Nanhermannia nanus
Creators: name: van der Hammen, L.
Publisher: name: Zenodo
Year: 1959
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Sarcoptiformes
Nanhermanniidae
Nanhermannia
Nanhermannia nanus

description: Nanhermannia nanus (Nicolet, 1855) (= elegantula auct.)
Nothrus nanus 1) Nicolet, 1853, p. 458, pl. 7 fig. 5.
Hermannia nana, Berlese, 1885c, p. 10; 1892b, fasc. 63 (1) 2); 1896b, p. 31.
Nanhermannia elegantula, Sellnick, 1928, p. 17; Willmann, 1931, p. 96, fig. 15; Strenzke, 1953, p. 72, fig. 3.
Nanhermannia nana, Lombardini, 1936, p. 45.
1) As Michael (1888, p. 455) already remarked, nanus is a noun; it appears to be incorrect to use the word as an adjective.
2) In the explanatory text the name of the genus is spelt as Hermanna.
The identity of the present species is important because Berlese designated it as the type of the genus Nanhermannia. In the following I demonstrate that this type has generally been misinterpreted. Although the original description and figure appear at first sight to be insufficient, the locality (forest near Paris) justifies the supposition that nanus is probably not identical with nana sensu Willmann; the last-mentioned species prefers bogs, moist meadows, alder-marshes, etc.
According to verbal information kindly provided by Grandjean, and as appears from material collected by him in the forests near Paris, two species only are found in the environs investigated by Nicolet.
According to the nomenclature used in the 1953 monograph by Strenzke, these two species should be named elegantula and areolata. The first-mentioned species is common near Paris, the second much more rare. On account of this we could choose " elegantula " already as the real nanus; there are, however, still better arguments.
When the species are studied in air, in reflected light, at a small enlargement, the Observation is comparable with that made a Century ago by Nicolet. In the case of " areolata " we state that the median part of the prodorsum looks like a longitudinal ridge, whilst the portion between the bothridia is not strikingly convex. In " elegantula " the median part is broader and not like a ridge, whilst the prodorsum is distinctly embossed between the bothridia; this elevated part is posteriorly divided by a median furrow.
It is evident that the prodorsal structure as figured by Nicolet has a striking resemblance to that of our " elegantula ", so that the identity of nanus is certain. I point further to the triangular, deepened portion, drawn by Nicolet in the posterior part of the prodorsum, which is certainly the space between the two conical projections (this space is absent in nana sensu Willmann). I remark that Nicolet did not see the part of the projections, which overlaps the notogaster; the length recorded by him (0.400 mm) is inaccurate.
From the above it is apparent that Nothrus nanus Nicolet is the same species that later authors (except Berlese and Grandjean) named " elegantula ". Below I demonstrate that the real N. elegantula Berlese (1913) is identical with the species that Strenzke (1953) described as N. areolata.
To avoid future misunderstanding I selected a neotype from one of the topotypical specimens of nanus; this neotype is preserved in the Collection of the "Rijksmuseum van Natuurlijke Historie", Leiden.
It appears that Berlese (probably by chance, because it was the first Nanhermannia species he collected) correctly identified nanus. Although he enumerated the species among the representatives of Hermannia in "Note", fasc. 3 (1885c), the description followed much later (1892b).
The original specimens (from the Colli Euganei) are no more present, but two other preparations from North Italy (nos. 214/9, 1O from Belluno Pedavena and Castions di Strada respectively) are indeed nanus. Berlese's drawing (1892b) points moreover to this species.
I remark that Berlese (1892b) recorded a length of 0.400 mm (apparently taken from Nicolet), whilst later (1896b) he recorded a length of 0.510 mm (probably cited from Michael's description of a Hermannia nana that is a different species). The measurements of N. nanus are those mentioned by me in 1952 (sub elegantula): length 0.550-0.600; breadth 0.250-270 1).
1) Nanhermannia elegantissima Hammer (1958, p. 14, fig. 1), a species from South America, appears to be closely related to N. nanus (Nicolet); the differential characters are not obvious.
description: Published as part of van der Hammen, L., 1959, Berlese's Primitive Oribatid Mites, pp. 1-93 in Zoologische Verhandelingen 40 on pages 78-80