Species with large distribution ranges provide unique opportunities to investigate the mechanisms behind population divergence. Wood tiger moths, Arctia plantaginis, have a wide Holarctic distribution in which males have either yellow or white hindwings (some populations have males of both hindwing colours). Caucasian populations, however, have detectable genetic and phenotypic differences from the European populations, with males displaying a continuous variation in hindwing colour from yellow through to red.
We are currently studying which selective mechanisms differentiate these populations, and whether there are signs of pre- or post-zygotic isolation. We are also investigating why red-winged males exist only in this particular population, and the eco-evolutionary role of wing coloration in population divergence, both within the Caucasus and between Caucasian and European populations. For this purpose we have employed different approaches such as experiments with moth models in the field (above); detailed analysis of colour traits; analyses of chemical defences and their efficacy in predator deterrence; and molecular analyses. This work is a collective effort with my colleagues Ossi Nokelainen, Janne Valkonen, Johanna Mappes, Katja Rönkä, Emily Burdfield-Steel, Juan Galarza, Tõnis Tasane and Tamar Chunashvili