Mystrium camillae Emery

Bihn, J. H. & Verhaagh, M., 2007, A review of the genus Mystrium (Hymenoptera: Formicidae) in the Indo-Australian region., Zootaxa 1642, pp. 1-12 : 2-3

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Mystrium camillae Emery


Mystrium camillae Emery   HNS

Fig. 1-3, 10, 13

Mystrium Camillae   HNS [sic] Emery, 1889: 491, pl. 10, figs. 1-3. Syntype worker and queen: Myanmar (as "Birmania": Bhamd (Fea) [ MCSN] (not examined; photographs of syntype worker and queen examined on AntWeb ( CASENT0102123 (worker), CASENT0102124 (queen)).

Mystrium camillae Emery subsp. javana Karawaiew   HNS , 1925: 73, figs. 1 & 2. Syntype worker: Java, limestone mountain near Tjampea , no. 2389 , 2 workers on the ground, under leaves (Karawaiew) (not examined). Synonymy by Brown, 1960: 170.

Mystrium camillae   HNS ; Menozzi, 1929: 535-536, fig. 9. Revision of the genus and key to species.

Mystrium oculatum   HNS Xu, 1998: 161, figs. 1 & 2. Holotype worker: China: Yunnan Province, Mengla County, Menglun Town, Bakaxiaozhai (Xu Zheng-hui) [ SWFC] (not examined ; photographs of paratype examined on AntWeb ( CASENT0104982 (worker)) . New synonymy.

Material examined. Indonesia: Sumatra: Lampung, Tulang Bawang, Gn. Tanggang , 05°43.933' S, 105°06.598' E, 580m (1 worker, 9.VIII.2006, A. Riedel) [ SMNK] GoogleMaps ; Sumatra: Lampung, Tulang Bawang, Gn. Tanggang , 05°43.938' S, 105°06.440' E, 580m (5 workers, 9.VIII.2006, A. Riedel) [ SMNK] GoogleMaps ; Java: Jawa Barat, Ciamis, Gn. Sawal, Batu Cakra , 07°14'55'' S, 108°15'46'' E, 990m (1 worker, 1.X.2005, A. Riedel) [ SMNK] GoogleMaps . Malaysia (West): Negri Sembilan, Simpang Pertang, Pasoh Forest Reserve , 02°59' N, 102°19' E (1 worker, 29.III.1992, K. Rosciszewski) [ SMNK] GoogleMaps ; Malaysia (West): Terengganu, Lake Kenyir , 04°58' N, 102°49' E, 300-400m (22 workers, 7.-12.VII.2001, A. Schulz) [ SMNK] GoogleMaps .

Measurements and indices. Workers: HL 0.81-1.75, HW 0.85-1.64, CI 88-105, SL 0.50-1.00, SI 54- 64, ML 0.52-1.75, WL 0.91-1.49, PW 0.47-0.80 (n = 31).

Diagnosis (worker). The following character combination differentiates M. camillae   HNS from all its congeners in the Indo-Australian region: the apex of each mandible distinctly expanded and rounded in lateral view, with a more or less triangular and caudally directed tip on the inner side; outer face of labrum entirely covered with a weakly developed, irregular rugoreticulum; maxillary palps 4-segmented; the second segment of the maxillary palp shorter than the basal (first) segment and less than half as broad as the basal segment; antennal segment III shorter than twice its width; each anterolateral corner of the head produced into a short, nearly triangular, pointed spine; dorsum of head with rugose-reticulate cuticular sculpture and spatulate hairs; minute compound eyes; petiolar node not broader than twice its length measured in dorsal view.

Distribution. Widely distributed in the Indo-Australian region and neighboring countries. Recorded from Australia, Brunei, China, India, Indonesia, Malaysia, Myanmar, Papua New Guinea, the Philippines and Singapore.

Comments. Brown (1960, p. 170) gave no justification for the synonymy of M. camillae subsp. javana   HNS under M. camillae   HNS but the differences between the taxa given in the description of Karawaiew (1925) fall within the variation of the senior synonym. The most important difference between the taxa - the shape of the mandible apex - depends on the angle from which the mandible is viewed. The triangular tip is highly variable in the specimens examined and often worn out. The number of truncated teeth at the anterior clypeal margin varies from 6-7 in the specimens we have seen and thus is not a character to distinguish the taxa. In most cases there is a toothless gap between the left and right group of these teeth (but see the specimens from Northern Australia depicted on AntWeb [ CASENT0172841 , CASENT0172082 GoogleMaps ]. From Karawaiew's description it is clear that he never had a specimen of M. camillae   HNS at hand but made his judgment of the species just from the description and the drawings of Emery (1889).

Xu (1998: 161, figs. 1 & 2) notes in his description of M. oculatum   HNS that this species is close to M. camillae   HNS but differs from it by: "small eyes present; central dorsum of hat flat; metanotal groove only shallowly depressed; declivity of propodeum flat, not depressed; anterodorsal angle of petiolar node more extruding." All examined specimens of M. camillae   HNS possess minute compound eyes. The presence of eyes was already noted in the original description of M. camillae   HNS by Emery (1889) and again in Menozzi's revision. Therefore, the presence of eyes in M. oculatum   HNS cannot be regarded as a diagnostic character to distinguish it from M. camillae   HNS . All other diagnostic characters given for M. oculatum   HNS by Xu vary much among individuals of M. camillae   HNS . The morphology of M. oculatum   HNS as described by Xu (1998: 161-162, figs. 1 & 2) and shown by photographs of a paratype of M. oculatum   HNS on AntWeb ( CASENT0104982) falls well within the range of morphological variation exhibited by the examined specimens of M. camillae   HNS . Additionally, all but one metric character of M. oculatum   HNS fall into the range of M. camillae   HNS . The exception is CI, which is slightly higher.


Italy, Genova, Museo Civico di Storia Naturale




Germany, Karlsruhe, Staatliches Museum fuer Naturkunde Karlsruhe