Aenictus artipus

Jaitrong et al. (2010) - Little is known about the bionomics of A. artipus. Nothing is mentioned by Wilson (1964) on it. However, judging from the specimens examined this species mainly inhabits forests located in continental Southeast Asia. This species has been collected in various habitats such as hill evergreen forest, savanna forest, evergreen forest, disturbed forest and agricultural area located near natural seasonal forest. Jaitrong and Wiwatwitaya (2006) found A. artipus (mentioned as Aenictus sp. C) only in the highland (more than 800 m alt.), while our data show that it is occasionally collected also in the lowland (200-500 m alt.). Most colonies of this ant were collected from foraging columns on the forest floor. The single exception was the colony that was collected from a bivouac found under a stone in a dry evergreen forest in the Sakhaerat Ecological Research Station (NE. Thailand) in October (winter). The colony contained larvae but no pupa. So far we have no information about the prey.

Identification
A member of the wroughtonii group. This species is closely related to Aenictus sagei; and Aenictus wroughtonii, all sharing the rounded propodeal junction and smooth and shiny body. A. artipus, however, is distinguished from the latter two by the subpetiolar process with clearly angulate anteroventral corner and denser punctuation in the upper portion of meso- and metapleura.

Distribution based on Regional Taxon Lists
Oriental Region: Thailand, Vietnam. Palaearctic Region: China.

Castes
Known only from the worker caste.

Nomenclature

 *  artipus. Aenictus artipus Wilson, 1964a: 449, fig. 60 (w.) THAILAND. See also: Jaitrong, et al. 2010: 36.

Worker
Holotype: HW 0.46mm, HL 0.55 mm, SL 0.63 mm, Sl 137. Closely resembling the syntypes of wroughtoni Forel (q. v.), but differing in the strikingly longer scapes. Also, the diameter of the propodeal spiracle is greater (about 0.06 mm maximum diameter); pedicel somewhat more elongate; pilosity somewhat sparser, especially on mesosoma; and certain areas of mesosoma weakly microreticulate (albeit still feebly shining), namely the dorsal 1/4 of mesopleuron, a narrow strip embracing propodeal-mesopleural junction and posterior 1/2 of the sides of propodeum.

Paratypes: 8 workers, evidently from the same colony as the holotype. HW 0.45-0.47 mm. Two workers chosen at random have the following measurements : HW 0.46 mm, HL 0.57 mm, SL 0.65 mm, Sl 141; HW 0.45 mm, HL 0.58 mm, SL 0.64 mm, Sl 142.

Jaitrong et al. (2010) - Measurements (5 non-type workers). TL 3.2-3.3 mm; HL 0.60-0.63 mm; HW 0.50-0.53 mm; SL 0.65-0.70 mm: ML 1.03-1.05 mm; MTL 0.65-0.68 mm; PL 0.25 mm: CI 80- 84; SI 130-140.

Head in full-face view dearly longer than broad, with its sides slightly convex and posterior margin almost straight. Antennal scape long, extending beyond posterolateral corner of head: antennal segments II-X each longer than broad; II as long as III or less; III as long as IV and V combined; VI shorter than II; VII as long as VI: VIII and IX combined as long as the terminal segment (X). Frontal carina short, not reaching level of posterior margin of torulus. Clypeus short, with its anterior margin bearing 7-10 denticles. Mandible with the apical tooth large and curved, followed by 10-12 minute teeth on masticatory margin. Mesosoma narrow and elongate, seen in profile pronotum convex dorsally: promesonotum sloping gradually to metanotal groove; propodeum slightly lower with its dorsal outline almost straight. Propodeal junction rounded: declivity of propodeum slightly convex. Petiole very narrow, seen from above almost parallel-sided, in profile slightly longer than high, rounded dorsally, with rather flat dorsal face: subpetiolar process weaklyproduce below; its anteroventral corner bluntly angulate; postpetiole slightly shorter than petiole, with its node elevated posteriorly.

Head and antennal scape smooth and shiny. Mesosoma almost entirely smooth and shiny except for upper portion of meso- and metapleura; a groove present between mesopleuron and metapleuron; area between propodeal spiracle and metapleural gland bulla with punctures and rugae.

Body with relatively sparse, obliquely standing hairs mixed with short hairs over the surface; length of the longest pronotal hair 0.13-0.15 mm. Entire body deep yellow to pale brown, with mandible, part of antenna and legs paler.

Type Material
Jaitrong et al. (2010) - Holotype and six paratypes from Chiengmai [Chiang Mai], Siam [Thailand], X-27-20 (, examined).