Polyrhachis murina

Identification
Polyrhachis murina is morphologically a relatively stable species with specimens from Borneo and Sumatra closely comparable. Apart from some differences in the length of the pronotal spines, length and shape of the lateral petiolar spines and colour of the pubescence, which ranges from golden to silvery or just dull greyish, I found them all very similar and undoubtedly conspecific. (Kohout, 2013)

Distribution
This taxon was described from Borneo. It is also found in Philippines.

Nomenclature

 *  murina. Polyrhachis murina Emery, 1893e: 198 (w.) BORNEO. Combination in P. (Myrma): Wheeler, W.M. 1919e: 123.

Type Material


Kohout (2013): In his original description of P. murina, Emery (1893) listed Sarawak in Borneo and Jolo in the Philippines as localities for his new species, evidently considering specimens from both locations to be conspecific. I have examined two syntype workers of P. murina from Sarawak in the Emery collection in Genova, both bearing identical labels as follows: ‘Sarawak, Bedot’ and ‘Polyrhachis murina Emery’. I have also examined three additional specimens from Sumatra, deposited in the general collection of that museum and labelled ‘P. murina teste Emery’, and several specimens identified as P. murina from the Philippines. This examination has shown that specimens from the Philippines stand well apart from the syntypes of P. murina from Sarawak, with a number of characters exceeding the variability that would be expected between different populations of a single biological species. I therefore believe that the Philippine specimens represent a different species from P. murina, which is described as Polyrhachis starri.

Lectotype designation. To establish the nomenclatural stability of Polyrhachis murina and to prevent any future selection of a lectotype from specimens other than those from Sarawak, I here designate, in accordance with Article 74.7.3 of the International Code of Zoological Nomenclature (1999), one of the syntype workers from Sarawak mentioned above as the lectotype of Polyrhachis murina Emery, 1893. The specimen is lodged in the Emery collection and, in addition to the labels listed above, it now also bears a red tag: ‘Lectotype, Polyrhachis murina Emery, 1893, designated by R.J. Kohout, 2013’. The remaining specimens of the original series consequently become paralectotypes and are labelled accordingly.

Description
Worker. Dimensions (lectotype cited first): TL c. 6.75, 6.55-7.00; HL 1.78, 1.75-1.87; HW 1.40, 1.34-1.43; CI 79, 75-79; SL 2.21, 2.12-2.31; SI 158, 158-165; PW 1.22, 1.15-1.28; MTL 2.21, 2.12-2.31 (1+4 measured).

Sexuals and immature stages unknown.

Additional References

 * Kohout, R.J. 2013. A review of the Polyrhachis aculeata species-group of the subgenus Myrma Billberg (Hymenoptera: Formicidae: Formicinae), with keys and descriptions of new species. Australian Entomologist, 40, 137-171.