Proceratium longmenense

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Proceratium longmenense
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Proceratiinae
Tribe: Proceratiini
Genus: Proceratium
Species: P. longmenense
Binomial name
Proceratium longmenense
Xu, Z., 2006

Proceratium longmenense P holotype.jpg

Proceratium longmenense D holotype.jpg

The type worker was collected in subtropical evergreen broadleaf forest at 2050 m asl.

Identification

Close to Proceratium zhaoi but central clypeal process wide and triangular, subpetiolar process posteriorly without pointed tooth, propodeal teeth extrudent. (Xu 2006)

Staab et al. (2018) - Proceratium longmenense differs from the other members of the Proceratium itoi clade by the following character combination: medium-sized species (TL 3.2); sides of head and vertex weakly convex, almost straight; head (CI 85) and scapes (SI 68) relatively long; frontal carinae developed, their lateral lamellae relatively narrow, touching each other at their anteriormost level, not conspicuously broader above antennal insertions; posterodorsal corners of the propodeum broadly angular; posterior face of petiolar node in profile shorter and steeper than anterior face; petiole almost as broad as long (DPeI 91); subpetiolar process developed, roughly trapezoid; in addition to dense pubescence erect hairs present on dorsal surface of body, but only sparsely on head, scapes without erect hairs.

The unique hair patterns separate Proceratium longmenense from the other species of the Proceratium itoi clade. Proceratium williamsi and Proceratium zhaoi have no erect hairs that protrude from the dense pubescence on the dorsal surface of body (hairs present in Proceratium longmenense, but relatively sparsely, especially on head). All other species (Proceratium bruelheidei, Proceratium itoi, Proceratium kepingmai, Proceratium malesianum) have also such hairs on the scapes (absent on scapes in Proceratium longmenense). In addition to hairs, which may be worn down in old specimens, Proceratium longmenense is unique by the relatively long scapes (SI 68) combined with the relatively narrow head (CI 85). Among the other Chinese Proceratium itoi clade species, it differs furthermore from Proceratium zhaoi in size (WL 0.97; WL<80 in Proceratium zhaoi), from Proceratium itoi by the shape of the posterodorsal corners of the propodeum (broadly angular; rounded in Proceratium itoi), and from Proceratium bruelheidei, Proceratium itoi, and Proceratium kepingmai by the lamellae of the frontal carinae (touching each other at their anteriormost level; separated in the other three species).

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Palaearctic Region: China (type locality).


Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Very little is known about the biology of Proceratium ants. They nest in soil, rotten wood, under deep-set stones and, in a few cases, tree branches. For many species the nest consists of small rounded chambers hollowed out of soft rotten wood or in the soil. Toward the cooler limits of the range, particularly in North America, nests and foraging workers are found under deep set rocks instead of in rotten wood. The nest site is usually in forest shade, in old moist gardens, or similar habitats that are constantly moist. Some species of known to be egg predators of arthropods, especially of spiders.

Most Proceratium are relatively rare but this is not the full explanation for why they are not commonly collected. Colonies of most species are small. Based on anectdotal natural history information from a few species, it was once thought that most Proceratium would likely be found to have mature colonies that contain somewhere between 10 - 50 workers. Yet nests with more than 50, and in some cases up to 200, workers have been been reported. Besides small colonies, these ants also do not appear to forage in places where they are readily encountered.

Males and females are though to be produced in small numbers but we generally do not have enough data for colonies of any species to know what might be typical. Reproductive flights have been observered toward the end of the summer in some northern temperate areas. In these regions the nuptial flight occurs during the last half of August. Both sexes climb some distance from the nest entrance before taking flight. Workers too issue from the nest during the nuptial flight, as is often the case with otherwise cryptobiotic ants.

Castes

Worker

Nomenclature

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

  • longmenense. Proceratium longmenense Xu, 2006: 154, figs. 14 – 16 (w.) CHINA.

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 3.2, HL 0.87, HW 0.73, CI 85, SL 0.50, SI 68, ML 0.40, ED 0.02, PW 0.52, AL 0.97, PL 0.35, PH 0.33, DPW 0.32. Head nearly square, slightly longer than broad. Occipital margin straight. Occipital corners rounded. Lateral sides weakly convex. Masticatory margins of mandibles with 4 teeth, which reduced in sized from apex to base. Frontal carinae straight, convergent forward. Anterior margin of clypeus with a wide and triangular projection in the middle. Antennae thick, with 12 segments. Apices of scapes reached to 4/5 of the distance from antennal socket to occipital corner. Eyes with only one facet. In profile view, dorsum of alitrunk complete and weakly convex. Promesonotal suture and metanotal groove vanished on dorsum. Posterodorsal corner of propodeum extrudent into a right-angled tooth. Lateral lobes of propodeum blunt and rounded. Petiole roughly triangular and included backward, anterior and dorsal faces convex, anterodorsal corner rounded, posterior face short and straight. Subpetiolar process small and nearly rectangular, ventral face straight, anteroventral corner rightly angled, posterventral corner bluntly angled. Constriction between the two basal segments of gaster distinct, second segment very large, apical three segments short and under the second one.

Mandibles finely longitudinally striate. Head, alitrunk, petiole, and gaster finely densely punctate and dim. Gastral segments 3-5 smooth and shining. Dorsum of whole body with sparse short erect hairs and dense decumbent pubescence. Erect hairs abundant on dorsum of alitrunk. Dorsal faces of scapes and tibiae with dense decumbent pubescence, but without erect hairs. The while body yellowish brown. Mandibles, antenna, legs, and apex of gaster brownish yellow.

Type Material

China: Yunnan Province, Kunming City, Xishan Mountain Forest Park, Longmen, subtropical evergreen broadleaf forest, 2050 m, 5.V.2001, leg. Zhenghui Xu, No. A00514.

Staab et al. (2018) - Holotype. Pinned worker, Southwest Forestry University, Kunming, China), examined.

Etymology

Named after the type specimen locality Longmen, a place of the Xishan Mountain Forest Park.

References

References based on Global Ant Biodiversity Informatics

  • Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
  • Xu Z. 2006. Three new species of the ant genera Amblyopone Erichson, 1842 and Proceratium Roger, 1863 (Hymenoptera: Formicidae) from Yunnan, China. Myrmecologische Nachrichten 8: 151-155.