Genus Protanilla Taylor, 1990

Protanilla Taylor in Bolton, 1990: 279, figs 1–6.

Anomalomyrma Taylor in Bolton, 1990: 278, fig. 8. Synonymy by Griebenow (2024: 117).

Furcotanilla Xu, 2012: 481, figs 9–12. Synonymy by Hsu et al. (2017: 119).

Diagnosis

Worker

Medial mandibular margin with regularly spaced denticles; ventromedial teeth present or absent. Labrum with multiple rows of peg- or pencil-like chaetae (Griebenow 2024: figs 4c, 21a–b). Palp formula 4,1- 3. Clypeus distinct; epistomal sulcus present. Pair of medial chaetae on second protarsomere. Mesometapleural suture present, scrobiculate. Cuticular microsculpture absent from most sclerites; if present, irregularly reticulate to rugose.

Gyne

As in worker, but alate.

Male

Palp formula 4,1-3. Ocelli present; not set on tubercle. Notauli present or absent. Pterostigma present. Upper metapleuron distinct from metapectal-propodeal complex; lower metapleuron indistinct from metapectal-propodeal complex. Cupula present, annular (cf. Griebenow et al. 2023: 957, fig. 4a–c, e) or not (Griebenow et al. 2023: fig. 4d). Volsellae present; parossiculus and lateropenite distinct. Penial sclerites medially articulated.

Global key to workers of Protanilla

Condensed and amended from Griebenow (2024: 150–152).

1. Abdominal tergite II without distinct posterior face (Griebenow 2024: fig. 34c); peg-like chaetae absent from mandible ( Protanilla taylori species-group) ................................................................. 2

– Abdominal tergite II with distinct posterior face (Griebenow 2024: fig. 34b); peg-like chaetae present on mandible ...................................................................................................................................... 3

2. Cranium, pronotum and mesopleuron puncticulate to roughly sculptured; subpetiolar process lacking fenestra in profile view .................. Protanilla boltoni (Borowiec et al., 2011) (MALAYSIA: Perak)

– Cranium, pronotum and mesopleuron glabrous; subpetiolar process with fenestra in profile view.... .............................................. Protanilla helenae (Borowiec et al., 2011) (PHILIPPINES: Palawan)

3. Clypeus oblate-trapezoidal in outline, elevated above frons posteriorly (Griebenow 2024: fig. 35a); mandible bowed along anteroposterior axis of cranium ( Protanilla izanagi species-group) ............. ....................................................................... Protanilla izanagi Terayama, 2013 (JAPAN: Honshu)

– Clypeus campaniform in outline, not elevated above frons posteriorly (Fig. 11C); mandible straight ........................................................................................................................................................... 4

4. Mesotibia with one spur; mandible without laterodorsal longitudinal groove; anterior margin of clypeus concave ( Protanilla bicolor species-group) ........................................................................ 5

– Mesotibia without spurs; mandible with laterodorsal longitudinal groove; anterior margin of clypeus planar ( Protanilla rafflesi species-group) ......................................................................................... 6

5. Cranium black-brown; anterior face of petiolar node sloping in profile view ................................... .................................................. Protanilla gengma Xu, 2012 (CHINA: Yunnan; INDIA: Mizoram; VIETNAM: Dong Nai, Bac Giang, Ninh Binh)

– Cranium yellowish; anterior face of petiolar node subvertical in profile view .................................. .................................................................................. Protanilla bicolor Xu, 2002 (CHINA: Yunnan)

6. Abdominal sternite III linear to slightly concave in profile view; abdominal segments III –IV broadly conjoined, with abdominal tergite III lacking a distinct posterior face ............................................ 7

– Abdominal sternite III convex in profile view; abdominal segments III –IV not broadly conjoined, with abdominal tergite III having a distinct posterior face ............................................................... 8

7. Anterior margin of abdominal tergite IV emarginate in dorsal view; two ventrolateral teeth present on mandible .............................. Protanilla furcomandibula Xu & Zhang, 2002 (CHINA: Yunnan)

