Rasopone cryptergates, Longino, John T. & Branstetter, Michael G., 2020

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 : 22

Rasopone cryptergates New Species

( Fig. 7 ; Supp Figs. S8 and S 9 [online only])

(Zoobank LSID: urn:lsid:zoobank.org:act:FFE0F396-AC3E-46B5-A78F-B0786CBE44DE )

HOLOTYPE: 1 alate queen, Costa Rica, Heredia: La Selva Biological Station , 10.43748 −84.01381 ± 20 m, 50 m, 9-iii-2004, lowland rainforest, ALAS, M/25/787 [UCR, unique specimen identifier JTLC000008527 ] . PARATYPES: same data as holotype except 10.41745 −84.01627 ± 20 m, 50 m, 2-ii-2005, mature wet forest, ex sifted leaf litter, TEAM, AMI-1 -W-022-06 [1 worker, CAS, INB0003660648 ] ; 10.42519 −84.00399 ± 20 m, 50 m, 18-v-1993, light trap, ALAS, L/02/038 [1 alate queen, MCZC, INBIOCRI001276551 ; 1 alate queen, UCD, INBIOCRI001276552 ] ; 10.43333 −84.01667 ± 2 km, 50 m, 1-ix-2003, wet forest, H. A. Hespenheide [1 alate queen, USNM, JTLC000005546 ] .

Geographic range. Costa Rica.

Diagnosis

Lowland; mandible striate; anterior clypeal margin truncate; side of head with a few inconspicuous short setae; posterior margin of head in face view flat, posterolateral margins subangulate; petiole nearly cuboidal. Two species are within size and geographic range of R. cryptergates :

Rasopone costaricensis ( Fig. 9 ; Supp Figs. S3 and S 4 [online only]): montane; petiolar node more scale-like; posterolateral margins of head more rounded.

Rasopone MAS010 ( Fig. 7 ; Supp Fig. S47 [online only]): montane; side of head bare; posterolateral margins of vertex somewhat more rounded.

Measurements, worker: HW 1.07, HL 1.25, SL 0.84, PTL 0.47, PTH 0.82, CI 86, SI 79, PTI 57 (n = 1).

Measurements, queen: HW 1.16 (1.10–1.23, 9); HL 1.37 (1.28– 1.46, 9); SL 1.10 (1.06–1.13, 2); PTH 0.81 (0.76–0.92, 5); PTL 0.48 (0.44–0.55, 5); CI 85 (81–87, 9); SI 93 (92–94, 2); PTI 59 (57–60, 5).

Biology

This species occurs in lowland rainforest, from sea level to about 500 m elevation. Only one worker is known, from a Winkler sample of forest floor litter and rotten wood. Multiple alate queens are known, from Malaise traps, flight intercept traps, and light traps. One alate queen is from a Berlese sample of litter and soil; it is possible the queen was a contaminant, attracted to the light bulb of the Berlese funnel. The queen records are from the months of January, February, March, May, and September.

Comments

There has been intensive Winkler sampling at La Selva Biological Station, and workers of the smaller species R. pluviselva occur moderately frequently in these samples, yet only one worker of R. cryptergates has been discovered.The alate queens are the reverse, with moderately abundant queens of R. cryptergates , and a single alate queen of R. pluviselva . Dealate queens of R. pluviselva occur occasionally in Winkler samples. It is possible that R. cryptergates is more subterranean than R. pluviselva , and workers hardly ever forage in the litter. Alternatively, R. cryptergates may prefer open habitats such as pastures and lawns, and thus be more abundant in the agricultural landscape adjoining La Selva. Rasopone cryptergates may produce more abundant alate queens, or queens that fly greater distances or higher above the ground. In contrast, R. pluviselva may rely on fewer or less vagile queens that fly close to the ground, rarely being captured by Malaise or light traps.

UCE and COI data are available for the single worker specimen, placing it in a clade with three other species known only from Panama. However, the worker was associated with the queens based on morphology alone: the cuboidal shape of the petiolar node and matching size. There are currently no genetic data definitively associating the sequenced worker with the holotype queen, so future confirmation is warranted.

Figures

Fig. 7. Distribution map, face view, and lateral view of petiole of Rasopone MAS010 (worker, Costa Rica, 08COSTA-1723), R. cryptergates (worker, Costa Rica, INB0003660648), R. JTL042 (worker, Colombia, MCZ-ENT00716611),and R. JTL034 (worker, Mexico, CASENT0640282). On distribution maps, red dots are sites with UCE sequence data. Red boxes are type locality.

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.

Fig. 9. Distribution map, face view, and lateral view of petiole of Rasopone costaricensis (holotype worker), R. politognatha (holotype worker), R. JTL035 (worker, Mexico, CASENT0640453), and Rasopone JTL049 (worker, Colombia, CASENT0644557). On distribution maps, red dots are sites with UCE sequence data. Red boxes are type locality.

Fig. 3. Phylogenetic relationships among a curated set of COI barcode sequences for Rasopone. Black samples were sequenced for UCEs. Red samples were downloaded from the BOLD database.The tree was inferred using IQ-TREE with the data partitioned by codon position. Black circles on nodes indicate high support, which we define as ≥95% ultrafast bootstrap support and ≥95% SH-like branch support.Terminal names match taxonomic changes proposed in paper and provide useful sample identifiers (e.g., extraction codes [EX#] or BOLD process IDs).A complete,unpruned COI tree is available in Supp Fig. S1 (online only).

Fig. 4. Dealate queen of Rasopone ferruginea (Nicaragua, CASENT0624181). Scale bars are 0.5 mm for face view, 1.0 mm for dorsal and lateral views.