Aenictus laeviceps

Widespread and dominant in rainforests of Southeast Asia (Gotwald 1995).

Identification
A member of the laeviceps species group. A. laeviceps is closely related to Aenictus breviceps, Aenictus sonchaengi, and Aenictus rotundicollis in having only 2 standing hairs on the vertex of the head. It has a more weakly convex promesonotum in profile than the last two (promesonotum strongly convex in A. sonchaengi and A. rotundicollis). It is also separated from them by the absence of standing hairs on the pronotum (more than 4 hairs present in A. sonchaengi; 2–4 hairs in A. rotundicollis). Another character separating A. laeviceps from A. rotundicollis is the relative length of the petiole, which is longer than high in the former but shorter than high in the latter. For the differences between A. laeviceps and A. breviceps, see A. breviceps. (Jaitrong and Yamane 2011)

Distribution
E. Thailand, Malay Peninsula (S. Thailand and W. Malaysia), Sumatra, Borneo (Sabah, Sarawak, and Brunei), and Philippines (Jaitrong and Yamane 2011).

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia, Philippines, Singapore. Oriental Region: Bangladesh, India, Myanmar, Thailand, Vietnam. Palaearctic Region: China.

Biology
Jaitrong and Yamane (2011) - A. laeviceps is widespread and dominant in rainforests of Southeast Asia (Gotwald 1995). We found it foraging in lowland seasonal forests (dry evergreen forest) in eastern Thailand. Elsewhere it was collected from tropical rainforests generally at less than 1,000 m alt. A single colony may contain as many as 60,000 to 110,000 workers (Schneirla & Reyes 1966).



This species forages mainly on the ground (Hirosawa et al. 2000) but sometimes climbs up trees. We observed this species preying on other ants such as Anoplolepis gracilipes (Philippines), Camponotus (Sumatra, Thailand), Euprenolepis (Thailand), Polyrhachis (Borneo), Pseudolasius (Borneo), and also on grasshoppers (Thailand). Wilson (1964) mentioned that A. laeviceps preyed on other ant species such as Camponotus (Tanaemyrmex) carin, Diacamma sp., Echinopla sp., Hypoclinea sp. [Dolichoderus sp.], Myrmicaria sp., Pristomyrmex sp., Paratrechina longicornis, Polyrhachis (Polyrhachis) bellicosa, Polyrhachis (Myrmhopla) sp., and Polyrhachis (Myrma) sp., Ponera sp., Vollenhovia sp., and also on the social wasp, Ropalidia flavopicta''. Chapman (1964) found this species feeding on myriapods, termites, small staphylinid beetles, while Rościszewski and Maschwitz (1994) mentioned that ants of the genera Crematogaster, Paratrechina, Pheidole, Polyrhachis, and Prenolepis were the prey of A. laeviceps. Hirosawa et al. (2000) reported that dominant prey genera were Camponotus (48.2%), Pseudolasius (20.8%) and Polyrhachis (15.2%) in the vicinity of Poring, Sabah, Borneo at altitudes of 600–800 m.

Wheeler (1930) - Described from a single specimen taken by Dr. Chapman on May 23, 1923, from a colony that had been making raids for two days on other ants and miscellaneous insects near his camp in the mountains back of Dumaguete. This colony finally bivouacked under an overhanging rock and when a fire was built very near it and it again began to migrate, the female, many workers, much brood and a number of amictophiles were captured. The contracted and strongly overlapping segments of the gaster of the female indicate that she was not in an actively egglaying condition, and the many hundreds of workers and fullgrown larvae in the colony indicate that she must be either an old and exhausted mother or a young substitute queen that had not yet entered on her period of great fecundity. Her fresh and unabraded appearance would seem to argue in favor of the latter supposition.

