Robert B. Willey and William L. Brown, Jr.
New species of the ant genus Myopias (Hymenoptera: Formicidae: Ponerinae).
Psyche 90:249-286, 1983.

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NEW SPECIES OF THE ANT GENUS MYOPIAS
(HYMENOPTERA: FORMICIDAE: PONERINAE)
The work reported upon here began in the early 1950's as a revision of genus Myopias, including as a synonym Trapeziopelta. For a year or more it served as the trial focus of RBW's doctoral thesis research, until his interests shifted into other channels, and he laid the revisionary work aside. Meanwhile, WLB's interest in the revision continued, but he had no opportunity at that time to do much more than supervise the drafting of a set of illustrations by artist Nancy Buffler-many of which are now offered here-and to make some of the dissections of mouthparts, etc. As WLB's work on the reclassification progressed for over 25 years through the tribes of subfamily Ponerinae, much new material was added to what had been available for the original Myopias study, and additional new synonymies and new species were discov- ered, as well as valuable information on the larvae, males, distribu- tion and bionomics of species new and old. Even the status of Myopias as a genus apart from Pachycondyla came into question. Although in some ways it would be best if the old findings to which we both contributed could simply be incorporated in the reclassi- fication part dealing with tribe Ponerini s. str., there seemed in this course no convenient way to recognize the legitimate claim of RBW to authorship based on the considerable amount of work he had done on Myopias in 1955.
The compromise reached sees the larger Myopias review, with keys to species and discussions of synonymy, biology, etc. to be included in Brown's forthcoming Part VII of "Contributions toward a Reclassification of the Formicidae," while descriptions of the new species included in various drafts of our joint manuscript of the The University of Illinois at Chicago Circle, Biological Sciences, P.O. Box 4348, Chicago, IL 60680.
department of Entomology, Cornell University, Ithaca, NY 14853. (Address cor- respondence here.)
3A report of research from the Cornell Agricultural Experiment Station. Research supported by National Science Foundation Grant DEB-8003722. Manuscript received by the editor March 15, 1983



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250 Psyche [VOI. 90
1950's are presented here, together with a few notes on variation, on bionomics, and on the distribution of certain species. Figures of some old species are included with those of the new ones. The main collection used is that of the Museum of Comparative Zoology at Harvard University, Cambridge, Massachusetts (MCZ), for Myopias based mainly on collections by Eric Mjoberg, Edward 0. Wilson, James W. Chapman, William L. Brown, Jr. and Philip S. Ward. Secondary sources were the British Museum (Natural His- tory) in London (BMNH), collected by Barry Bolton and others, and the Australian National Insect Collection at Canberra (ANIC), collected by Robert W. Taylor and others. For the collectors named above, only surnames are cited in the text. Our thanks go to all who provided us with specimens.
The drawings provided here were mostly done during the mid- 1950's by Nancy Buffler. Fig. 4 is by James S. Miller. We are also grateful for a copy set of Edward Wilson's wonderful New Guinea field notes of 1955, which have yielded most of what we know about Myopias bionomics, here published for the first time. MEASUREMENTS AND RATIOS
Where series were available, measurements were usually taken on the largest and smallest (worker) specimens in each locality-series. The measurements and indices are mostly those standard in ant taxonomy for the past 30 years.
(total length) axial length of body, including closed mandi- bles; summed ML + HL + WL + petiole L + length of gaster.
(head length) maximum measurable length of head as seen in dorsal full-face view, using the anterior edges of the fron- tal lobes as the anterior reference point, and the posterior- most point or points of the cranial outline as the posterior reference point.
(head width) maximum measurable width of head, not including the eyes, as seen in dorsal full-face view. (cephalic index) HW X 100/HL.
(mandibular extension) maximum measurable distance be-



