Strumigenys carnassa

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Strumigenys carnassa
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. carnassa
Binomial name
Strumigenys carnassa
(Bolton, 2000)

MCZ-ENT Strumigenys carnassa holotype hal 0001.jpg

MCZ-ENT Strumigenys carnassa holotype had 0001.jpg

Type Specimen Label

Nothing is known about the biology of Strumigenys carnassa.

Identification

Bolton (2000) - A member of the Strumigenys semicompta-group. Of the four species known in this group the Australian Strumigenys flagellata is characterised by its possession of conspicuous pairs of long flagellate hairs: 5 pairs on the head, 2 on the pronotum, 1 each on the petiole and postpetiole, 2 at the base of the first gastral tergite. Flagellate hairs are absent in carnassa, Strumigenys pydrax and Strumigenys semicompta. In addition flagellata lacks a pale cuticular annulus around the orifice of the propodeal spiracle and has a short high petiole node, where the anterior and dorsal faces are sub equal in length. In contrast carnassa, pydrax and semicompta have a broad, pale cuticular annulus around the orifice of the spiracle, and have petiole nodes with the dorsum much longer than the anterior face in profile. S. carnassa and pydrax are much less densely hairy than semicompta. Apart from pilosity characters mentioned in the key, the dorsolateral margin of head in semicompta, in full-face view, has 10 or more elongate simple hairs that project freely from both the upper scrobe margin and the side of the occipital lobe; in the other two species 0-4 short simple hairs project from the side of the occipital lobe and none from the upper scrobe margin. Dorsal surfaces of the body are also distinctly less densely hairy in pydrax and carnassa. The former completely lacks hairs on the dorsal head and alitrunk; the latter has 7 of 8 pairs of standing hairs on the promesonotum, 2-3 pairs on the petiole dorsum and 3-4 pairs on the postpetiole. By comparison semicompta has 15 or more pairs on the promesonotum and 10 or more each on the petiole and postpetiole.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: New Guinea.

Distribution based on specimens

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The above specimen data are provided by AntWeb. Please see Strumigenys carnassa for further details

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.

  • carnassa. Pyramica carnassa Bolton, 2000: 465, figs. 279, 302 (w.) NEW GUINEA. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 117

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

Description

Worker

Holotype. TL 2.7, HL 0.70, HW 0.61, CI 87, ML 0.13, MI 19, SL 0.32, SI 52, PW 0.32, AL 0.73. Clypeus with minute appressed hairs, cephalic dorsum with subapressed to appressed small spatulate hairs. In full-face view the upper scrobe margin with a dense row of anteriorly curved small spatulate hairs, without freely projecting simple hairs. Margin of occipital lobe posterior to scrobe with 2-3 short straight freely projecting simple hairs. In profile a few short sub erect to erect simple hairs project from the cephalic dorsum behind the highest point of the vertex. Head, and remainder of body, entirely lacking flagellate hairs. Leading edge of scape with a row of narrowly spatulate curved hairs, directed toward apex of scape. Outer margins of fully closed mandibles intersect anterior clypeal margin some distance in from the anterolateral clypeal angles. With head in dorsolateral view the ventrolateral margin suddenly narrowed in front of the eye and somewhat concave behind it, so that the narrowly convex eye appears to be on a short tumulus and is very prominent. Pronotal dorsum transversely flattened and marginate laterally, the dorsum smooth and contrasting strongly with the finely rugulose and punctulate vertex. Mesonotum with faint vestiges of sculpture anteriorly but remainder of dorsal alitrunk, sides of alitrunk and waist segments unsculptured. First gastral tergite unsculptured except for the basigastral costulae, the latter very short, barely extending beyond the posterior margin of the limbus. Erect to suberect short hairs present on promesonotum, waist segments and first gastral tergite; without bizarre pilosity of any form. Orifice of propodeal spiracle surrounded by a broad pale cuticular annulus that posteriorly abuts the broad lamella of the declivity. Node of petiole in profile with a short, near-vertical anterior face and a much longer, shallowly convex dorsum. Lateral spongiform lobe of petiole extends almost the entire length of its side. Ventral curtain of petiole and both lobes of postpetiole large in profile. Petiole node in dorsal view longer than broad, as long as the postpetiole disc. In dorsal view tissue around the postpetiole disc more lamelliform than spongiform, completely surrounding the disc; the latter with its anterior margin transverse and its shallowly convex sides converging to a bluntly rounded point posteriorly.

Paratypes. TL 2.5-2.6, HL 0.67-0.71, HW 0.59-0.62, CI 85-90, ML 0.12-0.14, MI 18-20, SL 0.30-0.34, SI 49-55, PW 0.30-0.33, AL 0.70-0.75 (8 measured). As holotype but lateral margin of occipital lobe with 1-3 projecting short simple hairs in full-face view, the variation probably the result of abrasion. In the holotype and some paratypes the median area of the first gastral tergite is hairless, but other paratypes show that this area should be evenly pilose.

Type Material

Holotype worker, Papua New Guinea: Mt Hagan area, ca 2000 m., 5.vii.1974, B-280 (S. Peck) (Museum of Comparative Zoology).

Paratypes. 9 workers with same data as holotype (MCZ, The Natural History Museum, Australian National Insect Collection).

References

  • Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria.” 99: 1-191.
  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 465, figs. 279, 302 worker described)