Aenictus minipetiolus, 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 : 200-202

Aenictus minipetiolus sp. n. Fig. 14A-C

Type material examined.

Holotype. INDONESIA: Worker from Lombok, near Senaru, 27.X.1998, leg. I.K.T. Ginarsa, KT-100 (MZB). Paratypes. Four workers, same data as holotype (SKYC, THNHM).

Worker measurements

(holotype and paratypes, n = 5). TL 2.70-3.10 mm; HL 0.60-0.68 mm; HW 0.54-0.65 mm; SL 0.40-0.48 mm; ML 0.83-0.95 mm; PL 0.20-0.23 mm; CI 90-96; SI 72-74.

Worker description

(holotype and paratypes). Head in full-face view subrectangular, slightly longer than broad, sides weakly convex, posterior margin feebly concave; occipital margin bearing a distinct carina. Antennal scape relatively short, not reaching 2 /3 of head length. Frontal carina relatively short, reaching the level of posterior margin of torulus. Parafrontal ridge feeble and incomplete. Anterior clypeal margin almost straight, not concealed by curved anterior extension of frontal carina. Masticatory margin of mandible with large acute apical tooth followed by a medium-sized subapical tooth, 1-2 denticles, and a medium-sized basal tooth; basal margin bladed (distal 2/3 straight and proximal 1/3 sloping gradually to the base of mandible). Maximum width of gap between anterior clypeal margin and mandibles about 1.2 times as broad as maximum width of mandible. Promesonotum convex dorsally and sloping gradually to metanotal groove; mesopleuron relatively long, clearly demarcated from metapleuron by a groove; metapleural gland bulla relatively large, its maximum diameter about 1.6 times as long as distance between propodeal spiracle and metapleural gland bulla. Propodeum in profile with almost straight dorsal outline; propodeal junction angulate; declivity of propodeum flat, with blunt lateral carinae but not demarcated basally by a transverse carina. Petiole almost as long as high, node short, and dorsal outline convex; subpetiolar process low and short, its ventral outline convex. Postpetiole clearly larger than petiole, its dorsal outline slightly elevated posteriorly.

Head including mandible and antennal scape entirely smooth and shiny. Entire mesosoma smooth and shiny except for mesopleuron with relatively irregular longitudinal rugae; petiole and postpetiole entirely smooth and shiny.

Head and mesosoma dorsally with relatively sparse standing hairs; longest pronotal hair 0.23-0.25 mm long. Head, petiole, gaster, antennal scape, and legs yellowish brown; mesosoma reddish brown; mandible dark brown.

Etymology.

The specific name refers to the small petiole.

Distribution.

Lombok ( Fig. 26A ).

Bionomics.

So far this species has been known only from the type locality.

Remarks.

Aenictus minipetiolus is similar to Aenictus baliensis , Aenictus longicephalus and Aenictus wiwatwitayai (see under Aenictus baliensis ). It is a distinct species and is easily distinguished from the other species of the group by the almost entirely smooth and shiny body and the unique mandible (distal 2/3 of basal margin straight, proximal 1/3 concave).

Figures

Figure 14. Aenictus minipetiolus (holotype). 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.