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19831
MI
MLO
CLL,
CLW
SL
SI
EL
WL
Willey & Brown - Genus Myopias
25 1
tween the most distal apex of the closed mandibles and the anterior edges of the frontal lobes, as seen in same (dorsal full-face) view from which HL is taken.
(mandibulo-cephalic index) ML X 1001 HL. (mandibular outside length) maximum absolute chord length of left mandible measured from lateral insertion to apex.
(length, width of median clypeal lobe) as measured in dorsal full-face view.
(scape length) chord length of antenna1 scape, excluding radicle.
(scape index) SL X 1001 HW
(eye length) maximum measurable length of facetted part of eye.
(trunk length) diagonal length of trunk as measured from side view, from anterodorsal slope of pronotum (excluding cervix) to most posterior extremity of propodeum. Myopias gigas, new species
(Figures 1, 12)
Diagnosis, worker: A very large species of the M. loriai group, even larger than M. loriat, with proportionately longer mesonotum and petiolar node, and with the head dorsally, trunk dorsum and pleura of posterior section of trunk sharply and regularly striate; body otherwise prevailingly smooth and shining. Funicular segment I1 very long, longer than I.
Worker, holotype: TL 16.9, HL 2.50, HW 2.60 (CI 104), ML 2.26 (MI 90), SL 2.62 (SI 101), EL 0.45, WL 4.61, petiole L 1.7, hind femur L 3.7, hind tibia L 3.16 mm.
This, the largest known species of Myopias, has the broad, poste- riorly narrowed head of the loriai group; long, slender, curved mandibles and rather large eyes with many fine facets. A scape, when held straight back as seen in full-face view, surpasses the posterior border of the head by nearly 2% times the apical scape width. The posterior border of the head is transverse and nearly straight, varying from very feebly concave to subsinuate in slightly different views. As in M. loriai, the median clypeal lobe is apically biconvex, with a shallow median notch; the lobe is shorter and broader than in M. loriai, and tapers slightly from base to apex.



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252 Psyche [VOI. 90
Antenna1 funicular segment I1 is longer than I, 111 and all other funicular segments except the apical, and it is 2.5 times longer than its maximum (apical) width. No differentiated antenna1 club. Labrum with a sharp erect tooth at the apex of each labral lobe; no median labral tubercle. Palpi concealed, not seen. Mandibles as shown in Figure 1; apical tooth followed closely basad by 2 coarse denticles and a blunt tooth; middle tooth followed basad by a low, rounded basal angle. Strix (mandibular groove) well-developed from base to apex.
Trunk long and robust; mesonotum longer than in loriai, but wider than long (L/W - 0.7). Metanotum present as a deeply impressed groove, widening laterad on each end. In side view pro- file, pronotum strongly convex, although transversely impressed just in front of the raised, cariniform posterodorsal margin; meso- notum feebly convex and sloping downward behind, but its anterior margin raised slightly above the posterior pronotal margin, espe- cially (as in the type) when the two somites are flexed against each other. Promesonotum (without cervix) and propodeum subequal in length; propodeum broadly convex from front to rear, with its de- clivity steeper than its dorsum, but passing into dorsum through a gentle curve. Mesopleural suture distinct and complete, moderately deeply impressed (more distinct than in M. loriai). Propodeal spira- cle elongate and oblique, its opening about 2% times longer than wide.
Petiole (Fig. 12) loaf-shaped, longer than broad and longer than high; exact shape of subpetiolar process, if any, not determined because the extreme anterior end of the segment is hidden by the coxae. Gaster long, gently downcurved, with a distinct constriction between first and second segments; dorsally viewed, second seg- ments longer and a little wider than first. Sting long and strong, distinctly upcurved.
Dorsum of head completely finely and regularly striate in a longi- tudinal direction, the striae mesa1 to and behind the eyes tending to curve slightly outward. Dorsum and declivity of trunk similarly striate, but in a transverse direction, arching on pronotum. Sides of trunk behind pronotum with similar, oblique striation, continued from the propodeal dorsum through a curve. Remainder of head, body and appendages smooth and shining, including mandibles, cervical border of vertex and sides of pronotum. Coarse, spaced,



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Willey & Brown - Genus Myopias
Figs. 1-3, Myopias spp., heads of workers, sculpture and pilosity omitted. Fig. 1, M. gigas holotype in full-face view. Fig. 2, M. lobosa, paratype in full-face view. Fig. 3, M. lobosa, another paratype in side view. Scale bars for Figs. 2 and 3 are 0.5 mm.



