Type specimens carry valuable information that can facilitate biodiversity research, especially in an era of mass extinction and unprecedent anthropogenic climate change. For Orthoptera, a few initiatives, including the Orthoptera Species File and digitization of collections by numerous museums, have helped to make images and information about the type specimens available on the World Wide Web. However, many local collections, especially those from the poorly studied regions of Southeast Asia, are still not available to the public. The collection of Grylloidea and Tettigonioidea gathered at the Forest Research Center, Sepilok in Sandakan, Sabah (Borneo) is one such example. We examined, identified, and imaged 12 and 45 species of Grylloidea and Tettigonioidea respectively from the collection (deposited as of October 2019) to facilitate taxonomic research by making the species in the collection accessible for everyone.
Only one species of Pendleburyella Chopard, 1969 (Gryllidae, Pentacentrinae) was previously known to occur in Borneo: Pendleburyella eirmosa Tan, Muhammad & Wahab, 2023 from Brunei Darussalam. Here, two additional new species of crickets from the genus Pendleburyella are described from the highlands of Sabah, Borneo: Pendleburyella eremita sp. nov. from Bukit Hampuan and Pendleburyella nimba sp. nov. from Mount Trus Madi. In total, six species of Pendleburyella are currently known, three from Borneo and three from Malay Peninsula. It is likely that many more species are awaiting discovery owing to its cryptic morphology and elusive nature.
Based on recent field sampling in the highlands of western Sabah, a new species of Depressacca Ingrisch, 1998 (Conocephalinae: Agraeciini) is described from Tenompok, Depressacca macrolima sp. nov., that can be easily distinguish from two other known congeners by the presence of numerous large and falcate spines on the legs numerous large and falcate spines on its legs. Based on the new material, we also document here the live images and/or new locality records for other katydids of the tribes Agraeciini and Meconematini: Bispinolakis longicauda Ingrisch, 1998, Palaeoagraecia philippina (Karny, 1926) and Salomona borneensis Willemse, 1959; Alloteratura (Meconemopsis) longa Gorochov, 2008, Borneratura kinabaluana (Bey-Bienko, 1971) and Rhinoteratura pulchra Gorochov, 2008.
Three new species were described from Borneo: Itara (Bornitara) spinosa sp. nov. and Aphonoides duri sp. nov. from Brunei and Varitrella (Cantotrella) suikei sp. nov. from Sandakan in Sabah. We describe the call of Varitrella (Cantotrella) suikei sp. nov. In addition to the new species descriptions, we also report new locality records of other recently discovered species: Borneloria spinosa Gorochov, 2018 in Belait (Brunei Darussalam), species of Anemozara Gorochov, 2014 in Brunei Darussalam and Terrozacla borneo Gorochov, 2014 in Belait.
Orthoptera from Sandakan, Sabah are relatively understudied compared to some other parts of Borneo, and lack of information of species there can impede our understanding of the origins and biodiversity of orthopterans in Borneo and, in general, Southeast Asia. Based on a recent orthopteran survey in Sandakan, one new species of Lebinthus Stål is described: Lebinthus sandakan sp. nov. The male calling song of this new species is also presented. The calling song of Cardiodactylus borneoe Robillard Gorochov, 2014 is also described for the first time.
Recent orthopteran surveys in the hyper-diverse Borneo, i.e., Brunei Darussalam and Sandakan in Sabah, allow us to review the scaly crickets from the subfamily Mogoplistinae there. We discover and describe the male, as well as formally naming Cycloptiloides bimaculata Tan, Japir Chung, sp. nov. from Sandakan. This species was previously described as sp. 1 in a comprehensive revision by Ingrisch (2006) but only the females were known. We also describe Ectatoderus nigrofasciatus Tan Wahab, sp. nov. from Brunei Darussalam. New locality records are reported for Apterornebius kinabalu Ingrisch, 2006 in Sandakan (Sabah) and Ornebius pullus Ingrisch, 2006 in Belait District (Brunei).
Based on material collected during recent fieldwork in eastern Sabah, the males of Nisitrus danum Robillard & Tan and Cardiodactylus variegatus Gorochov & Robillard are described for the first time, along with their calling songs. New locality records of N. danum, N. vittatus (Haan), Falcerminthus sandakan (Tan et al.), Cardiodactylus borneoe Robillard & Gorochov and C. variegatus are also presented. New material of Nisitrus species-N. danum and N. vittatus-allowed us to compare these syntopic species.
Three species new to science of the Gryllid subfamilies Gryllinae and Pteroplistinae are described from Brunei: (1) Mimicogryllus splendens Tan, Gorochov Wahab, sp. nov., (2) Pteroplistes bruneiensis Tan, Gorochov Wahab, sp. nov., and (3) Tembelingiola belaitensis Tan, Gorochov Wahab, sp. nov. A new species of cricket of the subfamily Phaloriinae is also described from Sandakan, eastern Sabah: Vescelia sepilokensis Tan, Gorochov, Japir Chung, sp. nov.
