Rasopone lunaris (Emery)

Longino, John T. & Branstetter, Michael G., 2020, Phylogenomic Species Delimitation, Taxonomy, and ‘ Bird Guide’ Identification for the Neotropical Ant Genus Rasopone (Hymenoptera: Formicidae), Insect Systematics and Diversity 4 (2), No. 1, pp. 1-33 : 23-24

Rasopone lunaris (Emery)

( Fig. 8 ; Supp Figs. S 16–S18 [online only]) Ponera lunaris Emery, 1896: 55 , pl. 1, fig. 12.

Holotype worker: Paraguay (Balzan) [ MSNG, AntWeb image examined].

Pachycondyla lunaris: Emery, 1901: 45 ; Brown, in Bolton, 1995: 307. [Queen described by MacKay and MacKay, 2010: 445 is R. panamensis .]

Euponera (Trachymesopus) lunaris: Emery, 1911: 85 .

Trachymesopus lunaris: Kempf, 1960: 424 .

Rasopone lunaris: Schmidt and Shattuck, 2014: 210 .

Geographic range. Widespread in tropical South America.

Diagnosis

Mandible smooth and shining or very faintly striate; anterior clypeal margin truncate; side of head with short erect setae; petiolar node relatively long, posterior margin forming a continuous curve, without differentiated dorsal face. This is the only known species from Paraguay and southern Brazil.

Measurements, worker: HW 1.11 (0.98–1.23, 12); HL 1.22 (1.07– 1.34, 12); SL 0.86 (0.77–0.98, 12); PTH 0.78 (0.70–0.85, 11); PTL 0.47 (0.41–0.52, 11); CI 91 (88–96, 12); SI 78 (70–81, 12); PTI 60 (51–65, 11).

Measurements, queen: HW 1.16 (1.04–1.31, 4); HL 1.27 (1.15– 1.41, 4); SL 0.89 (0.82–0.98, 4); PTH 0.82 (0.74–0.90, 4); PTL 0.48 (0.41–0.53, 4); CI 92 (90–93, 4); SI 77 (74–79, 4); PTI 58 (55–62, 4).

Biology

This species occurs in lowland habitats, with records from sea level to 1,050 m elevation. Sampling methods, when indicated on specimen labels, are Winkler and ‘hypogaeic Winkler’.

Comments

UCE results reveal that most Rasopone species are in a clade of relatively smaller species that is sister to the large species R. cubitalis . These smaller species occur throughout Middle and South America. Within this clade of smaller species, three South American specimens were sequenced for UCEs, and these form a clade sister to all the Middle American specimens ( Panama northward). One of the sequenced South American specimens is from southern Brazil (Minas Gerais). The morphology closely matches the type of R. lunaris , and the locality is not too distant from the type locality. Thus, this specimen can be identified as R. lunaris with confidence. This specimen is sister to the two other sequenced specimens from South America. One of the latter is from Amazonian Colombia and was initially identified as R. lunaris , differing only in the lack of erect setae on the side of the head, and somewhat larger size. The other one is from French Guiana and has distinctive puncta on the face. The former is placed in the morphospecies JTL049, and the latter in JTL047. Given the sparse sampling from South America, we can expect continued discovery of cryptic species and geographic structuring there. The examined specimens of R. lunaris from southern South America are quite uniform and suggest a single widespread species at the southern range limit of the genus. However, the scattered records from northern South America are more variable and future sequencing work may identify them as multiple cryptic species, perhaps more related to the nearby morphospecies JTL047, JTL048, and JTL049.

MacKay and MacKay had a broad view of R. lunaris , identifying material from Guatemala to Paraguay as Pachycondyla lunaris . Our definition is narrower and more geographically limited.

Figures

Fig. 8. Distribution map, face view, and lateral view of petiole of Rasopone lunaris (worker, Brazil, Minas Gerais CASENT0644556), R. guatemalensis (holotype worker),R. costaricensis form c (worker,Costa Rica,INB0003659307),and R. JTL027 (worker,Panama,CASENT0633216).On distribution maps,red dots are sites with UCE sequence data. Red boxes are type locality.