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254 Psyche [VOI. 90
piligerous punctures are conspicuous in smooth areas, particularly the sides of the head, mandibles, femora and tibiae, petiole, and normally exposed surfaces of gastric terga. Pubescence appressed and decumbent, generally very sparse, except on antenna1 flagella, coxae, tarsi, flexor surfaces of fore tibiae, flexor surfaces of mid femora, extensor surfaces of mid tibiae, and apex of hypopygium. Rather abundant erect or suberect, fine, tapered hairs, from short to over 0.5 mm long, occur on almost all normally exposed surfaces of body and appendages. Color deep reddish brown, appendages mainly clear light red. Holotype (MCZ) a unique worker from Dobodura, Papua New Guinea (P. J. Darlington leg.).
This magnificent species is even larger than M. loriai, and has very different sculpture, but the two forms are obviously closely related. Because of the long mandibles and large size, we guess that M. gigas may be a millipede predator, but we have no direct evi- dence of feeding behavior for this species. Myopias julivora new species
(Figs. 5, 22)
Diagnosis, worker: Similar to M. tenuis, but larger (HW 0.80- 1.01), with relatively longer mandibles and antennae, MI > 65, scapes overreaching posterior border of head (when held straight back, full face view) by about their own apical width to nearly twice their apical width; all antennomeres longer than broad. Shafts of mandibles approximately straight over middle half of their length. Worker, holotype: TL 6.2, HL 1.04, HW 0.94 (CI 90), ML 0.73 (MI 70), MLO 1.0 1, SL 0.90 (SI 96), EL 0.09, W L 1.74, hind femur L 1.00, hind tibia L 0.94 mm.
Worker, paratypes (n = 6 of 34 representing 7 colonies from 6 localities, including largest and smallest specimens): TL 5.8-6.7, HL 0.91-1.14, HW 0.81-1.01 (CI 88-90), ML 0.62-0.83 (MI 66-73), MLO 0.86-1.14, SL 0.86-1.09 (SI 96-108), EL 0.06-0.10, WL 1.66-1.93, hind femur L 0.89-1.15, hind tibia L 0.87-1.12 mm. Description limited to details not covered in diagnosis and mea- surements. Median frontal sulcus extends approximately to middle of HL, followed posteriad after a gap by a shallow pit marking location in queen of anterior ocellus; this pit is usually absent in M. tenuis, but is occasionally faintly indicated there. Compound eye



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19831 Willey & Brown - Genus Myopias 255 essentially reduced to a single convex lens, but at high magnifica- tions, traces of an ommatidial grid can be made out; reduction approaches the state in M. tenuis, but does not go quite so far. Median clypeal lobe trapezoidal, widest near apex (CLL 0.12, CLW 0.16 mm), but by optical illusion may seem as long as or longer than wide; free corners rounded; anterior margin straight, convex, or even slightly sinuate. Basal oblique mandibular groove (strix) sub- lateral in origin, difficult to see in dorsal view, but distinct with its ventrolateral extension in side view. Submedian tooth situated in seventh tenth of the shaft length, counting from base. Basal angle obsolete.
The upturned tooth on each labral lobe and 3,3 palpal segmenta- tion formula are as in tenuis.
Trunk formed much as in M. tenuis; promesonotum subequal in length to propodeum; side view outline rather low and weakly con- vex, with a distinctly, but not deeply, impressed metanotal groove; propodeal dorsum only feebly convex, and sometimes very feebly impressed near midlength. Petiolar node slightly longer than broad, about as broad as long, or slightly broader than long, in different series (as in M. tenuis also), summit convex, slightly higher behind. Gaster with first segment strongly rounded above, tergum rising caudad; segment I1 distinctly constricted in front at juncture with its acrotergite; about as high at maximum height as segment I, and slightly wider. As seen from above, anterior margin of segment I straight or feebly convex; shallowly concave in Vanimo worker (and queen). Sting long (extruded up to 0.6 mm), sharp, upcurved. Sculpture prevailingly smooth and shining; punctures minute and widely spaced, more numerous and coarser on head, especially in Vanimo worker and queen, and on propodeum, but even here still obscure. Pilosity of uneven length, fine, tapered, erect to suberect hairs, mostly 0.05 to 0.30 mm long; pubescence decumbent to sub- erect, very dilute on anterior dorsum of head, but more abundant on antennae and legs, especially extremities. Color averaging lighter than in fully pigmented M. tenuis workers, light to medium brownish red to dark brownish red, light orange brown in some workers, possibly callow. Appendages usu- ally lighter, more yellowish, than basic body color. Worker variation, as mostly discussed already above, involves mainly size-related features and shape of clypeal lobe, distinctness



