Key to species of Atropacarus (Hoplophorella) Ewing, 1917 of Madagascar

1. Notogaster with a pair of longitudinal, rolled dorsal cristae; two pairs of tubercules in dorsal, posterior part............................................................. A. (H.) distinctus Niedbała & Starý, 2014 (Niedbała & Starý 2014a)

-. Notogaster without cristae; tubercules, if present are more numerous............................................. 2

2. Notogaster with numerous tubercules.................................................................... 3

-. Notogaster without tubercules............................................................................ 5

3. Prodorsum with powerful quadrangular median crista with three anterior projections; notogaster with well-developed anterior hood............................................... A. (H.) tuberculosissimus (Mahunka, 1978) (Mahunka 1978b)

-. Prodorsum with simple median crista only; notogaster without anterior hood...................................... 4

4. Notogaster anteriorly with sharp crest and concavity; setae ad 3 remote from paraxial border....................................................................................................... A. (H.) balazsi (Mahunka, 1983)

-. Notogaster with thick anterior collar; setae ad 3 very close to an 2........................ A. (H.) mwali (Mahunka, 1994)

5. All notogastral setae with phyliform, spoon or leaf-shaped setae................................................ 6

-. Notogaster with filiform, spiniform setae or slightly dilated or similar to aspergillum................................ 8

6. Notogaster with developed anterior collar........................................ A. (H.) cucullatus (Ewing, 1909)

-. Notogaster without anterior collar......................................................................... 7

7. Rostral setae directed inwards; setae c 1 remote from anterior border, more than other c setae.. A. (H.) vitrinus (Berlese, 1913)

-. Rostral setae directed forwards; setae c 1 nearer anterior border, more than other c setae...... A. (H.) hamatus (Ewing, 1909)

8. Sensilli long, whip-shaped; notogaster with setae similar to aspergillum, covered with spines in distal half................................................................................... A. (H.) mahunkai Niedbała & Starý, 2013

-. Sensilli not whip-shaped; other shape of notogastral setae...................................................... 9

9. Setae of ano-adanal plates minute, not longer than distances between them....................................... 10

-. Setae of ano-adanal plates longer than distances between them (except ad 3 setae).................................. 13

10. Notogaster without anterior hood....................................................................... 11

-. Notogaster with anterior hood........................................................................... 12

11. Notogastral setae longer, length of setae c 1- c 3 similar to distance between them.............. A. (H.) paralemurius sp. nov.

-. Notogastral setae shorter, length of setae c 1- c 3 shorter than distance between them............................................................................................ A. (H.) minisetosus (Mahunka, 1978) (Mahunka 1978a)

12. Notogaster with weak anterior hood, behind it a deep median hollow.................... A. (H.) lemurius Mahunka, 1993

-. Notogaster with anterior triangular hood reaching above prodorsum, hollow absent......................................................................................... A. (H.) multirugosus (Mahunka, 1978) (Mahunka 1978a)

13. Interlamellar setae erect, considerably different in shape from lamellar setae, setae ad 3 shorter but similar to notogastral setae......................................................................... A. (H.) singularis (Sellnick, 1959)

-. Interlamellar and lamellar setae procumbent, similar in shape, setae ad 3 spiniform, similar to other adanal setae........ 14

14. Sensilli longer, sickle-shaped; interlamellar and lamellar setae slightly lanceolate, similar in shape; exobothridial setae vestig- ial; notogastral setae lanceolate................................................. A. (H.) stilifer (Hammer, 1961)

-. Sensilli short, club-like; interlamellar setae spiniform; exobothridial setae minute; notogastral setae spiniform; notogastral setae spiniform............................................................ A. (H.) oblongus (Niedbała, 1983)