Atropos migrant insect review – End of July 2010

Numbers of the regular migrant butterflies Clouded Yellow Colias croceus, Red Admiral Vanessa atalanta and Painted Lady V. cardui continued to be in short supply although there was an increase in the latter two species over 19th – 20th in the Dungeness area. What must have been a spectacular sight though was c3,000 ‘White butterflies’ coming in off the sea at Spurn, East Yorkshire, on 19th in a period of 20 minutes, along with 140 Peacock Inachis io. Various reports of out-of-range Silver-washed Fritillary Argynnis paphia came from East Anglia, but it is not clear whether or not these are deliberate releases or progeny from earlier releases.

In contrast to the butterflies, it was a very exciting second half to the month for Odonata. Sightings included Lesser Emperor Anax parthenope at Cliffe Marshes on 21st and Dungeness between 25th – 29th (both Kent) and in Hampshire at Shortheath Common on 20th. However, following large numbers recently in France, the undoubted highlight has been the appearance of the Southern Migrant Hawker Aeshna affinis (also known as the Blue-eyed Hawker) at several sites in Essex and Kent – the first time this species has been ‘twitchable’ in the British Isles. At least seven were noted at Hadleigh Castle Country Park, near Benfleet, Essex, right up to the month’s end with Cliffe Marshes, Kent, hosting at least two. Directions to Hadleigh Castle Country Park: Use Benfleet Station car park, then follow central path east for 2/3 mile to pond just north of railway and south of ridge. View vegetated ditch running south TQ 788 857. The Red-veined Darter Sympetrum fonscolombii was reported from Norfolk, Wiltshire and Dorset.

Damselfly sightings included Southern Emerald Damselfly Lestes barbarus again at Cliffe Marshes, Kent - up to two until the month’s end. Directions: Cliffe RSPB 300 yards NW of second viewing mound 200 yards W of track in dyke running South TQ 719 779. Last year’s mega damselfly – the Willow Emerald Damselfly Lestes viridis seems to have been paled into insignificance. Suffolk currently seems to be a good County with reports from half a dozen or so localities. Directions to a reliable site: Candlet Farm, Trimley St Mary, near Felixstowe, walk along North/South footpath east of pond at TM 292 366.

It was a very busy second half of July for mothing, with many rare immigrant species appearing. Following the report of five Splendid Brocade Lacanobia splendens in the previous summary; there was an unprecedented arrival when all records were smashed, perhaps as many as fifty appeared in Kent during the second half of the month. Multiple counts were made from the Dungeness, Dymchurch, Thanet, Sandwich Bay and Sissinghurst areas. A few made it to Dorset and Sussex with a singleton northwards to Essex – Clacton on 16th.

Another rare migrant – the Orache Moth Trachea atriplicis also put in a very good showing with six records from the Dungeness area alone in the latter half of July. Further records on the night of 19th came from Staplecross, East Sussex; Langton Matravers, Dorset, and Bonchurch, Isle of Wight.

The regular immigrant moths Vestal Rhodometra sacraria, Gem Orthonama obstipata, Small Mottled Willow Spodoptera exigua and Bordered Straw Helicoverpa armigera were in very short supply with just a handful appearing, mostly at coastal stations although an exigua at Norchard, Worcestershire, on 16th was an excellent inland record.

One species which bucked this trend was the Silver Y Autographa gamma. This species appeared in plague proportions, particularly in Norfolk, with some very large counts made: ‘several hundred thousand’ on Scolt Head and c90,000 on Sea Lavender at Titchwell on 21st. Large numbers were also light trapped with 1,200 at Orfordness, Suffolk on 24th.

Only one Convolvulus Hawk-moth Agrius convolvuli was noted: at Rye Harbour, East Sussex on 24th. Rarer still was the Death’s-head Hawk-moth Acherontia atropos which survived being strimmed at Dover, Kent, on 27th! Humming-bird Hawk-moth Macroglossum stellatarum were widely recorded with a significant influx taking place and records as far north as Shetland with a single on Whalsay and one which landed on a fishing boat 10 miles west of Muckle Flugga.

Rare immigrant moths abounded with the highlight being only the second British record in 77 years (since the extinction of the species as a British resident) of Marsh Dagger Acronicta strigosa at Pagham, West Sussex on 18th (I. Lang). Interestingly the previous British immigrant record was from Rye in East Sussex in 1996. Other extreme rarities included Dusky Hook-tip Drepana curvatula at Dungeness, Kent on 19th (D. Beck) and some late news of a Scar Bank Gem Ctenoplusia limbirena on Thanet on 14th.

At least five Plumed Fan-foot Pechipogo plumigeralis were noted from Kent and East Sussex during the latter half of the month. There were two records of Small Marbled Eublemma parva – both from Essex (Mashbury on 16th and a belated report from Great Tey on 9th). Dewick’s Plusia MacDunnoughia confusa put on a good showing with records from Lydd, Kent on 18th; St. Osyth, Essex; Richmond Park, Surrey and Southwell, Dorset all on 20th and Ipswich, Suffolk.

Notable pyralids during late July included Conobathra tumidana on the night of 20th at Pegwell, Kent, with Duponchelia fovealis at Stubbington, Hampshire (D. Houghton) and Haimbachia cicatricella at Greatstone, Kent (P. Trodd) - both trapped on 26th.

As we look forward to August, it is a good month for further records of Camberwell Beauty Nymphalis antiopa. Odonata may well include a few Yellow-winged Darter Sympetrum flaveolum given suitable weather conditions.

The first half of August often produces some rare immigrant moths – Gypsy Moth Lymantria dispar is one that regularly turns up. Towards the middle of the month if the winds turn north-easterly keep a look out for immigrant Great Brocade Eurois occulta and Scarce Silver Y Syngrapha interrogationis.

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