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256 Psyche [VOI. 90
and density of the obscure puncturation, length and degree of apical taper of petiolar node, size and pigmentation of compound eyes, length of antenna1 scapes, and depth of body color. Queen, dealate (from type nest series, Wilson No. 905), TL 7.1, HL 1.10, HW 0.97 (CI 88), ML 0.74 (MI 67), MLO 1.02, SL 0.96 (SI 99), EL 0.26, WL 2.03 mm. Combined measurements for the largest queen specimen (above), another queen from the type local- ity, colony No. 1048, and a smaller queen from near Vanimo, are: TL 5.6-7.1, HL 0.93-1.10, HW 0.84-0.97 (CI 88-90), ML 0.63-0.76 (MI 67-72), MLO 0.87-1.03, SL 0.87-0.96 (SI 99-104), EL 0.22- 0.26, WL 1.78-2.03 mm.
The queen differs from accompanying workers by the usual pone- rine characters, and is also darker in color, prevailingly piceous, or even blackish in the Vanimo specimen. On trunk, centers of scutum and scutellum are infuscated, while marginal areas of these and other sclerites are lighter and more reddish. Appendages lighter, more yellowish.
Male unknown.
Described from material representing seven separate collections from six localities in Papua New Guinea. Holotype (MCZ) from Wilson's colony No. 905, lower Busu River, Huon Peninsula, Papua New Guinea, 3 May 1955, a nest in rain forest in a small Zoraptera- stage rotten log, in a part of the log somewhat raised off the ground, containing one queen, about 30-40 workers, and brood of all stages, with pupae predominating. Abundant remains of millipedes were found in the brood chamber and galleries leading away. One fresh millipede corpse was among larvae; the prey all seemed to belong to one kind.
Another colony (Wilson No. 1048) also came from the lower Busu River tract, 15 May 1955, from cavities in an old, hard polypore fungus growing on a large Passalus-stage log, containing a queen and about 75 workers, plus abundant brood of all stages, without notable preponderance. Half of a freshly dead millipede was found with the brood; the midden remains were collected (but later lost with the nest residue in alcohol).
A worker and a dealate queen were found in lowland (40 m) rain forest next to the quarry at Km 2 on the Bewani Road, near Vanimo, West Sepik District, Papua New Guinea, 27 February 198 1, leg. Brown (No. 8 1-48). The nest was in a small rotten stick



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19831 Willey & Brown - Genus Myopias 257 lying on the ground, and contained larvae as well as the remains of small millipede prey. (Paratypes in MCZ, BMNH, ANIC, etc.) In addition, single strays come from three widespread localities: Dobodura, March to July 1944, leg. P. J. Darlington, Jr.; Iora Creek, 17 km. S. of Kokoda at 1400 m, leg. Ward (No. 183 1) rotten log, montane rain forest; Baiyer River, Western Highlands, about 1200 m, 6 July 1974, leg. S. Peck, berlesate B-281. The last specimen is the largest one of the species seen; it is also the darkest in color, has somewhat coarser punctures than usual on the head, and has the longest scapes, so that it might be thought transitional to M. media, but the form of the mandibles and clypeal lobe is typical for julivora.
The name of this species derives from the Latin julus, a millipede, and vorare, to devour. The new species is close to the very variable M. tenuis, but seems constantly distinct from it, even where the two species occur in intimate sympatry, as they do in the Busu River tract. For relationship to M. media, see under that species below. Myopias media new species
(Figs. 6, 23)
Diagnosis, worker: member of tenuis group, very similar to M. julivora in habitus, color, etc., but larger, head wider, with more robust and more strongly curved mandibles, the submedian tooth situated closer to the midlength (at the seventh twelfth from base along MLO). Antennae long; scapes overreaching posterior border of head (when held straight back) by nearly twice their apical width. Worker, holotype: TL 7.6, HL 1.25, HW 1.24 (CI 99), ML 0.93 (MI 74), MLO 1.26, SL 1.27 (SI 102), EL 0.13, WL 2.20, hind femur L 1.40, hind tibia L 1.35 mm.
Details additional to diagnosis: Viewed at apparent full-face, pos- terior border of head feebly convex, almost straight, but even a slight tilting of the cranium forward yields a concave border, and an increase in HL to 1.30, so that from this view, CI would be about 95. Anterolateral corners of head more prominent (at a lower level of focus), so that, excluding eyes, head is widest just behind clypeus. Median frontal sulcus continuing past mid-HL to include anterior clypeal pit. Eyes as in M. julivora, but relatively a little larger, and with remnants of facetting a bit more evident. Median clypeal lobe very obviously broader than long (CLL 0.13, CLW 0.20), with



