New species of Southeast Asian Dwarf Tarantula from Thailand: Phlogiellus Pocock, 1897 (Theraphosidae, Selenocosmiinae)

Abstract A new record of the tarantula genus Phlogiellus Pocock, 1897 from Thailand is described. Distributional data, natural history, morphological characters, and illustrations of male and female are provided. The Thai specimens belong to a new species, Phlogiellus longipalpus sp. n. The diagnosis of the new species and related species are discussed.


Introduction
Four genera of Theraphosidae are currently known from Thailand: Cyriopagopus Simon, 1887, Ornithoctonus Pocock, 1892, Chilobrachys Karsch, 1892and Phlogiellus Pocock, 1897(World Spider Catalog, 2017. Phlogiellus, the Asian dwarf tarantulas, was erected for Phlogiellus atriceps Pocock, 1897. It is mainly distributed in Southeast Asia, peninsular Malaysia, Indonesia, the Philippines, Taiwan (Orchid Island), and some islands west of Wallace's Line (West et al. 2012, Nunn et al. 2016, World Spider Catalog 2017. Phlogiellus moniqueverdezae Nunn et al., 2016 is the only Phlogiellus heretofore reported from Thailand (Nunn et al. 2016); here we report a second Thai species, Phlogiellus longipalpus sp. n. Collection sites for P. moniqueverdezae and P. longipalpus sp. n. are shown in Figure 1. According to West et al. (2012) Phlogiellus shares the following combination of characters: number of labial cuspules between 200-350, length of posterior lateral spinnerets nearly or equal to length of metatarsus IV, and deep fovea. However, Nunn et al. (2016) recanted the use of posterior lateral spinnerets length to length of metatarsus IV as the group synapomorphic character. Kishida (1920) proposed the genus Yamia for some species now placed in Phlogiellus, citing complete lack of a lyra on the prolateral face of the maxilla as a diagnostic character. By this criterion seven species of Phlogiellus would be included in Yamia: P. aper (Simon, 1891), P. brevipes (Thorell, 1897), P. watasei (Kishida, 1920), P. mutus (Giltay, 1935), P. bundokalbo (Barrion & Litsinger, 1995), P. moniqueverdezae Nunn et al., 2016 and P. longipalpus sp. n. Haupt and Schmidt (2004) and Zhu and Zhang (2008) also proposed the generic status of Yamia but without supporting phylogenetic analyses. A cladistic analysis of the subfamily Selenocosmiinae Simon, 1889 by West et al. (2012) using a morphological data set showed monophyly of [Phlogiellus + Yamia] and did not resolve relationships among Phlogiellus and the putative Yamia species. Raven (2005) considers Yamia a junior synonym of Phlogiellus, and suggests that the maxillary lyra may be lost secondarily in Phlogiellus as well as other selenocosmiine genera. Here, we document a second Phlogiellus from central and northern Thailand and describe it as a new species, P. longipalpus sp. n. Illustrations of the body and copulatory organs are provided, as well as information on natural history and remarks on morphological characters distinguishing this species from previously known species.

Materials and methods
Collections were carried out in Kamphaengphet, Lamphun, Lampang and Saraburi provinces, Thailand on 12 May 2014, 27 May 2014, 16 July 2015, and 8 Aug 2015, respectively. All tarantulas were collected and preserved in 95% ethanol. Specimens were transferred to the Center of Excellence in Entomology, Chulalongkorn University, Bangkok, for dissection and identification. All measurements were carried out using a Zeiss Stemi DV4 stereomicroscope equipped with an eyepiece micrometer. Diagnostic features were photographed using an Olympus Camedia c-4040zoom digital camera mounted to the phototube of an Olympus SZ60 stereoscope. Leg length and width measures were made on the left side of all specimens. Length of each leg segment was measured from the dorsal aspect, and leg width was measured at the basal end of the leg segment viewed from dorsal aspect. Tarsal measurements did not include claws. The relation factor (RF) was calculated as the ratio of the length of leg I to leg IV multiplied by 100 (von Wirth and Striffler 2005). Leg formula, the leg lengths in decreasing order, is also presented. Legs, pedipalps, stridulatory organs (cheliceral strikers and maxillae) were measured from the left side of all specimens. Color of morphological parts are as seen in alcohol-preserved specimens unless otherwise noted. The copulatory organs of females were dissected and cleared in 3M aqueous KOH solution. Specimens were identified by comparison of our measurements and images to those in Haupt & Schmidt (2004), Zhu and Zhang (2008), Schmidt (2010), West et al. (2012) and Nunn et al. (2016). All type and voucher specimens are deposited at the Chulalongkorn University Museum of Zoology (CUMZ), Bangkok, Thailand. The following abbreviations are used in the text: AER anterior eye row; AME anterior median eyes; ALE anterior lateral eyes; MOA median ocular area; PER = posterior eye row; PLE = posterior lateral eyes; PME = posterior median eyes; PLE = posterior lateral eyes, PLS = posterior lateral spinnerets, PME = posterior median eyes, PMS = posterior median spinnerets, Fem = femur, Pat = patella, Tib = tibia, Met = metatarsus, Tar = tarsus.
All measures are given in millimeters (mm). Etymology. The specific name refers to the Latin longus ("long"), which describes both male pedipalp and female spermatheca, and palpus ("palm of the hand" or "feeler").
Scopulae: Met I, II, III, undivided; Met IV, divided. Tar I, II, undivided; Tar III, IV, divided by several rows of long spines (Fig. 18). Met I, II, III, complete; Met IV, extension ¾, denser at distal end than at proximal end. Scopula extension on Tar I, II, III, IV complete; Tar IV scopula denser at the distal end and with a small, nearly hairless oval ("bald spot") at the proximal end (see Fig. 18). Hairs of distal scopula on Tar II, III and IV more evenly distributed than in the male, not forming tufts of hair (compare Figs. 15,18). Spines: Met I and II, absent; Met III, 7 spines; Met IV, 6 spines. Tar I-III with 2 claws, Tar  IV with   Distribution and natural history. Specimens were collected near villages in Lampang, Lamphun and Kampangpet provinces at approximately 200-500 meters in elevation. The habitat was disturbed by human activity and organic agriculture, including cultivation of mango, coconut, and bamboo (Fig. 25). Some specimens were collected from houses in the rainy season and others in shaded forest habitats; they appear to choose moist habitats. Some nests were built in colonies of termites or ants, which are used as prey (Figs 26-27). The nest consists of a shallow (1-2 cm deep) subterranean system of silken retreat tubes under stones or logs. One part of their web appeared to be used for accumulated prey scraps. Specimens from Saraburi province were collected in forest under rock and timber.
Remarks. Nunn et al. (2016) recently revised Phlogiellus and gave very strong support for two synapomorphies of Phlogiellus: number of labial cuspules between 160-320, fewer than other selenocosmiine genera and very deep fovea. However, R. Raven (pers. comm.) pointed out that in Nunn et al. (2016), P. pelidnus Nunn et al., 2016 was described and shown to have more than 320 labial cuspules. This inconsistency of using the number of labial cuspules as a valid synapomorphic characters of Phlogiellus remains to be investigated. For our study, P. longipalpus sp. n. is placed in Phlogiellus as it has deep fovea, while the labial cuspule numbers are between 202-317  n., P. mutas, P. aper, P. watasei, P. bundokalbo, and P. moniqueverdezae), indicating whether scopulae are entire, divided by rows of bristles or absent (grey -undivided, grey with black vertical line -divided, white -absent).