Five Days on Mount Kinabalu Reveal Rare Crickets and Katydids Never Recorded Before

On the fog-drenched northwestern slopes of Mount Kinabalu, the highest mountain in Borneo, a five-day survey has delivered the first systematic look at the grasshoppers, crickets and katydids of one of Southeast Asia’s least-studied mountain plateaus. The expedition, conducted in October 2023 as part of the Marai Parai–West Gurkha Hut Kota Belud Scientific Expedition, yielded thirty-two species of Orthoptera from nine families, including at least nine species never before recorded in the Mount Kinabalu region and four recorded for the first time anywhere in the Malaysian state of Sabah. The findings, published in the Journal of Orthoptera Research, come with an annotated and illustrated checklist intended to serve as the foundation for all future work on the region’s orthopteran fauna.

The survey targeted two sites that could hardly be more different in character. Marai Parai, at roughly 1,652 metres above sea level, is an ultramafic plateau on the mountain’s western slope, named after the Dusun word for Tetraria pilisepala, a graminoid sedge that flourishes there. Its soils are nutrient-poor and waterlogged, its climate cold and humid, and its vegetation includes endemic plants and several species of carnivorous pitcher plants. Despite expeditions reaching the area as early as 1858, no published records of Orthoptera from Marai Parai existed before this study. The second site, Nunuk camp at 1,215 metres, sits at the border of Kinabalu Park within the community forest reserve of Kiau Nuluh, a village in the neighbouring district of Kota Belud that serves as the trailhead for the route.

Collecting was deliberately opportunistic and intensive. The first author worked both daytime hours, from 0830 to 1500, and nighttime hours, from 1900 to 2200, over five consecutive days from 13 to 17 October 2023. Specimens were photographed in the field with a macro setup and later preserved, first in absolute analytic-grade ethanol and then pinned and dry-preserved. Where species identity hinged on genital anatomy, the male titillators or phallus were dissected from softened specimens, cleaned in aqueous potassium hydroxide and stored in glycerine for examination and imaging. Identifications were made against published keys and the Orthoptera Species File, and verified by specialist taxonomists for the major groups, including Luc Willemse for Acridoidea, Andrej V. Gorochov for Stenopelmatoidea, and Josip Skejo, Karmela Adžić and Maks Deranja for the pygmy grasshoppers of Tetrigoidea.

The taxonomic spread of the haul is itself informative. The thirty-two species represent eight of the seventeen monophyletic orthopteran superfamilies, covering half of the lineages in the orthopteran tree of life. The suborder Ensifera, the long-horned orthopterans that include crickets and katydids, dominated with twenty-five species against only seven for the short-horned Caelifera. Katydids of the superfamily Tettigonioidea led the count with twelve species, followed by true crickets of Grylloidea with six, pygmy grasshoppers of Tetrigoidea with four, and camel crickets of Rhaphidophoroidea with two. Eumastacoidea and Gryllotalpoidea, the monkey grasshoppers and mole crickets, were each represented by a single species.

Perhaps the most striking statistic is that twenty-one of the thirty-two species, some 65.6 percent, were singletons, represented by a single collected individual. The authors interpret this as evidence that many species on Mount Kinabalu are genuinely rare or of low abundance, or simply that the survey window fell in the wrong season for them. Either way, the figure underscores how preliminary any five-day snapshot must be, and how much diversity likely remains unrecorded even on a mountain that naturalists have been climbing for more than a century and a half.

Geography shaped the results in unexpected ways. Only one species, the cricket Nisitrus musicus, turned up at both Marai Parai and Nunuk camp, making it the sole common denominator between the two sites. Four species were exclusive to Marai Parai, including the grasshopper Traulacris nr. erecta, the katydid Cratioma cf. borneense, Despoina spinosa, and the recently described katydid Subtilodecma bilobata, while the remaining twenty-seven species were collected at Nunuk. The authors attribute this near-total turnover to the mountain’s dramatic habitat heterogeneity, which produces sharply different vegetation zones at different altitudes and aspects, and which likely governs the spatial distribution of niche-specific orthopteran species.

Several finds carry particular biogeographic weight. The pygmy grasshopper Potua cf. morbillosa, collected from rotten logs at Nunuk, represents the first official record of the species for both Mount Kinabalu and Sabah, its only other known Bornean localities being its type locality in Sarawak and a site in Brunei. The cricket Repapa trusmadi, found calling from bark crevices of a rotten log, had previously been known only from its type locality on Mount Trusmadi, sixty kilometres to the south. Similarly, the cricket Anemozara vera and the wetas-like Sia bugajus both extend known ranges northward from the Crocker Range and Trusmadi regions. The raspy cricket Zalarnaca cf. teuthroides, whose type locality lies more than 400 kilometres away on Mount Dulit in Sarawak, is likewise a first for the state, though the authors note that species-level determination within this group remains problematic until a revision of Asiatic gryllacridine genera is completed.

Not every specimen could be confidently named, and the checklist is candid about the limits of current taxonomy. A grasshopper resembling Traulacris erecta differs in leg coloration from the described species and may represent something undescribed, pending comparison with type material. A pygmy grasshopper close to Potua morbillosa carries two extra pronotal humps, a group notorious for pronotal variation. Several crickets, including a female Itara and a female Aphonoides, cannot be identified to species at all because most Bornean species in those genera were described from males alone. Two Rhaphidophora camel crickets from separate rotten stumps differ from known relatives only in details of the male abdominal apex, a group the senior taxonomist describes as speciose and difficult across Southeast Asia. These open questions are not failures of the survey but a measure of how much basic taxonomic work remains undone in Borneo.

The study arrives amid a flurry of recent discoveries that suggest Mount Kinabalu’s orthopteran fauna is far richer than the roughly eighty-nine species documented there as of May 2024. New katydid genera and species have recently been described from the mountain and its neighbours, including Borneratura atromacula, Depressacca kinabalu, and two species of Subtilodecma, both of which occur in Kinabalu National Park and one of which was rediscovered on this expedition. Comparable recent finds on Mount Trusmadi, the Crocker Range and at Tenompok reinforce the authors’ argument that continued sampling of less-explored terrain across these vast mountain ranges will keep producing species new to science.

There is also a conservation edge to the work. The authors note that knowledge of Bornean orthopterans extends barely beyond morphology, with the calling songs and natural history of most species undocumented, even as the island’s biodiversity faces intensifying pressure from deforestation and other human activities. Because orthopterans are tightly tied to specific vegetation types and microhabitats, from waterlogged sedge flats to the interiors of rotten logs, habitat loss can erase species before they are ever collected. A preliminary checklist from a single five-day survey may seem a modest instrument against that backdrop, but for Marai Parai and the surrounding slopes it is the first baseline the region has ever had, and the authors expect that extended sampling will ultimately reveal more species than this first count contains.

Subject of Research: Orthoptera diversity survey on the northwestern slopes of Mount Kinabalu, Sabah, Malaysia

Article Title: The diversity of Orthoptera in the northwestern parts of Mount Kinabalu, Sabah, Malaysia

Article References: Muhammad, A. A., & Tan, M. K. (2025). The diversity of Orthoptera in the northwestern parts of Mount Kinabalu, Sabah, Malaysia. Journal of Orthoptera Research, 34(1), 95-118. https://doi.org/10.3897/jor.34.128225

Image Credits: AI Generated

DOI: 10.3897/jor.34.128225

Keywords: Orthoptera, Mount Kinabalu, Sabah, Borneo, biodiversity survey, crickets, katydids, pygmy grasshoppers, new species records, taxonomy, Marai Parai, tropical entomology