Cyphomyrmex longiscapus

Kempf, W. W., 1966, A revision of the Neotropical fungus-growing ants of the genus Cyphomyrmex Mayr. Part II. Group of rimosus (Spinola) (Hym. Formicidae)., Studia Entomologica (N. S.) 8, pp. 161-200 : 161-165

Group of Cyphomyrmex rimosus

The rimosus-group has previously (Kempf, 1962: 30; 1964: 4) been defined by the ensemble of the following characters in the worker (and female) caste: Mandibles with 5 teeth only; two or no midpronotal tubercles present; preocular carina either curving mesad above eyes (most species of the group) or fading out above eyes, yet with the postero-lateral border of the antennal scrobe more or less defined as in the strigatus-group ( longiscapus , wheeleri , costatus and presumably also flavidus ). Following is a list of the presently recognized forms, including the not yet analyzed infraspecific forms of rimosus and several new synonyms (W = worker; F = female; M = male):

bicornis Forel , 1895, W, eastern Brazil

championi Forel , 1899, Al, Panama (= salvini Forel ?)

costatus Mann , 1922, W, F, M, Honduras, Panama, Colombia

= colombianus Weber , 1940 - NOV. SYN.

dentatus Forel , 1901, W, F, Mexico - NOV. STAT.

flavidus Pergande , 1895, W, Mexico

foxi Em. Andre , 1892, W, F, Jamaica

hamulatus Weber , 1938, W, Bolivia, Panama - NOV. STAT.

kirbyi Mayr , 1887, W, F, Colombia, Ecuador

laevigatus Weber , 1938, W, Bolivia, Dutch Guiana

longiscapus Weber , 1940, W, F, Colombia, Panama

peltatus Kempf , n. sp., W, F - southern Brazil

rimosus (Spinola, 1851), W, Brazil: Para

= difformis (Fr. Smith, 1858)

r. var. arnoldi Aguayo , 1932, W, Jamaica (=: foxi Em. Andre ?)

r. var. major Forel , 1912, W, Guatemala, Brazil: S. Paulo

r. atratus Forel , 1912, W, F, M, Colombia

r. breviscapus Weber , 1940, W, Panama

r. cochunae Kusnezov , 1949, W, Argentina: Tucuman

r. flavescens Weber , 1948, W, Haiti

r. fuscus Emery , 1894, W, F, M, Cisandean South America

= fusculus Emery , 1922

= curiapensis Weber , 1938

r. minutus Mayr , 1862, W, F, M, from U.S.A. to n. S. America

= deformis Roger , 1863

= steinheili Forel , 1884

= var. comalensis Wheeler , 1907

r. trinitatis Weber , 1938, W, F, Trinidad, Guianas, Panama

r. venezuelensis Weber , 1938, W, Venezuela

salvini Forel , 1899, W, F, M, Panama, Costa Rica

= acutus Weber , 1940 - NOV. SYN.

transversus Emery , 1894, W, F, M, Brazil, Argentina - NOV. STAT.

- olindanus Forel , 1901

= pencosensis Forel , 1914 - NOV. SYN.

vorticis Weber , 1940, W, Bolivia, Brazil: Rondonia

wheeleri Forel , 1900, W, F, M, U.S.A.: Tex., Cal.; Mexico

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. peltatus n. 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)