Aenictus piercei Wheeler & Chapman, 1930

Jaitrong, Weeyawat & Yamane, Seiki, 2012, Review of the Southeast Asian species of the Aenictus javanus and Aenictus philippinensis species groups (Hymenoptera, Formicidae, Aenictinae), ZooKeys 193, pp. 49-78 : 61-62

Aenictus piercei Wheeler & Chapman, 1930 Figs 67B

Aenictus piercei Wheeler & Chapman, in Wheeler 1930: 209, fig. 7 e–g; Wilson 1964: 474, figs 61-62; Bolton 1995: 60.

Types.

Two syntype workers on a pin, the Philippines, Negros, Cadiz, 2.VI.1924, leg. Dr. Pierce (MCZC, examined). The worker located below on the pin is selected as the lectotype (Fig. 6B).

Measurements.

Lectotype: TL 2.15 mm; HL 0.53 mm; HW 0.48 mm; SL 0.28 mm; ML 0.70 mm; PL 0.20 mm; CI 90; SI 58.

Paralectotypes (n = 2): TL 2.15 mm; HL 0.53-0.58 mm; HW 0.48-0.50 mm; SL 0.28-0.33 mm; ML 0.70-0.83 mm; PL 0.20-0.23 mm; CI 87-90; SI 58-65.

Description of worker

(lectotype, paralectotype and a non-type worker). Head in full-face view slightly longer than broad, subrectangular, with sides feebly convex and posterior margin almost straight; seen in profile occipital corner of head rounded. Antennal scape reaching midlength of head; antennal segment II longer and narrower than each of III–VI; terminal segment almost as long as VII+VIII+IX and 1.9 times as long as broad. Anterior margin of clypeus bearing 9-10 denticles (this observation is based on the single non-type worker, since in the lectotype mouth parts are buried in glue and the head of the paralectotype was missing). Masticatory margin of mandible with 3 acute teeth including large apical tooth; basal margin lacking denticles. Promesonotum in profile almost flat dorsally; in profile propodeum almost flat dorsally; propodeal junction angulate, right-angled; declivity of propodeum nearly flat, with blunt lateral carinae, but not demarcated basally by a transverse carina. Petiole almost as long as high, its dorsal outline convex; subpetiolar process well developed, subrectangular, its ventral margin slightly convex and longer than posterior margin; postpetiole almost as long as petiole.

Head including antennal scape entirely smooth and shiny. Mandible finely striate except along masticatory and outer margins. Pronotum entirely smooth and shiny except for anteriormost part microreticulate; mesonotum smooth and shiny; mesopleuron, metapleuron and propodeum microreticulate. Petiole entirely microreticulate. Postpetiole microreticulate except for a small smooth and shiny area on dorsal surface.

Head and mesosoma dorsally with relatively sparse standing hairs mixed with sparse short hairs; longest pronotal hairs 0.09-0.10 mm long. Entire body yellowish brown or reddish brown; legs palest.

Non-type material examined.

We examined a worker collected from the same place by Chapman but in a different year (2/6/29). It bears a small piece of white paper with handwriting “cotype”, and a small piece of red paper. As this specimen was not mentioned in the original description, it is not part of the type series. However, all the three specimens belong to the same species without doubt.

Distribution.

Philippines (Negros and Mindanao) (Fig. 7B).

Bionomics.

Little is known about the bionomics of Aenictus piercei . Nothing is mentioned by Wheeler (1930) on it. However, judging from the hitherto known localities (Negros and Mindanao) (see Wilson 1964) this species inhabits lowland (15-600 m) and is probably restricted to the Philippines. Wilson (1964) cited India, Solon (ca. 1400 m), as a locality of Aenictus piercei , but the identification should be reconfirmed.

Remarks.

This species is most similar to Aenictus duengkaei (see under Aenictus duengkaei for differences). According to Wilson (1964) the clypeus of Aenictus piercei has an entire anterior margin without denticles. Following this information, Jaitrong and Yamane (2011) treated Aenictus piercei as a member of their Aenictus piercei group (no denticles in this group). However, the non-type specimen mentioned above has nine denticles on the anterior clypeal margin. After carefully examining the type material of Aenictus piercei we concluded that this species should be removed from the Aenictus piercei group and that it is a member of the Aenictus javanus group.