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Psyche
[Vo 1. 90
weakly concave sides, nearly straight apical margin, and one free corner rounded, the other rectangular. Mandibles thicker, particu- larly in the stretch between the obsolescent basal angle and the submedian tooth, which is also feebly convex mesally (concave or straight along mesa1 margin in M.julivora). Labrum toothed as in M. julivora.
Sculpture as in M. julivora, but small, widely spaced punctures (diameter 0.01-0.02 mm) are perhaps more distinct on head and trunk. A small patch of longitudinal costulation lies below spiracle on side of propodeum (as in M. julivora). Posterior corners of propodeum less broadly rounded, tending more towards angula rity, both in side and dorsal views, than in M. julivora, and both the pilosity and pubescence seem to be less copious and a trifle longer. Color deep brownish red; legs yellowish red; antennae and man- dibles dark yellowish brown.
Holotype and only known specimen (MCZ) a stray collected from rotten wood at Joangeng, a village in the Mongi River Watershed of the Huon Peninsula, Papua New Guinea, at about 1500 m, 7-8 April 1955, in montane rain forest, leg. Wilson, No. 752. We describe this species with some misgiving because it is based on a unique, and because it is so similar to M.julivora, especially to the largest (Baiyer River) specimen of the lattter. The mandibles, however, differ enough that we feel inclusion of the big Joangeng specimen in M. julivora would unduly strain the concept of that species. Further collections will of course help to demonstrate whether our decision is correct or not. The name media refers to the
size of the body, intermediate in the tenuis group between M. tenuis and such large forms as loriai and gigas. Myopias concava new species
(Figs. 4, 18)
Diagnosis, worker and queen: A medium-sized, stout-bodied spe- cies with head slightly broader than long, widest just behind eyes. Median labral tooth absent, but an erect apical tooth on each lateral lobe. Eyes of worker large and multifacetted, occupying more than a quarter of the length of the sides of the head. Posterior margin of head weakly concave; sides convex. Median lobe of clypeus distinct but very short, rectangular. Mandibles short and stout, each with 2



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19831 Willey & Brown - Genus Myopias 259 small teeth at apex, 2 large blunt teeth basad of these, and an obtusely rounded basal angle. Antenna1 scapes overreaching poste- rior margin of head. Trunk compact, promesonotum and propo- deum subequal in length, forming separate weak convexities meeting at a distinct and depressed metanotal groove. Petiolar node massive, subcuboidal, broader than long. Anterior face of gastric segment I weakly concave as seen from dorsal view. Integument prevailingly smooth and shining, but with abundant, coarse piliger- ous foveolae, sometimes contiguous on head, and tending to become elongate on first two gastric terga. Color brownish red. Worker, holotype: TL 7.1, HL 1.25, HW 1.3 1 (CI 105), ML 0.7 1 (MI 57), MLO 1.26, SL 1.11 (SI 85), EL 0.33, WL 2.16, hind femur L 1.25, hind tibia L 1.20 mm.
Worker, paratypes (n = 6 of 42 from 4 colonies, including largest and smallest specimens): TL 6.5-8.6, HL 1J7-1.43, HW 1.21- 1.47 (CI 100-105), ML 0.67-0.81 (MI 53-66), SL 1.00-1.24 (SI 83-88), EL 0.30-0.40, WL 2.00-2.46 mm.
Head broader than long, with sides convex, broadest immediately behind eyes, and narrowed slightly in front of eyes; posterior border broadly and shallowly concave. (The head can be lengthened slightly by tilting it forward from the full-face plane; this has the effect of foreshortening the mandibles and deepening the concavity of the posterior margin, and of course decreasing CI.) Eyes large and convex, with about 18-19 ommatidia in the longest diagonal row, each eye occupying nearly 3/ 10 of the length of its side of the head, situated about 213 its own length from mandibular insertion. Clypeal lobe distinctly projecting but short, rectangular, more than twice as broad as long, with parallel sides, a nearly straight anterior margin, and subrectangular free corners (in Wau Creek series, anterior margin weakly convex, free corners more rounded). Labrum with the transverse ridge feebly sinuate in front view, lack- ing a median tubercle; labral lobes each with a small upturned apical tooth. Maxillary palpi each 3-merous; basal segment broadest, with one subapical lateral sensillum; apical segment with a single apical sensillum. Labial palpi each with 3 subequal segments; basal seg- ment with 2 adjacent submedian sensilla; I1 with one subapical lat- eral sensillum; I11 with the same, plus 2 apical sensilla. Mandibles stout, gently bowed, each with two small teeth at apex, a blunt tooth near apical quarter of ML, a large, blunt submedian



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260 Psyche [VOI. 90
Fig. 4. Myopias concova, head of worker paratype in full-face view. Scale bar is0.5 mm.
tooth, and a distinct but rounded basal angle. Oblique groove at base continued as a broad lateral-marginal groove (strix) to apex. Median frontal suicus of head extends to or nearly to posterior quarter of head length. Scapes gently curved, moderately incrassate apicad, overreaching posterior border by more than their apical width when head is viewed full-face. Funiculus relatively slender, all segments longer than broad; apical segments not forming a club;



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19831 Willey & Brown - Genus Myopias 26 1 pedicel (funiculus I) longer than I1 as 4:3. Trunk robust, with a weakly convex dorsal profile as seen from the side; propodeum subequal in length to promesonotum; mesono- turn convex, about half as long as propodeal dorsum, and separated