Redescription of Folsomia loftyensis Womersley with notes on the sensillary arrangement of the genital segment in the genus (Collembola: Isotomidae)

Folsomia loftyensis Womersley is redescribed based on material from South Australia, Victoria and Queensland. The species exhibits, for the genus, an unusual sensillary pattern on the posterior abdominal segments. The arrangement and form of the five sensilla on the genital segment of most described species of Folsomia from the Palearctic are analysed and species divided into groups based on these characters. Several different lineages are detected.