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

Species 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 prob- lematic 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.

Auteurs: Gael  J. Kergoat, Emmanuel F. A. Toussaint, Claire Capdevielle-dulac, Anne-Laure Clamens, George Ong’amo, Desmond Conlong, Johnnie Van Den  Berg, Domingos Cugala, Beatrice Pallangyo, Onesime Mubenga, Gilson Chipabika, Rose  Ndemah, Michel Sezonlin, Gregoire Bani,  Richard Molo, Abdalla  Ali,  Paul-Andre Calatayud, Laure  Kaiser, Jean-francois Silvain, and  Bruno Le Ru