Strumigenys kichijo

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Strumigenys kichijo
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. kichijo
Binomial name
Strumigenys kichijo
(Terayama, Lin & Wu, W.-J., 1996)

Pyramica kichijo side (www.niaes.affrc.go.jp).jpg

Pyramica kichijo top (www.niaes.affrc.go.jp).jpg

Specimen labels

This is a widespread species in Asia, though rarely collected. It has been found in rainforest and rubber plantations and, in Hong Kong, in a secondary forest at a relatively high elevation (572 m) (Tang et al., 2019).

Identification

Bolton (2000) - The only member of the Strumigenys kichijo-group. At present this is the only species known from these regions which has numerous conspicuous standing hairs on the dorsal surface of the mandibles. The sparse samples from different states show some variation in dimensions but agree overall. Nevertheless, it is possible that more than one species is represented here and the group should be reviewed later, when more material is available.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Oriental Region: Bhutan, Taiwan (type locality), Thailand, Vietnam.
Palaearctic Region: China, Japan.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Strumigenys were once thought to be rare. The development and increased use of litter sampling methods has led to the discovery of a tremendous diversity of species. Many species are specialized predators (e.g. see Strumigenys membranifera and Strumigenys louisianae). Collembola (springtails) and other tiny soil arthropods are typically favored prey. Species with long linear mandibles employ trap-jaws to sieze their stalked prey (see Dacetine trap-jaws). Larvae feed directly on insect prey brought to them by workers. Trophallaxis is rarely practiced. Most species live in the soil, leaf litter, decaying wood or opportunistically move into inhabitable cavities on or under the soil. Colonies are small, typically less than 100 individuals but in some species many hundreds. Moist warm habitats and micro-habitats are preferred. A few better known tramp and otherwise widely ranging species tolerate drier conditions. Foraging is often in the leaf litter and humus. Workers of many species rarely venture above ground or into exposed, open areas. Individuals are typically small, slow moving and cryptic in coloration. When disturbed individuals freeze and remain motionless. Males are not known for a large majority of species.

Castes

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • kichijo. Smithistruma kichijo Terayama, Lin & Wu, 1996: 335, figs. 23-25, 28, 29 (w.) TAIWAN. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 122. See also: Bolton, 2000: 427.

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

Description

Worker

Bolton (2000) - TL 2.4-2.6, HL 0.56-0.64, HW 0.43-0.48, CI 75-79, ML 0.11-0.14, MI 18-24, SL 0.32-0.36, SI 60-70, PW 0.30-0.33, AL 0.58-0.68 (6 measured).

Dorsal surface of mandible with numerous erect to suberect short curved hairs. Curved standing hairs on clypeal dorsum as long as hairs on vertex immediately behind the posterior clypeal margin. With head in profile the dorsum from posterior clypeal margin to occipital margin with abundant simple hairs that are curved anteriorly in the area immediately behind the clypeus, anteromedially to medially on the remainder of the vertex to its highest point, and curved anteriorly from just behind the highest point to the occipital margin. Close to the occipital margin there are also 2 or more very elongate fine simple hairs that curve forward and are distinct from the main pilosity. Eye with only 5-9 ommatidia in total. With head in full-face view the outer margins of the mandibles with anterolaterally projecting simple short hairs. Dorsolateral margins of head with freely projecting upcurved hairs, similar to those that are numerous on the dorsum and present from the frontal lobes to the occipital corners. Apicoscrobal hair extremely long and fine, curved to flagellate; a second similar hair projects from the margin close to the occipital corner. Upper scrobe margin a bluntly angular rim, not a sharp projecting edge or flange; the scrobe broad and shallow. Clypeal dorsum reticulate-punctate except for the anteromedian area which is smooth, otherwise dorsum of head reticulate-granular everywhere. Dorsal alitrunk reticulate-punctate, the pronotum with traces of sparse minute rugulae. Pleurae and side of propodeum mostly to entirely smooth and shining. Pronotum with medially-curved hairs similar to those on the head, and with a few much longer finer standing hairs. On mesonotum the shorter curved pilosity sparser and the longer finer hairs more numerous. Elongate fine standing hairs present on waist segments and first gastral tergite. Lamellae on propodeum broad and moderately spongiform. Petiole node in dorsal view reticulate-punctate and with a broad posterior collar. Disc of postpetiole smooth medially but laterally with faint traces of weak longitudinal costulae. Spongiform tissue surrounding disc thick laterally and posterolaterally but the posterior collar with a distinct median indentation or gap. Basigastral costulae arise across entire width of tergite, not from each side of a median clear area.

Type Material

Bolton (2000) - Holotype worker, TAIWAN: Taichung Hsien, Kukuan, 1060 m., 30.vii.1988 (no collector's name given). Paratype workers, JAPAN: Okinawa Pref., Okinawa-jima I., Onna-son, Yamada, 20.viii.1994 (M. Terayama, S. Kubota & H. Takamine) (National Institute of Agro-Environmental Sciences, Museum of Nature and Human Activities, National Science Museum (Natural History)) [examined].

References