Nomenclature

 *  laeviceps. Typhlatta laeviceps Smith, F. 1857a: 79 (w.) BORNEO. Wheeler, W.M. 1930g: 200 (q.); Wheeler, G.C. & Wheeler, J. 1984: 265 (l.). Combination in Aenictus: Forel, 1890b: ciii. Senior synonym of  smythiesii, sundaica: Wilson, 1964a: 467. See also: Jaitrong & Yamane, 2011: 36.
 * smythiesii. Aenictus laeviceps var. smythiesii Forel, 1901a: 465 (diagnosis in key) (w.) INDIA. Junior synonym of laeviceps: Wilson, 1964a: 467.
 * sundaica. Eciton (Aenictus) fergusoni var. sundaica Karavaiev, 1927e: 7 (w.) INDONESIA (Java). [Unresolved junior secondary homonym of sundaicus Forel, above.] Junior synonym of laeviceps: Wilson, 1964a: 467.

Type Material
Typhlatta laeviceps

Two worker syntypes in. Labelled “SAR. 38.”

Jaitrong and Yamane (2011) - Typhlatta laeviceps: Three syntype workers from Borneo, Sarawak ( and, examined). A syntype in BMNH is selected as the lectotype, others as paralectotypes.

'Eciton (Aenictus) fergusoni'' var. sundaica'''. Type locality: Prinsen I. [Panaitan I.], Sunda Strait, nr Java.

Jaitrong and Yamane (2011) - The specimens collected from southern Thailand, Sumatra, and Borneo (Sarawak, Sabah, and Brunei) agree well with the lectotype from Sarawak, except in 2 colonies (SU07-SKY-199 and SU08-Kei282) from Sumatra in which the workers have 1–2 standing hairs on the pronotum. In the single colony (PH98-SKY-26) from the Philippines the propodeal junction of the worker is rounder than in the lectotype, and also the body size is slightly smaller. Zhou (2001) cited Guangxi, southern China as a locality of A. laeviceps, but according to the distribution range of this species the identification is doubtful.

Worker
Jaitrong and Yamane (2011) - Measurements. A worker lectotype: TL 4.15 mm; HL 0.93 mm; HW 0.80 mm; SL 0.83 mm; ML 1.35 mm; PL 0.33 mm; CI 86; SI 103. Non-type workers (n = 9): TL 3.90–4.15 mm; HL 0.88–0.92 mm; HW 0.70–0.82 mm; SL 0.73–0.87 mm; ML 1.30–1.40 mm; PL 0.28–0.33 mm; CI 86–92; SI 103–113.

Lectotype and non-type material from Borneo - Head in full-face view clearly longer than broad, with sides and posterior margin strongly convex; occipital margin bearing a carina. Antenna relatively long, scape almost reaching the posterolateral corner of head; antennal segments II–X each longer than broad. Frontal carina short, slightly extending beyond the level of the posterior margin of torulus. Anterior margin of clypeus convex, bearing 6–8 denticles. Masticatory margin of mandible with a large apical tooth followed by a medium-sized subapical tooth, 4–5 denticles, and a medium-sized basal tooth; basal margin lacking denticles. Promesonotum in profile convex dorsally; propodeum much lower than promesonotum, and in profile its dorsal outline almost straight; propodeal junction right-angled; declivity of propodeum weakly concave, encircled with an indistinct rim. Mesopleuron demarcated from metapleuron by a shallow groove. Petiole longer than high, in profile its dorsal outline almost straight or weakly convex in posterior portion; subpetiolar process well developed, its lobe surmounted by a thin, acute flange that is directed downward and backward; postpetiole slightly shorter than petiole, in dorsal view scarcely longer than broad.

Head entirely smooth and shiny. Antennal scape microrecticulate and subopaque, slightly shiny. Mandible finely microsculptured and feebly shiny. Pronotum smooth and shiny, its anteriormost portion punctate; mesothorax, metapleuron and propodeum with dense punctures; upper portion of mesopleuron and metapleuron with 15-20 irregular longitudinal rugulae; propodeum with about 40 densely packed, nearly straight, fine rugulae; interrugal spaces irregulary microrecticulate and opaque to feebly shiny. Petiole with dense punctures; postpetiole entirely smooth and shiny. Femora extensively but superficially reticulate and shiny; tibiae very finely reticulate.

