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Clearwing moths in Scotland

The Clearwings are a very elusive and scarce group of day-flying moths which mimic insects of other orders such as flies or wasps. In recent years the recording of the group has been transformed by the availability of pheromone lures that attract male moths to a synthetically produced sex pheromone. A total of seven Clearwing species are known to occur in Scotland. 

Please read on for details of how to take part in the survey, more information on the moths, pheromone lures available to loan and details of a field trip to see these lovely and very elusive moths.

Clearwing Surveys

To enable a better understanding of their flight periods, habitats and distribution we are encouraging surveys for three Scottish species that are of significant conservation interest - Welsh, White-barred and Large Red-belted Clearwings. 

Orange-tailed Clearwing - Sue Davies
Clearwing moth at lure -Sue Davis

Clearwing moths can be attracted to a lure that replicates the sex pheromones released by females (lures are available for purchase from specialist suppliers and are in the form of a rubber bung). Lures can be used by placing them in a small net or in a pheromone trap and hanging on a tree in sunny weather during the flight season.

Moths may settle on or nearby the lure, or in some cases may simply investigate briefly and fly off so it is important to wait by the lure to observe if any moths are attracted in. Lures should only be used for short periods; up to 30 minutes should be sufficient time for a moth to arrive in suitable habitat if it is present that day. Lures are most effective on sunny, warm days during the flight period of the target species. Detailed guidance on using lures and best practice can be found here

Surveys can be conducted with pheromone lures at known sites or in areas with suitable looking habitat. The maps below show the current known species distributions. For details of known sites for surveys, please contact Anthony McCluskey on @email

To request pheromone lures to take part in surveys, contact Anthony McCluskey on @email (for surveys in Argyll, contact David Hill on @email.)

A survey form is available below for anyone conducting surveys. BC Scotland would be very glad to receive completed forms whether any clearwings were seen or not. 




Field Trips
There will be a field trip to Glen Finglas on 4th June. Click here to visit the page for details on that event.


Flight Periods

Most of what we know about flight periods is from pheromone lure sightings. General timings are below but it is possible that species may fly earlier or later as most people try lures during the known periods. 

  • Welsh Clearwing - late-May to the end of July
  • White-barred Clearwing - mid-June to end of July (very few records)
  • Large Red-belted Clearwing - mid-May to late-June

Flight period graphs for all Scottish species can be viewed here 

Please note that the pheromone lure for White-barred Clearwing also attracts Currant Clearwing, another uncommon species in Scotland with very few records, so please check all moths attending lures to be sure of their identification! 

Welsh Clearwing - Synanthedon scoliaeformis

Welsh Clearwing - Iain Leach
Welsh Clearwing - Iain Leach

A fairly large clearwing moth, which is mostly black with two narrow yellow bands on the abdomen and a bright orange tail-fan. The caterpillar feeds on living wood in mature birch trees. The moth seems to have a distinct preference for sun-lit trunks so inhabited trees tend to be in open woodland or on the woodland edge. Further photos and information on the moth's ecology can be found here.

In Scotland, Welsh Clearwing is known from the Trossachs, Highland Perthshire, the Great Glen and one locality in Sutherland. In recent years the moth has also been found on Mull for the first time, indicating that it may be more widespread than previously thought. 

During the flight season it is also worth looking at the trunks of mature birch trees for the characteristic emergence holes. Sometimes, if the holes are fresh, pupal cases can be found protruding from the hole. This evidence is enough to confirm presence of the moth. Emergence holes will last for years, so sites can be scoped all-year round for later recording. Holes are around the diameter of a regular pencil (5mm), are perfectly round in shape and will be in live wood. The Common Longhorn beetle Rhagium mordax creates similar holes in dead wood. 

Map of Welsh Clearwing distribution in Scotland
Map of Welsh Clearwing distribution in Scotland

Large Red-belted Clearwing - Synanthedon culiciformis

Large Red-belted Clearwing - Allan Drewitt
Large Red-belted Clearwing - Allan Drewitt

A large clearwing moth, which sports a wide, bright red band across its abdomen. Combined with a scattering of reddish scales at the base of the wings, this separates it from all other species of British clearwing. The caterpillar is known to feed within recently cut stumps of birch trees. Further photos and information can be found here.

Judging by past records, the moth is widespread but very local in Scotland, with records ranging from the Borders to the Great Glen and Moray. To date, most records have been from eastern Scotland and the Highlands, although a record from Mull in 2021 suggest it could be more widespread in the west than we know.

Map of Large Red-belted Clearwing distribution in Scotland
Map of Large Red-belted Clearwing distribution in Scotland

White-barred Clearwing - Synanthedon spheciformis

White Barred Clearwing - Garry Barlow
White-barred Clearwing

A fairly dark-looking clearwing moth with a single narrow white band across the base of the abdomen and white bands on the antennae. The caterpillars feed within the base and roots of birch and alder trees. Further photos and information can be found here.

White-barred Clearwing was surprisingly discovered as new to Scotland in the Aberfoyle area of the Trossachs in 2021 and was re-found in the same area in 2022. The habitat at the site is generally maturing birch scrub on damp heathy ground. Searches of similar habitat elsewhere in Scotland could prove fruitful. 

Other Scottish Clearwing species

There are four other species of clearwing family moths recorded in Scotland: 

  • Lunar Hornet Moth - Sesia bembeciformis
  • Red-tipped Clearwing - Synanthedon formicaeformis
  • Currant Clearwing - Synanthedon tipuliformis
  • Thrift Clearwing - Pyropteron muscaeformis