Keys for species of the genus Gustavia (Updated from Pérez-Íñigo 1987, 1997)

Gustavia magnilamellata (Ewing, 1909) (= Serrarius connexus Berlesle, 1916), Gustavia parvula (Banks, 1909) and Gustavia rugosa Balogh, 1958 were not included in this key because their descriptions do not provide sufficient information on their morphology.

1 Sejugal suture present.................................................................................. 2

- Sejugal suture absent.................................................................................. 4

2 Translamella absent............................................ Gustavia mexicana sp. nov. Distribution: Mexico.

- Translamella present................................................................................... 3

3 Setae barbulate; in smooth; translamella with deep depression; fusiform sensillum, thin head covered with short spines...................................... Gustavia magnifica Golosova & Karppinen, 1984 . Distribution: East Asian Russia.

- le setae smooth; in slightly barbed; depression of translamella slightly deep; sensillum fusiform, head widened and smooth.................................................... Gustavia latolamellata Hammer, 1977 . Distribution: Pakistan.

4 Translamella absent................................................................................... 5

- Vestigial, incomplete or absent translamellae.............................................................. 10

5 Rostrum with pointed or rounded end..................................................................... 6

- Rostrum not pointed or rounded, concave in center........................................................... 7

6 Setas in slightly barbed, lamellae considerably broad; rostrum slightly elongated and broad; apophyses adjacent to rostrum broad and evident................................... Gustavia transylvanica Mahunka, 2006 . Distribution: Romania.

- Setae in smooth setae; lamellae narrowly flared; rostrum elongated, ending in a point and with narrow, inconspicuous apophyses............................ Gustavia maior (Berlese, 1903) (= Gustavia microcephala longirostris Mihelčič, 1957). See description and diagrams in: (Pérez-Íñigo 1997). Distribution: Mediterranean.

7 Short rostrum, barely projecting beyond the lamellar cusps ……………………………………………………….……… Gustavia microcephala (Nicolet, 1855) (= Gustavia sol Kramer, 1879). See description and diagrams in: (Pérez-Íñigo 1997). Distribution: Palearctic (frequent), Eastern and Mexico?

- Rostrum elongate, projecting beyond lamellar cusps.......................................................... 8

8 Rostrum and translamella with deep depression............. Gustavia aethiopica Mahunka, 1982 . Distribution: Ethiopic.

- Rostrum and translamella straight........................................................................ 9

9 Long lamellar cusps; sensillum with short spines covered head..................... Gustavia longicornis (Berlese, 1903) . See description and diagrams in: (Pérez-Íñigo 1997). Distribution: Mediterranean and Oriental.

- Short lamellar cusps; sensillum with elongated head equal to half its length, with a few setae at the end........................................ Gustavia fusifer (Koch, 1841) (= Neozetes bicornis Berlese, 1885; = Oribata globula Koch, 1841). See description and diagrams in: (Pérez-Íñigo 1997). Distribution: Western Palearctic.

10 Long modified gnathosoma, almost as long as rostral Setae................................................... 11

- Short modified gnathosoma, hidden under the rostral tectum.................................................. 12

11 Lamellar cusps shorter than lamellae width; sensillum head covered distally with small spines; setae p1, p2 and p3 present...................................................... Gustavia ornata Mahunka, 2011 . Distribution: Madagascar.

- Lamellar cusps longer than the width of the lamellae; sensillum head covered distally with 2–3 short spines and very long setiform termination; setae p1 long, p2 and p3 represented only by alveoli............................................................................................ Gustavia sineornata Mahunka, 2011 . Distribution: Madagascar.

12 Translamella absent; lanceolate sensillum..................... Gustavia aominensis Fujikawa, 2008 . Distribution: Japan

- Incomplete translamella; fusiform sensillum.............................................................. 13

13 Setae in long, almost reaching the anterior end of the setae le; sensillum lanceolate, with very small spines on the head; p1 setae very long, setae p2 and p3 setae absent, represented by alveoli............................................................ Gustavia longiseta Mahunka, 1984 . See description and diagrams in: (Ermilov et al. 2013). Distribution: Ethiopic

- Setas in short, barely reaching the insertion points of the setae le; sensillum fusiform; setae p1, p2 and p3 present, setiform and short.................................................................................................. Gustavia oceanica Pérez-Íñigo, 1987 . Distribution: Southern Palearctic (western Mediterranean) and Eastern (India: West Bengal, and Philippines)