Nowadays molecular species delimitation methods promote the identification of species boundaries within complex taxonomic groups by adopting innovative species concepts and theories (e.g. branching patterns, coalescence). As some of them can efficiently deal with large single-locus datasets, they could speed up the process of species discovery compared to more time consuming molecular methods, and benefit from the existence of large public datasets; these methods can also particularly favour scientific research and actions dealing with threatened or economically important taxa. In this study we aim to investigate and clarify the status of economically important moths species belonging to the genus Spodoptera (Lepidoptera, Noctuidae), a complex group in which previous phylogenetic analyses and integrative approaches already suggested the possible occurrence of cryptic species and taxonomic ambiguities. In this work, the effectiveness of innovative (and faster) species delimitation approaches to infer putative species boundaries has been successfully tested in Spodoptera, by processing the most comprehensive dataset (in terms of number of species and specimens) ever achieved; results are congruent and reliable, irrespective of the set of parameters and phylogenetic models applied. Our analyses confirm the existence of three potential new species clusters (for S. exigua (Hübner, 1808), S. frugiperda (J.E. Smith, 1797) and S. mauritia (Boisduval, 1833)) and support the synonymy of S. marima (Schaus, 1904) with S. ornithogalli (Guenée, 1852). They also highlight the ambiguity of the status of S. cosmiodes (Walker, 1858) and S. descoinsi Lalanne-Cassou & Silvain, 1994. This case study highlights the interest of molecular species delimitation methods as valuable tools for species discovery and to emphasize taxonomic ambiguities.

Between the late Oligocene and the early Miocene, climatic changes have shattered the faunal and floral communities and drove the apparition of new ecological niches. Grassland biomes began to supplant forestlands, thus favouring a large-scale ecosystem turnover. The independent adaptive radiations of several mammal lineages through the evolution of key innovations are classic examples of these changes. However, little is known concerning the evolutionary history of other herbivorous groups in relation with this modified environment. It is especially the case in phytophagous insect communities, which have been rarely studied in this context despite their ecological importance. Here, we investigate the phylogenetic and evolutionary patterns of grass-specialist moths from the species-rich tribe Apameini (Lepidoptera, Noctuidae). The molecular dating analyses carried out over the corresponding phylogenetic framework reveal an origin around 29 million years ago for the Apameini. Ancestral state reconstructions indicate (i) a potential Palaearctic origin of the tribe Apameini associated with a major dispersal event in Afrotropics for the subtribe Sesamiina; (ii) a recent colonization from Palaearctic of the New World and Oriental regions by several independent lineages; and (iii) an ancestral association of the tribe Apameini over grasses (Poaceae). Diversification analyses indicate that diversification rates have not remained constant during the evolution of the group, as underlined by a significant shift in diversification rates during the early Miocene. Interestingly, this age estimate is congruent with the development of grasslands at this time. Rather than clade ages, variations in diversification rates among genera better explain the current differences in species diversity. Our results underpin a potential adaptive radiation of these phytophagous moths with the family Poaceae in relation with the major environmental shifts that have occurred in the Miocene.

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21In water, transparency seems an ideal concealment strategy, as testified by the variety of transparent 22 aquatic organisms. By contrast, transparency is nearly absent on land, with the exception of insect 23 wings, and knowledge is scarce about its functions and evolution, with fragmentary studies and no 24 comparative perspective. Lepidoptera (butterflies and moths) represent an outstanding group to 25 investigate transparency on land, as species typically harbour opaque wings covered with coloured 26 2 scales, a key multifunctional innovation. Yet, many Lepidoptera species have evolved partially or 27 fully transparent wings. At the interface between physics and biology, the present study investigates 28 transparency in 123 Lepidopteran species (from 31 families) for its structural basis, optical 29 properties and biological relevance in relation to thermoregulation and vision. Our results establish 30 that transparency has likely evolved multiple times independently. Efficiency at transmitting light 31 is largely determined by clearwing microstructure (scale shape, insertion, colouration, dimensions 32 and density) and macrostructure (clearwing area, species size or wing area). Microstructural traits -33 density, dimensions -are tightly linked in their evolution, with different constraints according to 34 scale shape, insertion, and colouration. Transparency appears highly relevant for vision, especially 35 for camouflage, with size-dependent and activity-rhythm dependent variations. Links between 36 transparency and latitude are consistent with an ecological relevance of transparency in 37 thermoregulation, and not so for protection against UV radiation. Altogether, our results shed new 38 light on the physical and ecological processes driving the evolution of transparency on land and 39 underline that transparency is a more complex than previously thought colouration strategy. 40 41