Another new moth in the light trap last weekend, and a smart one it is too. However, it took a little research and some help from my gurus on the Garden Moth Scheme Facebook page to get the identification confirmed. Hadena bicruris – Lynchis, is very similar to the Campion (Hadena rivularis), and I had to really look to decide. The only difference I could see was in the in the oval and kidney marks on the forewing. In the Lychnis these are almost always separated (1). This still a neat moth, with complicated cryptic markings, and with a forewing length of between 15-17mm, a medium sized Noctuid. It has one flight generation, and first appears in late May, remaining on the wing until July.
Lychnis is an important pollinator of White and Red Campions. But it also has a negative effect on these plants by laying it’s eggs on the flower head after it has completed the pollination. The caterpillars then feed on the seeds, reducing the plants ability to reproduce. There are a host of research papers on Lynchis and it’s effect on populations of Campions. One paper demonstrates that weather conditions can affect egg laying of Lychnis. The rise in the average day temperature of 1 degree can increase the oviposition in White Campion by 3% (2). When it is too large to remain hidden in the seed capsules, the larva hides by day near the ground, coming out to feed at night (1).
And lastly a little etymology, and why not as I’ve got the book next to me. Hadena comes from Hades, the Underworld of Greek mythology. Bicruris, is a combination of ‘bi’ for two, and ‘cruris’ – the leg. In this case the ‘legs’ refer to the stigmata on the wings (3). And of course let’s have it’s Welsh name while we’re at it – Gwyfynod Gludlys.
Lychnis has a wide distribution throughout Western Europe into Scandinavia. That distribution is reflected in the NBN distribution map, with fewer reported sightings in Northern Scotland (4).
- Waring,P. Townsend,M. And Lewington,R. (2011) Field Guide to the Moths of Great Britain and Ireland (2nd ed) British Wildlife Publishing.
- Biere, A. & Honders, S.C. 2006. Coping with third parties in a nursery pollination mutualism: Hadena bicruris avoids oviposition on pathogen-infected, less rewarding Silene latifolia. New Phytol. 169(4): 719–727.
- Emmet,A.M. (1991) The Scientific Names of British Lepidoptera: Their History and Meaning. Harley Books: Colchester.
- NBN. Hadena bicruris. https://species.nbnatlas.org/species/NBNSYS0000006266