John L Yukang’s scientific contributions

Moths form a very large insect group under the order Lepidoptera. There are about 10,000 species in Borneo. Mostly night-flying, they range in wingspan from 3 mm to about 28 cm of the gigantic Atlas Moth, Attacus atlas, which is among the largest insects in the world. Vital roles of moths in the tropical ecosystem include pollinators, biodiversity and environmental health indicators, and a source of food for other wildlife. The larvae of some species can cause severe damage in forestry and agriculture, as defoliators, stem and shoot borers. Showcased here are 71 moth species in varying sizes, patterns and colours from the tropical rainforests of Sabah.

Katydids, crickets and grasshoppers belong to the insect order Orthoptera. Katydids (bush crickets) and crickets are mainly active at night, having long antennae and distinct ovipositor (female) while grasshoppers are active by day, with short antennae and barely developed ovipositor. It is estimated that there are at least 785 species of katydids, crickets and grasshoppers in Borneo. Some katydids and crickets are significant in the ecosystems as pollinators and predators. Some grasshoppers, however, cause considerable damage to plant foliage. Featured here are some of the Orthoptera species found in Sabah (Photos are not according to scale).

Insect diversity of Sungai Serudong Forest Reserve in Sabah was investigated under the Heart of Borneo programme in Sabah. The nocturnal insect diversity was evaluated by using light-trap from 7:00 p.m. until 9:00 p.m. for three consecutive nights. Diurnal insects were sampled using sweep net. A total of nine insect orders were recorded namely Coleoptera, Hemiptera, Hymenoptera, Isoptera, Lepidoptera, Neuroptera, Odonata, and Phasmida. There were four Bornean endemic species recorded during the survey, namely Chalcosoma moellenkampi (Coleoptera: Scarabaeidae), Aethalida borneana (Lepidoptera: Erebidae), Amata prepuncta (Lepidoptera: Erebidae) and Calvisia sammannani (Phasmida: Diapheromeridae). The mean Shannon Index was 4.00, Simpson Index was 47.76 and Fisher Alpha Index was 83.64. The diversity is considered high, however moderate when compared to other forest reserves in Sabah, Malaysia. This study was able to identify insect communities inside the reserve. It was also able to identify the potential threats affecting the insect diversity. The documented data can serve as baseline information to be used in forest management plan and other relevant research.

Sg. Serudong Forest Reserve is located adjacent to the forests of Kalabakan and Tibow in Tawau, Sabah and it is very close to the boundary of Malaysia and Kalimantan of the Republic of Indonesia. Besides that, sweep nets and forceps were used for diurnal insect documentation. The mean Shannon Index was 4.00 while Simpson Index was 47.76 and Fisher Alpha Index was 83.64. In terms of diversity, it is moderate when compared to 28 other forest reserves in Sabah, with mean of 74 insect species recorded in a square metre of light-trapping cloth and the most recorded insect group was moth. There were five Bornean endemic species recorded during the survey. Forest fire is the main threat to the conservation area and its land use changes, such as oil palm plantation at the surrounding area may adversely affect the insect diversity. Cooperation among relevant agencies such as Sabah Forestry Department, Sabah Wildlife Department and Fire and Rescue Department will enhance effort in conservation and curb future incidences of forest fire. Last but not least, the documented data can serve as baseline information for future research.

The nocturnal insect diversity was very high, with more than 100 insect species in a square metre in all light-trapping sites. The mean Shannon Index was 4.60 while Simpson Index was 176.72. It is interesting to note that Sg. Kangkawat insect richness appears to be the second highest after Crocker Range, when compared with 25 other forest reserves in Sabah. There were more than 13 endemic species and a subspecies recorded during the survey, including an undescribed species of moth (Geometridae, Plutodes sp.). In view of the high diversity and intriguing insect fauna, Sg Kangkawat Research Station has potential in promoting nature tourism for special interest tourists. Encroachment is among the threats within this forest reserve. For the general public, the boundary of some parts of the forest reserve is still not clear. Hence, it is important to have more signages to denote the forest reserve boundary. Public awareness and environmental education have to be enhanced among the local communities so that they are aware of the significance of biodiversity conservation of forest resources. The threats and issues have indirectly affected the insect fauna. As such, the forest quality would have to be enhanced in order to maintain the interesting and endemic insect fauna for biodiversity conservation. Ongoing cooperation with the relevant authorities, such as Sabah Forestry Department and Sabah Wildlife Department, will enhance conservation efforts and curb future encroachment. Further biodiversity research with relevant agencies should be encouraged.

