Origin and Genetic Structure of the Trachyspahera lobata population in the U.K.
Object of research:
Millipedes, Myriapoda, Diplopoda
Less than 30 years ago, an isolated population of thwe dwarf pill millipede genus Trachysphaera was discovered on the English Isle of Wight, which were tentatively identified as T. lobata (Ribaut, 1954), albeit male specimens were lacking (Joes & Keay 1986 ). T. lobata is a species known mainly from SE France (Kime & Enghoff 2011), and is difficult to distinguish from four other little known Trachysphaera species occurring at the Spanish-French border, which are above all the very similar T. pyrenaica (Ribaut, 1907), as well as the little known T. rousseti (Demange, 1959), T. drescoi (Demange & Condé, 1961) and T. ribauti (Demange & Condé, 1961).
The discovery of an additional Trachysphaera population in Wales, and of several more specimens of the population on the Isle of Wight, including several males, raised the hope to get deeper insights in the history and identity of the Trachysphaera populations in Great Britain, some of the northernmost occurrences of the genus.
For that we chose an integrative (molecular and morphological) approach for the first time in pill millipedes. The analysis of morphology and sequence data from same specimen allows a direct comparison of morphological and genetic variation. With this approach we want to answer the question of the origin of the British Trachysphaera population, to find out whether the two disjunct populations resemble relics or more recent (anthropogenic?) introductions.