Two new species of the genus Acherontiella (Collembola, Hypogastruridae) from caves of the Alborz and Kopet Dagh mountains in Iran

Two new subterranean species of the genus Acherontiella Absolon, 1913 from Iran are described, illustrated, and morphologically differentiated from similar species. Acherontiella nezamdoosti sp. nov. has larger distribution range covering caves of North Khorasan, Razavi Khorasan, and Tehran provinces, while A. palaciosi sp. nov. is probably restricted to Moghan Cave in Razavi Khorasan province. Both new species are characterized by absence of eyes, PAO, empodium, furca, and retinaculum.

Acherontiella nezamdoosti sp. nov. is distinguished from other species by having two small anal spines, Th II – III with setae m 1, m 4, and m 5, and four thickened anterior setae on the labrum. Acherontiella palaciosi sp. nov. is characterized by bearing two medial setae in the anterior row of the labrum thickened into spines and apically dentate, and by the absence of setae m 3 on Th I and p 3 on Th II – III. An updated key and a table summarizing diagnostic characters of world species of the genus Acherontiella are provided.