Key to Protanilla species

The following key is based on: [[Media:Man, P., Ran, H. et al. 2017. The northern-most record of Leptanillinae in China with description of Protanilla beijingensis.pdf|Man, P., Ran, H., Chen, Z., Xu, Z. 2017. The northern-most record of Leptanillinae in China with description of Protanilla beijingensis sp. nov. (Hymenoptera: Formicidae). Asian Myrmecology 9: e009008 (DOI 10.20362/am.009008).]]

Protanilla

1

 * In profile view dorsal face of mandible with a large roughly rectangular lobe which occupied about 4/5 of the dorsal margin. Petiolar node roughly triangular with a distinct summit. Postpetiolar node inclined posteriorly, subpostpetiolar process not developed with almost straight ventral margin. In dorsal view petiolar node distinctly narrower than postpetiolar node. Head, pronotum and mesonotum microreticulate (Japan) . . . . . Protanilla izanagi


 * In profile view dorsal face of mandible without a large roughly rectangular lobe. Petiolar node roughly tapezoidal with a distinct dorsal margin. Postpetiolar node nearly vertical or inclined anteriorly, subpostpetiolar process developed with distinct ventral lobe. In dorsal view petiolar node about as broad as postpetiolar node. Head, pronotum and mesonotum smooth and shining . . . . . 2

2
return to couplet #1
 * In full face view anterior margin of clypeus deeply concave. Laterodorsal surface of mandible without longitudinal groove. In dorsal view petiolar node laterally compressed and roughly elliptic, distinctly longer than broad . . . . . 3


 * In full face view anterior margin of clypeus straight to weakly concave. Laterodorsal surface of mandible with a distinct longitudinal groove. In dorsal view petiolar node nearly square or anteroposteriorly compressed, almost as broad as long or broader than long . . . . . 4

3
return to couplet #2
 * In full face view anterior 1/3 of the head distinctly narrowed anteriorly. In profile view anterodorsal corner of petiolar node roundly prominent. Head brownish yellow. Body small with TL 2.7-3.0 mm (China: Yunnan Province) . . . . . Protanilla bicolor


 * In full face view anterior 1/2 of the head distinctly narrowed anteriorly. In profile view anterodorsal corner of petiolar node rounded. Head light black to blackish brown. Body large with TL 4.1-4.5 mm (China: Yunnan Province) . . . . . Protanilla gengma

4
return to couplet #2
 * In profile view anterior margin of petiolar node obviously concave . . . . . 5


 * In profile view anterior margin of petiolar node straight or convex, never concave . . . . . 6

5
return to couplet #4
 * In profile view anterodorsal corner of petiolar node broadly angled and formed a blunt angle. Postpetiolar node inclined anteriorly with posterodorsal corner rounded. Body color brownish yellow (Singapore, Malaysia) . . . . . Protanilla rafflesi
 * In profile view anterodorsal corner of petiolar node narrowly angled and formed a right angle. Postpetiolar node vertical with posterodorsal corner bluntly angled. Body color blackish brown (India) . . . . . Protanilla wardi

6
return to couplet #4
 * In dorsal view petiolar node nearly square, almost as broad as long. In profile view postpetiolar node vertical, not inclined anteriorly . . . . . 7
 * In dorsal view petiolar node anteroposteriorly compressed, distinctly broader than long. In profile view postpetiolar node strongly inclined anteriorly . . . . . 8

7
return to couplet #6
 * In profile view petiolar node relatively higher with bluntly angled anterodorsal corner. Dorsum of postpetiolar node moderately convex, subpostpetiolar process longer with anteroventral corner rounded. Body size smaller with TL 2.9 and HL 0.60. Body color yellowish brown (China: Taiwan Province) . . . . . Protanilla lini
 * In profile view petiolar node relatively lower with rounded anterodorsal corner. Dorsum of postpetiolar node almost straight, subpostpetiolar process longer with anteroventral corner rounded. Body size larger with TL 3.9 to 4.0 and HL 0.65 to 0.70. Body color reddish brown, posterior half of mesothorax and metathorax black (China: Beijing) . . . . . Protanilla beijingensis

8
return to couplet #6
 * In full face view lateral margin of head without a small tooth at antennal socket position. In profile view petiolar node relatively thinner, dorsal face very short, about 1/2 length of anterior face. Anteroventral corner of subpostpetiolar process rounded, not obliquely truncated (China: Yunnan Province) . . . . . Protanilla concolor


 * In full face view lateral margin of head with a small tooth at antennal socket position. In profile view petiolar node relatively thicker, dorsal face long, about as long as anterior face. Anteroventral corner of subpostpetiolar process obliquely truncated (China: Tibet Region) . . . . . Protanilla tibeta