Trhypochthonius species

Weigmann, Gerd & Raspotnig, Günther, 2009, Comparative morphological and biometrical studies on Trhypochthonius species of the tectorum species group (Acari: Oribatida: Trhypochthoniidae), Zootaxa 2269 (1), pp. 1-31 : 28-29

Key to adults of the Central European Trhypochthonius species

Alternative characters within each key-couplet before (+), additional characters of the species behind (+).

1. Notogastral setae smooth or sparsely setulosed, more or less pointed ........................................................................ 5

- Anterior and dorsal notogastral setae blunt and densely setulosed (setae of the p-row may be smooth and pointed) 2

2. Notogastral setae remarkably short: lateral setae c 3 – e 2 at most about 30 µm, p 1 the longest, 40–50 µm; prodorsal setae moderately short, at most 70 µm (in). (+) The shortest notogastral setae c 1, c 2, d 1, d 2 lesser 20µm. 7–9 pairs of genital setae. Body length 500–590 µm ..................................................................................................... T. nigricans

- Notogastral setae not remarkably short: lateral setae c 3 – e 2 at least 30 µm; p 1 the longest, at least 55 µm; prodorsal setae long, in at least 80 µm.......................................................................................................................................... 3

3. Notogastral seta c 2 nearly as long as c 3 and other lateral setae (d 3 – f 2). Without distinct notogastral boss. (+) Most notogastral setae (except posterior ones) distally broadened and spinosely setulated; seta d 2 distinctly smaller and thinner than other notogastral setae. 7–11 pairs of genital setae, mostly 9–11. Body length 600–700 µm. T. tectorum

- Notogastral seta c 2 about half the length of c 3 and d 3. With distinct notogastral boss .................................................. 4

4. Body length 550–620 µm; 6–8 pairs of genital setae. (+) Anterior dorsal notogastral setae c 1, c 2, d 1 and d 2 distinctly small, less than 20 µm; e 1 and f 2 less than 30 µm; p 1 the longest, at least 55 µm ...................... T. silvestris europaeus

- Body length 680–750 µm; 12–14 pairs of genital setae. (+) Anterior dorsal notogastral setae small, c 1, d 1 and d 2 less than 26 µm, c 2 less than 30 µm; p 1 the longest, at least 90 µm .................................... T. japonicus forma occidentalis

5. Prodorsal setae smooth and pointed. (+) Notogastral setae pointed, smooth or indistinctly setulated. 8 pairs of genital setae. Body length 480–550 µm................................................................................. T. cladonicola ( Willmann, 1919)

- Prodorsal setae setulated and pointed. (+) Notogastral setae smooth, more or less blunt. 7 pairs of genital setae. Body length 560–580 µm ................................................................................................... T. semovitusi Szywilewska, 2004