Protoribates chistyakovi, Ermilov, Sergey G. & Starý, Josef, 2017

Ermilov, Sergey G. & Starý, Josef, 2017, New Protoribates (Acari, Oribatida, Haplozetidae) from Vietnam, Zootaxa 4258 (6), pp. 501-524 : 522-523

Key to the Vietnamese species of the genus Protoribates

1. Bothridial setae setiform............................................................................... 2

- Bothridial setae with developed (dilated unilaterally) heads................................................... 6

2. Legs bidactylous; rostral and lamellar setae and epimeral setae 3b and 4a bacilliform; body size: 381–431 × 182–249......................... P. heterodactylus Ermilov & Anichkin, 2011 (see Ermilov & Anichkin 2011 a). Distribution: Vietnam.

- Legs mono- or tridactylous; rostral and lamellar setae and epimeral setae 3b and 4a setiform........................ 3

3. Legs monodactylous................................................................................... 4

- Legs tridactylous......................................................................................5

4. Lamellar setae minute, inserted medially to the lamellar ends; adanal setae ad 1 and ad 2 short, similar to anal setae in length; distance between notogastral porose areas A1–A1 longer than A2–A2; body size: 315–348 × 140–166......................................... P. cattienensis Ermilov & Anichkin, 2011 (see Ermilov & Anichkin 2011 b). Distribution: Vietnam.

- Lamellar setae long, inserted on the lamellar ends; adanal setae ad 1 and ad 2 distinctly longer than anal setae; distance between notogastral porose areas A1–A1 shorter than A2–A2; body size: 525–565 × 300–330................................................................ P. lophotrichus ( Berlese, 1904) (see Miko et al. 1994). Distribution: semicosmopolitan.

5. Adanal setae ad 1 and ad 2 of medium size, similar in length; interlamellar setae specifically curved mediodistally; dorsophragmata longitudinally elongated; body size: 630–680 × 431–498.............. P. chistyakovi sp. nov. Distribution: Vietnam.

- Adanal setae ad 1 of medium size, ad 2 short; interlamellar setae straight; dorsophragmata semi-oval; body length: 490–680........................................................ P. duosetus ( Hammer, 1979) . Distribution: Oriental region.

6. Legs I monodactylous, legs II–IV tridactylou1s............................................................. 7

- All legs monodactylous or tridactylous.....................................................................8

7. Adanal setae ad 1 and ad 2 of medium size, similar in length; body surface distinctly foveolate; pedotecta II dentate anteriorly; body size: 647–680 × 415–431...................................... P. shaldybinae sp. nov. Distribution: Vietnam.

- Adanal setae ad 1 of medium size, ad 2 short; body surface not distinctly foveolate; pedotecta II rounded anteriorly; body length: 470–555............................... P. dentatus ( Berlese, 1883) (see Weigmann et al. 1993). Distribution: Vietnam.

8. Legs monodactylous.................................................................................. 9

- Legs tridactylous................................................................................... 11

9. Heads of bothridial narrowly dilated; adanal setae ad 1 and ad 2 short, slightly differs from anal setae in length; body size: 320– 440 × 238–266.......................................................................................... P. capucinus Berlese , 190 2 8 (see Hammer 1961; Pérez-Íñigo 1974; Weigmann 2006; Bayartogtokh 2010). Distribution: cosmopolitan.

- Heads of bothridial setae broadly dilated; adanal setae ad 1 and ad 2 of medium size, distinctly longer than anal setae..... 10

10. Lamellar setae inserted on the lamellar ends; lamellar setae longer than rostral setae, interlamellar setae longer than bothridial setae; dorsophragmata comparatively short; body size: 448–464 × 249–265.. P. shvanderovi sp. nov. Distribution: Vietnam.

- Lamellar setae inserted on the prodorsum, medially to the lamellar ends; lamellar setae shorter than rostral setae, interlamellar setae shorter than bothridial setae; dorsophragmata comparatively long; body size: 340 × 180................................................................................ P. gracilis ( Aoki, 1982) . Distribution: Japan and Vietnam.

11. Adanal setae ad 1 and ad 2 short, similar in length; interlamellar setae not longer than lamellar setae; body length: 680............................................................... P. acutus ( Hammer, 1979) . Distribution: Oriental region.

- Adanal setae ad 1 of medium size, ad 2 short; interlamellar setae distinctly longer than lamellar setae................... 12

1. The typical case is given. However, sometimes the number of leg claws in P. dentatus is variable (see Weigmann et al. 1993).

2. Mahunka (1988 b) described P. paracapucinus from Malaysia. At present, it was recorded from the Palaearctic, Oriental, Neotropical and Ethiopian regions and Vanuatu ( Subías 2004, online version 2016; Weigmann & Ermilov 2016). This species differs from P. capucinus by the presence of 10 pairs of notogastral setae (vs. 11) and 12 barbs on bothridial setae (vs. more than 20), and the localization of notogastral porose areas A3 (between h 1 and p 1 vs. p 1 and p 2) (see Mahunka 1988 b). However, the literature analysis (e.g. Hammer 1961; Pérez-Íñigo 1974; Weigmann 2006; Bayartogtokh 2010) shows that some populations of P. capucinus also have ten pairs of notogastral setae, numerous barbs on bothridial setae and localization of porose areas A3 between h 1 and p 1. Thus, P. capucinus and P. paracapucinus are morphologically very similar and the clear differences between them are not visible, therefore, potentially, the latter is a junior synonym of P. capucinus , but the additional research is necessary.

12. Body surface distinctly foveolate; distance between notogastral porose areas A1–A1 shorter than A2–A2; femora II rounded ventroanteriorly; body size: 448–798 × 266–532..................................................................... P. bisculpturatus (Mahunka, 1988) (see Mahunka 1988 b and also Corpuz-Raros 2013). Distribution: Oriental region.

- Body surface not distinctly foveolate; distance between notogastral porose areas A1–A1 and A2–A2 similar; femora II pointed ventroanteriorly; body size: 836–976 × 582–664......................................................................................... P. maximus (Mahunka, 1988) (see Mahunka 1988 a). Distribution: Oriental region and Iran.