Tuesday, July 22, 2025

[Arachnida • 2025] Phlogiellus khampheng • A New Species of Southeast Asian Dwarf Tarantula in the Genus Phlogiellus Pocock, 1897 (Araneae: Theraphosidae: Selenocosmiinae) from Lao PDR

 

Phlogiellus khampheng Sriranan, Songsangchote & Chomphuphuang,

in Sriranan, Songsangchote, Sihavong, Sayavongsa, Sidavong, Satakoun, Inkhavilay, Chomphuphuang et Gabriel, 2025. 

Abstract
A new species of Southeast Asian dwarf tarantula, Phlogiellus khampheng Sriranan, Songsangchote & Chomphuphuang, sp. nov., is described from Pakse, Champasack Province, Lao PDR. The species is placed within the Yamia group of the genus Phlogiellus, which is characterized by the absence of maxillary lyra. Phlogiellus khampheng Sriranan, Songsangchote & Chomphuphuang, sp. nov. can be distinguished from other species within the Yamia group by the unique morphology of the female spermathecae and the male embolus. The habitat and natural history of P. khampheng Sriranan, Songsangchote & Chomphuphuang, sp. nov. are also discussed, with specimens found in mixed deciduous forests near Pakse, Lao PDR, inhabiting various microhabitats such as soil walls, under rocks, and within tree hollows. An updated comparison of scopula characteristics and labial cuspule counts across Phlogiellus species highlights the variability of these traits and their limitations as diagnostic features. Molecular phylogenetic analyses and species delimitation methods (ABGD and ASAP) further support the recognition of P. khampheng Sriranan, Songsangchote & Chomphuphuang, sp. nov. as a distinct species.

Key words: Distribution, Mygalomorphae, Tarantula, Taxonomy, Theraphosidae, Yamia

Phlogiellus khampheng sp. nov.
 A. Holotype ♂, NUoL00058–PKP0001; B. Paratype ♀, NUoL00058–PKP0003.

Phlogiellus khampheng sp. nov.
A. Non-type NUoL00058–PKP0006 ♀ adult carrying an egg sac; B. Subterranean system of silk tube retreats under rock.

Phlogiellus khampheng Sriranan, Songsangchote & Chomphuphuang, sp. nov.

Diagnosis. Phlogiellus khampheng sp. nov. was included in Phlogiellus based on the presence of a strong single retrolateral keel on the male embolus and a third claw on leg IV. P. khampheng sp. nov. is classified in the Yamia group (Kishida 1920) of Phlogiellus, similar to P. aper, P. birulai, P. brevipes, P. bundokalbo, P. daweiensis, P. longipalpus, P. moniqueverdezae, P. mutus, P. quanyui, P. raveni, and P. watasei due to the absence of maxillary lyra in female specimens. The P. khampheng sp. nov. differs from P. aper, P. birulai, P. brevipes, P. daweiensis, P. longipalpus, P. mutus, and P. watasei in having all metatarsal scopulae undivided, and differs from P. raveni and female P. bundokalbo in tarsal scopula division (divided on tarsus II, III and IV). The male P. khampheng sp. nov. differs from P. brevipes, P. daweiensis, P. moniqueverdezae, P. quanyui, P. raveni, and P. watasei, except P. longipalpus, by having a longer and more slender embolus with a distinct curve (Fig. 8). It can be further distinguished from P. moniqueverdezae by the narrower width at the base of the embolus. P. khampheng sp. nov. can also be distinguished from P. moniqueverdezae by geographical distribution with P. moniqueverdezae being found nearly 1,000 km away across the Gulf of Thailand. Furthermore, the male P. khampheng sp. nov. can be distinguished by the angle between the lowest and highest point of the embolus (ALH), which is 59°, compared to 77° in P. longipalpus and 44° in P. moniqueverdezae (Fig. 8). The female of P. khampheng sp. nov. differs from all other species in the Yamia group in the shape of the female spermathecae (Except female P. aper does not have described) which are twin receptacles with sub-apical buds (Fig. 6).

Etymology. The species name “Khampheng” originates from the Lao and Thai languages, particularly in the Northeastern region, where it is used as a term of endearment to refer to someone who is cherished and precious to the speaker. The word carries a strong connotation of deep affection and high esteem, and it is often used in a loving and respectful manner when addressing or describing a person of great importance in one’s life. By choosing this name, the authors sought to convey the special and valuable relationship between Thailand and Laos, the two countries that collaborated closely in the discovery of this remarkable new tarantula species. “Khampheng” symbolizes the mutual respect, friendship, and cooperation that enabled the two nations to work together in advancing our understanding of the natural world and the incredible biodiversity it contains.


 Patipan Sriranan, Chaowalit Songsangchote, Odeth Sihavong, Phoukhanh Sayavongsa, Keolamphanh Sidavong, Lilammone Satakoun, Khamla Inkhavilay, Narin Chomphuphuang and Ray Gabriel. 2025. A New Species of Southeast Asian Dwarf Tarantula in the Genus Phlogiellus Pocock, 1897, from Lao PDR (Theraphosidae, Selenocosmiinae). ZooKeys. 1247: 19-43. DOI: doi.org/10.3897/zookeys.1247.155398