Taxonomic history
Schultz et al., 2002 PDF: 333 (q.m.).See also: Kempf, 1966 PDF: 165.The rimosus-group is much more widely distributed than the strigatus-group, ranging from southern U.S.A. both over the Antilles and Central America south to central Argentina. Yet only rimosus with its puzzling "races" and morphs occupies the entire range of the territory (except for northeastern Brazil!), whereas the remaining species are seemingly rather restricted in their distribution. The group reaches its highest degree of diversity and endemism in northern South America and in Central America.
Most of the collected material, over 90% of the total, belongs to the ubiquitous rimosus s. L, whose striking variability is still not understood and had to be left out for a future study. Yet a slight improvement is introduced here by raising dentatus , hamulatus and transversus to full specific rank.
In short, the presently proposed arrangement, while exhausting the best of my possibilites and efforts, is not to be considered as final. Only more copious material and a better knowledge of the variability, distribution and biology of all forms will permit to raise our knowledge of the Cyphomyrmex ants to a satisfactory level.
Bionomics. - With the exception of a few well studied species, such as rimosus minutus Mayr (Weber, 1955) and costatus Mann (Weber, 1957a), very little, if any, information is available for most forms. One fact, however, regarding the fungi cultivated by these ants, has become firmly established in the meantime. Whereas some species ( costatus and wheeleri ) grow a basidiomycete fungus of the family Agaricaceae, which under the care of the ants forms bromatia of loosely clustered hyphal swellings or gongylidia (fungus garden of the flocculent type), other species ( rimosus , dentatus , transversus ) cultivate bromatia consisting of polygonal solid masses of cells of a yeastlike fungus, which Wheeler (1907: 772) named Tyridiomyces formicarum, but so far has not been truly identified.
It is interesting to note that in the aforesaid species the difference in type of fungus and bromatia coincides with a morphological difference, shown by the development and direction of the preocular carina and the postero-lateral limit of the antennal scrobe; in costatus and wheeleri the preocular carina fades out above the eye, but the postero-lateral limit of the scrobe behind the eye is somehow indicated, whereas in rimosus and allies the preocular carina curves strongly mesad above the eye, and there is no proper postero-lateral limit to the scrobe. Only future research will show whether or not this relationship is constant and may be generalized.
Key to the species for workers
( C. flavidus is not included; C. championi is known only in the male caste).
1. Antennal scrobe reticulate and quite shining; preocular carina not curving mesad above eye, postero-lateral limit of antennal scrobe marked at least by difference of sculpture (Figs. 2, 19)........ 2
- Antennal scrobe densely but indistinctly granulate and opaque; preocular carina curving mesad above eye, the postero-laferaj border of scrobe being formed by another carina (if present), which arises from the occipital corner and extends foreward to the inferior or posterior border of eye, never joining the preocular carina (Figs. 3, 6, 11)..................................................... 4
2. Antennal scape in repose surpassing the occipital lobe (Fig. 2); pronotal tubercles absent (Fig. 18); cheeks immarginate below .... 1. longiscapus Weber
- Antennal scape not surpassing occipital corners when in repose; lateral pronotal tubercles developed; cheeks marginate below.... 3
3. Disc of tergum I of gaster with a pair of strong longitudinal carinae (Fig. 19); midpronotal tubercles absent; postero-dorsal margin of petiole not drawn out nor bidentate (Fig. 38) .... 4. costatus Mann
- Disc of tergum I of gaster lacking a pair of longitudinal carinae; midpronotal tubercles present (Fig. 25); postero-dorsal margin of petiole drawn out as a foliaceous bidentate lamina (Fig. 37) .... 2. wheeleri Forel
4. Antennal scapes not surpassing the strikingly auriculate occipital lobes (Figs. 4, 5); pronotum completely unarmed (Figs. 23, 26), its sides marginate only ....................................... 5
- Antennal scapes usually surpassing the scarcely or gently drawn out occipital lobes; pronotum with the lateral tubercles always present.. 6
5. Anterior mesonotal tubercles conical, posterior ones low and tumuliform(Fig. 23); petiolar node much less than thrice as broad as long (Fig. 33)................................. 5. bicornis Forel
- Thorax completely unarmed, its dorsum in profile evenly rounded (Fig. 26); petiolar node strikingly transverse, thrice as broad as long (Fig. 32) .............................. 6. laevigatus Weber
6. Paired midpronotal tubercles absent ........................... 7
- Paired midpronotal tubercles' present ........................... 9
7. Hind femora not dilated nor ventrally carinate at basal third (Fig. 42); funicular segments II-VIII longer than broad .... 7. kirbyi Mayr
- Hind femora dilated and ventrally carinate at basal third (Figs. 46| 50); funicular segments II-VIII about as long as broad ........ 8
8. Epinotum unarmed, rounded in both directions (Fig. 20); antennal scapes well projecting beyond occipital corners (Fig. 13) ...... 8. peltatusn. sp.
