Integrative taxonomy reveals six new species related to the Mediterranean corn stalk borerSesamia nonagrioides(Lefèbvre) (Lepidoptera, Noctuidae, Sesamiina)

Abstract

244Species in the stem borer noctuid subtribe Sesamiina are notoriously difficult to distinguish because most related species have homogeneous wing patterns and almost indistinguishable genitalia. The latter is potentially problematic because this group includes several important pest species that are usually baregly distinguishable from non-pest species. In this study we focus on the Mediterranean corn stalk borer Sesamia nonagrioides (Lefèbvre), an important pest of maize with a wide area of distribution that covers most of Africa and extends to the south of Europe and western Asia. According to a recent study, this pest consists of three allopatric populations that were formerly considered as distinct species or subspecies. Here we rely on recent collections of 5470 specimens (sampled in 17 countries and 175 localities) that putatively belong to S. nonagrioides. Integrative taxonomy studies allowed us to unravel the existence of six new species that are closely related to S. nonagrioides and described in this paper. In contrast to S. nonagrioides these new species have more specific ecological preferences, as they are associated with a limited number of plant species and habitats. Dating and population genetic analyses carried out on 100 S. nonagrioides specimens also indicate a more complex population structure than previously thought for S. nonagrioides, which can probably be accounted for by late Cenozoic environmental changes.

Phylogeography of the Wheat Stem Sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae): Implications for Pest Management

“…In phytophagous insects, host plant, habitat fragmentation, reproductive system, dispersal capacity and geographical or reproductive barrier are reported as the main drivers of genetic structure [16, 17, 69]. In this study, no conclusion can be drawn regarding host plant as only two genera ( i .…”

“…This was further confirmed by the analysis of 16S sequences [53] and the PTP analysis. Although the PTP procedure is not error-free and the resulting species delimitation is putative [29], this method has been implemented in several recent studies [17, 54–57] and the procedure appears to be quite robust to different phylogenetic methods [58]. Furthermore, the high genetic diversity observed across North America both on mtDNA and microsatellite markers is also compatible with the idea of a native area on this continent [59, 60].…”

“…Color differences are common criteria to distinguish between Cephus species, but coloration varies, hence it may cloud the systematics for those species [63]. An integrative taxonomic approach, using behavior, ecology, genetics and morphology, would be particularly relevant when dealing with morphologically closely related species complexes [17, 64]. …”

“…The patterns of genetic structure in natural populations may offer new insights into the evolutionary processes and the dynamics of natural populations, and such information can be further utilized for pest management. Genetic approaches have demonstrated their usefulness for insect pest management by allowing the reconstruction of invasion routes [14–16], the identification of cryptic species and divergent lineages [16, 17] and also estimating gene flow between populations [18, 19] and providing inference of past histories ( i . e .…”

Phylogeography of Sesamia nonagrioides (Lepidoptera: Noctuidae) in Iran inferred from mitochondrial DNA

“…In this case, the European population may have originated either from such pioneer populations expanding to the northern Mediterranean from East Africa (Arabian Peninsula) or from West Africa following a forceps-like colonisation. However, this scenario of unique colonization of the Palaearctic region from East Africa as suggested recently by Kergoat et al (2015) requires more studies to be confirmed.…”