73.0041 Boathouse Gem Thysanoplusia daubei – a migrant new to Ireland

73.0041 (BF 2433a) Boathouse Gem Thysanoplusia daubei (Boisduval, 1840) (Lep.: Noctuidae), a migrant new to Ireland

An example of the Boathouse Gem Thysanoplusia daubei (Boisduval, 1840) was taken by me at light at Tramore, Co. Waterford (Vice-county H6; Irish grid reference S577013), on the south-east coast of Ireland on 2 September 2020. Other migrants trapped at the time included a Diamond-back Moth Plutella xylostella (L.) and Palpita vitrealis (Rossi.), two Convolvulus Hawk-moths Agrius convolvuli (L.) and two Silver Y Autographa gamma (L.). Additionally, at dusk five Hawk-moths were seen nectaring simultaneously at the Tobacco plants Nicotiana spp., although I suspect three or four more were probably visiting them. A Dark Sword-grass Agrotis ipsilon (Hufn.) was also noted nectaring.

Colin Plant informs me (personal communication) that the night of 2 September 2020 was also a night of significant primary immigrant activity in Hertfordshire, south-east England. The moth was identified with reference to Tunmore (2015. The First British Record of Boathouse Gem Thysanoplusia daubei (Boisd., 1840), Atropos: 55: 3- 13), Waring, P. Townsend, M. & Lewington, R., (2017. Field Guide to the Moths of Great Britain and Ireland, 3rd edition, Bloomsbury Publishing) and http://www.lepiforum.de/lepiwiki.pl?Thysanoplusia_Daubei.

Native to Africa, and also resident along the European Mediterranean coastline https://fauna-eu.org/, T. daubei can be found on the wing from May to November frequenting garrigue scrub, coastal dunes and rough ground, where its larvae feed on members of the daisy family Asteraceae, sow-thistles Sonchus spp., chicory Cichorium spp., mint Mentha spp. and many other herbaceous plants (Waring et. al. op. cit.). It is most likely to have originated from the Iberian Peninsula or North Africa. The closely related T. indicator (Walker, 1858) is also a resident in Africa, where its range overlaps with that of T. daubei. The forewing of T. daubei is lighter and greyer than that of T. indicator and has the stigmata less defined and less “silvery” in colour. The genitalia of both sexes provide more finite differences (Behounek, Ronkay & Ronkay, 2010. The Witt Catalogue. A taxonomic atlas of the Eurasian and North African Noctuoidea. 4. Plusiinae 2. Heterocera Press).

Thysanoplusia daubei was added to the British list in 2014 from the Lizard, Cornwall (Tunmore op. cit.) and there was a second specimen reported from Littlehampton, West Sussex during late July 2020. The Irish example, thus represents the third occurrence in the British Isles as well as the first for Ireland. The specimen will be lodged with the National Museum of Ireland, Natural History, Dublin. I would like to thank Colin Plant for his help with this note.

Bryant, T., 2020. Boathouse Gem Thysanoplusia daubei (Boisduval, 1840) (Lep.: Noctuidae), a migrant new to Ireland. Entomologist’s Record & Journal of Variation 132: 218-219.

Tony Bryant