- - Epinotum dentate; basal face laterally marginate to carinate (Fig. 21); antennal scapes scarcely projecting beyond tip of occipital corners (Fig. 8) ............................. 9. dentatus Forel
9. Maximum expansion of frontal carinae less than interocular width (Fig. 6); thorax finely but distinctly rugose; lateral. pronotal and anterior mesonotal projections long and spine-like (Fig. 14) .... 10. foxi Forel
- Maximum expansion of frontal carinae exceeding interocular width; thorax lacking distinct rugulae; lateral pronotal and anterior mesonotal projections short, tubercular or at best conical ...... 10
10. Apex of occipital lobes drawn out into a spine (Figs. 1, 3); anterior mesonotal tubercles high and conical (Figs. 15, 16) ...... 11
'- Apex of occipital lobes not drawn out into a spine; anterior mesonotal tubercle low and usually tumuliform ................ 12
11. Body without appressed scale-like hairs; basal face of epinotum sharply carinate in its entire length; posterior mesonotal tubercles low, not tooth-like (Fig. 15) ................ 11. vorticis Weber
- Body hairs scale-like; basal face of epinotum bluntly carinate on anterior half; posterior mesonotal projections conical (Fig. 16) ...... 12. salvini Forel
12. Petiole strikingly transverse, thrice as broad as long (Fig. 30); postpetiole discally deeply and broadly impressed; body hairs thickly squamous .................................. 14. transversus Emery
- Petiole narrower, not thrice as broad as long (Fig. 39); postpetiole with a shallower middorsal impression; body hairs finer ...... 13
13. Hairs on head and gaster recurved or hook-like, not appressed nor strictly scale-like; thoracic tubercles sharply pointed (Fig. 22).. 15. hamulatus Weber
- Hairs on head and gaster appressed and scale-like; thoracic tubercles low and tumuliform, never pointed .......... 16. rimosus (Spinola)
(Figs. 2, 18, 29, 45)
Cyphomyrmex longiscapus Weber , 1940: 410 (Worker; Colombia: Rio Porce). - Kempi, 1904: 4.
Types. - Several workers, collected at an altitude of 1020 m (3400') by Prof. N. A. Weber; 3 specimens seen.
Worker (lectotype). - Total length 3.7 mm; head length 0.91 mm; head width 0.67 mm; thorax length 1.23 mm; hind femur length 1.17 mm. Fuscous brown; appendages lighter. Integument of body and appendages densely and sharply reticulate-punctate; body with densely distributed foveolae, which are rather difficult to see on account of the microsculpture, extending equally over both pits and intervals.
Head as shown in Fig. 2. Mandibles longitudinally striolate, strikingly elongate. Clypeus with prominent and strongly convex, mesially vestigially notched, anterior apron; postero-mesially, in front of each anterior corner of frontal lobes, a vestigial tooth. Frontal lobes very little expanded laterad, continued posteriorly by the nearly straight, subparallel, strongly carinate, frontal carinae, which attain the triangular occipital lobes. Vertex with a pair of strong carinae. Preocular carinae fading out at level Of eyes, not curving mesad nor prolonged caudad. Antennal scrobe neatly differentiated in its posterior half from the cheeks by the absence of coarse pits. No supraocular tumulus. Eyes strongly convex with about 7-8 facets across their greatest diameter. Cheeks immarginate below. Occiput prolonged into a low, collarlike prominence around foramen. Scapes elongate-clavate, projecting beyond the occipital lobes by a distance exceeding twice their maximum width. Funicular segment I very long, subequal to 1I-IV combined; segments II-IX distinctly elongate.
