Specimen highlights

Dr Graham Rotheray, entomology curator at the National Museum of Scotland, highlights four interesting specimens from the Canna House Lepidoptera collection.
Triphaena pronuba – large yellow underwing moth

Triphaena pronuba – large yellow underwing moth

The yellow underwing moth occurs widely across the UK. In some years, numbers are boosted by migrants coming from the south. However, in recent decades the yellow underwing moth has undergone an unexplained decline. The Canna data can help us identify environmental factors that might explain this decline.

Arctia caja – garden tiger moth

Arctia caja – garden tiger moth

The garden tiger moth is similar to the yellow underwing in that it has declined in numbers. Downturns like these are affecting many of Europe’s plants and animals. Analysing the variation in numbers of those species caught on Canna and looking at how they match up to climate conditions and other environmental factors, such as availability of food plants, can help explain these declines and suggest what needs to be done to halt or reverse such losses.

Hadena caesia – grey moth

Hadena caesia – grey moth

A specimen of this moth was caught and identified by Dr John Lorne Campbell in 1952. It was the first time this species had been recorded anywhere in Scotland, having previously only been recorded in England.

Zygaena ssp – burnet moths

Zygaena ssp – burnet moths

Unusually, these are day-flying moths. Their distinctive red and black wings act as a defence against predators who read their colours as bad tasting. Dr Campbell recorded colonies in sheltered grassland on the cliffs of Canna and Sanday. Today, several colonies persist in this habitat on both islands.