Myrmamblys

Eastern False Cork-head Ants

(Compare with Colobopsis, Pseudocolobopsis and Hypercolobopsis, the cork-head, western false cork-head, and hyper false cork-head ants, respectively.)

Myrmamblys was split into five subgenera by Santschi (1926): Myrmespera, Myrmopelta, Myrmotemnus, Paramyrmamblys, and Myrmamblys sensu stricto. For this reason, two diagnoses of Myrmamblys are provided below, one sensu Emery, the other sensu Santschi.

Myrmamblys sensu Emery

Diagnosis: Emery (1925): "Worker, soldier, and queen. - Medium to small species; worker dimorphism generally accentuated; many species with few or no intermediate between majors (soldiers) and minors. Head of majors (or soldiers) and queens, in general, significantly longer than wide (species with short heads are exceptional), with tendency to have parallel dimensions; often more-or-less obtusely truncate anteriorly, truncation usually comprising entire clypeus. Head of minors of various forms, usually elongated, with posterior margin rounded, while this margin truncate or somewhat effaced in majors and queens. Clypeus of different forms. In minors, clypeus generally occupying almost whole of buccal rim and usually carinate and produced anteriorly as rounded lobe. In majors (soldier) and queens, clypeus usually reduced to its median part, bounded by anterior tentorial pits, this part depressed, without median carina or anterior lobe, and dominated in full-face view by the cheeks (i.e., with facies of Colobopsis).

Development of the cheeks at the expense of the clypeus is a characteristic feature of the cranial dimorphism of the subgenus Myrmamblys; it is also found, but to a lesser degree, in other subgenera, and to a degree equal to, if not more pronounced, in Colobopsis, Pseudocolobopsis, Hypercolobopsis, Myrmaphaenus, Myrmobrachys, etc. A small group of African species have majors with the middle of the anterior margin of the clypeus produced anteriorly.

Frontal carinae in general sinuate; antennal insertions placed distinctly anterior to midlength of frontal carinae. Mesosomal dorsum of workers usually continuous, but often more-or-less impressed anterior to propodeum; propodeum rarely concave posteriorly, forming saddle-like profile, or laterally marginate. Petiolar scale thin or, more rarely, thick and low. Cuticle in general shining and with fine sculpture; head of majors (and of the soldiers) and queens often wholly or partly dull and with more-or-less coarse sculpture; exceptionally, cuticle largely dull and hairy (some species of African group vividus). Male. - I know too few species of this sex to formulate a diagnosis of this heterogeneous subgenus.

Geographic Distribution of Species. - Indomalaya, Japan, Australia, Oceania, Afrotropics.

Note: (1) This subgenus is very heterogeneous and perhaps deserves to be subdivided, which could be done very easily by choosing extreme forms and providing these divisions with formal names; these species would thus become the types of new subgenera. (2) I have chosen a number of notable species, around which I have gathered informal groups, only for the purpose of facilitating orientation and research."

Myrmamblys sensu Santschi

Diagnosis. Santschi (1926). - "I restrict this subgenus to the species which group around C. reticulatus Roger and corresponding to the first group of EMERY. The worker and major (soldier) have obtusely truncate heads. Clypeus rectangular, flat or fairly flat, without medial carina or anterior lobe, is usually impressed anteromedially. Clypeus entirely included in cephalic truncation. Clypeus trapezoidal in minors and often carinate. Mesosomal dorsum continuous or interrupted. Propodeum is often saddle-shaped, without margination, except in a small group.

This saddle-shape to the mesosoma brings together Myrmamblys and Myrmosaga Forel; there may be an indication to follow. Most Myrmamblys, however, have many affinities with the subgenus Myrmentoma sensu EMERY. The species with continuous mesosomal dorsa have affinities to the group caryae, and those whose propodeum is bordered (second group C. greeni Forel) with the real Myrmentoma Forel.''

(Translated and edited by B. E. Boudinot, 17 February 2017.)

Myrmamblys is currently a subgenus of Camponotus.

Species groups of Myrmamblys
Emery (1925) divided Myrmamblys into seven species groups, within which he also indicated species with uncertain affinities. Santschi (1926) transferred several of these species groups to their own subgenera (see below).

"SPECIES OF ASIA, MALAYSIA, OCEANIA, AND AUSTRALIA

Group I: reticulatus

Diagnosis. - Dorsum of worker mesosoma continuous or interrupted, but not straight; propodeum often concave, with saddle-like profile, but neither marginate nor compressed.

Group II: greeni

Diagnosis. - Dorsal face of worker propodeum depressed and laterally marginate.

Group III: moeschi

Note: this group was placed in its own subgenus, Myrmotemnus, by Santschi (1926), and today are members of the genus Colobopsis

Diagnosis. - Mesosoma of workers distinctly constricted anterior to propodeum; propodeum raised as bump. Eyes situated very posteriorly.

inquilinus

proposed by Zettel et al. 2018.

Diagnosis: Species of the inquilinus group differ from other Asian Myrmamblys species by an unmodified propodeum.

Their overall great similarity to species of the Colobopsis cylindrica group (“exploding ants”) is interpreted as a type of mimicry, as species of these two groups are often found in close proximity.

SPECIES OF AFRICA

Group IV: emarginatus

[Note: this group was placed in its own subgenus, Myrmespera, by Santschi (1926).]

Diagnosis. - Clypeus of majors more-or-less produced anteriorly. Petiolar scale thin with sharp apex.

Group V: simus

[Note: this group was placed in its own subgenus, Paramyrmamblys, by Santschi (1926).]

Diagnosis: - Defined by negative characters; mostly small species; in some species, head of majors riddled with large punctures as in Myrmotrema.

Group VII: vividus

[Note: this group was placed in its own subgenus, Myrmopelta, by Santschi (1926).]

Diagnosis. - Species usually rather large. Head of majors and queens with lateral margins more-or-less parallel, with narrow clypeus which is depressed and less produced than cheeks. Worker mesosoma often impressed anterior to propodeum (Myrmopelta (part), sensu Santschi)."

Nomenclature

 *  MYRMAMBLYS [subgenus of Camponotus]
 * Myrmamblys Forel, 1912i: 90 [as subgenus of Camponotus]. Type-species: Camponotus reticulatus, by subsequent designation of Wheeler, W.M. 1913a: 80.
 * [Type-species not Camponotus fastigatus, unjustified subsequent designation by Forel, 1914a: 263.]