Thorax as shown in Fig. 18. Pronotum completely unarmed, lacking also lateral carinae on disc; antero-inferior corner obtusely dentate. Mesonotum with two pairs of rather strong tubercles. Mesoepinotal constriction present. Epinotum completely unarmed; spiracle on a slight prominence. Legs rather long and thin; hind femora (Fig. 45) not dilated ventrally on basal third; posteroventral border vestigially carinulate.
Pedicel as shown in Figs. 18 and 29. Petiolar node, as seen from above, one and a half times as broad as long, its anterior corners broadly rounded; lacking dorsal carinae and tumuli. Postpetiole with an oblique anterior face nearly at right angle to the dorsal face; the latter with a pair of approximated small tubercles on anterior corners, another pair, blunter, stronger and more widely separated, on posterior corners; posterior border between tubercles slightly excised. Anterior border of first gastric tergum and sternum marginate; sides of tergum I practically immarginate.
Pilosity inconspicuous, consisting solely of fine, thin, silvery, decumbent hairs.
Female (cf. below) and male unknown.
Specimens examined: 3 workers taken by N. A. Weber at Rio Porce, Cordillera Central, Colombia, 3400 feet, Nov. 1938 (NAW n. 1088), lectotype (NAW) and paratypes (MCZ, WWK).
Discussion. - The present species, still known only from the type series, is highly distinctive both in general aspect (elongate head, mandibles and scape) and in several features not shared by any other known species of the group: the long mandibles, the scarcely expanded frontal lobes, the neck-like collar on occiput, and above all the configuration of the antennal scrobe which, although lacking the posterolateral limit of a postocular carina, is nevertheless similar to that of the strigatus-group. Fore the preocular carina does not curve mesad above eyes, and the postero-lateral limit of the scrobe is indicated by a difference in sculpture. The dentition of the mandibles, however, is of the rimosus-group, i. e. consisting of only five teeth.
There is no close relative for this species, even though wheeleri and costatus have the same reticulate-punctate sculpture of the antennal scrobe, and their preocular carina likewise does not curve mesad above eyes; wheeleri , in addition, even possesses the reticulate-punctate sculpture of the integument of body and appendages.
Note. - Although basically resembling, 1 hesitate in definitely ascribing to the present species a lone worker and female, taken by W. L. Brown, Jr. and E. S. McCluskey on Barro Colorado Island, Panama Canal Zone, in January 1960 (n. B-55), on account of the following aberrant features:
Worker. - Decidedly smaller than type: total length 3.0 mm; head length 0.72 mm; head width 0.56 mm; thorax length 1.01 mm; hind femur length 0.82 mm. Reticulate-punctate body sculpture more superficial, hence the integument is shinier. Mesonotum having only the anterior pair of tubercles developed, the rest being flat. Mesoepinotal impression obsolete. Hind femora ventrally lobate and carinate on basal third. Petiole and postpetiole slightly broader (6:9 and 11:10), the latter with a deeper middorsal impression, stronger posterior paired tubercles, which project beyond the mesially deeply excised posterior border.
Female. - Total length 3.8 mm; head length 0.88 mm; head width 0.69 mm; thorax length 1.22 mm; hind femur length 0.98 mm. Similar to the worker. Pronotum unarmed, with humeral angles only feebly marked. Mesonotum: scutum flat, notauli present, no Mayrian furrows. Scutellum posteriorly weakly excised. Epinotum practically lacking a basal face, completely unarmed. Petiole and postpetiole similar to those of worker.
We need more material to decide whether these specimens represent a discrete form or just an extreme variant of longiscapus .
Cyphomyrmex longiscapus is een mierensoort uit de onderfamilie van de Myrmicinae.[1][2] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1940 door Weber.
Bronnen, noten en/of referenties
Cyphomyrmex longiscapus é uma espécie de inseto do gênero Cyphomyrmex, pertencente à família Formicidae.[1]
Cyphomyrmex longiscapus é uma espécie de inseto do gênero Cyphomyrmex, pertencente à família Formicidae.
