Species of the Month - June 2017

Transparent Burnet

Zygaena purpuralis

The Transparent Burnet is one of several rare Burnet moths that are restricted to a few localities on the Scottish west coast and islands.  Some of these species are hard to tell apart, but the Transparent Burnet is easy to recognise as it has red bars instead of spots.  Be careful not to confuse it with the Cinnabar Moth whose wings each have one narrow line and two spots in red on a black background.  The Transparent Burnet has 3 broad bars on each wing and no round spots.
 

This moth inhabits south-facing slopes below rock outcrops that support Wild Thyme, its larval foodplant.  It has colonies on Mull, Skye and the Small Isles, and mainland colonies in Lorn and Kintyre.  Colonies are usually near the coast.  Even in dull weather the moths sit around conspicuously on the vegetation, and in sunshine they are very active.  Like all Burnet moths they are a day-flying species.  The flight period is from early June to early July.
 

The black part of its wing is not exactly transparent, but is certainly translucent, as this photo shows.  Andrew Masterman, the county moth recorder, is conducting extensive survey work on this species, and has asked LNHG to help with this project.  We have pheromone lures which we can lend out to anyone who's interested.  It is likely that new colonies remain to be discovered.
 

This one, taken in late June, is getting on a bit and showing signs of wear.

The larva is distinctive, hard to spot but easy to recognise once found.  Most sightings have been in early May, when the larva is full-grown and about to pupate, which it usually does in an exposed position on bare rock, risking predation to maximise heat intake.  Some pupate in the colder but safer soil layer at the base of the foodplant.

Please send in your Transparent Burnet sightings using the form below, or email sightings@lnhg.org.uk with the details if you prefer.  If you are not sure of the identity of your moth, please send a photo to sightings@lnhg.org.uk, or put one on the LNHG Facebook page.