Aenictus huonicus Wilson

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 : 18-19

Aenictus huonicus Wilson

( Figs. 13–14 )

Aenictus huonicus Wilson, 1964: 465 , figs. 24–25; Bolton, 1995: 59.

Types. Holotype and three paratype workers from New Guinea, Huon Peninsula, Mongi-Mape Watershed, Wamuki, 800 m alt., 19–20 IV 1955. E. O. Wilson leg. (MCZC, examined).

Measurements. Worker holotype and paratypes (n = 4): TL 4.20–4.25 mm; HL 0.90–0.95 mm; HW 0.75–0.80 mm; SL 0.70–0.73 mm; ML 1.38–1.53 mm; PL 0.35–0.38 mm; CI 81–86; SI 87–94.

Redescription of worker (holotype and paratypes). Head in full-face view clearly longer than broad, with sides slightly convex and posterior margin almost straight or feebly concave; occipital margin bearing a narrow collar. Antennal scape extending 2/3 of head length; antennal segments II–VI each longer than broad and of approximately same length; VII–IX thicker and slightly longer; X longer than VIII+IX. Frontal carina short, not extending beyond the level of posterior margin of torulus. Parafrontal ridge essentially absent. Masticatory margin of mandible with a large apical tooth followed by a medium-sized subapical tooth and 6–7 denticles. Mesosoma slender; promesonotum in profile convex dorsally and sloping gradually to metanotal groove; mesopleuron clearly demarcated from metapleuron by a groove. Propodeum in profile with convex dorsal outline; propodeal junction marked by a distinct carina; declivity of propodeum short, shallowly concave, and encircled with a thin rim; metapleural gland bulla large, raised; distance between propodeal spiracle and the bulla less than spiracular diameter; opening of the spiracle clearly circular, about 2.7 times as long as diameter of postpetiolar spiracle. Petiole slightly longer than high, with its dorsal outline convex; subpetiolar process low, with its anteroventral corner angular and ventral margin almost straight or feebly convex. Postpetiole slightly shorter than petiole and almost as long as high, with its dorsal outline convex.

Head including mandible and antennal scape entirely smooth and shiny. Pronotum smooth and shiny except for the anteriormost portion punctate; mesonotum smooth and shiny; mesopleuron sculptured, anepisternum wrinkled while katepisternum macroreticulate; mesopleuron with several irregular longitudinal ridges; matpleural gland bulla almost smooth; propodeal dorsum smooth and shiny; lateral face of propodeum with several irregular longitudinal ridges, but shiny. Petiole smooth and shiny dorsally, its anterior and posterior portion punctate, lateral face microreticulate or shagreened with smooth and shiny bottoms. Postpetiole entirely smooth and shiny. Legs entirely smooth and shiny.

Head with some shorter standing hairs in addition to two long hairs on vertex; mesosoma with relatively sparse standing hairs mixed with sparse short hairs over the surface; longest pronotal hair 0.35–0.40 mm long. Entire body dark reddish-brown, with a relatively small typhlatta spot on each occipital corner.

Distribution. New Guinea.

Bionomics. Little is known about the bionomics of A. huonicus . In Wamuki, New Guinea workers were found on a bright sunny morning, running in file over a log at the edge of a native trail in open secondary rainforest ( Wilson 1964).

Remarks. A. huonicus is very similar in general appearance to A. currax , A. diclops , A. pfeifferi , A. parahuonicus , and A. wayani . Among them this species is closely related to A. pfeifferi and A. parahuonicus more than the others, the former two sharing a shorter antennal scape with SI 75–94 (more than 96 in A. currax , A. diclops , and A. wayani ). However A. huonicus is easily separated from A. pfeifferi by the head having some shorter standing hairs in addition to two long hairs on vertex (only 2 long standing hairs present on vertex in A. pfeifferi ) and the longest pronotal hair (0.35–0.40 mm) being longer than in A. pfeifferi (0.23–0.25 mm). A. huonicus differs from A. parahuonicus in having the declivity of the propodeum encircled with a thin rim (declivity not encircled with a rim in the latter).

Figures

FIGURES 11 – 16. Workers of Aenictus currax group. 11, 12, A. currax, lectotype; 13, 14, A. huonicus, holotype; 15, 16, A. diclops, paratype. 11, 13, 15, Head in full-face view; 12, 14, 16, habitus in profile.