During the past week there has been an irruption of White Satin Moth, (Leucoma salicis) at Ainsdale Local nature Reserve. The event is very localised occurring in an area of just 200 square metres, south of the Ainsdale Discovery centre.
A fortnight ago whilst walking in the area I noticed that many of the creeping Willow shrubs had been stripped of their leaves. On closer examination I discovered hundreds of caterpillars which had eaten the leaves and were now beginning to pupate. I knew that in a couple of weeks time they would begin to emerge and I did not want to miss the event.
I returned early in the morning of 10th June to find that many moths had emerged during the night and were now expanding their wings.
As soon as they were able to fly the males were eager to mate and tracked down the females as soon as they had emerged.
I went back again two days later and almost all of the moths had emerged leaving the empty pupa cases. The females lay their eggs on the scrub willow bushes. The caterpillars emerge and begin to feed but then overwinter in the caterpillar stage. They resume feeding in the spring and the cycle continues.
The adult moth has a wingspan of 40 – 50 mm. The glossy satin surface of the wings give rise to the moth’s English name. The moth has black and white ringed legs and the female is larger than the male.
The adult White Satin Moth
This annual Irruption of White Satin Moths now seems to be an established event on the Sefton Coast and is a memorable occasion.