Pygmarrhopalites dubius ( Christiansen, 1966 )

Zeppelini, Douglas, Taylor, Steven J. & Slay, Michael E., 2009, Cave Pygmarrhopalites Vargovitsh, 2009 (Collembola, Symphypleona, Arrhopalitidae) in United States, Zootaxa 2204, pp. 1-18 : 14

Pygmarrhopalites dubius ( Christiansen, 1966)

Material examined: USA: ARKANSAS: Marion Co.: Forest Trail Ridge Cave, 5-vi-04, M.E. Slay, E. Frank, J. Terry.

Remarks. This species was described from caves in Iowa and Minnesota ( Christiansen 1966), so the occurrence in Arkansas is intriguing. Although P. dubius may only be a geographic variant of P. pygmaeus ( Christiansen 1966, Christiansen & Bellinger 1998), there is sufficient morphological differentiation to designate them as a separate species. Additionally, they were collected from the same cave, Forest Trail Ridge Cave, which provides support for a separate status of the species.