A massive migration of CLOUDED YELLOW BUTTERFLIES is taking place now (3pm) in the North Hertfordshire/Essex border area – ones and twos have been passing over the Bishops Stortford area for the past several hours.
Clouded Yellows (Colias croceus) are fast-flying migrants to Britain. Large influxes occur in some years. The underwings are greenish yellow with two silver-white spots. It aways rests with wings closed. Upperwings are deep orange-yellow with broad dark wing margins.
HORNET CLEARWING MOTHS (Hornet Moth, sesia apiformis) were seen emerging from the base of poplar trees at 8.30 this morning in Stevenage Town Centre.
Hertfordshire Moth Recorder, Colin Plant said – ‘this is unusual, these Hornet Moths have emerged six weeks earlier than the norm.’
Clearwings are amongst the most unusual of British moths, by virtue of the transparent 'window' on their wings. In newly emerged adults these are covered with sparse scales, but on the maiden flight they are lost leaving transparent areas of wing membrane that give the group its name.
As a defence mechanism Hornet Moths have evolved to mimic a real Hornet. However Hornet Moths are completely harmless.
For more information about these fascinating Moths see Colin Plant's book – The Moths of Hertfordshire – published by HNHS last year and available to buy from HNHS for £45 post free.
