Aenictus sundalandensis, Jaitrong & Yamane, 2013

Jaitrong, Weeyawat & Yamane, Seiki, 2013, The Aenictus ceylonicus species group (Hymenoptera, Formicidae, Aenictinae) from Southeast Asia, Journal of Hymenoptera Research 31, pp. 165-233 : 206-207

Aenictus sundalandensis sp. n. Fig. 22-C

Type material examined.

Holotype. INDONESIA: Worker from W. Java, Cibodas Botanical Garden, 28.XI.2009, leg. W. Jaitrong, WJT09-ID01 (MZB). Paratypes. Twenty-six workers, same data as holotype (BMHN, MCZC, MZB, SKYC, THNHM).

Non-type material examined.

MALAYSIA: E. Malaysia, Borneo, Sabah, Danum Valley, 4.XI.1996, leg. K. Eguchi, Eg96-BOR-175 (SKYC, THNHM). INDONESIA: Riaw, Pelalawan, 3.I.2009, leg. Yulminarti, LC2-TS2 (SKYC, THNHM); E. Kalimantan, Sungai Wain Protection Area, 13.III.2001, leg. G. Fredriksson (SKYC; THNHM); same loc., WJT99-ID02 (THNHM); E. Java, Purwodadi Botanical Garden, 28.VIII.2003, leg. F. Ito, FI03-80 (SKYC).

Measurements

(Holotype and paratype workers, n = 10). TL 3.00-3.30 mm; HL 0.61-0.68 mm; HW 0.65-0.73 mm; SL 0.54-0.56 mm; ML 1.03-1.13 mm; PL 0.25-0.29 mm; CI 106-108; SI 78-83.

Description of worker

(holotype and paratypes). Head in full-face view round, slightly broader than long, sides convex, posterior margin almost straight or feebly convex. Antennal scape relatively long, slightly extending beyond 2/3 of head length. Frontal carina relatively long, slightly extending beyond the level of posterior margin of torulus. Parafrontal ridge feeble and incomplete. Anterior clypeal margin concave, concealed by curved anterior extension of frontal carina. Masticatory margin of mandible with 4 teeth including a large apical tooth; basal margin almost straight or feebly concave. Maximum width of gap between anterior clypeal margin and mandibles about 1.9 times as broad as maximum width of mandible. Promesonotum strongly convex dorsally and sloping gradually to metanotal groove; mesopleuron not clearly demarcated from metapleuron; metapleural gland bulla relatively large, its maximum diameter about 2.7 times as long as distance between propodeal spiracle and metapleural gland bulla. Propodeum in profile with almost straight dorsal outline; propo deal junction acutely angulate, overhanging the declivitous face of propodeum; the declivity broadly and shallowly concave, encircled with a rim. Petiole subcylindrical, clearly longer than high, with its dorsal outline almost straight and elevated posteriad; subpetiolar process low, variable in shape (subtriangular to subrectangular). Postpetiole as long as petiole, convex dorsally and slightly elevated posteriorlly.

Head and gaster entirely smooth and shiny. Mandible very finely striate. Antennal scape supficially reticulate but shiny. Promesonotum reticulate with smooth and shiny bottoms except for anteriormost portion punctate and small area on dorsum smooth and shiny; upper portion of mesopleuron and upper portion of metapleuron with longitudinal rugae; lower portion of mesopleuron reticulate; propodeum entirely reticulate; in addition lateral face of propodeum with 2-3 longitudinal rugae. Petiole and postpetiole entirely reticulate. Legs entirely smooth and shiny except basal portion of femora superficially microreticulate.

Head and mesosoma dorsally with relatively sparse standing hairs mixed with sparse shorter hairs; longest pronotal hair 0.15-0.18 mm long. Head including antennal scape reddish brown; mandible, mesosoma, petiole, and postpetiole dark reddish brown; gaster and legs yellowish brown but gaster paler than legs.

Etymology.

The specific name refers to the range of the species, Sundaland (Sumatra, Borneo and Java).

Distribution.

Sumatra, Borneo (Sabah and E. Kalimantan), and Java ( Fig. 26B ).

Bionomics.

The type series of this species was collected from the highland (ca. 1300 m alt., W. Java) in the night in an open site at a forest edge. The non-type colonies from Sumatra and Borneo were collected in both primary and disturbed forests.

Remarks.

Aenictus sundalandensis is similar to Aenictus fuchuanensis , Aenictus pinkaewi , and Aenictus maneerati in having the long cylindrical petiole and short head (CI 100-112). However, it is easily separated from the latter three by the central area of pronotum being superficially shagreened or reticulate, rather shiny, and the lateral face being reticulate with smooth and shiny bottoms.

Figures

Figure 22. Aenictus sundalandensis (specimen from Java). A Head in full-face view B body in dorsal view C body in profile.

Figure 26. Distribution of Aenictus ceylonicus group. A Aenictus baliensis, Aenictus gonioccipus, Aenictus longicephalus, Aenictus minipetiolus, Aenictus pilosus B Aenictus appressipilosus, Aenictus cylindripetiolus, Aenictus itoi, Aenictus jawadwipa, Aenictus sundalandensis.