Aenictus peguensis Emery, 1895

Jaitrong, Weeyawat & Hashimoto, Yoshiaki, 2012, Revision of the Aenictus minutulus species group (Hymenoptera: Formicidae: Aenictinae) from Southeast Asia, Zootaxa 3426 (1), pp. 29-44 : 38

Aenictus peguensis Emery, 1895

( Figs 5 A–F, 7)

Aenictus peguensis Emery, 1895: 452 .

Aenictus peguensis: Wilson, 1964: 471 , figs 34, 35; Bolton, 1995: 60.

Types. Eighteen syntype workers from Palon, at Pegu, Burma, L. Fea leg., 8.IX.1887 ( MCSN, examined). One worker among them is selected as lectotype.

Measurements. Lectotype: TL 3.25 mm; HL 0.73 mm; HW 0.60 mm; SL 0.48 mm; ML 1.00 mm; PL 0.23 mm; CI 83; SI 79.

Paralectotypes (n = 5): TL 2.95–3.15 mm; HL 0.60–0.70 mm; HW 0.52–0.58 mm; SL 0.40–0.45 mm; ML 0.88–0.95 mm; PL 0.20–0.23 mm; CI 82–96; SI 74–79.

Description of worker (lectotype and paralectotypes). Head in full-face view slightly longer than broad, with convex sides and feebly convex posterior margin; occipital margin bearing a carina. Antennal scape reaching midlength of head; antennal segments II–X each longer than broad; II and III slenderer than IV–VI; terminal segment almost as long as VII+VIII+IX and 2.4 times as long as broad. Frontal carina short, posteriorly fused to form a single carina, slightly extending beyond the level of posterior margin of torulus. Masticatory margin of mandible with a large apical tooth followed by a medium–sized subapical tooth, 5–6 denticles, and a medium-sized basal tooth; basal margin with 4–5 small denticles. Promesonotum in profile strongly convex dorsally and sloping gradually to metanotal groove; metapleural gland bulla relatively small and transparent; distance between propodeal spiracle and metapleural gland bulla clearly longer than spiracular diameter ( Fig. 5 E). Propodeum in profile with convex dorsal outline; propodeal junction right-angled; declivity of propodeum seen from back convergent above. Petiole excluding subpetiolar process shorter than high, with its dorsal outline convex; subpetiolar process rather developed, with a sharply pointed lamellate appendage directed downward. Postpetiole clearly shorter than petiole, its dorsal outline convex.

Head including mandible and antennal scape smooth and shiny; basal portion of scape finely sculptured. Entire pronotum smooth and shiny except for its anteriormost portion punctate; mesothorax, petiole, and postpetiole entirely punctate but metapleuron at least partly impunctate. Legs entirely smooth and shiny.

Head and mesosoma dorsally with relatively sparse standing hairs mixed with sparse short hairs over the surface; longest pronotal hair 0.18–0.23 mm long. Head, pronotum and gaster yelwish-brown; methothrax, propodeum, waist darker and often slightly reddish.

Non-type material examined. VIETNAM: S. Vietnam, Dong Nai, S. Cat Tien N.P. (ca. 160 m), 21.X.2004, K. Eguchi leg., Eg04-VN-762 ( SKYC).

Distribution. Vietnam and Myanmar ( Fig. 7 ).

Bionomics. No biological information is available for A. peguensis . However, judging from the type locality and the locality of non-type material examined this species inhabits lowlands.

Remarks. Aenictus peguensis is most similar in general appearance to A. subterraneus but is distinguished from the latter as follows: distinctly larger than the latter (TL 2.95–3.25 mm, HW 0.52–0.60 mm in A. peguensis ; TL 2.10–2.15 mm, HW 0.48–0.50 mm in the latter); propodeal junction angulated, right-angled (roundly angulated in the latter); with head in full-face view posterior margin convex (feebly concave in the latter).

Figures

FIGURE 5. Aenictus peguensis (A, C, lectotype; B, D, E, non-type from S. Vietnam). A, Head in full-face view; B, body in dorsal view; C, body in profile; D, declivity of propodeum, obliquely posterior view; E, propodeal junction, petiole and postpetiole in profile; F, mandible.

FIGURE 7. Distribution of the Aenictus minutulus group.