Myopias ruthae

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Myopias ruthae
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Myopias
Species: M. ruthae
Binomial name
Myopias ruthae
Willey & Brown, 1983

MCZ0124-Myopias ruthae hal.jpg

MCZ0124-Myopias ruthae had.jpg

Type Specimen Label

The holotype was found in a lowland Papua New Guinea "high-graded rainforest." The worker was foraging under the bark of a large rotting log.


Willey and Brown (1983) - Worker: A modest-sized Myopias; head longer than broad, with nearly parallel but gently convex sides and weakly convex posterior border; scapes curved, barely surpassing posterior border; funicular club indistinctly 6-merous. Median frontal groove deep and wide, reaching to the posterior quarter of head length. Median clypeal lobe broad, short, rectangular, widest basad. Labrum without a median tubercle. Eyes fairly large, convex, finely faceted. Mandibles robust, gently curved, with 4 teeth and a low basal angle. Body robust, metanotal groove distinct but weakly impressed. Petiolar node massive, subcuboidal; gaster short and thick. Sculpture of numerous coarse punctures or foveolae, dense and contiguous, or nearly so on most of head and sides of petiolar node; foveolae sparser mesad on vertex, trunk and succeeding terga, the surface here prevailingly smooth and shining. Color piceous, nearly black, with contrasting tan appendages.

This species is distinct from all congeners, but difficult to place to a group. Probably it comes closest to the tenuis group than any other so far described, but the longish head, bulging eyes, short scapes and coarsely foveolate sculpture will distinguish it from all tenuis-group species.

Keys including this Species


Latitudinal Distribution Pattern

Latitudinal Range: -5.333° to -6.666922°.

Tropical South

Distribution based on Regional Taxon Lists

Indo-Australian Region: New Guinea (type locality).

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.




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

  • ruthae. Myopias ruthae Willey & Brown, 1983: 274, figs. 7, 20 (w.) NEW GUINEA (Papua New Guinea).
    • Type-material: holotype worker.
    • Type-locality: Papua New Guinea: Bubia, ca 13 km. NW Lae, ca 20 m., 26.iii.1955 (E.O. Wilson).
    • Type-depository: MCZC.
    • Status as species: Bolton, 1995b: 270; Probst, Guénard & Boudinot, 2015: 205 (in key).
    • Distribution: Papua New Guinea.

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



holotype: TL 5.2, HL 0.96, HW 0.86 (CI 90), ML 0.48 (MI 50), SL 0.73 (SI 85), EL 0.14, WL 1.60, hind femur L 0.80, hind tibia L 0.83 mm.

Description mainly directed at details not fully covered in the diagnosis and figures. Antennal scape broadly curved in basal half, incrassate distad; apical width about 0.12 mm, or slightly less than maximum eye length. Funicular segment I about twice the length of II. Eye with distinct but fine ommatidia, numbering about 11 or 12 units in the longest diagonal row, darkly pigmented. Median clypeal lobe about 0.05 mm long (CLL) and about 0.14 wide (CLW) at apex, about 0.15 mm wide at base where it meets frontal lobes; anterior border straight, free corners subrectangular. In examining the single, intact specimen, no upturned teeth could be seen at the apex of each labral lobe, but a dissection would be needed to make sure that they are really absent. Mandibular armament consists of an acute apical tooth and a small adjacent tooth, then after a gap another large, blunt tooth, another gap and a similar-sized but more acute median tooth, then halfway from this to the base, a low, rounded basal angle. Oblique groove (strix) near dorsal base of mandible distinct, continuing along lateral margin to near apex. MLO 0.77 mm.

Trunk robust, dorsal outline in side view nearly straight, the mesonotum feebly sunken; metanotal groove slightly impressed, but distinct; propodeal dorsum very feebly convex, rounding obtusely into declivity, but sides of declivity forming blunt angles with pleural faces of trunk. Propodeal spiracle small and round, situated at mid height. Petiolar node massive, subcuboidal, slightly wider behind than long; slightly higher than long if one ignores the small, hooklike anterior subpetiolar process; dorsal surface convex in both directions.

First gastric (postpetiolar) segment higher and wider (by about 4:3) than long. Succeeding (gastric II) segment about as wide as the first, and only slightly longer, but slightly thinner dorsoventrally. Sting long and slender, gently upcurved.

Sculpture distinctive, consisting basically of a smooth, shining integument invaded by coarse, mostly umbilicate, piligerous foveolae. The foveolae are densest and smallest (0.02-0.03 mm diameter) on anterior and sides of head, where most are contiguous and yield a reticulate-foveolate surface that is subopaque in most lights. This kind of sculpture, a bit more loosely distributed, covers the upper sides and dorsum of trunk and petiole, except for median posterior part of vertex, midline of trunk, and dorsal midline of petiole, which have wide spaces free of most foveolae, and are smooth, shining. Sides of trunk below largely smooth, with sparse foveolae, and posteriorly, low down, with a few fine, longitudinal costulae. Sides of petiolar node foveolate-striate. Gaster with spaced foveolae, becoming smaller (0.02 mm) and sparser caudad, interspaces smooth and shining, but a double band of foveolae along apical margin of second gastric tergum. Mandibles and legs with sparse punctures, generally otherwise smooth and shining; scapes and middle tibiae, and all tarsi, more densely punctulate, but still shining.

Hairs numerous, fine, tapered, suberect to decumbent, mostly 0.04 to 0.25 mm long; those on head and appendages mostly short, while those on clypeal lobe, trunk, petiole, and especially gastric apex are longer.

Type Material

Holotype (Museum of Comparative Zoology) a unique worker specimen from Bubia, about 13 km NW of Lae, Papua New Guinea, about 20 m above sea level, in high-graded rainforest, 26 March 1955, by E. O. Wilson (MCZ). The worker was foraging under the bark of a large Zoraptera-stage (rotting) log.


The species is named for Dr. Ruth Lippitt Willey.


References based on Global Ant Biodiversity Informatics

  • Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on Accessed on 24th Feb. 2011.
  • Willey R. B.; W. L., Jr Brown. 1983. New species of the ant genus Myopias (Hymenoptera: Formicidae: Ponerinae). Psyche (Cambridge) 90: 249-285.
  • Wilson Edward O. 1959. Adaptive Shift and Dispersal in a Tropical Ant Fauna. Evolution 13(1): 122-144