Duolandrevus

Ma, Libin, Gorochov, Andrej V. & Zhang, Yalin, 2015, A new species of the genus Duolandrevus (Orthoptera: Gryllidae: Landrevinae) from China, Zootaxa 3963 (3), pp. 443-449 : 445

Key to Duolandrevus subgenera worldwide

1. Fore tibia usually with two tympana, but sometimes this tibia with one tympanum. Male tegmina with developed stridulatory apparatus............................................................................................ 2

- Fore tibiae without tympana. Male tegmina with only traces of stridulatory apparatus (this apparatus almost lost). [Sumatra]............................................................................. Surdolandrevus Gorochov, 2003

2. Head distinctly depressed dorsoventrally, with more or less angular rostral projection in profile. Hind tibia with articulated dorsal spines moderately long and unarticulated dorsal spines short, denticle-like...................................... 3

- Head slightly depressed or almost not depressed dorsoventrally, with rounded rostral projection in profile. Hind tibia with all dorsal spines more or less long. [Sumatra]......................................... Spinolandrevus Gorochov, 1999

3. Male genitalia with posterolateral epiphalluc lobes large and plate-like widened, or these lobes with numerous small denticles.................................................................................................... 4

- Male genitalia with posterolateral lobes not plate-like widened and lacking denticles................................ 5

4. Head moderately depressed dorsoventrally. Male genitalia with posterolateral epiphallic lobes rather small (not widened) and having numerous small denticles. [ Taiwan, Philippines, New Guinea, Lombok I.]..................... Jorama Otte, 1988

- Head strongly depressed dorsoventrally. Male genitalia with posterolateral lobes large and plate-like widened but lacking denticles. [New Guinea].......................................................... Platylandrevus Gorochov, 2005

5. Male genitalia with epiphallus lacking distinct transverse fold or folds in middle part................................ 6

- Male genitalia with epiphallus having distinct transverse fold or a pair of lateral ones in middle part.................... 7

6. Male anal plate with dorsoapical denticle and / or with bundle of dense and rather strong setae in apical part. [Sumatra, Malacca, Sulawesi; possibly also Borneo, but all species described from Borneo unrevised in accordance to recent views]........................................................................................... Bejorama Otte, 1988

- Male anal plate without both dorsoapical denticle and distinct bundle of setae in apical part. [Java, Lombok I.]............................................................................................. Duolandrevus Kirby, 1906

7. Male tegmen with lateral field much shorter than dorsal field. [Central Vietnam]............. Vietlandrevus Gorochov, 1996

- Male tegmen with lateral field not shorter or insignificantly shorter than dorsal field [from Japan and China to Northern Vietnam and Taiwan; see also notes below]............................................. Eulandrevus Gorochov, 1988