May

Emperor moth

A majestic moth that will stop you in your tracks!

It is that time of year when my to-do list explodes even further than normal and field season is upon me within a blink of an eye – I am sure it was only Christmas two weeks ago, so apologies this month’s edition is halfway through the month! Thankfully for me (not the farmers who still desperately need rain!) the weather has been quite stable, so dawn breeding bird surveys have been a joy, as with other surveys, while trying to get my last reports written in between being out in the field to undertake time-sensitive surveys.  There has been little time to venture too far off my surveys transects, so on the weekend I went to Martin Down NNR, which is in the heart of the two wonderful Farmer Clusters I work with (Allenford and Martin Down Farmer Cluster), to look out for turtle doves and see what else was around now things have warmed up, and I wasn’t disappointed!

While catching five minutes to myself while my little daughter hunted for orchids, I wandered down a grass track, listening to skylarks, whitethroats, garden warblers and blackcaps trying to out-sing each other and I looked down in the grass and saw the most amazing moth, one that I have never seen before and always wanted to – an emperor moth (Saturnia pavonia).

Distribution and identification

The emperor moth is widespread, but never very common. They are found on heathland, moorland, woodland rides, sand dunes and grassland scrub. But they are unmistakable as they are a very large moth, with the females having a wingspan of up to 10cm, but the male is smaller, with large, feathery antennae (which is the way to sex them).

The emperor moth is a fluffy moth that is grey-brown with big, peacock-like eyespots on all four wings and pinky-red markings at the wingtips. It is the only large moth with eyespots on all four wings. The smaller eyed hawk-moth has two large eyespots on the hindwings only.

During the day, the females rest in low vegetation – like the one I found, releasing a special scent to attract males – and fly at night. The males are brighter and fly swiftly during the day, looking for the females and are often mistaken for butterflies.

When to see

April and May

Caterpillars

The caterpillars are green with black hoops around their bodies, containing yellow wart-like spots. They feed on woody plants – heather, bramble, meadowsweet, alder buckthorn, hawthorn, sallows and blackthorn. They overwinter as chrysalides, sometimes for two winters.

Did you know?

• One of the UK’s largest insects
• There are in the region of 2,300 different species of silk moths in the world, but the emperor moth is the UK’s only member of the silk-moth family. The caterpillars spin a silk cocoon in which they spend the winter.
• Once mated, the female lays her eggs in neatly arranged batches on or around the stems of various plants such as heather, bramble, and sallow. Depending on the temperature, the eggs hatch some two to three weeks later.
• First described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.

Seeing a species for the first time is always an exciting moment, but spotting this moth was a very special one for me as I have been longing to see one for such a long time – I hope you get to see one too!