New records of the mites Geckobia bataviensis Vitzthum, 1926 and Pterygosoma dracoensis Jack, 1962 (Trombidiformes: Pterygosomatidae) from Timor-Leste

We report on the presence of scale mites (Trombidiformes: Pterygosomatidae) parasitizing three species of lizards in Timor-Leste. Geckobia bataviensis Vitzthum, 1926 was found associated with the Common House Gecko, Hemidactylus frenatus Duméril & Bibron, 1836, and the Indopacific Tree Gecko, Hemiphyllodactylus typus Bleeker, 1860, whereas Pterygosoma dracoensis Jack, 1962 was found on the patagia of a Timor Flying Dragon, Draco timoriensis Kuhl, 1820. The association of G. bataviensis with H. frenatus was well documented previously, but this is the first properly documented record of this mite for Timor-Leste. Our report of G. bataviensis on H. typus is the first association of this mite with this gecko. This is the second report of P. dracoensis on D. timoriensis and the first for Timor-Leste.

Lizard specimens included in this report were collected in Timor-Leste during two research surveys (January-February 2010, June-July 2012). They were euthanized using pericardial injections with 1% procaine, fixed in 10% formalin, and preserved in 70% ethanol. Mites were removed by gentle tugging with fine-point forceps during the post-mortem, pre-fixation examination and preserved in 95% ethanol.
Scale mites were removed from preservative and slide-mounted in Hoyer's medium, following the procedure described by Barros-Battesti et al. (2021). Mite specimens were deposited in the Acarological Collection of the Instituto Butantan, São Paulo, Brazil (IBSP) under accession numbers IBSP 16506-16511. They were identified to genus using the key to pterygosomatid genera of Bertrand (2013), and to species using keys for Geckobia (Bertrand 2013) and Pterygosoma (Fajfer 2020). Microscope images were taken using a Leica DM4000B compound microscope with phase contrast. Extended focal range images were compiled using the Leica Application Suite v. 2.5.0, and images were further improved using Adobe Photoshop v. 13.0. Vitzthum, 1926 Specimens. We recovered a total of 52 female specimens of G. bataviensis Records. Geckobia bataviensis is a widely distributed scale mite that has been recorded parasitizing several species of the lizard genera Hemidactylus Goldfuss, 1820, Gehyra Gray, 1834, and Gekko Laurenti, 1768. It is the most common scale mite associated with H. frenatus ( Fig. 2A), a human commensal gecko that has been introduced to many tropical and subtropical areas all over the world from its presumed Indo-Malayan origin (Vitzthum 1926;Domrow 1983;Haitlinger 1988; Domrow 1991;Lever 2003;Paredes-León et al. 2008;Hoskin 2011;Prawasti et al. 2013;Heath & Whitaker 2015;Díaz et al. 2020). Other than H. frenatus, G. bataviensis is known to parasitize several other members of the genus Hemidactylus, including H. "brookii" in Asia (Bochkov & Mironov 2000), H. turcicus (Linnaeus, 1758)  Island. However, these authors did not specifically connect localities and hosts, making a specific host-parasite association impossible.

Scientific Note
Taxonomy. Geckobia bataviensis displays significant morphological variability and was once was considered distinct from its current junior synonyms G. gleadoviana Hirst, 1926, G. nepalii Hiregaudar, Joshee & Soman, 1959, and G. cosymboti Cuy, 1973(Domrow 1983Haitlinger 1988). However, studies using integrative tools and species delimitation might be able to confirm if these morphological variations are indeed intraspecific or should be considered species specific. According to Bertrand (2013), G. bataviensis can be reliably identified by the absence of setae in Genua I and IV (Fig. 1 A-C).
Association. Our report of G. bataviensis on H. typus is the first association of this mite with this gecko. Our specimens confirm the association of G. bataviensis with H. frenatus, and this is the first locality-specific record for this scale mite in Timor-Leste. Among the parasitized individuals, mites were invariably present on the toes, in the spaces between the claw and the lamellae ( Fig. 2A). There did not appear to be any difference in mite numbers or position between front and hind toe infections. Additional areas of mite attachment were primarily the ventral parts of the hind legs, with very few mites found on the venter itself. We never located these mites on dorsal surfaces.

Pterygosoma dracoensis Jack, 1962
Specimens. Even though multiple specimens were present on the body of the lizard (Fig. 2B), we were only able to recover a single complete female specimen of P. dracoensis (IBSP 16510; Fig. 1D Records. Pterygosoma dracoensis was originally described by Jack (1962) from type material collected from different specimens on different islands in the Indonesian archipelago. Jack (1962) based the description on female and male type specimens obtained from Draco lineatus amboinensis (Lesson, 1834) in the Moluccas (Ambon, Seram), and a nymph and larvae from D. boschmai Hennig, 1936(reported as D. reticulatus Günther, 1864  Taxonomy. Pterygosoma dracoensis can be identified by the type of ps setae (tapered and serrate) and the numerous dorsal-median setae (Fig. 1D-F).
Association. Here, we report the second association of P. dracoensis with D. timoriensis, from a new locality, Timor-Leste. The female Draco with these mites was the only individual among the entire collection, on which we were able to locate parasites. Mites were attached on the ventral surface of the left patagium (Fig. 2B), including one additional adult and several nymphs. The collection was complex based on the size and vulnerability of these organisms, and only a single adult was ultimately available for study.  Vitzthum, 1926 (Pterygosomatidae), on its toe. The exposed mite shows the position mites generally take between the claw and the lamellae. One toe to the right, the red body of another mite can barely be seen, showing how the attachment position of the mites provides some protection during the gecko's movement.
(B) Ventral surface of the left patagium of a female Draco timoriensis Kuhl, 1820 (Agamidae) (USNM 579711), showing two adults Pterygosoma dracoensis Jack, 1962 (Pterygosomatidae). The several small red spots on the patagial surface are nymphs of the same species, which could not be extracted intact due to equipment limitations in our field laboratory. Sanchez, Dan Suzio, David Taylor, Marianna Tucci, and MJ Weil. Our fieldwork would not have been as productive nor entertaining without the wonderful assistance of our young Timorese colleagues, Venancio Lopes Carvalho, Luis Lemos de Araujo, Agivedo Varela Ribeiro, and Zito Afranio Soares, who transitioned from student to professional during our work in the country. Very special thanks go to the Timor survey's co-leader, Mark O'Shea (University of Wolverhampton), whose ability to conduct fieldwork from dawn to dusk, regale students with research tales, and still produce essay-length blog entries is legendary. We also thank our esteemed colleague Sven Mecke, who has been instrumental in field-and lab work throughout the Timor survey. We acknowledge the help of Aaron Bauer (Villanova University), who helped with the identification of house gecko species. Our studies in Timor-Leste would not have been possible without the support of Their Excellencies, former President José Ramos-Horta, former Prime Minister Xanana Gusmão, and former Minister Ágio Pereira. Their assistance at critical times and their friendship has been much appreciated. We also wish to express our gratitude to Claudia Abate-Debat, former special advisor in Prime Minister Gusmão's Office, who opened many doors and helped us in so many ways overcome hurdles. We thank Manuel Mendes, Director of National Parks, for issuing collecting and export permits.

Authors' Contributions
FCJ and RB-S examined, confirmed the identification of the mites and deposited the slides ate the IBSP Collection. FCJ, RB-S, and FHO performed the study. HK confirmed the identification of the hosts and collected the samples. FCJ, RB-S, FHO, and HK co-wrote the manuscript.