A museum-based taxonomic study of jumping plant lice from Mount Kinabalu in Sabah, Malaysia, has identified two previously undescribed species, Ctenarytaina lienhardi and Ctenarytaina smetanai , while correcting the identification of female specimens previously assigned to C. daleae . The analysis brings the number of apparently endemic Ctenarytaina species recorded from the mountain to six. Based on preserved specimens collected from 1982 to 1987, the work documents insect diversity and revises species boundaries rather than reporting a contemporary population change, an outbreak or a new biological threat.
Mount Kinabalu reaches an elevation of about 4,100 metres and supports plant communities with exceptionally high diversity and endemism. Its lower slopes were originally covered by lowland dipterocarp forest, much of which has disappeared through human activities. Lowland and montane forests extend to roughly 2,500 metres and are characterized by Oriental plant elements.
Above that elevation, taxa shared with the Himalayan flora, including groups in Ericaceae, and with the Australian flora, including Myrtaceae, become more dominant. The psyllids examined in the study reflect a comparable biogeographic pattern: four previously reported Paurocephala species are characteristic Oriental taxa associated with Pterospermum , Artocarpus and Ficus , whereas the Ctenarytaina and Boreioglycaspis species represent an Australian-associated element linked mainly to plants in the myrtle family, Myrtaceae. Psylloidea is a group of small, phloem-feeding hemipteran insects within Sternorrhyncha.
It includes more than 4,000 described species worldwide and is particularly diverse in tropical and south-temperate regions. The subfamily Spondyliaspidinae contains 23 recognized genera, most of them restricted to the Australian biogeographical realm and associated with Myrtaceae. Ctenarytaina is exceptional among these genera because it also occurs outside Australia.
Its 29 described species are distributed across tropical Asia, Australia, Oceania and Africa. The new analysis adds two Ctenarytaina species and revises the taxonomy of C. daleae . That species had been described from a male holotype and two female paratypes collected in the mountain’s summit region.
Examination of the long series available to the authors showed that the holotype corresponds to the population associated with Leptospermum , whereas the two females belong to the distinct species now named C. smetanai . The head and forewing structures of the three Mount Kinabalu forms are similar, so differences in male and female terminalia provide the most decisive separation. The revised C. daleae has an oblong-oval forewing that is broadly rounded apically and 2.3–2.7 times as long as broad.
Its surface spinules form irregular hexagonal groupings with two indistinct rows in the cell above the bifurcation of vein M. The genal processes at the front of the head are about three-tenths of the vertex length along the midline and are contiguous medially. In the male terminalia, the basal proctiger segment is weakly curved posteriorly and has a row of stout setae along its hind margin, while the distal portion of the aedeagus broadens evenly toward its rounded apex.
The female proctiger narrows strongly toward the middle and bears an apical process, with the dorsal edge serrated over its apical third. These details distinguish the species from the similar C. insularis . Collections of C. daleae adults were large on two shrubs in the family Myrtaceae, Leptospermum javanicum and L. recurvum , suggesting that both are hosts.
L. javanicum is widely distributed from Burma and southern Thailand to the Philippines, the Moluccas and the Lesser Sunda Islands. By contrast, L. recurvum is endemic to Mount Kinabalu, where it can grow as a tree or, at high elevations, as a prostrate shrub on an outcrop of ultrabasic rocks. It is one of the principal shrub species of the summit zone above about 3,200 metres.
Most type material of C. daleae was collected between 2,600 and 3,300 metres, including records from the summit trail and around Layang Layang. One male recorded on Syzygium korthalsianum was judged unlikely to represent a genuine host association. Ctenarytaina lienhardi is named for C.
Lienhard, a Geneva-based specialist in Psocodea who collected most of the type series. The species is represented by a holotype male and four additional specimens from approximately 1,700–1,850 metres on Mount Kinabalu. The available male has a body length of 2.0 millimetres, and a female measures 2.4 millimetres.
Its forewings are relatively narrow, measuring 2.5–2.6 times as long as broad, and the surface spinules in the cell above the bifurcation of vein M form irregular hexagonal groupings with one or two indistinct rows. Extra pore fields are present on the abdominal intersegmental membrane, a feature absent from C. daleae and C. smetanai . The female proctiger is blade-shaped beyond the circumanal ring and smooth along its dorsal margin.
The host relationship of C. lienhardi remains uncertain. A single female was collected on Tristaniopsis , another Myrtaceae plant, but that isolated association does not establish the plant as a host. The species is considered probably endemic to Mount Kinabalu, although its immature stages and biology remain unknown.
Morphologically, it shares narrow forewings and a weakly curved posterior section of the male proctiger with C. daleae , C. insularis and C. taylori . Its smooth, blade-shaped female proctiger distinguishes it from C. daleae and C. insularis , while the absence of the dark-brown basal patch on the forewing separates it from C. taylori . Only one male and two females were measured, so the available body dimensions and other quantitative characters have a restricted evidentiary basis.
Ctenarytaina smetanai is named after the late A. Smetana, an Ottawa-based specialist in staphylinid beetles and collector of the holotype. It is darker than the other two forms described from Mount Kinabalu, with the head and thorax ranging from dark reddish brown to almost black and the abdomen also dark dorsally.
Its forewing surface has irregular hexagonal spinule groupings with one row in the cell above the bifurcation of vein M. The male proctiger has a trapezoidal basal segment whose subapical angle on the hind margin bears five short peg-like setae, a character that distinguishes it from other congeners. The distal aedeagal segment is slender and weakly inflated apically.
In the female, the proctiger has an angularly concave dorsal margin near the caudal end of the circumanal ring, followed by a smooth, weakly convex and pointed apex. The available C. smetanai material is sparse. One female was swept from Syzygium punctilimbum in moss forest, making that species a possible host rather than a confirmed one.
One male and one female came from an interception trap, and another female was taken by sweeping vegetation. The type locality lies below Layang Layang at 2,600 metres, while another female was recorded at 1,700 metres. C. smetanai is also regarded as probably endemic to the mountain.
Together with C. daleae , C. lienhardi , C. baliota , C. loebli and C. taylori , it brings the total number of known Ctenarytaina species from Mount Kinabalu to six, all of which appear endemic. The authors describe such local endemism as relatively unusual among psyllids. The study demonstrates that long-held museum material can reveal overlooked species and revise earlier identifications, but it does not resolve the immature stages or confirm the hosts of either newly described species.
Subject of Research: Taxonomic description of two new Ctenarytaina jumping plant lice from Mount Kinabalu, Malaysia
Article Title: On some Ctenarytaina species ( Hemiptera , Psylloidea ) from Gunung Kinabalu (Malaysia, Sabah)
Article References: Burckhardt, D. (2021). On some Ctenarytaina species (Hemiptera, Psylloidea) from Gunung Kinabalu (Malaysia, Sabah). Alpine Entomology, 5, 107-113. https://doi.org/10.3897/alpento.5.77751
Image Credits: AI Generated
Keywords: Ctenarytaina, Mount Kinabalu, Sabah, Malaysia, jumping plant lice, Psylloidea, taxonomy, Myrtaceae, insect biodiversity, endemic species, some, species
News Source: Drew Townsend. (October 20, 2026). Two new psyllid species and a revised identification from Mount Kinabalu. Scienmag.
