Aenictus parahuonicus

Aenictus parahuonicus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Dorylinae
Genus:	Aenictus
Species:	A. parahuonicus
Binomial name
	Aenictus parahuonicus; Jaitrong & Yamane, 2011 Specimen Labels

Aenictus parahuonicus is widespread, distributed from northern Vietnam to southern Thailand (Sundaland). This species carries out its raids and emigrations on the surface in highly varied situations, from open areas, plantation, and light cover to deep forest during the day as well as at night. We observed this species preying on ants of the genera Pheidologeton and Dolichoderus (Thailand, TA970719-01) and also on termites (type series, WJT09-TH2007). (Jaitrong and Yamane 2011)

Identification

Jaitrong and Yamane (2011) - A member of the currax group. Aenictus parahuonicus is very similar in general appearance to Aenictus currax, Aenictus diclops, Aenictus huonicus, Aenictus pfeifferi, and Aenictus wayani. However, it is easily distinguished from the other species of this group by having the declivity of propodeum not demarcated from dorsum by a carina (bluntly margined laterally), while in the others it is encircled with a distinct rim.

Keys including this Species

Key to Aenictus currax group species

Distribution

Vietnam, Laos, Thailand, and Malay Peninsula (S. Thailand).

Distribution based on Regional Taxon Lists

Oriental Region: Laos, Thailand (type locality), Vietnam.

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

Explore Overview of Aenictus biology

Little is known about the biology of Aenictus parahuonicus. The genus is comprised of species that live an army ant lifestyle. Aenictus typically prey on other ants, from other genera, or other insects such as wasps or termites. There are reports of Aenictus preying on other insects as well and even have been observed collecting honeydew from homopterans (Santschi, 1933; Gotwald, 1995) but this appears, at least from available evidence, to be uncommon. Foraging raids can occur day or night across the ground surface. Occasionally raids are arboreal. During a raid numerous workers attack a single nest or small area, with several workers coordinating their efforts to carry large prey items back to the nest or bivouac. Aenictus have a nomadic life style, alternating between a migratory phase in which nests are temporary bivouacs in sheltered places above the ground and a stationary phase where semi-permanent underground nests are formed. During the nomadic phase bivouacs move regularly, sometimes more than once a day when larvae require large amounts of food. Individual nests usually contain up to several thousand workers, although nest fragments containing only a few hundred workers are often encountered. Queens are highly specialised and look less like workers than in most ant species. They have greatly enlarged gasters (dichthadiform) and remain flightless throughout their life. New colonies are formed by the division of existing colonies (fission) rather than by individual queens starting colonies on their own.

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Castes

Known only from the worker caste.

Nomenclature

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

parahuonicus. Aenictus parahuonicus Jaitrong & Yamane, 2011: 19, figs. 17-19 (w.) THAILAND, VIETNAM, LAOS.
- Type-material: holotype worker, 35 paratype workers.
- Type-locality: holotype Thailand: Trang Prov., Yan Takhao Dist., Thung Khai Botanical Garden, 9.viii.2009, WJT09-TH2007 (W. Jaitrong); paratypes with same data.
- Type-depositories: TNHM (holotype); BMNH, FFKT, MCZC, MHNG, SKYC, TNHM (paratypes).
- Status as species: Jaitrong, Guénard, et al. 2016: 26.
- Distribution: Laos, Thailand, Vietnam

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

Description

Worker

Measurements. Holotype and paratypes(n = 8): TL 3.85–4.25 mm; HL 0.80–0.93 mm; HW 0.70–0.85 mm; SL 0.60–0.73 mm; ML 1.27–1.73 mm; PL 0.30–0.35mm; CI 86–92; SI 83–87.

Description of worker (holotype and paratypes). Head in full-face view subrectangular, slightly longer than broad, with sides feebly convex and posterior margin almost straight; occipital carina often evanescent medially. Antennal scape relatively short, extending only 2/3 of head length; antennal segments II–X each longer than broad; II almost as long as each of III–VI. Frontal carina short, slightly extending beyond the level of posterior margin of torulus. Parafrontal ridge essentially absent. Masticatory margin of mandible with a large apical tooth followed by a medium-sized subapical tooth and 6 denticles; basal margin sinuate with a series of ill-defined denticles. Mesosoma relatively elongate and stout; promesonotum in profile convex dorsally and sloping gradually to metanotal groove. Propodeum in profile with feebly convex dorsal outline; propodeal junction rounded; declivity of propodeum feebly convex, with blunt lateral carinae but not demarcated basally by a transverse carina; area below propodeal spiracle distinctly impressed; opening of propodeal spiracle clearly circular with its diameter about 2.5 times as long as diameter of postpetiolar spiracle. Petiole clearly longer than high, with its dorsal outline convex; subpetiolar process well developed, triangular or roundly produced anteriorly, with its ventral outline feebly convex. Postpetiole shorter than petiole and almost as long as high, with its dorsal outline convex.

Head including mandible entirely smooth and shiny; antennal scape dorsally smooth but ventrally sculptured. Pronotum smooth and shiny except for the anterior portion which is punctate; mesonotum smooth and shiny; mesopleuron wrinkled and macroreticulate; metapleuron and propodeum punctate but the punctation weaker than in mesopleuron. Petiole with dense micropunctures except for a small area on dorsal surface which is smooth and shiny. Postpetiole smooth and shiny except for anterior and lateral portions which are punctate. Legs smooth and shiny.

Head with some short standing hairs in addition to two long hairs on vertex; mesosoma with relatively sparse standing hairs mixed with sparse suberect short hairs over the surface; length of the longest pronotal hair 0.35–0.40 mm. Entire body dark reddish-brown, with a relatively large typhlatta spot on occipital corner.

Type Material

Holotype. Worker from S. Thailand, Trang Prov., Yan Takhao Dist., Thung Khai Botanical Garden, 9 VIII 2009, W. Jaitrong leg., WJT09-TH2007 (Natural History Museum of the National Science Museum). Thirty-five paratype workers, same data as holotype (Ant Museum, The Natural History Museum, Museum of Comparative Zoology, Musee d'Histoire Naturelle Genève, SKY Collection, THNHM).

Etymology

The specific name is based on the close affinity of this species to Aenictus huonicus.

References

Khachonpisitsak, S., Yamane, S., Sriwichai, P., Jaitrong, W. 2020. An updated checklist of the ants of Thailand (Hymenoptera, Formicidae). ZooKeys 998, 1–182 (doi:10.3897/zookeys.998.54902).
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. PDF

References based on Global Ant Biodiversity Informatics

Borowiec M. L. 2016. Generic revision of the ant subfamily Dorylinae (Hymenoptera, Formicidae). ZooKeys 608: 1–280.
Eguchi K., B. T. Viet, and S. Yamane. 2014. Generic Synopsis of the Formicidae of Vietnam (Insecta: Hymenoptera), Part IICerapachyinae, Aenictinae, Dorylinae, Leptanillinae, Amblyoponinae, Ponerinae, Ectatomminae and Proceratiinae. Zootaxa 3860: 001-046.
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., B. Guenard, E. P. Economo, N. Buddhakala, and S. Yamane. 2016. A checklist of known ant species of Laos (Hymenoptera: Formicidae). Asian Myrmecology 8: 1-32. DOI: 10.20362/am.008019
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.