Aenictus samungi

Aenictus samungi
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Dorylinae
Genus:	Aenictus
Species group:	wroughtonii
Species:	A. samungi
Binomial name
	Aenictus samungi; Jaitrong & Ruangsittichai, 2018

Aenictus samungi is a rare species and is known only from the type locality (ca 1100 m a.s.l.). The type series was collected from a foraging column on a forest path in a dry evergreen forest, western Thailand near the Myanmar border; no immature and prey were seen along the column. Workers were fast-running.

Identification

Jaitrong & Ruangsittichai (2018) - A member of the wroughtonii group. Aenictus samungi can be easily distinguished from other wroughtonii group species group by the following characteristics: smallest species of the group (HW 0.31–0.33 mm in A. samungi; HW > 3.7 mm in other members); petiole shorter than high (as long as or longer than high in other members); promesonotum with almost flat or straight dorsal outline (convex and sloping gradually to metanotal groove in other members); antennal scape short only just reaching mid-length of the head (at least two-thirds of the head length or beyond the posterolateral corner of the head in other members). Both Aenictus nuchiti and A. samungi have small bodies and short antennae, but can be easily separated from each other by the different conditions of the propodeum.

This species is also similar to members of the minutulus group in general appearance and by having a short petiole, short antennal scapes (reaching only to mid-length of the head) and subtriangular mandibles (masticatory margin with a large apical tooth, medium-sized subapical and basal teeth and 2–6 denticles between them). However this species possesses a serrate anterior clypeal margin, the most important characteristic that separates the A. wroughtonii group from the A. minutulus group (anterior clypeal margin without denticles in the A. minutulus group).

Keys including this Species

Key to Aenictus wroughtonii group species

Distribution

Western Thailand (Tak Province).

Latitudinal Distribution Pattern

Latitudinal Range: 15.44861111° to 15.44861111°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Oriental Region: Thailand (type locality).

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Type locality of Aenictus samungi, dry evergreen forest in Tak Province, western Thailand.

Castes

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

samungi. Aenictus samungi Jaitrong & Ruangsittichai, 2018: 109, figs. 3, 5 (w.q.) THAILAND.
- Type-material: holotype worker, 15 paratype workers.
- Type-locality: holotype Thailand: Tak Prov., Um Phang Dist., Thung Yai Wildlife Sanctuary, Yuyi Junction, DEF, 15.44861111°N, 99.04694444°E, ca 1100 m., 25.ix.2016, TH16-WJT-1069 (W. Jaitrong); paratypes with same data.
- Type-depositories: TNHM (holotype); MHNG, SKYC, TNHM, USNM (paratypes).
- Distribution: Thailand.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Holotype: HL 0.41; HW 0.31; ML 0.53; PH 0.17; PL 0.12; SL 0.20; TL 1.75; CI 76; PI 143; SI 63. Paratypes (n = 11): HL 0.40–0.43; HW 0.31–0.33; ML 0.51–0.53; PH 0.17–0.18; PL 0.12–0.13; SL 0.20–0.23; TL1.72–1.78; CI 76–80; PI 138–143; SI 63–70.

(holotype and paratypes). Head in full-face view clearly longer than broad, with its sides weakly convex and posterior margin almost straight or feebly concave. Antennal scape short, only slightly extending mid-length of head; antennal segment II (pedicel) clearly longer than each of III–VI; X longer than VII, VIII and IX combined. Frontal carinae fused at level of anterior margin of torulus, extending beyond level of posterior margin of torulus. Clypeus short, with its anterior margin bearing 7 denticles. Mandible subtriangular, with apical tooth large and curved, followed by a medium-sized subapical tooth, 4–5 minute teeth and a medium-sized basal tooth on masticatory margin. Mesosoma in profile almost flat dorsally; metanotal groove distinct. Propodeum in profile with a nearly straight dorsal outline; propodeal junction rounded; propodeal declivity weakly convex, not encircled by a rim. Petiole including subpetiolar process shorter than high, with its dorsal outline convex; subpetiolar process rather developed, with its ventral outline roundly convex, without angle or tooth; postpetiole shorter than petiole and shorter than high, in profile slightly elevated posteriorly.

Head, antennal scape, promesonotum, propodeal dorsum, petiole, postpetiole, gaster, femora and tibiae of legs entirely or extensively smooth and shiny; mesopleuron, metapleuron and lateral face of propodeum superficially reticulate. Antennal flagellum densely finely punctate.

Body with relatively sparse standing hairs mixed with sparse short hairs over surface; longest pronotal hair 0.07–0.08 mm long. Head, mesosoma, waist, gaster, antennae and legs yellowish brown; mandible dark brown.

Type Material

Holotype (THNHM-I-02615, Natural History Museum of the National Science Museum) and 15 paratype workers (THNHM-I-02616, Musee d'Histoire Naturelle Genève, SKY Collection, THNHM, National Museum of Natural History), Thailand, Tak Province, Um Phang District, Thung Yai Wildlife Sanctuary, Yuyi Junction, DEF (dry evergreen forest), 15.44861111°N, 99.04694444°E, ca 1100 m a.s.l., 25.IX.2016, W. Jaitrong leg., TH16-WJT-1069.

Etymology

The species is named after Mr Yuthana Samung (Faculty of Tropical Medicine, Mahidol University, Thailand) who kindly helped us in taking pictures of Thai ants, including the two new species discovered in the present study.

References

References based on Global Ant Biodiversity Informatics

Jaitrong W., and J. Ruangsittichai. 2018. Two new species of the Aenictus wroughtonii species group (Hymenoptera, Formicidae, Dorylinae) from Thailand. Zookeys 775: 103-115.