Aenictus currax

Wilson (1964) reported on a colony of Aenictus currax: "The Karema (Papua New Guinea) colony was found on the morning of March 9 or 10, 1955, on the open floor of virgin lowland rain forest. It consisted of a packed mass of workers, which must have numbered at least 100,000, collected around the base of a small spiny palm tree. The mass extended up the trunk to about 1 m. The colony was apparently entirely above ground. When it was knocked onto a ground cloth and scattered, the queen and brood were easily collected. The colony was evidently in the nomadic phase. The queen's abdomen was not enlarged, i. e., the gastric sclerites overlapped; and the brood consisted mostly of mature larvae, nearly as long as a worker, together with a few smaller larvae and prepupae. Although no raids were being conducted at time, the workers were carrying bodies of adult workers and && of an unidentified species of Crematogaster. The currax workers were not at all aggressive when disturbed. They dispersed rapidly over the forest floor and rarely attempted to sting my hands as I handled them., the morning of March 1955, on the open floor of a virgin lowland rainforest. It consisted of a packed mass of workers, which must have numbered at least 100,000. The workers extended up the tree trunk to about 1 m. The colony was apparently entirely above ground, and the workers were carrying bodies of adult workers and males of the ant genus Crematogaster.

Identification
A member of the currax group. Jaitrong and Yamane (2011) - Aenictus currax is very similar in general appearance to Aenictus diclops, Aenictus huonicus, Aenictus pfeifferi, Aenictus parahuonicus and Aenictus wayani. Among these this species is more closely related to A. diclops and A. wayani than to the others in having a slender mesosoma and relatively long antennal scape (SI 97–104, while SI is less than 95 in A. pfeifferi, A. huonicus, and A. parahuonicus). Aenictus currax can be separated from A. diclops by having the propodeal and petiolar dorsa smooth and shiny (entirely sculptured in A. diclops), and it is easily distunguished from A. wayani as follows: antennal scape relatively longer (SI 104 in A. currax, 97–100 in A. wayani); basal margin of mandible sinuate with 3–4 ill-defined denticles in A. currax (denticles absent in A. wayani). All the species mentioned above are completely allpatric.

Distribution based on Regional Taxon Lists
Indo-Australian Region: New Guinea.

Castes
Known only from the worker caste.

Nomenclature

 *  currax. Aenictus currax Emery, 1900c: 310, pl. 8, fig. 1 (w.) NEW GUINEA. See also: Wilson, 1964a: 459; Jaitrong & Yamane, 2011: 13.



Worker
Jaitrong and Yamane (2011) - Measurements. lectotype: TL 4.15 mm; HL 0.88 mm; HW 0.70 mm; SL 0.73 mm; ML 1.33 mm; PL 0.30 mm; CI 80; SI 104.

(lectotype and non-type specimens). Head in full-face view distinctly longer than broad, with sides slightly convex and posterior margin feebly concave; occipital margin bearing a distinct carina. Antenna relatively thick; scape not reaching posterolaterial corner of head; antennal segments II–X each longer than broad, but V–VIII rather short; II slightly longer than each of III–VI. Frontal carina short, slightly extending beyond the level of posterior margin of torulus. Parafrontal ridge short. Masticatory margin of mandible with a large apical tooth followed by a medium-sized subapical tooth and 4–6 denticles; basal margin of mandible sinuate with 3–4 ill-defined denticles. Mesosoma elongate; promesosoma in profile convex dorsally and sloping gradually to metanotal groove; mesopleuron clearly demarcated from metapleuron by a groove. Propodeum in profile with moderately convex (in smaller specimens almost flat) dorsal outline; propodeal junction obtusely angulate; declivity of propodeum shallowly concave and encircled with a thin rim; area below propodeal spiracle distinctly impressed; distance between propodeal spiracle and metapleural gland bulla almost as long as spiracular diameter; the spiracle clearly circular, in diameter about 2.5 times as long as postpetiolar spiracle. Petiole distinctly longer than high, with its dorsal outline convex; subpetiolar process reduced, low, anteriorly right-angulate. Postpetiole round, almost as long as high.

Head including mandible and antennal scape extensively smooth and shiny; basal 1/3 of scape superficially sculptured. Pronotum smooth and shiny except for the anteriormost portion which is punctate; mesonotum smooth and shiny; mesopleuron macroreticulate, with several short longitudinal rugulae; propodeum bearing scattered, thin, straight longitudinal rugae, whose interspaces are smooth and shiny. Petiole smooth and shiny dorsally, its anterior portion, lateral faces and posterior portion punctate. Postpetiole entirely smooth and shiny except for anteriormost portion which is punctate. Legs smooth and shiny.

Body with relatively sparse standing hairs; longest pronotal hair 0.23–0.25 mm long. Entire body brownishyellow except for a much darker median area from upper frons to vertex between large typhlatta spots occupying the occipital corner; basal 1/3 of antennal scape also darker.

References based on Global Ant Biodiversity Informatics

 * Borowiec M. L. 2016. Generic revision of the ant subfamily Dorylinae (Hymenoptera, Formicidae). ZooKeys 608: 1–280.
 * Chapman J. W. 1965.  Studies on the ecology of the army ants of the Philippines genus Aenictus Schuckard (Hymenoptera: Formicidae). Philippine Journal of Science. 93: 551-595.
 * Emery C. 1900. Formicidarum species novae vel minus cognitae in collectione Musaei Nationalis Hungarici quas in Nova-Guinea, colonia germanica, collegit L. Biró. Publicatio secunda. Természetrajzi Füzetek 23: 310-338.
 * Emery C. 1910. Hymenoptera. Fam. Formicidae. Subfam. Dorylinae. Genera Insectorum 102: 1-34.
 * Forel A. 1911. Die Ameisen des K. Zoologischen Museums in München. Sitzungsber. Math.-Phys. Kl. K. Bayer. Akad. Wiss. Münch. 11: 249-303.
 * 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.
 * Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on http://www.newguineants.org/. Accessed on 24th Feb. 2011.
 * Viehmeyer H. 1912. Ameisen aus Deutsch Neuguinea gesammelt von Dr. O. Schlaginhaufen. Nebst einem Verzeichnisse der papuanischen Arten. Abhandlungen und Berichte des Königlichen Zoologischen und Anthropologische-Ethnographischen Museums zu Dresden 14: 1-26.
 * Wilson E. O. 1959. Some ecological characteristics of ants in New Guinea rain forests. Ecology 40: 437-447.
 * Wilson E. O. 1964. The true army ants of the Indo-Australian area (Hymenoptera: Formicidae: Dorylinae). Pacific Insects 6: 427-483.
 * Wilson E. O. 1965. A consistency test for phylogenies based on contemporaneous species. Systematic Zoology 14: 214-220.