Aenictus ceylonicus (Mayr)

Shattuck, S. O., 2008, Review of the ant genus Aenictus (Hymenoptera: Formicidae) in Australia with notes on A. ceylonicus (Mayr)., Zootaxa 1926, pp. 1-19 : 16-17

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Aenictus ceylonicus (Mayr)


Aenictus ceylonicus (Mayr)   HNS

Typhlatta ceylonica Mayr   HNS , 1866: 505 (combination in Aenictus   HNS by Dalla Torre, 1893: 7).

Aenictus ceylonicus var. latro Forel   HNS , 1901: 477 (junior synonym of A. ceylonicus   HNS by Wilson, 1964: 452).

Aenictus ceylonicus var. formosensis Forel   HNS , 1913: 188 (junior synonym of A. ceylonicus   HNS by Wilson, 1964: 452).

Types. Typhlatta ceylonica   HNS : Worker syntypes from Sri Lanka ( NHMW, not examined). Aenictus ceylonicus var. latro   HNS : Three worker syntypes from Poona, India ( MCZC, examined). Aenictus ceylonicus var. formosensis   HNS : Worker syntypes from Taiwan (not examined).

Comments. As previously conceived (Wilson, 1964: 452) this species extended from India and Sri Lanka eastward to Taiwan and south to Australia and contained eight junior synonyms ( formosensis Forel   HNS , latro Forel   HNS , orientalis Karavaiev   HNS , papuanus Donisthorpe   HNS , similis Donisthorpe   HNS , and turneri Forel   HNS (with its junior synonyms deuqueti Crawley   HNS and exiguus Clark   HNS )). When discussing the specimens placed in ceylonicus Wilson   HNS (1964) recognised at least some of the variation noted in this study (for example, see Wilson's figs. 37-44), but interpreted this variation as intraspecific. For example he mentioned that the subpetiolar process varies considerably in its development, but did not appreciate that this variation occurs in discrete states and shows a strong geographic pattern suggesting that a series of species are involved. A careful re-examination of these characters, combined with considerably more material, has resulted in significantly different conclusions being drawn compared to Wilson (1964).

An examination of currently available material has found that the old "ceylonicus'" contains a large number of species, including A. ceylonicus   HNS (strict sense), A. acerbus,   HNS A. orientalis,   HNS A. papuanus,   HNS A. prolixus   HNS and A. turneri   HNS . To determine the identity of A. ceylonicus   HNS itself will require considerable work and is beyond the scope of the present study. However, there are a wealth of morphological characters which allow the development of robust species hypotheses as has been demonstrated above for the Australian fauna. Having said that, morphological differences among species are often subtle and require considerable attention to detail to decipher. The following notes are provided as a starting point for a full revision of these ants.

Most of the Indian specimens share the configuration of the subpetiolar process, which forms a rounded anterior lobe followed by a posterior flat to concave extension ending at the junction with the postpetiole. Others have an elongate rectangular subpetiolar process, including the types of A. latro   HNS . Specimens with both of these morphologies can be found throughout Asia including in Taiwan, the Philippines, Vietnam and Indonesia. But while material from Vietnam has a rectangular subpetiolar process it has the dorsal surface of the mesosoma smooth and lacking any indication of the metanotal groove (most other species have at least a weak angle at the metanotal groove). Thus while the shape of the subpetiolar process is important it must be used in conjunction with other characters when determining species boundaries.

While the work undertaken here is preliminary, it clearly shows that the situation surrounding this species, and close relatives, is much more complex than that recognised by earlier workers. As a first step in clarifying this situation the names A. orientalis   HNS and A. turneri   HNS are treated as valid species, A. papuanus   HNS and A. similis   HNS are transferred to synonymy with A. orientalis   HNS while A. formosensis   HNS and A. latro   HNS are retained as junior synonyms of A. ceylonicus   HNS . However this should be treated as preliminary until all relevant material can be studied in detail.


Austria, Wien, Naturhistorisches Museum Wien


USA, Massachusetts, Cambridge, Harvard University, Museum of Comparative Zoology














Aenictus ceylonicus (Mayr)

Shattuck, S. O. 2008

Typhlatta ceylonica Mayr

Smith 1857