Cyphomyrmex

Kempf, W. W., 1964, A revision of the Neotropical fungus-growing ants of the genus Cyphomyrmex Mayr. Part I. Group of strigatus Mayr (Hym., Formicidae)., Studia Entomologica (N. S.) 7, pp. 1-44 : 3-7

Cyphomyrmex Mayr

Cyphomyrmex Mayr, 1862: 690 (Type: Cyphomyrmex minutus Mayr , 1862 = C. rimosus minutus Mayr , worker, monobasic). - Kempf, 1962: 29-30 (Syn.).

Cyphomyrmex (Cyphomyrmex) : Emery, 1913: 251. - Emery, 1922: 340-342.

Cyphomyrmex (Cyphomannia) Weber, 1938: 183 (Type: Cyphomyrmex (Cyphomannia) laevigatus Weber , 1938, worker, by original designation and monobasic).

As regards the generic features, the reader is referred to Emery's diagnosis in the Myrmicinae section of Genera Insectorum (1922: 341). It needs only one correction that concerns the development of the preocular carinae, which either curve mesad above eyes in the usual Attine fashion (most species of the rimosus -group), or run caudad as a straight pleat to the occipital corner where they join, after forming a loop, the posterior extension of the frontal carinae (all species of the strigatusgroup).

The subgenus Cyphomannia was sunk as a synonym, because its type species, laevigatas, belongs to the same group that contains the type species of the nominal subgenus, rimosus minutus (cf. Kempf, 1962: 29-30).

To date, Cyphomyrmex comprehends 28 species and 17 subspecies and varieties, 12 of which are attached to rimosus , 3 to bigibbosus , 1 to salvini and 1 to olitor . As shown previously (Kempf, 1962: 30) the genus is divisible into two rather welldefined species groups, according to characters found in the worker and female caste:

I. Group of rimosus : Preocular carina curving mesad above eyes, not joining up with the postocular carina, which extends from the occipital corner to posterior or inferior border of eye (this character is not well-expressed in longiscapus and allies, which resemble the strigatus -group in this respect); mandibles with 5 teeth only; two or no median pronotal tubercles present. A revision of this group will be taken up in Part li of the presenl study, to be published at a later date.

II. Group of strigatus : Preocular carina extending all the way back to the occipital corner, forming the inferior border of the antennal scrobe; mandibles with 7 or more teeth, gradually diminishing in size towards base; a single median pronotal tubercle usually well-developed in the worker caste.

The present study concerns itself with this group, which comprises the following species and new synonyms (W = worker; F = female; M = male):

1. auritus Mayr , 1887, W F M

2. strigatus Mayr , 1887, W F M

3. plaumanni Kempf , 1962, W

4. paniscus Wheeler , 1925, W F M

5. bigibbosus Emery , 1894, W F M

= tumulus Weber , 1938, NOV. SYN.

6. faunulus Wheeler , 1925, WF - NOV. STAT.

= petiolatus Weber , 1938, NOV. SYN.

7. morschi Emery , 1887, W F

= personatus Santschi , 1923, NOV. SYN.

8. daguerrei Santschi , 1933, W

9. olitor Forel , 1893, W F M

= quebradae Kusnezov , 1949, NOV. SYN.

10. vallensis Kusnezov , 1949, W

11. bruchi Santschi , 1917, W

12. lectus Forel , 1911, W - NOV. STAT.

13. nemei Kusnezov , 1957, W F M

14. lilloanus Kusnezov , 1949, W

15. occultus n. sp., F (M)

Types of all forms, with the exception of strigatus , bigibbosus , vallensis and lilloanus , have been examined.

The group as a whole, is confined to continental South America, and attains its highest degree of diversity in southeastern Brazil and northern Argentina.

On the species level, the present review recognizes 15 species, one of them being described as new to science. Whereas two forms hitherto considered as subspecies are raised to specific rank, four forms are placed into synonymy. The above proposed arrangement is not to be considered as final. Several species, especially those in the vicinity of olitor , viz. daguerrei , vallensis , bruchi and nemei , are still known only from scanty type material. Inasmuch as the extent of their infraspecific variability has not yet been explored, these species continue subject to doubt and hesitation. That this range is appreciable seems to be suggested by olitor , of which copious material is known from southeastern Brazil.

The revision undertaken in the following pages deals exclusively with the worker and female caste. The males are completely set aside, because they are known of only half of the described species. In addition, the scarce material available does not permit a comparative treatment, without which isolated descriptions are practically useless.

Note on measurements. - The total length is the sum of the maximum lengths of head with closed mandibles, thorax, petiole, postpetiole and normally expanded gaster. The head length is the maximum length of the head capsule, in full-face view, between two parallel lines drawn across the anteriormost point of clypeus and the posteriormost point of occiput or occipital lobes: the head width is the maximum width of the head capsule behind the eyes; the thorax length (Weber's length) is obtained in profile, and consists of the distance between the anteriormost point of the pronotum proper and the metasternal angle.

Key to the species for workers

( C. nemei and vallensis are not included. The worker of occultus is still unknown).

