Celebargiolestes, Kennedy, 1925

Vincent J. Kalkman, 2016, Revision of the genus Celebargiolestes Kennedy, 1925 (Odonata: Argiolestidae), Odonatologica 45 (3), pp. 235-269 : 264-266

Distribution of Celebargiolestes

The genus Celebargiolestes is endemic to Sulawesi and nearby islands. The distribution of the species is shown in Figure 46 . The island has a complex geological history and consists of an amalgamation of continental fragments, each with its own history, which were merged together into its present form only during the last 5 My. VAN TOL & GASSMANN (2007) provide a summary of the geological history of Sulawesi. It is not clear if these fragments have been above sea-level during their whole history and successfully carried flora and fauna from their origin to present day Sulawesi. Like in many other groups of animals the dragonfly fauna of Sulawesi seems to have a predominantly Sundaland origin with most ancestors of present day Sulawesi species probably arriving from Borneo. There are however a few examples of genera that probably originated from the Papuan region and from there arrived in Sulawesi ( Argiolestes sensu stricto, Nososticta , Nannophlebia , Diplacina ). A molecular phylogeny of the family Argiolestidae showed that Celebargiolestes probably originated in Australia and that its ancestors either colonised New Guinea and from there Sulawesi or colonised Sulawesi directly from Australia ( KALKMAN et al. 2013). It is not known if the ancestors of Celebargiolestes were carried to present day Sulawesi on one of the rafting fragments or if the ancestors arrived airborne. The fact that Celebargiolestes is a well-defined genus suggests that it has been present on Sulawesi for a considerable period. The non-overlapping ranges of the four species on the other hand suggest a relatively recent arrival or a low rate of speciation in this group.

Habitat of Celebargiolestes

Based on the information on the labels the habitat of the species of Celebargiolestes is best described as brooks and small rivers in forest. The altitudinal range given for the species is 90–800m ( C. cinctus ), 275–1 100m ( C.orri sp. nov.), and 150–1 500m ( C. toli sp. nov.). It seems that the species are most common in the lower parts of mountains. This agrees with remarks on the labels on the habitat, for instance »fast flowing«, »currents« and »waterfalls«. The species seems to be absent from more slowly flowing, deeper and more sluggish habitats found in the lowland. Most records are from largely undisturbed forest. This is however probably an artefact of the higher collecting intensity at these sites. Celebargiolestes cinctus , C. orri and C. toli have also been noted from disturbed and largely unshaded habitats. For instance, C.cinctus was found in a brook »with ponded sites and currents, semicultivated areas, nearly unshaded, some emergent vegetation« while C. orri was found in a river described as »width 10 m, large boulders, torrents, seepage areas, rather open secondary forest overhanging from bank, otherwise not shaded«. Species of Celebargiolestes seem to be capable to reproduce in brooks in plantations. For instance, C. cinctus was found on Sangihe at »riverine gardens, coconut plantations« while C. orri was found at a brook in a »coffee plantation«. Based on this it seems likely that species of Celebargiolestes are capable to have populations in secondary forest and low intensity plantations as long as the structural integrity of the brook is maintained. The presumed larva of Celebargiolestes collected on Button Island was found at an altitude between 500–950 m in undisturbed forest ( CuLHANE 2005).

Figures

Figure 46. Distribution of species of Celebargiolestes in Sulawesi. ■ − C. askewi sp. nov.; ■ − C. cinctus; ● − C. orri sp. nov.; ▲ − C. toli sp. nov.; ● − Celebargiolestes sp.