70.127 Horisme tersata (Fern)
fw: 14-18mm; Jun-Aug; travellers joy (Clematis vitalba); common on calcareous soils in the southern half of England and S.Wales
ID: Characterised by the black line formed from the dorsal portion of the 2nd cross-line on each forewing and the posterior margin of the dorsum of the first abdominal segment. H.vitalbata (Small Waved Umber) has a much more solidly black median fascia and a contrastingly pale costal portion of the forewing; together with an extensively black dorsum of the abdomen. H.radicaria (Cryptic Fern) has recently been added to the British list following its discovery in Kent and Sussex - it is very similar to H.tersata; it may be suspected by pallor of the forewing apex costal to the black apical streak, and absence of a forewing discal spot, but requires confirmation by genital dissection.
Male genitalia: see image right and see H.radicata for more detail |
§1 Folkestone Warren, Kent; 04/07/2013; male; fw 14.8mm
§2 Foulness, Essex; 13/06/2020; male; fw 14.7mm
§3 Foulness, Essex; 08/07/2023; female; fw 15.1mm
§4 Heydon, Cambridgeshire; 22/05/2024
All images © Chris Lewis
§2 Foulness, Essex; 13/06/2020; male; fw 14.7mm
§3 Foulness, Essex; 08/07/2023; female; fw 15.1mm
§4 Heydon, Cambridgeshire; 22/05/2024
All images © Chris Lewis
Page published 29/04/2013 (§1-2) | §3 added 22/04/2014 | §4 added 28/06/2020 | §1&2 re-identified as H.radicata and removed, §3&4 renumbered as §1&2 28/05/2022 | §3 added 04/10/2023 | §4 added 27/05/2024