1. Promesonohim without tubercles.............14. lilloanus Kusnezov

- Promesonotum with at least some of the tubercles developed..... 2

2. Occipital lobes distinctly auriculate (Figs. 1-6), protruding also in profile (Figs. 44-49); antennal scrobe opaque with indistinct microsculpture................................................. 3

- Occipital lobes not auriculate (Figs. 7-12), or if somewhat projecting in full-face view, they do not project in profile (Figs. 50-55); antennal scrobe superficially reticulate and somewhat shining............. 8

3. Tergum 1 of gaster laterally carinate with two additional longitudinal carinae on disc......................................... 4

- Tergum I of gaster lacking discal carinae, lateral ones usually not well-developed ............................................ 6

4. Occipital lobes horn-like, longer than their maximum width (Fig. 1); mesonotum with high, acute conical spines (Fig. 13)............ 1. auritus Mayr

- Occipital lobes distinctly shorter than their maximum width (Figs. 4, 6); mesonotum bluntly tuberculata (Figs. 17, 18).............. 5

5. Frontal lobes nearly straight and scarcely constricted behind, subcontinuous with frontal carinae (Fig. 4); hind femora noticeably broadened and angulate beneath at basal third, with a prominent foliaceous rim on posterior border............ 3. plaumanni Kempf

- Frontal lobes more rounded and distinctly constricted behind, not continuous with frontal carinae (Fig. 6); hind femora not conspicuously broadened nor angulate at basal third, lacking a foliaceous rim on posterior border.............. 2. strigatus Mayr

6. Scape in repose surpassing occipital lobe (Fig. 3); pronotal and posterior mesonotal tubercles well-developed and conical; epinotum in profile angulate or dentate (Fig. 20)....... 4. paniscus Wheeler

- Scape in repose not surpassing occipital lobe (Figs. 2, 5); only anterior mesonotal tubercles well-developed, high and conical, all other very low, tumuliform (Figs. 15, 16); epinotum in profile rounded and unarmed ............................................... 7

7. Posterior border of postpetiole deeply excised (Fig. 30)........... 5. bigibbosus Emery

- Posterior border of postpetiole straight (Fig. 31)................. 6. faunulus Wheeler

8. Basal face of epinotum very short and completely unarmed (Fig. 14); frontal carinae covering the upper orbit of eye in full-face view (Fig. 12); inferior occipital corner with a foliaceous rim (Fig. 55).. ....................................... 12. lectus Forel

- Basal face of epinotum almost as long as declivous face, bearing posteriorly a pair of at least feeb'e tubercles or teeth; frontal carinae less expanded laterad, not reaching the upper orbit of eye in fullface view; inferior corner of occiput without a foliaceous rim.... 9

9. Posterior loop of antennal scrobe only vestigially marginate, its lateral border not coinciding with lateral border of head (Fig. 11); antero-inferior corner of pronotum produced foreward in a short spine (Fig. 24)................................ 7. morschi Emery

- Posterior loop of antennal scrobe sharply marginate, its lateral border coinciding with lateral border of head; antero-inferior corner of pronotum subrectangular................................ 10

10. Scape in repose conspicuously surpassing the occipital corner (Fig. 8); hind femora longer than maximum length of head capsule, ventrally not dilated nor carinate at basal third..................

8. daguerrei Santschi

- Scape in repose barely if at all surpassing the occipital corner; hind femora not longer than maximum length of head capsule, ventrally dilated or angulate and carinate at basal third................. 11

11. Lateral lobes of petiole ventrally deeply excavate, outer borders broadly foliaceous; midpronotal and antero-lateral mesonotal tubercles indistinct, dorsum of thorax in profile strikingly flat (Fig. 21)..... 10. bruchi Santschi

- Lateral obes of petiole ventrally at most shallowly excavate and mostly solid; midpronotal and antero-lateral mesonotal tubercles distinct, dorsum of thorax in profile convex with prominent tubercles and deeper impressions (Figs. 19, 23)............... 9. olitor Forel

Key to the known females

1. Tergum 1 of gaster with 4 longitudinal carinae, two on disc and one on each side. ............................................ 2

- Tergum I cf gaster lacking a pair of longitudinal carinae on disc; sides either marginate or immarginate.......................... 3

2. Occipital lobes long, horn-like, longer than their width at base; midpronotal tubercles usually present; epinotal spines well-developed 1. auritus Mayr

- Occipital lobes short and rounded, shorter than their width at base; midpronotal tubercles always absent; epinotum practically unarmed.. 2. strigatus Mayr

3. Antennal scrobe densely but indistinctly granulate and opaque; paraptera of mesonotum with a tooth that either projects upward or caudad ................................................. 4

- Antennal scrobe sharply and distinctly reticulate and somewhat shining; paraptera of mesonotum flattened above, its lateral and posterior margin completely rounded without a projecting tooth.. 6

4. Antennal scape in repose surpassing occipital lobes; epinotal spines well developed; lateral borders of gastric tergum 1 marginate...... 4. paniscus Wheeler

- Antennal scape in repose not surpassing occipital lobes; epinotal spines at best vestigial; lateral borders of gastric tergum I immarginate ............................................... 5

5. Posterior border of postpetiole with a deep mesial excision, flanked by prominent tubercles...................... 5. bigibbosus Emery

- Posterior border of postpetiole straight, without a mesial excision.. 6. faunulus Wheeler

6. Hind femora longer than head capsule, slender, ventrally not gradually dilated towards basal third nor angulate, their posterior ventral border not carinate; antennal scape in repose surpassing occipital angle or lobe .............................................. 7

- Hind femora shorter than head capsule, ventrally gradually dilated towards basal third where they form a more or less distinct angle; their postero-ventral border carinate to crested; antennal scape in repose not surpassing occipital lobe............................. 8

7. Petiole longer than broad, its dorsum with a pair of prominent and laterally compressed teeth; maximum diameter of eyes nearly one third of head length............................ 15. occultus n. sp.

- Petiole broader than long, dorsally completely flattened without teeth; maximum diameter of eyes less than one fourth of head length ...................................... 7. morschi Emery

8. Longitudinal furrow on tergum 1 of gaster broad and distinct, traversed by regulae; epinotal spines almost obsolete............. 13. nemei Kusnezov

- Longitudinal furrow on tergum 1 of gaster less distinctly impressed, not traversed by regulae; epinotal spines usually fairly well developed 9. olitor Forel