– Anterior margin of abdominal tergite IV entire in dorsal view; one ventrolateral tooth present on mandible ...................................................................... Protanilla jongi Hsu et al., 2017 (TAIWAN)

8. Anterior face of petiolar node concave in profile view .................................................................... 9

– Anterior face of petiolar node linear in profile view ...................................................................... 10

9. In profile view anterodorsal corner of petiolar node projecting anteriorly; larger species (WL> 0.8 mm) .................................................................................................................................... .............................. Protanilla rafflesi Taylor, 1990 (SINGAPORE; MALAYSIA: Sabah, Sarawak)

– In profile view anterodorsal corner of petiolar node not projecting anteriorly; smaller species (WL = 0.70–0.80 mm) (n = 2) .............................. Protanilla wardi Bharti & Akbar, 2015 (INDIA: Kerala)

10. In dorsal view petiolar node breadth and length subequal; postpetiolar node not inclined anteriorly in profile view ..................................................................................................................................11

– In dorsal view petiolar node distinctly broader than long; postpetiolar node inclined anteriorly in profile view ..................................................................................................................................... 15

11. Coloration castaneous (Griebenow 2024: fig. 22a); larger species (HL = 0.63–0.70 mm; WL = 0.99 mm) (n = 1) ................................................................................................................................. ..... Protanilla beijingensis Man et al., 2017 (CHINA: Beijing; PAKISTAN: Khyber Pakhtunkhwa)

– Coloration coppery or yellowish; smaller species (HL = 0.42–0.59 mm; WL = 0.61–0.94 mm) (n = 16) ................................................................................................................................................... 12

12. Scape not extending beyond occipital vertex of cranium in full-face view (SI ≤90); coloration coppery ................................................... Protanilla flamma Baidya & Bagchi, 2020 (INDIA: Goa)

– Scape extending beyond occipital vertex of cranium in full-face view (SI>90); coloration yellowish (Griebenow 2024: fig. 4a–c) ........................................................................................................... 13

13. Larger species (WL≥ 0.75 mm) (n = 14); postpetiolar node prominent in profile view, with anterior and posterior declivities equally rounded (Griebenow 2024: fig. 6a) ................................................ ..................................................... Protanilla lini Terayama, 2009 (TAIWAN; CHINA: Hong Kong; JAPAN: Okinawa, Ryukyu Islands; Senkaku Islands)

– Smaller species (WL<0.75 mm) (n = 11); postpetiolar node shallow in profile view, with posterior declivity more gradual than anterior declivity (Griebenow 2024: fig. 5a) ..................................... 14

14. Dorsal mandibular articulation obtuse; subpetiolar process not extending ventrad remainder of abdominal sternite II (Fig. 4A) ........................................................................................................... ............................................. Protanilla wallacei Griebenow, 2024 (MALAYSIA: Sabah, Selangor)

– Dorsal mandibular articulation acute; subpetiolar process extending ventrad remainder of abdominal sternite II (Fig. 4B) .............................................. Protanilla rong sp. nov. (VIETNAM: Ninh Binh)

15. Lateral margin of head with acute dorsal mandibular articulation in full-face view; anteroventral corner of sub-post-petiolar process obliquely truncated ..................................................................... ..................................................................................... Protanilla tibeta Xu, 2012 (CHINA: Xizang)

– Lateral margin of head without dorsal mandibular articulation apparent in full-face view (Griebenow 2024: fig. 24a); anteroventral corner of sub-post-petiolar process rounded ................................... 16

16. Meso-metapleural furrow deeply excavated in profile view; very large species (HW = 0.82–0.84 mm) (n = 3) (Satria et al. 2023) .............. Protanilla eguchii Satria et al., 2023 (INDONESIA: Sumatra)

– Meso-metapleural furrow shallowly excavated in profile view; smaller species (HW = 0.48 mm) (n = 1) ................................................................... Protanilla concolor Xu, 2002 (CHINA: Yunnan)