Aenictus alticola Wheeler et Chapman

Jaitrong, Weeyawat & Yamane, Seiki, 2011, Synopsis of Aenictus species groups and revision of the A. curra x and A. laeviceps groups in the eastern Oriental, Indo-Australian, and Australasian regions (Hymenoptera: Formicidae: Aenictinae), Zootaxa 3128, pp. 1-46 : 25

Aenictus alticola Wheeler et Chapman

( Figs. 26–27 )

Aenictus alticola Wheeler and Chapman , in Wheeler, 1930: 205, fig. 5; Bolton, 1995: 58. Aenictus alticolus: Wilson, 1964: 445 , Fig. 18 .

Types. Twenty-one syntype workers on three pins (two on a pin, eight on another, eleven on the other) from Philippines, Luzon, Bontoc, Polis Pass, 1,800 m (MCZC, examined). One worker among them (top on the first pin) is selected as the lectotype, the others as paralectotypes.

Measurements. Worker lectotype and paralectotypes (n = 6): TL 4.35–4.75 mm; HL 0.90–1.00 mm; HW 0.80–0.85 mm; SL 0.78–0.88 mm; ML 1.43–1.50 mm; PL 0.30–0.35 mm; CI 84–87; SI 100–106.

Redescription of worker (lectotype and paralectotypes). Head in full-face view clearly longer than broad, with sides slightly convex and posterior margin convex; occipital margin bearing a narrow collar. Antennal scape extending beyond midlength of head, but not reaching the posterolateral corner of head; antennal segments II–X each longer than broad; II slightly longer than each of III–VI; VII, VIII and IX combined almost as long as terminal segment (X). Frontal carina short, not reaching the level of the posterior margin of torulus. Parafrontal ridge short and ill defined, or absent. Anterior margin of clypeus convex and bearing 6–7 denticles. 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 sinuate with a series of 2–3 ill-defined denticles. Mesosoma rather elongate and stout; promesonotum in profile strongly convex dorsally and sloping to metanotal groove; metanotal groove very weak. Propodeal junction evenly rounded; declivity not margined dorsally and laterally. Petiole subsessile and short, its node almost as long as high and rounded dorsally; subpetiolar process well developed, triangular, its apex directed downward. Postpetiole shorter than petiole, with globular node.

Head entirely smooth and shiny. Mandible very finely striate except along masticatory and outer margins. Antennal scape almost smooth and shiny. Mososoma extensively smooth and shiny; upper portion of mesopleuron and metapleuron provided with about 10 longitudinal, irregular rugulae; dorsa of mesonotum and propodeum superficially sculptured; metanotal groove bearing short longitudinal rugulae; propodeal dorsum with several short longitudinal rugae in front of the junction. Petiole and postpetiole entirely smooth and shiny. Legs entirely smooth and shiny.

Head and mesosoma with relatively sparse standing hairs mixed with sparse short hairs over the surface; longest pronotal hair 0.20–0.25 mm long. Entire body reddish-brown except for vertex of head darker than other parts of body; ventral surface of antennal segments VII–X pale yellow. Typhlatta spot located anterior to occipital corner.

Distribution. Philippines (Luzon) ( Fig. 63 ).

Bionomics. No biological information is available for A. alticola . However, judging from the type locality this species inhabits highlands.

Remarks. A. alticola is most similar to A. luzoni in having the subpetiolar process low and anteriorly angulate; the ventral appendage not spiniform. However, this species is distinctly larger than the latter (HW 0.80–0.85 in A. alticola ; 0.78 in A. luzoni ). The ventral appendage of the subpetiolar process is high and subtriangular in A. alticola , but rudimentary, with the highest point at anterior portion in A. luzoni . Antennal scape is almost as long as or longer than head width in A. alticola (SI 100–106), while it is shorter than head width in A. luzoni (SI 97).

Figures

FIGURES 26 – 32. Workers of Aenictus laeviceps group. 26, 27, A. alticola, lectotype; 28 – 30, A. fulvus sp. nov., holotype; 31, 32, A. luzoni, lectotype. 26, 28, 31, Head in full-face view; 27, 29, 32, habitus in profile; 30, dorsal view of body.

FIGURES 17 – 22. Workers of Aenictus currax group. 17 – 19, A. parahuonicus sp. nov., holotype; 20 – 22, A. wayani sp. nov, holotype. 17, 21, Head in full-face view; 18, 22, habitus in profile; 19, 20, dorsal view of body.

FIGURES 63 – 66. Distribution of Aenictus laeviceps group. 63, A. alticola, A. binghami, and A. fulvus sp. nov., A. luzoni; 64, A. bodongjaya sp. nov., A. breviceps, A. brevinodus sp. nov., and A. montivagus sp. nov.; 65, A. hodgsoni, and A. laeviceps; 66, A. sonchaengi sp. nov., A. rotundicollis sp. nov., and A. siamensis sp. nov.