The scientific name of any species mentioned in a manuscript must be provided upon the first mention of the common name of the species ONLY--the example at this link correctly provides the scientific name.  Remember the names of a genus, species, and subspecies are alway italicized or underlined. Subsequently in the text one can use either the common or scientific name.  After the initial mention of a genus, it is appropriate to abbreviate the genus with only the first letter (e.g. O. virginianus)