Reproductive barriers between strains of Spodoptera frugiperda This project aims at deciphering the factors at play in the divergence of the two sympatric strains of the fall armyworm (FAW) named corn- and rice-strain from their preferences for different host plants . This noctuid moth is an ideal model organism to investigate different reproductive barriers causing speciation. While indistinguishable, the two strains can be differentiated genetically, and they exhibit a number of phenotypic differences that can function as pre-or post-zygotic reproductive barriers. The objectives of the project are: 1) Unambiguous identification and characterization of diverging genetic loci between the strains. 2) Identification of the origin of post-zygotic reproductive isolation in invasive populations. 3) To investigate the causes of strain-specific host plant differentiation 4) To determine the causes of the strain-specific timing differentiation The aim is to decipher diverging loci between the strains, identify reproductive barriers in invaisve populations, investigate the role of the host plant and of allochronism in strain differentiation