Pyroppia Hammer, 1955

Lindo, Zoë, 2018, Diversity of Peloppiidae (Oribatida) in North America, Acarologia 58 (8), pp. 91-97 : 94-95

Pyroppia Hammer

Described species of Pyroppia in North America are recorded from subarctic and arctic areas: P. lanceolata Hammer was described based on material from Alaska ( Hammer 1955), and also recorded in Yukon and Northwest Territories of Canada ( Behan 1978), while P. dentata Krivolutsky , described from the Far East of Russia, has also been recorded in Alaska ( Behan 1978). Undetermined Pyroppia have been recorded from both western ( Berch et al. 2007) and eastern ( Dwyer et al. 1997, 1998) Canada. The western species appear similar to descriptions of P. lanceolata except for possessing longer prodorsal setae and lacking distinct lamellar cusps. I have not observed specimens of Pyroppia from Newfoundland, Canada ( Dwyer et al. 1997, 1998), but specimens from Maine USA, Nova Scotia and Ontario, Canada are clearly different from the western species. They exhibit longer, lanceolate bothridial setae and likely represent a new species. That said, the specimens are very similar in appearance to the suggested undescribed species of Parapyroppia from eastern Canada (see above), except that they are tridactyl.

This raises a question about the distinctness of Pyroppia and Parapyroppia . In two cases

I have observed single specimens of each genus, collected at the same sample location, which have very similar character states with the exception of pretarsal claw number. Intraspecific variability in claw number has been reported in Acrotritia ardua (C.L. Koch) ( Lions 1964) , and Ameronothrus schneideri (Oudemans) ( Boelé and van der Hammen 1982) , however Shimano (2004) considered that variation in other traits was sufficient to consider monodactylous and bidactylous specimens of A. ardua to be separate species. Whether difference in claw number as the main morphological distinction warrants separating the genera Parapyroppia and Pyroppia will require close examination of the undescribed species from eastern North America, especially in locations where the two genera co-occur.