Echinopla species groups

The following is based on: [[Media:Zettel, H., Laciny, A. 2017. Further additions to the taxonomy and distribution of the ant genus Echinopla.pdf|Zettel, H. & Laciny, A. 2017. Further additions to the taxonomy and distribution of the ant genus Echinopla. Annalen des Naturhistorischen Museums in Wien, B, 119: 7-16.]]

Based on morphological characteristics Xu & Zhou (2015) divided Echinopla into five species groups. The system must be expanded and slightly modified to include the species described by Zettel & Laciny (2015) and in this study:

Echinopla mistura group
Includes one species, Echinopla mistura from the Moluccas. No change, but see also Echinopla mezgeri group.

Echinopla striata group
Includes six species as listed by Xu & Zhou (2015) plus Echinopla senilis (removed from synonymy by Zettel & Laciny 2015) and Echinopla lateropilosa (this study). Some infraspecific taxa of E. striata are probably distinct species, as well. This is the group with the widest geographical distribution, reaching from southern China and the Nicobar Islands eastwards to New Guinea. The morphological definition needs expansion, because the body dorsum is – as an exception – not striate in E. lateropilosa.

Echinopla melanarctos group
Includes four species as listed by Xu & Zhou (2015) plus Echinopla circulus.

Echinopla nitida group
Includes one species, Echinopla nitida from the Moluccas.

Echinopla serrata group
Includes eleven species as listed by Xu & Zhou (2015) plus five species described by Zettel & Laciny (2015): Echinopla angustata, Echinopla brevisetosa, Echinopla fisheri, Echinopla madli, and Echinopla wardi. This group has a wide distribution from the Malay Peninsula to north-eastern Australia. The diagnosis of Xu & Zhou (2015) needs expansion for the biconvex mesosomal dorsum of E. fisheri.

Echinopla mezgeri group
Includes one species, Echinopla mezgeri from Borneo. This species is similar to E. mistura, but for the reasons given by Zettel & Laciny (2015) a close relationship of the two species remains uncertain.

Diagnosis: Head longer than wide. Eyes positioned at mid-length of head. Palp formula 5, 3. Antennal fossae largely covered by frontal carinae. Mesosoma elongated, with weakly impressed mesometanotal suture; pronotum with tooth-like protrusions. Petiolar ventrally curved posterior margin; following gastral segments protruding ventrally. Body surface dull black, with extremely fine sculpture, almost without standing setae.

Echinopla subtilis group
Includes one species, Echinopla subtilis from Borneo. This species is very distinct from all congeners.

Diagnosis: Head wider than long. Eyes positioned behind mid-length. Frontal lobes oriented horizontally, covering most of antennal fossae. Maxillary palpi extremely long. Dorsal outline of mesosoma almost forming a straight line, with sharp, narrow metanotal groove and complete promesonotal suture. Petiole with prominent lateral spines and dorsal crest bearing small teeth and tubercles. Irregularly winding impressed sculpture on dorsal surface of head and mesonotum. Gaster tergites with very fine, dense puncturation. Dorsal surface of body with white, relatively short setae.