Head with a pair of standing hairs on vertex; mesosoma devoid of pilosity. Entire body dark reddish brown. Typhlatta spot located anterior to occipital corner.

References based on Global Ant Biodiversity Informatics

 * Borowiec M. L. 2016. Generic revision of the ant subfamily Dorylinae (Hymenoptera, Formicidae). ZooKeys 608: 1–280.
 * Bui T.V. 2002. Result of ant survey in Tam Dao National Park. Hoi Nghi Con Trung Hoc Toan Quoc, Ha Noi 495-498.
 * CSIRO Collection
 * Chapman J. W. 1963. Some new and interesting Philippine ants (Hymenoptera: Formicidae). Philipp. J. Sci. 92: 247-263.
 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Chapman, J.W. and S.R. Capco. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monographs of the Institute of Science and Technology (Manila) 1: 1- 327
 * Chen Y. Q., Q. Li, Y. L. Chen, Z. X. Lu, X. Y. Zhou. 2011. Ant diversity and bio-indicators in land management of lac insect agroecosystem in Southwestern China. Biodivers. Conserv. 20: 3017-3038.
 * Cheng D., Z. Chen, and S. Zhou. 2015. An analysis on the ant fauna of Jinzhongshan Nature Reserve in Gunagxi, China. Journal of Guangxi Normal University: Natural Science Edition 33(3): 129.137.
 * Dad J. M., S. A. Akbar, H. Bharti, and A. A. Wachkoo. 2019. Community structure and ant species diversity across select sites ofWestern Ghats, India. Acta Ecologica Sinica 39: 219–228.
 * Emery C. 1901. Formiciden von Celebes. Zoologische Jahrbücher. Abteilung für Systematik, Geographie und Biologie der Tiere 14:565-580.
 * Emery C. 1910. Hymenoptera. Fam. Formicidae. Subfam. Dorylinae. Genera Insectorum 102: 1-34.
 * Emery, C.. "Catalogo delle formiche esistenti nelle collezioni del Museo Civico di Genova. Parte terza. Formiche della regione Indo-Malese e dell'Australia (continuazione e fine)." Annali del Museo Civico di Storia Naturale Giacomo Doria (Genova) (2) 5, no. 25 (1887): 427-473.
 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Hamaguchi K., Matsumoto T., M. Maruyama, Y. Hashimoto, S. Yamane, and T. Itioka. 2007. Isolation and characterization of eight microsatellite loci in two morphotypes of the Southeast Asian army ant, Aenictus laeviceps. Molecular Ecology Notes 7: 984-986.
 * Hashimoto Y., S. Yamane, and T. Itioka. 1997. A preliminary study on dietary habits of ants in a Bornean rain forest. Japanese Journal of Entomology 65(4): 688-695.
 * Hashimoto Y., and S. Yamane. 1998. Army ants and ant collectors [1]--In quest of Asian army ants (Aenictinae) Insectarium 35: 4-8.
 * Hua Li-zhong. 2006. List of Chinese insects Vol. IV. Pages 262-273. Sun Yat-sen university Press, Guangzhou. 539 pages.
 * 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., and T. Ting-Nga. 2005. Ant fauna of Peninsular Botanical Garden (Khao Chong), Trang Province, Southern Thailand (Hymenoptera: Formicidae). The Thailand Natural History Museum Journal 1(2): 137-147.
 * Jaitrong W.; Nabhitabhata, J. 2005. A list of known ant species of Thailand. The Thailand Natural History Museum Journal 1(1): 9-54.
 * Jaitrong W.; Yamane, S. 2011. Synopsis of Aenictus species groups and revision of the A. currax and A. laeviceps groups in the eastern Oriental, Indo-Australian, and Australasian regions (Hymenoptera: Formicidae: Aenictinae). Zootaxa 3128:1-46.
 * Li Q., Y. Chen, S. Wang, Y. Zheng, Y. Zhu, and S. Wang. 2009. Diversity of ants in subtropical evergreen broadleaved forest in Pu'er City, Yunnan. Biodiversity Science 17(3): 233-239.
