Telosticta

''Telosticta'' is a genus of damselflies in the family Platystictidae, endemic to Borneo and Palawan. The genus was established with '' Telosticta feronia'' as the genotype.Dow, Rory & Orr, Albert. (2012). The Raffles Bulletin of Zoology. 60. 365-401. Currently, there are seventeen described species in ''Telosticta''.''Telosticta'' Dow & Orr, 2012 in GBIF Secretariat (2023). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2025-04-08.

Taxonomy

''Telosticta'' was established to address an artificial taxonomic distinction made within the family, ''Platystictidae'', particularly concerning the genera '' Drepanosticta'' and '' Protosticta''.

Historically, ''Drepanosticta'' was defined by the presence of an anal bridge vein, a minute venational characteristic that distinguished it from ''Protosticta''. However, this distinction has since, been deemed problematic as occasionally, specimens exhibit the ''Protosticta'' condition on one side and the ''Drepanosticta'' condition on the other. Additionally, this distinction is widely considered to be artificial as it separates closely related species on the basis of arbitrary structural differences. The limitations and inconsistencies of venation-based classification within the Old World Platystictidae have been critically examined by multiple researchers.

This issue became more apparent when Lieftinck (1933) described '' Protosticta feronia'' and '' Drepanosticta dupophila'', noting their close resemblance despite their placement in separate genera based on minor venational differences. Currently, there are seventeen described species in ''Telosticta''.

To resolve this, ''Telosticta'' was formally described as a new genus with '' Telosticta feronia'' designated as the type species.

Diagnosis

''Telosticta'' has species ranging from medium to long in body length. They are generally dark in colour but always have pale antehumeral markings and at least some pale markings on the tip of the abdomen.

Males can be distinguished from other ''Platystictidae'' by several key morphological traits including:

* A narrow vertex;

* Flattened, ventrally projecting lateral processes on the posterior pronotal lobe;

* Pale antehumeral markings and terminal segment of penis with a well-developed convex tongue-like structure between the horns;

* Superior anal appendages that curve downward, with a dorsal basal process or bulbous swelling; and

* An inferior anal appendage featuring an internal subapical spine and a scoop-like apical modification.

Etymology

The genus name ''Telosticta'' is a feminine noun. Its prefix, Telo, originates from the Greek word τ λος (télos), meaning "toll," and is named in honor of Jan van Tol, whose surname originates from the Dutch word of the same meaning, for his significant contributions to the study of the family ''Platystictidae''. The suffix, sticta, is a common generic ending within the family.

External morphology

''Telosticta'' have predominantly black-coloured heads, with pale areas on the face. The top of the head is narrow, with the eyes nearly touching at the vertex.

The thorax is mostly pale at the front, becoming darker towards the rear. A distinctive feature in males is a pair of downward-pointing, flattened processes on the back of the pronotum, sometimes referred to as “remarkable pending appendages.” These structures are less developed or absent in females. The synthorax is bronzy-black with pale markings on the sides, and the legs are mostly pale.

The abdomen is long and slim, mostly dark above, with pale rings or markings, especially on the rear segments. Males have distinct terminal appendages used in mating. The superior appendages have complex internal and external projections that vary between species. The inferior appendages are scoop-like, often with setae, and typically feature an inward-facing spine near the base.

Geographical distribution

''Telosticta'' is endemic to Southeast Asia. Of the 17 named species in this genus, 16 occur in Borneo, while '' T. paruatia'' is found in Palawan. Within Borneo, 15 species have been recorded in Sarawak, 1 in Brunei, and some occurrences have also been documented in Sabah. ''Telosticta fugispinosa'' Dow, Afendy & Rahman, 2016 in GBIF Secretariat (2023). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2025-04-08. However, compared to Sarawak and Brunei, relatively little sampling of '' T. Odonata'' in habitats suitable for ''Telosticta'' has been conducted in Kalimantan and Sabah.

Habitat

Although the habitat preferences of ''Telosticta'' species remain presently unclear, available records and research suggest that members of this genus seem to favour forested stream environments typically in hilly or mountainous terrain. They also seem to have some tolerance to disturbance, although it is noted that more research is needed to fully understand their ecological requirements and resilience to habitat changes.

'' Telosticta berawan'' for instance, has been recorded in the Paya Maga Conservation Area in Sarawak, where it inhabits moderately high gradient stream systems in a disturbed forest.Dow, R.A., Choong, C.Y. , 2021, Previously unpublished Odonata records from Sarawak, Borneo, part
VII: Odonata from Limbang Division. International Dragonfly Fund Report 37: 1-18

Similarly, '' Telosticta ulubaram'' has been recorded in the Ravenscourt Forest Management Unit (FMU) in Sarawak. Although it appears to be relatively common in the area, it is typically encountered at low densities. Field surveys in the Ravenscourt region have documented ''T. ulubaram'' along various steep, rocky forest streams and tributaries. While the species has been observed in forest areas that have been disturbed by logging, earlier records were primarily from pristine habitats or areas subjected only to more gradual or low-intensity disturbances, rather than large-scale commercial logging. This suggests that ''T. ulubaram'' may have some tolerance to habitat modification, though it may still show a preference for less disturbed environments.

Species

According to the Global Biodiversity Information Facility (GBIF) and recent taxonomic revisions, the genus ''Telosticta'' comprises the following species:
* '' Telosticta belalongensis'' Dow & Orr, 2012
* '' Telosticta berawan'' Dow & Orr, 2012
* '' Telosticta bidayuh'' Dow & Orr, 2012
* '' Telosticta dayak'' Dow & Orr, 2012
* '' Telosticta dupophila'' Lieftinck, 1933
* '' Telosticta feronia'' Lieftinck, 1933
* '' Telosticta fugispinosa'' Dow, Afendy & Rahman, 2016
* '' Telosticta gading'' Dow & Orr, 2012
* '' Telosticta iban'' Dow, 2014
* '' Telosticta janeus'' Dow & Orr, 2012
* '' Telosticta kajang'' Dow & Orr, 2012
* '' Telosticta longigaster'' Dow & Orr, 2012
* '' Telosticta paruatia'' van Tol, 2005
* '' Telosticta santubong'' Dow & Orr, 2012
* '' Telosticta serapi'' Dow & Orr, 2012
* '' Telosticta tubau'' Dow, 2010
* '' Telosticta ulubaram'' Dow & Orr, 2012
The genus ''Telosticta'' was formally established by Dow and Orr in 2012, with its description published in Volume 60 of The Raffles Bulletin of Zoology and '' Telosticta feronia''. In that publication, eleven species were newly described and assigned directly to the newly created genus. In addition, three previously described species were transferred from other genera into ''Telosticta'': '' Drepanosticta dupophila'', '' Protosticta paruatia'', and '' Protosticta tubau''. The genus was also redefined to accommodate ''Protosticta feronia'', which is now recognized as '' Telosticta feronia''.

Since the original 2012 publication, two additional species have been described and added to the genus: '' Telosticta iban'' and '' Telosticta fugispinosa''; both of which are also listed in GBIF.

References

External links

Genus ''Telosticta''
on GBIF

{{Authority control

Platystictidae
Odonata genera