, particularly in the south-east of England - Scarce Black Arches Nola aerugula.

The past two years have produced June records of the large immigrant form of the Rannoch Looper Itame brunneata with a large and widespread influx in 2009. It will be fascinating to see if any turn up this year.

Atropos would like to thank you for your contributions to the Flight Arrivals webpage. Please keep posting your migrant news and we look forward to an exciting June.