Ponera oreas

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Ponera oreas
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Ponera
Species: P. oreas
Binomial name
Ponera oreas
(Wheeler, W.M., 1933)

Ponera oreas P casent0281907.jpg

Ponera oreas D casent0281907.jpg

Specimen Label

Little is known about the biology of Ponera oreas.

Identification

Similar to Ponera sinensis (see sinensis identification section for distinguishing characteristics).

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Philippines (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

The general biology of species in the genus was summarized by Taylor (1967): Ponera are small ants that nest in rotting logs in forested areas or under stones in nonforested situations. In the tropical areas specimens are rarely encountered away from rain forest. In temperate areas, however, species may occur in relatively lightly forested areas. This appears to be the case with Ponera japonica, Ponera pennsylvanica and especially with Ponera coarctata. The Australian Ponera leae is essentially limited to rain forest in the northern parts of its range, but further south it may be found in dry, lightly forested areas.

Foraging is probably cryptobiotic, though some New Guinea species have been taken straying on the ground surface. Little information is available concerning feeding. However, most species are probably insectivorous. I have conducted feeding experiments with some of the New Guinea and Samoan species, including Ponera xenagos, Ponera elegantula, Ponera tenuis, Ponera incerta and Ponera woodwardi. These were unsuccessful with the larger species, except elegantula, which accepted moderately large (8-12 mm) campodeid and japygid Diplura. Tenuis and incerta accepted smaller (4-6 mm) campodeids, isotomid and sminthurid Collembola, and small newly hatched spiders (2 mm long). Negative feeding response was obtained with eggs and larvae of various ants, small crushed insects of various orders, and small myriapods. Stray workers were never observed carrying prey, and distinct middens of insect or other remains were not located near nests.

Colonies usually contain about 30 workers. Larvae and pupae are not segregated in most cases, but occasionally aggregations of pupae were observed. These may have included the total brood of the colonies involved. Larvae are attached to the floor or walls of the nest galleries by the glutinous abdominal tubercles described above, and the ants move them high up on the walls or ceilings of artificial nests, if they are flooded. Details of nuptial behavior of pennsylvanica were given by Wheeler (1900), and Haskins & Enzmann (1938). The flights appear to be of a pattern typical for ants, with the alates meeting in the air and mating there or on the ground. Colony foundation is non-claustral and independent in pennsylvanica (Kannowski 1959); judging from my observations this is typical for the genus.

Castes

Nomenclature

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

  • oreas. Selenopone oreas Wheeler, W.M. 1933g: 20, fig. 8 (w.) PHILIPPINES. Taylor, 1967a: 52 (q.m.). Combination in Ponera: Wilson, 1957b: 381.

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

Descriptions below based on the syntype series (4 workers and a male) plus 29 workers and 2 dealate queens from the J. W. Chapman collection (MCZ). All material is from the vicinity of Dumaguete, Negros.

Description

Worker

Length, 1.8-2 mm.

Head subrectangular, without the mandibles scarcely longer than broad, very nearly as broad in front as behind, with feebly convex sides and rather deeply, arcuately excised occipital border. Mandibles large, flattened, with straight external borders, three well-developed apical teeth and the basal portion of the masticatory border very indistinctly crenulate. Eyes very minute, convex, without distinct facets, situated at the anterior sixth of the lateral borders. Clypeus short, slightly convex but not carinate in the middle, its anterior border broadly rounded in the middle. Frontal carinae very small, contiguous, ciliate; frontal groove extending back nearly to the middle of the head. Antennae stout, scapes reaching the occipital border of the head; funiculi with thickened, indistinctly 5-jointed clubs, joints 2-7 short and transverse. Thorax with feebly and evenly arcuate dorsal outline, epinotum distinctly subangulate, with straight base and declivity; promesonotal and mesoepinotal sutures distinct, the former impressed, the latter less pronounced. Seen from above the pronotum is convex anteriorly and laterally, excluding the neck somewhat broader than long; mesonotum small, half as long as the pronotum and twice as broad as long; epinotum narrower, slightly broader behind than in front, its base one and one-half times as long as broad, with nearly parallel, submarginate borders, the declivity steep, flat and subcircular, shorter than the base, laterally sharply marginate. Petiole decidedly broader than the epinotum, from above semicircular, evenly convex in front, straight behind, scale in profile higher than long, straight and perpendicular anteriorly and posteriorly, the superior surface somewhat more rounded, especially posteriorly, and sloping backward and downward; ventral lamella prominent, with strong median tooth and circular anterior fenestra. Postpetiole broader than long, strongly truncated anteriorly and somewhat concave at the high insertion of the petiole. Gaster short, its first segment very similar to the postpetiole, remaining segments small and very short; sting long and stout. Legs rather long, femora and tibiae stout.

