Ethno-bamboo Approaches to the Pala’wan in the Mangrove Area of Palawan Island, the Philippines

Bamboo is an important resource in Southeast Asia, which is a hotspot of bamboo species diversity globally, and has historically contributed to livelihoods in various environments. Subsistence livelihoods are still widely found in Southeast Asia, especially in isolated villages, and various kinds of plant resources, including bamboo, support local livelihoods. Understanding the relationship between human society and plants is important to understand the historical process of expansion and adaptation of human society in Southeast Asia; however, despite its importance, information on bamboo utilization remains limited. A field survey was conducted in a village located in the mangrove area of Palawan Island, the Philippines. The residents were the Pala’wan. Data was obtained through participatory observation and interview survey to at least 30 villagers. In the village, 10 bamboo species, both wild and cultivated, were utilized for various purposes, with a large and specific demand for bamboo of cultivated species. These species are medium to large in size, and some are distributed widely both inmainland and insular Southeast Asia. These bamboo species are considered to have been brought by Southeast Asian people along with other useful plants and have adapted to the new environment. To understand the long-term relationship between Asian people and plants, it is necessary to consider bamboo, and multidisciplinary integration of knowledge, which can be called as the “ethno-bamboo approach,” can uncover new aspects of this relationship.

Seascape shadows: Life in the ruins of the edible bird's nest harvest in northern Palawan, the Philippines

The intensifying extraction, privatization, and conservation of maritime spaces are transforming seascapes globally. Amidst rapid coastal change and the ambiguous reconfiguration of oceans as frontiers are coastal dwellers who occupy the shadows of these seascapes. In contrast to the capture of high-profile marine species, the harvest of the edible nests of balinsasayaw (swiftlet, Aerodramus fuciphagus) remains largely concealed at the interstitial spaces between land, coast, and sea. In the Philippines, harvesters known as busyador negotiate social relations, political networks, and karst systems to extract these lucrative nests. Despite the nest industry growing in value in Southeast Asia, we show how the busyador struggle in precarious social relations and spaces peripheral to coastal governance in northern Palawan Island. Building on the concept of ‘seascape assemblages’, we emphasize the importance of the less visible human-nonhuman relations that shape the nest harvest and trade. We trace the marginal social histories of the balinsasayaw by highlighting the precarious nature of the harvest, revealing how the busyador are subject to unfair working conditions, dispossession, and violence. We argue that as state actors and local elites reconfigure oceans as frontiers for development and conservation, struggles over labour and tenure rights, livelihood opportunities, and justice at sea are disregarded.

Two new species of Rhinogobius (Gobiiformes: Oxudercidae) from Palawan, Philippines, with their phylogenetic placement

Two new species of Rhinogobius found in streams on central part of Palawan Island, Philippines are described. The two new species, Rhinogobius estrellae and Rhinogobius tandikan share unique transverse rows of sensory papillae on the cheek with Rhinogobius similis Gill, 1859, but differ from the latter in fin ray counts, arrangement of the scales, etc. The two new species are distinguished from each other by the pectoral-fin ray count, the longitudinal- and predorsal-scale counts, and colouration of the body. Rhinogobius estrellae new species and R. tandikan new species have been found allopatrically in a stream within Malatgao River system flowing into the Sulu Sea and in the Cayulo River flowing into the South China Sea, respectively. The Malatgao River system is the southernmost habitat of the genus Rhinogobius. Rhinogobius similis had been considered as the only member of the most basal lineage of this genus, but our mitochondrial genome analysis suggested that the two new species are additional members of this lineage. They are considered to be relicts of their common ancestor with R. similis, which probably had a wider distribution.

Vaccinium exiguum (Ericaceae, Vaccinieae), a new species from the ultramafic summit of Mt. Victoria, Palawan Island, Philippines

Vaccinium exiguum from the ultramafic summit of Mt. Victoria, Palawan Island, Philippines is here described as a new species of Ericaceae. It closely resembles V. hamiguitanense but is distinct by having much shorter petioles and leaves, longer and glabrous calyx lobes with serrate lobe margins, a larger corolla with deeper sulcations, and longer stamens with spurs oriented laterally. Vaccinium exiguum represents the third Vaccinium species found on the Island of Palawan and 36th in the Philippines.

