Crematogaster aberrans Forel, 1892

Hosoishi, Shingo, 2015, Revision of the Crematogaster ranavalonae - group in Asia, with description of two new species (Hymenoptera, Formicidae), Journal of Hymenoptera Research 42, pp. 63-92 : 69

Crematogaster aberrans Forel

Fig. 26

Crematogaster aberrans Forel, 1892: 532-534. Type locality: India, Thana. Combination in C. (Oxygyne) by Forel, 1901: 375; in C. (Crematogaster) by Blaimer, 2012b: 55.

Crematogaster (Oxygyne) aberrans var. assmuthi Forel, 1913: 662. Type locality: India, Bombay. syn. n.

Crematogaster (Oxygyne) aberrans var. inglebyi Forel, 1902: 201. Type locality: India, Travancore. syn. n.

Crematogaster (Oxygyne) soror Forel, 1902: 200. Type locality: India, Poona and Bombay. Combination in C. (Crematogaster) by Blaimer, 2012b: 55. syn. n.

Type material examined.

Crematogaster aberrans : lectotype worker (top specimen of three on one pin) by present designation and five paralectotype workers from India, Thana (MHNG, examined); one syntype worker from India, Thana (NHMB, examined). Crematogaster (Oxygyne) aberrans var. assmuthi : one syntype worker from India, Bombay (M. Assmuth) (MHNG, examined). Crematogaster (Oxygyne) aberrans var. inglebyi : three syntype worker from India, Travancore (Ferguson and Ingleby) (MHNG, examined). Crematogaster (Oxygyne) soror : five syntype workers from India, Poona (Wroughton) and Bombay (Rothney) (MHNG, examined); one syntype worker from India, Bombay (Rothney) (NHMB, examined).

Non-type material examined.

THAILAND: 8 workers, Doi Chiang Dao (500-600m alt.), nr Chiang Mai, N. Thailand. 2.iv.2005 (TH05-SKY-22) (Sk. Yamane); 5 workers, Ngao, Lampang, 17.ii.1991 (No collector’s name); 4 workers, Maegar, Phayao, 30.iii.1991 (No collector’s name).

Measurements and indices

(workers, n = 10). HW 0.82-0.96; HL 0.78-0.93; CI 102-109; SL 0.64-0.74; SI 75-82; EL 0.18-0.21; PW 0.50-0.58; WL 0.90-1.05; PSL 0.09-0.12; PtL 0.25-0.30; PtW 0.25-0.32; PtH 0.17-0.20; PpL 0.15-0.19; PpW 0.25-0.33; PtHI 61-76; PtWI 97-116; PpWI 167-213; WI 100-114.

General description of worker.

Head appearing rounded in front view. Mandible indistinctly striate, with four teeth, apical and subapical teeth large, basal two teeth smaller. Scape exceeding posterior corner of head, with sparse appressed setae, each of which is about as long as scape diameter. Compound eye slightly projecting beyond lateral margin of head in full face view.

Mesonotum highly convex in lateral view. Ventrolateral katepisternal ridge indistinct. Propodeal spine short and stout; the length variable, but generally as long as propodeal spiracle, dorsum not higher than anterior propodeum in lateral view. Propodeal spiracle as large as mesothoracic spiracle pit, situated apart from the propodeal declivity in lateral view, directed laterally.

In dorsal view, shape of petiole scoop with convex side, as long as broad. Petiole with anterolateral corner angulate. Petiolar spiracle big, as wide as half of propodeal spiracle in diameter, directed laterally. Postpetiole bilobed, with slight longitudinal median sulcus. Postpetiole slightly wider than petiole in dorsal view.

Integument essentially smooth and shiny. Clypeus generally smooth and shiny, but weakly striated with faint rugulae. Malar region with feeble longitudinal rugulae. Dorsal surface of promesonotum weakly punctuated. Lateral surface of pronotum shiny, but weakly punctuated. Mesopleuron weakly punctuated. Dorsal surface of propodeum smooth and shiny. Lateral propodeum smooth and shiny.

Erect pilosity almost absent. Dorsum of head, clypeus and mesosoma with short and appressed, sparse setae. Clypeus without pair of longer setae on anteriormost portion. Anterior clypeal margin with one single longer seta and one pair of longer setae on median portion, mixed with some shorter setae on side. One to three pairs of short, erect setae on pronotal shoulder. Posterolateral tubercle with two pairs of erect setae. Ventral surface of petiole with longer appressed setae. Postpetiole with two pairs of longer setae posteriorly. Fourth abdominal tergite with appressed setae.

Body color reddish brown.

Distribution.

This species is distributed in India and Thailand.

Comments.

This species is unique among Asian Crematogaster ranavalonae -group in having the scape with sparse setae and smaller propodeal spiracles, situated apart from the propodeal declivity.

The syntype workers of C. aberrans assmuthi match well with syntype workers of C. aberrans . I treated C. aberrans assmuthi as a junior synonym of C. aberrans . The syntype workers of C. aberrans inglebyi match well with syntype workers of C. aberrans , but with only the following small difference: the former has right brown colored body (cf. Forel 1902). I concluded that C. aberrans inglebyi is a junior synonym of C. aberrans . The syntype workers of C. soror match well with syntype workers of C. aberrans . In Forel’s original description ( Forel 1902), he mentioned that the head is subquadratic. However, the posterior margin of head is not angulate, appearing rounded in front view. Thus I here synonymize C. soror with C. aberrans .

Figures

Figure 26. Crematogaster aberrans [Doi Chiang Dao, nr. Chiang Mai, N. Thaiand]. A Lateral view of body B Full face view C Dorsal view of petiole and postpetiole.