Mandibles very smooth and shining, scarcely punctate; head opaque, covered with dense, rather fine, pubigerous punctures; clypeus more shining; thorax, postpetiole and first gastric segment distinctly shining, punctate, but the punctures on the thorax finer than on the head, those on the postpetiole and gaster coarser and on all these regions decidedly sparser than on the head; declivity of epinotum and petiole very smooth and shining, the latter with a few small, scattered punctures. Antennae and legs subopaque, finely and densely punctulate, appearing somewhat scabrous.

Pilosity and pubescence whitish, the pubescence short and rather abundant on the head and appendages, not strongly appressed; on the petiolar corners, postpetiole and gaster lengthening to form rather long, oblique or reclinate hairs.

Thorax, petiole and postpetiole castaneous brown; head and gaster darker, more blackish; mandibles, clypeus, frontal carinae, antennae, legs and terminal gastric segments brownish yellow.

Taylor 1967 Ponera fig 37-42

Taylor (1967) - 1. HL 0.50-0.54 mm; HW 0.47-0.51 mm; SL 0.38-0.41 mm; CI 92-95; SI 78-81; PW 0.35 -0.39 mm; PNL 0.15-0.19 mm; PH 0.35-0.37 mm; DPW 0.29-0.33 mm; PNI 82-85.

2. Mandibles with 3 large teeth occupying apical 1/2 of masticatory border, followed by an irregular series of 7 or 8 minute indistinct denticles. Palpal formula: Maxillary 2: Labial 2 (2 specimens dissected). Clypeus completely lacking a median tooth. Eyes small, with 3 to 6 indistinct facets, situated about 0.89 X the distance from the lateral occipital border to the midpoint of the anterior genal border. Scapes reaching, or very slightly exceeding, median occipital border. Antennal club rather indistinctly 4-segmented, apparently undifferentiated in some specimens. (It was described as 5-segmented by Wheeler, but see Wilson's (1957) notes.) Terminal antennomere slightly longer than the 2 preceding together.

3. Mesometanotal and lateral mesonotal sutures clearly defined. Posterolateral edges of propodeum slightly raised, forming angles of about 80° in dorsal view.

Other characters are discussed under Ponera sinensis.

Queen

Taylor (1967) - Two worker-associated dealates have the following dimensions: HL 0.54 mm, 0.57 mm; HW 0.52 mm, 0.54 mm; SL 0.41 mm, 0.43 mm; CI 96, 94; SI 89; PW 0.43 mm, 0.46 mm; PNL 0.20 mm, 0.21 mm; PH 0.40 mm, 0.42 mm; DPW 0.36 mm, 0.38 mm; PNI 84, 83; maximum diameter of eye 0.13 mm, 0.14 mm; ocular index 25, 26; palpal formula not determined. Differing from the worker in the usual features. Scapes extending posteriorly as in worker, parapsidal lines distinctly impressed, mesosomal structure complete, node not very markedly narrowed above relative to that of worker. The diagnostic characters of the sinensis complex workers are probably generally applicable to the queens; namely medium size, broad head, and feebly differentiated antennal club.

Male

Taylor (1967) - A single specimen originally mounted with the syntype workers has the following dimensions: HL 0.46 mm; HW across eyes 0.50 mm; CI 109; WL 0.89 mm; PNL 0.19 mm; PH 0.25 mm; DPW 0.19 mm; maximum diameter of eye 0.23 mm; ocular index 46; palpal formula (dissected): Maxillary 3: Labial 2. General structure of head, mesosoma, antennae, legs and node, as in P. pennsylvanica. Terminal abdominal sclerites and genitalia conforming to general plan for the genus. Pygidial spine somewhat longer than in pennsyivanica; basal ring of genital capsule with plane of genital foramen almost oblique to its longitudinal axis, so that the ring is nearly as long ventrally as it is dorsally. Dorsal process of paramere almost as long as ventral one, digitate in side view, with its lower edge thickened. This process in dorsal view is thin and arcuate, inclined mesally. Volsellae and penis valves as in pennsyivanica, the posterodorsal angle of the latter almost right angled. Wing venation of "caarctata type." Color medium dark brown.

Type Material

Described from four specimens taken by Dr. F. X. Williams, at an altitude of 4000 feet on the Cuernos Mts., near Dumaguete, Negros Oriental, Philippines.

Taylor (1967) - Syntypes examined, Museum of Comparative Zoology. The types and most of the other specimens are deposited in the MCZ collection, and duplicates of the additional material are in Bernice P. Bishop Museum, The Natural History Museum, Australian National Insect Collection (including queen) and National Museum of Natural History.

References

  • Taylor, R. W. 1967a. A monographic revision of the ant genus Ponera Latreille (Hymenoptera: Formicidae). Pac. Insects Monogr. 13: 1-112 (page 52, queen, male described)
  • Wheeler, W. M. 1933g. Three obscure genera of ponerine ants. Am. Mus. Novit. 672: 1-23 (page 20, fig. 8 worker described)
  • Wilson, E. O. 1957b. The tenuis and selenophora groups of the ant genus Ponera (Hymenoptera: Formicidae). Bull. Mus. Comp. Zool. 116: 355-386 (page 381, Combination in Ponera)