Oxyepoecus, Santschi, 1926

Albuquerque, Nicolas Lavour de & Brandão, Carlos Roberto Ferreira, 2009, A revision of the Neotropical Solenopsidini ant genus OXYEPOECUS Santschi, 1926 (Hymenoptera: Formicidae: Myrmicinae). 2. Final. Key for species and revision of the Rastratus species-group, Papéis Avulsos de Zoologia 49 (23), pp. 289-309 : 292-293

Key for the identification of Oxyepoecus workers

1. Cephalic dorsum mostly smooth and shining; sculpture, if present, confined to anterior portions of genae and between the frontal carinae, where the costulae may prolong caudad into two patches always separated by a smooth median frontal stripe ( Vezenyii Species-Group ).................................................2

1’. Cephalic dorsum either entirely sculptured, or if partially smooth, at least the median frontal stripe is covered by microsculpture ( Rastratus Species-Group ) ........................................................................11

2. Mesosoma with irregular reticulate sculpture (better seen over 80X magnifications); head clearly longer than wide, (c.i. 70)........................................................................................................ O. longicephalus

2’. Mesosoma lacking irregular reticulate sculpture; head clearly wider than long, (c.i.> 70)........................3

3. Compound eye with more than 7 ommatidia across greatest diameter, total number of ommatidia more than 30 ................................................................................................................................................4

3’. Compound eye with less than 7 ommatidia across greatest diameter, total number of ommatidia less than 30 ........................................................................................................................................................5

4. Petiole antero-posteriorly compressed in a scale-like fashion, pronotum convex and rounded above, whole propodeum and metapleura with well marked costulae ........................................................................6

4’. Petiole not antero-posteriorly compressed but club shaped, integument almost entirely smooth and shinning........................................................................................................................... O. punctifrons

5. Propodeum saddle shaped; posterior margin of katepisternum and posterior face of the postpetiole smooth and shinning.................................................................................................................... O. ephippiatus

5’. Propodeum dorsum at the same level of mesonotum, as in other species in the genus; posterior end of katepisternum and posterior face of postpetiole longitudinally costulate............................ O. inquilinus

6. Antero-lateral margin of the pronotum in dorsal view rounded...............................................................7

6’. Antero-lateral margin of the pronotum in dorsal view angulated.............................................................8

7. Metanotal groove not impressed (p.v.), overall size minute, the smallest of the Vezenyii species-group (1.7 mm) ................................................................................................................................ O. kempfi

7’. Metanotal groove impressed (p.v.), overall size median in comparison with others species to the Vezenyii species-group (2.7 mm)..................................................................................................... O. crassinodus

8. Antero-lateral margin of the pronotum in dorsal view rounded, not forming an angle ............. O. vezenyii

8’. Antero-lateral margin of the pronotum in dorsal view forming an angle .................................................9

9. Pronotal disk without costulae; subpostpetiolar process very much ventrally projecting, surpassing the level of the postpetiolar socket................................................................................................. O. bruchi

9’. Pronotal disk with costulae; subpostpetiolar process not much ventrally projecting, attaining at most the level of the postpetiolar socket............................................................................................................10

10. Dorsal margin of the petiole in lateral view rounded; length of the declivous margin of the propodeum less than half of the basal margin length ....................................................................................... O. browni

10’. Dorsal margin of the petiole subquadrate; length of the declivous margin of the propodeum more than half the basal length ........................................................................................................... O. quadratus

11. At least the posterior third of the pronotal lateral face covered by sculpture; katepisternum and metapleuron mostly covered by reticulations ..........................................................................................................12

11’. Posterior third of pronotal lateral face mostly smooth (faint rugae covering at most the mesothoraxic spiracle in O. rastratus ); katepisternum and metapleuron mostly covered by longitudinal costulae .............................................................................................................................. 14

12. Mesosoma and petiole dorsum entirely reticulate ( Fig. 1b ). Tiny compound eye with three ommatidia r.g.d. and circa five in all ( Fig. 1a ) ................................................................................... O. myops n. sp.

12’. Mesosoma and petiole node dorsum either smooth or covered by different sculpturing. Compound eye with more than 6 ommatidia. ............................................................................................................13

13. Head dorsum laterally and at vertex mostly smooth, costulae confined to median cephalic dorsum ( Fig. 5a ), sculpture on lateral pronotal face mostly effaced; katepisternum and metapleuron covered by reticulations only ( Fig. 5b ) ............................................................................................... O. rosai n. sp.

13’. Head dorsum and vertex completely sculptured ( Fig. 4a ); lateral face of pronotum longitudinally costulate (sometimes reticulate), katepisternum and metapleuron irregularly reticulate and punctate, coarser on metapleuron....................................................................................................................... O. reticulatus

14. Costulae on head dorsum prolonged caudad but not attaining posteriorly the vertex margin ( Fig. 2a ) ...... ........................................................................................................................................ O. plaumanni

14’. Costulae on head dorsum prolonged caudad and attaining posteriorly the vertex margin......................15

15. Costulae on head dorsum prolonged laterally and do not reaching posterad of compound eye... O. daguerrei

15’. Costulae on head dorsum prolonged laterally and reaching posterad of compound eye ( Fig. 3a ) ............... ............................................................................................................................................ O. rastratus

Figures

FIGURE 1: Scanning electron micrograph of the workers of O. myops n. sp.; a) head in full-face view; b) mesosoma in profile view; c) Petiole and postpetiole in dorsal view.

FIGURE 2: Scanning electron micrograph of the workers of O. plaumanni; a) head in full-face view; b) mesosoma in profile view; c) Petiole and postpetiole in dorsal view.

FIGURE 3: Scanning electron micrograph of the workers of O. rastratus; a) head in full-face view; b) mesosoma in profile view; c) Petiole and postpetiole in dorsal view.

FIGURE 4: Scanning electron micrograph of the workers of O. reticulatus; a) head in full-face view; b) mesosoma in profile view; c) Petiole and postpetiole in dorsal view.

FIGURE 5: Scanning electron micrograph of the workers of O. rosai n. sp.; a) head in full-face view; b) mesosoma in profile view; c) Petiole and postpetiole in dorsal view.