Aenictus hottai

Aenictus hottai, together with its close relative Aenictus yamanei, are the only known members of the A. hottai species group. Both are probably restricted to Sundaland (south-east Asia) and inhabit lowland primary rainforests.

Identification
A member of the hottai species group.

Wiwatwitaya and Jaitrong (2011) - A. hottai is very similar to Aenictus yamanei in general appearance as they share the dense punctation on the head and mesosoma, the peculiar subpetiolar process and the superficially reticulate first gastral segment. However, A. hottai is separated from A. yamanei by the following conditions: body much larger (HW 0.93-1.00 mm, ML 1.63-1.75 mm in A. hottai; HW 0.63-0.70 mm; ML 1.22-1.27 mm in A. yamanei), head relatively shorter (CI 88-91 vs 79-85), posterior face of petiole feebly convex and wrinkled and not marginated with a rim (shallowly concave without longitudinal wrinkles and marginated with a very thin rim in A. yamanei).


 * Larger species (HW 0.93-1.00 mm; ML 1.63-1.75 mm); head relatively shorter (CI 88-91) . . . . . Aenictus hottai


 * Smaller species (HW 0.63-0.70 mm; ML 1.22-1.27 mm); head relatively longer (CI 79-85) . . . . . Aenictus yamanei

Key to Aenictus species groups

Distribution
Malay Peninsula (southern Thailand and Malaysia), Borneo (Sarawak), Sumatra.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia, Malaysia. Oriental Region: Thailand.

Biology
Wiwatwitaya and Jaitrong (2011) - According to the specimen examined, all colonies of A. hottai were collected from the forest floor in the lowland primary forest. Rościszewski & Mashchwitz (1994), Malsch et al. (2003) also observed this species in a lowland primary forest in Pasoh, Malay Peninsula. This species is probably a Sundaland species; so far northern limit of its range in latitude is the Thai- Malay border (ca. 7˚N) near the Kangar-Pattani line (see Woodruff 2003). Rościszewski & Mashchwitz (1994) reported that in the Pasoh Forest Reserve A. hottai preyed on ants of the ponerine genus Odontomachus.

Castes
Known only from the worker caste.

Nomenclature

 *  hottai. Aenictus hottai Terayama & Yamane, 1989: 598, figs. 1, 2 (w.) INDONESIA (Sumatra). See also: Wiwatwitaya & Jaitrong, 2011: 559.

Worker
Wiwatwitaya and Jaitrong (2011) - (n = 10 including two paratypes): TL 4.65-5.00 mm; HL 1.05-1.13 mm; HW 0.93-1.00 mm; SL 0.93-1.00 mm; ML 1.63-1.75 mm; PL 0.40-0.43 mm; CI 88-91; SI 93-100.

(paratypes and non-type specimens). Head in full-face view slightly longer than broad, with sides convex and posterior margin almost straight. Antennal scape almost reaching posterolateral corner of head. Frontal carina not reaching midlength of head, well developed anteriorly and poorly developed posteriorly; parafrontal ridge extending posterior less than 1/3 of head length; seen in profile its anterior part raised high and subtriangular, and poorly developed posteriorly. Mandible broad and triangular, its masticatory margin with a large apical tooth followed by a small subapical tooth and a series of 16-17 minute denticles of uniform size; basal margin of mandible lacking denticles. Mososoma stout; anepisternum clearly demarcated from katepisternum. Propodeum in profile with almost striaght dorsal outline; propodeal junction acutely angulate; opening of propodeal spiracle clearly circular with its diameter about 2.4 times as long as diameter of postpetiolar spiracle. Petiole round and almost as long as high; posterior slope of petiole seen in profile feebly convex, seen from above with blunt lateral carinae but not margined basally by a carina; subpetiolar process large with anterior corner rounded, posteroventrally produced into an arm with a blunt tip; margin connecting anterior corner and the tip of the arm clearly concave. Postpetiole slightly longer than petiole, its dorsal outline slightly elevated posteriorly.

Head, mesosoma, petiole, postpetiole, and legs densely punctate and opaque; mandible densely punctate extensively, finely striate along basal margin, and smooth and shiny along masticatory margin and at apex; antennal scape micropunctate. Proprodeal dorsum with several short longitudinal ridges in front of junction. Posterior face of petiole wrinkled. Gaster with weaker sculpturation than head, finely and superficially reticulate, subopaque and slightly shining.

Head with a pair of long standing hairs mixed with relatively sparse short hairs over the surface; mesosoma with relatively sparse long standing hairs mixed with sparse short hairs over the surface; length of the longest pronotal hair 0.50-0.53 mm. Entire Body dark reddish-brown.

Type Material
Wiwatwitaya and Jaitrong (2011) - The holotype and 9 paratype workers ( and ) from Ulu Gadut nr Padang, W. Sumatra, Indonesia, 27-30 VIII 1985 (two paratypes were examined, SKYC).

References based on Global Ant Biodiversity Informatics

 * Borowiec M. L. 2016. Generic revision of the ant subfamily Dorylinae (Hymenoptera, Formicidae). ZooKeys 608: 1–280.
 * Jaitrong W. 2015. A revision of the Thai species of the ant genus Aenictus Shuckard, 1840 (Hymenoptera: Formicidae: Dorylinae). The Thailand Natural History Museum Journal 9(1): 1-94.
 * Jaitrong W.; Nabhitabhata, J. 2005. A list of known ant species of Thailand. The Thailand Natural History Museum Journal 1(1): 9-54.
 * Malsch A. K. F., K. Rosciszewski, and U. Maschwitz. 2003. The ant species richness and diversity of a primary lowland rain forest, the Pasoh Forest reserve, West Malaysia. in T. Okuda, N. Manokaran, Y. Matsumoto, K. Niiyama, S. C. Thomas, and P. S. Ashton, eds. Pasoh: Ecology and Natural History of a Southeast Asin Lowland Tropical Rain Forest, pp 347-374.
 * Matsumoto T., T. Itioka, S. Yamane, and K. Momose. 2009. Traditional land use associated with swidden agriculture chnages encounter rates of the top predator, the army ant, in Southern Asian tropical rain forests. Biodivers. Conserv. 18: 3139-3151.
 * Terayama M.; Yamane, S. 1989. The army ant genus Aenictus (Hymenoptera, Formicidae) from Sumatra, with descriptions of three new species. Japanese Journal of Entomology 57:597-603.
 * Wiwatwitaya D.; Jaitrong, W. 2011. The army ant Aenictus hottai (Hymenoptera: Formicidae: Aenictinae) and related species in Southeast Asia, with a description of a new species. Sociobiology 58:557-565.
 * Yamane S.; Nona, A. R. 1994. Ants from Lambir Hills National Park, Sarawak. Pp. 222-226 in: Inoue, T.; Hamid, A. A. (eds.) 1994. Plant reproductive systems and animal seasonal dynamics. Long-term study of dipterocarp forests in Sarawak. Kyoto: Center for Ecological Research, Kyoto University, vii + 255 pp.