This insect survey was conducted from 13 th to 18 th of January, 2020 in Mount Silam forest, Lahad Datu, Sabah. An average of 108 nocturnal insect species from 148 individuals was recorded from a one-metre-square area of the light-trapping cloth. The mean Shannon Index was 4.17 while Simpson Index was 129.84 and Fisher Alpha Index was 193.36. At least 15 Bornean endemic species were recorded during the brief survey. These pioneer data will serve as baseline information for other research work in future. The data will further strengthen the management of Mount Silam within Sapagaya Forest Reserve as a Class I Forest Reserve (Protection). The information on insect diversity and the aesthetic value of some of the flagship species can be used to promote sustainable nature tourism in Mount Silam since this area is a tourist attraction in Lahad Datu.

This article highlights various insect species visiting beluno flowers. Flies were the most abundant insect group. They were seen in almost all inflorescences. Bluebottle flies of the genus Chrysomya were frequently encountered. The house fly, Musca domestica, was also sighted but was not as abundant as the former. Other insect groups are featured in the paper.

This insect diversity survey by the Sabah Forestry Department team was carried out from 16 th to 20 th of August, 2017 in Imbak Canyon-Batu Timbang area. Nocturnal insect diversity was assessed through light-trapping while diurnal insects were documented through fruit-baited traps, sweep nets and forceps. The mean nocturnal insect species richness was 48 species while the mean abundance was 55 individuals. These values were affected by the presence of many wild honeybees, Apis dorsata and the unexpectedly wet weather. Some Bornean endemic species were recorded, which included moths, beetles, dragonflies and a butterfly species. The Bornean endemic butterfly, Papilio acheron, is a rare species documented during the survey. Interesting and iconic species recorded are the Malaysia national butterfly, Trogonoptera brookiana and the world's largest bush cricket, Macrolyristes imperator. These insect data provide salient information to enhance the conservation of the Batu Timbang forest. They will serve as baseline information for other insect research work in future. Threats, such as forest fire, fragmentation, illegal clearing of vegetation and poaching are likely to indirectly affect the insect fauna. As such, continuous monitoring and enforcement at strategic locations are important to minimize these threats.

Some 31 Odonata species were recorded in Sg.Rawog Conservation Area during the survey, Sixteen of them were dragonflies while the remaining were damselflies. The number of species recorded is high, considering that sampling was only conducted for three working days. The survey was carried out along the riverine area of Sg. Rawog, a few ponds adjacent to the base camp in compartment 56, and forested trails in Compartments 49 and 61. For damselflies, Three Bornean endemic species were recorded, namely Rhinagrion elopurae, Coeliccia nigrohamata and Prodasineura hyperythra. The Flatwing, Rhinagrion elopurae, is listed as a near threatened species under the IUCN Red List. It is also interesting to note that Pixie, Brachygonia oculata, was found in abundance in the stagnant water within the mixed dipterocarp and heath forest floor in Compartment 61. It is among the smallest dragonflies in the world.

Nocturnal insect diversity was assessed through light-trapping while diurnal insects were documented through sweep nets and forceps. A mean 104 species of nocturnal insects was recorded from a one-square-metre of the light-trapping cloth, with an average of 128 individuals. The mean Shannon Index was 4.52 while Simpson Index was 173.6 and Fisher Alpha Index was 266.7. When the nocturnal insect richness was compared with 24 other forest reserves in Sabah, it is interesting to note that Sg. Rawog insect richness appears to be the third highest after Crocker Range and Bukit Hampuan FRs. In terms of nocturnal insect diversity as reflected by Shannon Index, it is the second highest after Crocker Range FR. One undescribed moth species (Plutodes sp., Geometridae) and at least 13 Bornean endemic species were recorded during the survey. The endemics and other insect species recorded during the survey provide significant information to enhance the conservation of Sg. Rawog area. Continuous monitoring and enforcement at strategic locations within the conservation area are important to minimize the threats and adverse issues. This will ensure that the forest quality would be improved in order to maintain the interesting biodiversity, including insects. On-going cooperation with the relevant authorities, such as Sabah Forestry Department and Sabah Wildlife Department, will enhance effort in conservation and curb future incidences of encroachment. Further biodiversity research with academic institutions, such as Universiti Malaysia Sabah as well as Forest Research Centre, Sepilok, is also encouraged. In view of the high wildlife diversity, Sg. Rawog is potentially important for nature tourism.