The seasonal dynamics and biting behavior of potential Anopheles vectors of Plasmodium knowlesi in Palawan, Philippines

Background A small number of human cases of the zoonotic malaria Plasmodium knowlesi have been reported in Palawan Island, the Philippines. Identification of potential vector species and their bionomics is crucial for understanding human exposure risk in this setting. Here, we combined longitudinal surveillance with a trap-evaluation study to address knowledge gaps about the ecology and potential for zoonotic spillover of this macaque malaria in Palawan Island. Methods The abundance, diversity and biting behavior of human-biting Anopheles mosquitoes were assessed through monthly outdoor human landing catches (HLC) in three ecotypes representing different land use (forest edge, forest and agricultural area) across 8 months. Additionally, the host preference and biting activity of potential Anopheles vectors were assessed through comparison of their abundance and capture time in traps baited with humans (HLC, human-baited electrocuting net—HEN) or macaques (monkey-baited trap—MBT, monkey-baited electrocuting net—MEN). All female Anopheles mosquitoes were tested for the presence of Plasmodium parasites by PCR. Results Previously incriminated vectors Anopheles balabacensis and An. flavirostris accounted for > 95% of anophelines caught in longitudinal surveillance. However, human biting densities were relatively low (An. balabacensis: 0.34–1.20 per night, An. flavirostris: 0–2 bites per night). Biting densities of An. balabacensis were highest in the forest edge, while An. flavirostris was most abundant in the agricultural area. The abundance of An. balabacensis and An. flavirostris was significantly higher in HLC than in MBT. None of the 357 female Anopheles mosquitoes tested for Plasmodium infection were positive. Conclusions The relatively low density and lack of malaria infection in Anopheles mosquitoes sampled here indicates that exposure to P. knowlesi in this setting is considerably lower than in neighboring countries (i.e. Malaysia), where it is now the primary cause of malaria in humans. Although anophelines had lower abundance in MBTs than in HLCs, An. balabacensis and An. flavirostris were caught by both methods, suggesting they could act as bridge vectors between humans and macaques. These species bite primarily outdoors during the early evening, confirming that insecticide-treated nets are unlikely to provide protection against P. knowlesi vectors. Graphical abstract

Sophianus palawanensis sp. nov., the first Isometopine (Hemiptera, Heteroptera, Miridae) from the Philippines

A new species, Sophianus palawanensis sp. nov. (Hemiptera, Heteroptera, Miridae, Sophianini) is described from the Palawan Island in the Philippines. Photographs of the male habitus and genital structures, as well as detailed SEM micrographs of selected morphological structures, are presented. Trichobothrial patterns of Sophianini and their importance for the hypothesizing relationships within Isometopinae are discussed.

New distribution record of Hoya sipitangensis Kloppenb. & Wiberg (Apocynaceae, Asclepiadoideae) from Palawan, Philippines

We report Hoya sipitangensis Kloppenb. & Wiberg for the first time on Palawan Island, Philippines. This record extends its distribution northward from Borneo to the Philippines. Additional taxonomic information and photographs from field collections are provided.

The Seasonal Dynamics and Biting Behavior of Potential Anopheles Vectors of Plasmodium Knowlesi in Palawan, Philippines

Background: A small number of human cases of the zoonotic malaria Plasmodium knowlesi have been reported in Palawan Island, the Philippines. Identification of potential vector species and their bionomics is crucial for understanding of human exposure risk in this setting. Here, we combined longitudinal surveillance with a trap-evaluation study to address knowledge gaps about the ecology and potential for zoonotic spillover of this macaque malaria in Palawan Island.Methods: The abundance, diversity and biting behavior of human-biting Anopheles mosquitoes were assessed through monthly outdoor Human Landing Catches (HLC) in three ecotypes representing different land use (forest-edge, forest and agricultural area) across 8 months. Additionally, the host preference and biting activity of potential Anopheles vectors was assessed through comparison of their abundance and capture time in traps baited with humans (HLC, human-baited electrocuting net – HEN) or macaques (monkey-baited trap – MBT, monkey-baited electrocuting net – HEN). All female Anopheles mosquitoes were tested for presence of Plasmodium parasite by PCR.Results: Previously incriminated vectors Anopheles balabacensis and An. flavirostris accounted for >95% of Anophelines caught in longitudinal surveillance. However human biting densities were relatively low (An. balabacensis: 0.34 -1.20 per night, An. flavirostris: 0-2 bites per night). Biting densities of An. balabacensis were highest in the forest-edge while An. flavirostris was most abundant in the agricultural area. The abundance of An. balabacensis and An. flavirostris was significantly higher in HLC than MBT. None of the 357 female Anopheles mosquitoes tested for Plasmodium infection were positive.Conclusions: The relatively low density and lack of malaria infection in Anopheles mosquitoes sampled here indicates that exposure to P. knowlesi in this setting is considerably lower than neighbouring countries (Malaysia) where it is now the primary cause of malaria in humans. Although Anophelines had lower abundance in MBT than HLC, An. balabacensis and An. flavirostris were caught by both methods suggesting they could act as bridge vectors between humans and macaques. These species bite primarily outdoors and in early evening; confirming that Insecticide Treated Nets are unlikely to provide protection against P. knowlesi vectors.