 * Li Qiao, Chen You-qing, Guo Xiao, Duan Yan, Chen Yan-lin, and Xu Zheng-hui. 2007. Diversity of ants in differents habitats in Yuanmou arid-hot valley, Yunnan. Journal of Fujian College of Forestry 27(3): 272-277.
 * Li Z.h. 2006. List of Chinese Insects. Volume 4. Sun Yat-sen University Press
 * Lopwichan S., and S. Khachonpisitsak. 2015. Ant diversity in Nong Tha Yu Arboretum, Si Racha District, Chon Buri Province. Proceedings The 7 th National Science Research Conference. 30-31 March 2015. Naresuan University.
 * Lu Z., B. D. Hoffmann, and Y. Chen. 2016. Can reforested and plantation habitats effectively conserve SW China’s ant biodiversity? Biodivers. Conserv. DOI 10.1007/s10531-016-1090-1
 * Maruyama M., T. Matsumoto, and T. Itioka. 2011. Rove beetles (Coleoptera: Staphylinidae) associated with Aenictus laeviceps (Hymenoptera: Formicidae) in Sarawak, Malaysia: strict host specificity, and first myrmecois Aleocharini. Zootaxa 3102: 1-26.
 * Mathew R., and R. N. Tiwari. 2000. Insecta: Hymenoptera: Formicidae. Pp. 251-409 in: Director; Zoological Survey of India (ed.) 2000. Fauna of of Meghalaya. Part 7. [State Fauna Series 4.] Insecta 2000. Calcutta: Zoological Survey of India, 621 pp.
 * 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.
 * Pfeiffer M., D. Mezger, and J. Dyckmans. 2013. Trophic ecology of tropical leaf litter ants (Hymenoptera: Formicidae) - a stable isotope study in four types of Bornean rain forest. Myrmecological News 19: 31-41.
 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
 * Radchenko A. G. 1993. Ants from Vietnam in the collection of the Institute of Zoology, PAS, Warsaw. I. Pseudomyrmicinae, Dorylinae, Ponerinae. Annales Zoologici (Warsaw) 44: 75-82.
 * Smith, F.. "Catalogue of the hymenopterous insects collected at Sarawak, Borneo; Mount Ophir, Malacca; and at Singapore, by A. R. Wallace." Journal of the Proceedings of the Linnean Society of London, Zoology 2 (1857): 42-88.
 * Song Y., Z Xu, C Li, N. Zhang, L. Zhang, H. Jiang, and F Mo. 2013. An analysis on the ant fauna of the Nangun River Nature Reserve in Yunnan, China. Forest Research 26(6): 773-780.
 * Song Y., Z. Xu, C. Li, N. Zhang, L. Zhang, H. Jiang, and F. Mo. 2013. An Analysis on the Ant Fauna of the Nangun river Nature Reserve in Yunnan, China. Forest Research 26(6): 773-780.
 * 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.
 * Wheeler W. M. 1919. The ants of Borneo. Bulletin of the Museum of Comparative Zoology 63:43-147.
 * Wheeler W. M. 1930. Philippine ants of the genus Aenictus with descriptions of the females of two species. Journal of the New York Entomological Society 38: 193-212.
 * Wheeler W. M., and J. W. Chapman. 1925. The ants of the Philippine Islands. Part I, Dorylinae and Ponerinae. Philipp. J. Sci. 28: 47-73.
 * Wilson E. O. 1964. The true army ants of the Indo-Australian area (Hymenoptera: Formicidae: Dorylinae). Pacific Insects 6: 427-483.
 * 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.
 * Zhang W., and S. Zhou. 2016. An investigation on Formicidae species of Nanling National Park. Journal of Huizhou University 36(3): 27-30.
 * Zhang Xiang, and Hou You-Ming. 2009. Five new record genus and thirty one new records species of ants (Hymenoptera; Formicidae) in Fujian Province. Journal of Fujian Agriculture and Forestry University 38(5): 479-484.