A new species of Meconematini is described from Tabin Wildlife Reserve in eastern Sabah: Cercoteratura repens sp. nov. This is the first report of the genus Cercoteratura in Sabah. Two species of Phisidini, Carliphisis acutipennis (Carl, 1908) and Neophisis (Indophisis) longipennis Jin, 1992, are reported in eastern Sabah for the first time. The calling song of Neophisis (Indophisis) longipennis with a near-complete ultrasonic spectrum is also described.
A species of scaly cricket is described here: Ornebius lupus sp. nov. from the mangrove forests in Singapore. Ornebius pullus Ingrisch, 2006 is recorded in eastern Sabah for the first time. The calling songs of Cycloptiloides bimaculatus Tan et al., 2021 and Ornebius pullus from Sabah are described. We also revise the diagnosis of Ectatoderus nigrofasciatus Tan et al., 2021 from Brunei Darussalam.
The taxonomy of the crickets from the genus Odontogryllodes Chopard, 1969 is reviewed. Two species new to science are described here, one from Peninsular Malaysia (part of Malay Peninsula) and another from East Malaysia (part of Borneo): Odontogryllodes undatus Tan, Muhammad & Abdullah sp. nov. from Panti Forest Reserve and Odontogryllodes magnus Tan, Japir & Chung sp. nov. from Tenompok Forest Reserve, respectively. We also present an updated key to the species of Odontogryllodes. In total, nine species are currently known.
A new species of Itara (Phormincter) is described from Mindanao in the Philippines: Itara (Phormincter) mindanao Tan, Grumo, Gono & Bahoy, sp. nov. This represents the first record of this subgenus in the Philippines, having previously known only from Borneo, Java, Malay Peninsula and Sumatra; as well as only the second species of Itara known from the Philippines and the first from Mindanao Island. The male calling song of the holotype was also recorded and is described here. Additionally, the male calling song of another congener, Itara (Singitara) singularis Gorochov, 1997 from Sabah, is described here. A new species of Itara (Bornitara) is also described from Sabah in Borneo: Itara (Bornitara) tenompok Tan, Japir & Chung, sp. nov.
Spiky pygmy devils (Tetrigidae: Discotettiginae) are, because of the spiky pronotal projections and widened subapical antennal segments, among the most unique pygmy grasshoppers in Southeast (SE) Asia. The taxonomy of the group was unclear in the past, so this study brings a taxonomic and biographical review of the genus Discotettix Costa, 1864. New terminology of the pronotal projections is proposed for Scelimeninae. All valid species hitherto included in the genus are redescribed; a new genus is established for Discotettix shelfordi Hancock, 1907, Disconius Skejo, Pushkar et Tumbrinck gen. n., so a new combination is established for the species (Disconius shelfordi comb. n.). New synonymy is established: Discotettix selysi Bolívar, 1887 = Discotettix selangori Mahmood, Idris et Salmah, 2007 syn. n. Three new species are described and a key to Discotettix species is provided. The genus now includes seven species (1) Discotettix aruanus Skejo, Pushkar et Tumbrinck sp. n. from Aru; (2) D. belzebuth (Serville, 1838) from Borneo; (3) D. doriae Bolívar, 1898 stat. resurr. from the Mentawai islands; (4) D. kirscheyi Skejo, Pushkar, Tumbrinck et Tan sp. n. from Northeast (NE) Borneo; (5) D. scabridus (Stål, 1877) endemic to Mindanao and Samar; (6) D. selysi Bolívar, 1887 from Sumatra and peninsular Malaysia; (7) D. sumatrensis Skejo, Pushkar et Tumbrinck sp. n. endemic to southern Sumatra. Moreover, Discotettix is again subdivided into two subgenera: Mnesarchus Stål, 1877 stat. resurr. (D. scabridus) and nominotypical one (other species). Widened antennal segments are the only character common to all Discotettiginae genera, but this trait does not have great taxonomic importance, as it is homoplastic, meaning that it appeared in distant Tetrigidae groups independently. Discotettix is herewith transferred to the subfamily Scelimeninae and accordingly, the subfamily Discotettiginae Hancock, 1907 syn. n. becomes a junior synonym of the subfamily Scelimeninae Bolívar, 1887. The tribe Discotettigini stat. resurr., on the other hand, gathers corticolous genera of the Scelimeninae (Austrohancockia Günther, 1938, Bidentatettix Zheng, 1992, Disconius gen. n. Discotettix, Eufalconius Günther, 1938, Gibbotettix Zheng, 1992, Paragavialidium Zheng, 1994, Gavialidium Saussure, 1862, and Tegotettix Hancock, 1913), while the tribe Scelimenini becomes restricted to amphibious taxa. All taxa are described and amply depicted with both museum specimens and in situ photographs. An identification key is provided. The morphology and function of widened antennae in Discotettigini are discussed.