Migrant Butterflies and Moths




Many south coast mothers were fortunate enough to witness THE greatest winter migration of moths on record. The numbers and species involved would be seen as remarkable for September and October, let alone February!

A smattering of Small Mottled Willow in Cornwall, Isles of Scilly, Dorset and East Sussex on 3rd was the first indication of migrant activity. On 4th, a Vestal was taken at light on St Mary's, Isles of Scilly winter records are extremely rare, together with a sandy form of the Nutmeg. A Scarce Bordered Straw and two Bordered Straw were taken in Weymouth, Dorset, and a Ni Moth at Staplegrove, Somerset. Humming-bird Hawk-moth (2), White-speck (1), and several Small Mottled Willow were also reported in the south on 4th. On 5 th, several more Small Mottled Willow were recorded in the south, including an impressive 23 at Portland Bird Observatory, Dorset. A Striped Hawk-moth was taken at light at Durlston Country Park, Dorset, and a Bordered Straw at Weymouth. There was little activity between 6th and 9th, with just a smattering of Small Mottled Willow in the south.

News came from abroad of huge migrations of moths passing through the Canary Islands and Portugal between 5th and 8th February; however high pressure had become firmly established over the UK, ending any hopes of the migration reaching our shores – at least that's what we thought at the time!!! On the 10th, the first goodie arrived in the shape of a Levant Blackneck, taken at light in Maen Porth, Cornwall. This was the 11th British record of this African species. On 11th, the masses arrived – 4 more Levant Blackneck in Dorset (Portland (2), West Bexington, and Puddletown; 4 Ni Moth (Portland (3) and Guernsey, Channel Islands); 16 examples of the rare pyralid Euchromius ocellea, including 12 at Portland, Dorset. This figure alone beats the highest ever annual total! Huge numbers of Small Mottled Willow were also recorded on 11th, including 164 at Portland BO. This figure may be the highest ever recorded on one night in the UK. On 12th, 3 more Levant Blackneck were taken (2 on Portland, and 1 on Guernsey); 6 Euchromius ocellea (all Dorset); A Red-headed Chestnut was taken at light at Shaugh Prior, Devon; 2 Cosmopolitan were taken on St Mary's, Isles of Scilly and Weymouth, Dorset; and 3 Ni Moth (Dorset 2, and Cornwall). On 13th, the very rare immigrant Eastern Bordered Straw was taken at light at Maen Porth, Cornwall; a Red-headed Chestnut at Ventnor, Isle of Wight, Cosmopolitan at Portland; and a Ni Moth at Codgen, Dorset. A few stragglers were recorded in the south on subsequent nights, including 2 Euchromius ocellea at Portland BO, on 16th. Very few migrants were recorded during the rest of the month.

All of the common immigrant species were recorded in good numbers throughout February, Rush Veneer and Dark Sword-grass in particular.


March was, as expected, a huge anticlimax following last month's fun and games; however a couple of notable species were recorded.

On 6th, came the surprising discovery of a Red-headed Chestnut in a Heath trap left overnight in Orchard Wood, Somerset. It is possible that the moth successfully over wintered in this country or, perhaps more likely, migrated here with the two moths taken in mid-February. 18 White-speck were recorded at light on St Mary's, Isles of Scilly between 3rd and 31st. A Gem and a Bordered Straw were taken at light on St Mary's, on 17th and 18th respectively. On 28th, the first Isles of Scilly record of Red Sword-grass was taken at light on St Mary's. This is likely to have been a migrant. Several Humming-bird Hawk-moth were recorded during the month, in Cornwall, Dorset (5), Kent (2), Essex (3), Bedfordshire, Cambridgeshire, and Shropshire.

All of the common species of immigrant were noted in small numbers, with the exception of Dark Sword-grass, which was taken in many counties throughout the month.



Not to be outdone by the moths, immigrant butterflies were noted in exceptional numbers during February.

The first Painted Lady of the month was observed on Portland, Dorset, on 3rd. A larger influx of butterflies arrived on 4th, with 20-30 noted along the south coast, between Kent and Cornwall. Numbers increased each day between 5th and 11th, with over 350 recorded in the southern coastal counties, and the occasional record further north. A few butterflies were observed on most days during mid to late February, however these were thought to have been stragglers from the earlier migration. The dates and locations of the 16 Red Admiral recorded during the month suggest that these butterflies were post-hibernators rather than primary immigrants. The only exception could be the 4 butterflies recorded on or near the coast in Dorset and Sussex on 4th.


March was a fairly average month for immigrant butterflies, with the exception of a very early Clouded Yellow at Seaton, Cornwall, on 16th. Butterflies were noted at this location during late autumn, and so it is possible this example over wintered as a larva or pupa. 15 Painted Lady were recorded during the month, mostly on or near the south coast, however one was noted as far north as Dunsop Valley, Lancashire on 1st. 10 Red Admiral were noted during the month. The five examples seen in Cornwall on 16th and 23rd may have been primary immigrants. One was also noted as far north as Washington, Tyne and Wear, on 27th.

You can send in your migrant butterfly or moth records by either completing the form on the website www.migrantmoth.com, or emailing steve@migrantmoth.com.
Written by: Steve Nash