Species Account

Select species and region:



Summary Data

Season (Adult / Immature):

National Status: Migrant

Local Status: Scarce and local migrant.

Local Record: Grade 3   See here for explanation

Flight time: Arrive May-Nov.

Forewing: 12-14mm.

Foodplant: Unknown.

IMPORTANT - Please note that the maps and accounts are provisional, subject to change and further update.  The whole dataset still needs to go through the final verification process and it is likely that a very small number of records will not satisfy the present requirements and there are other records that have not been formally submitted.  The information is for guidance only.

Record breakdown:

Year first recorded193519871935
Year last recorded201120112011
Number of records498251046
Number of individuals718311498
Unique positions838182
Unique locations729162
Adult records492251034
Immature records000

For the region, we have a total of 1046 records from 162 sites. Earliest record on file is in 1935.


1720 Gem 07
© Julian Francis
1720 Gem 08
© Julian Francis
1720 Gem 06
© Will Bown
1720 Gem 05
© Will Bown
1720 Gem 04
© Jack Oughton
1720 Gem 03
© Paul Harris
1720 Gem 02
© Phyl England
1720 Gem 01
© Tom Morris

Species Account

For further information refer UK Moths.

Davey, P., 2009: A strongly migratory species with a global distribution (apart from Australasia) occurring annually across southern districts of England, the larval foodplant is unknown. Like the Vestal, this species does not seem to be able to survive the UK winter in any stage. The markings and light brown colouration of the adult male are in stark contrast to the much darker, purple-hued, female. In Dorset, the moth has been recorded in sixteen of the past twenty years. In favourable seasons, immigrants spawn up to two resident broods, and these are undoubtedly supplemented by further influxes from abroad whenever suitable weather conditions arise. Brood peaks double or treble in size with time. The moth has been recorded in twenty-four of the past twenty-seven years.

Two moths were trapped at light within an alder swamp at St Leonard's Peats on 6 July 1998 (P Davey), in a year when relatively large numbers of Gems were recorded. The locality contains much common marsh-bedstraw (Galium palustre) and fen bedstraw (Galium uliginosum), host plants for many 'Carpets'. There was no opportunity for immigration at the time of capture.

See background to species accounts.  Index of Vernacular names - Search - Random Species