Quadrimaera sirindhornae sp. nov. was described from specimens collected from algae in a coral reef in Chon Buri Province, Thailand. The new amphipod species can be distinguished from its closest relative by its accessory flagellum with seven articles, gnathopod 2 propodus 1.8x longer than wide, uropod 3 ratio of outer ramus and peduncle is 1.2. The illustration and comparison of diagnostic charac-teristics in male Quadrimaera reported in Southeast Asia were provided.

A novel cupulate basidiomycete fungus was discovered during a survey of mangrove-associated fungi in Chanthaburi and Phetchaburi Provinces, Thailand. This species, found exclusively on decaying Rhizophora mucronata hypocotyls in intertidal zones, forms minute fruiting bodies and shows close morphological and molecular resemblance to Calathella mangrovei Jones & Agerer, 1992. Phylogenetic analyses of ITS and LSU rDNA regions confirmed its placement within Calathella, as a distinct sister lineage to C. mangrovei. Therefore, these isolates represent a novel species, for which the name Calathella sirindhorniae sp. nov. is proposed.

Tetraponera Smith, 1852, a large ant genus comprising 87 extant and seven fossil species, is primarily distributed in the Afrotropical, Oriental, and Australasian regions. A new species, T. sirindhornae Yodprasit, Tasen & Jaitrong, sp. nov., is described from southern Thailand based on worker, dealate queen, and male castes. The new species exhibits worker dimorphism and is morphologically similar to T. binghami (Forel, 1902), T. connectens Ward, 2001, and T. notabilis Ward, 2001 in possessing an elongated head, but differs by the presence of a distinct mandibular gap between masticatory margins when the mandibles are closed (in the case of major worker and queen). The new species was found nesting in a dead rubber tree branch on a tree within a rubber plantation near a stream.

This study investigated the taxonomy and phylogenetic relationships of the freshwater mussel genus Pseudodon Gould, 1844, with a specific focus on Indochinese populations, using a comprehensive molecular dataset and morphometric analyses. Our findings confirm the valid status of seven among the nine currently recognized extant Pseudodon species, and include the discovery of a new cryptic species, P. septuaginta sp. nov., from the Mekong River Basin in northeastern Thailand. The new species is characterized by a compressed, sub-trigonal shell outline, the presence of a posterior wing, weakly developed pseudocardinal teeth, and obsolete lateral teeth. Phylogenetic analysis revealed this new species as the sister taxon to the adjacent allopatric P. vagulus, which is distributed in Mekong River tributaries in the upper Khorat Plateau, exhibiting a 6.71% uncorrected COI p-distance. Despite some morphological overlap, these two species are distinguishable by pseudocardinal tooth structure and overall shell shape. Furthermore, phylogenetic analyses support a potential Bornean origin for Pseudodon, followed by dispersal into Myanmar and Indochina, with paleo-drainage isolation driving diversification within the Indochinese lineages.

A second species of the rogadine braconid wasp genus, Batothecoides Watanabe, 1958 is described from Thailand, the genus having been known only from the type species for the past 66 years. The new species, Batothecoides sirindhornae Ranjith, Butcher & Quicke, sp. nov., is distinguished from the type species of the genus, B. yakushimensis (Watanabe, 1938), by morphology, color and DNA sequence data. The type species is redescribed based on images of the holotype. A molecular phylogeny of all members of the subtribe Spinariina for which barcode data are available is presented.

The millipede genus Yuennanina Attems, 1936 has been known so far only from Yunnan Province, southwestern China. Currently, it comprises three species: Y. ceratogaster Attems, 1936, Y. aceratogaster Zhang & Li, 1977, and Y. petalolobodes Chang & Zhang, 1989. Herein, we describe Y. sirindhornae sp. nov., from Huai Nam Dang, Chiang Mai Province, northern Thailand, representing the first formal record of this genus not only from Thailand, but also from entire Southeast Asia. The new species is characterized by its unique gonopodal solenophore the shape of which resembles a young fern frond with fimbriate edges. A detailed redescription of the type species, Y. ceratogaster, is provided based on a revision of type material. An updated identification key to all four presently known Yuennanina species is also provided.

The taxonomic significance of leaf anatomy within the genera Canthium, Canthiumera, Meyna, and Psydrax (Rubiaceae: Vanguerieae) in Thailand were investigated. Leaf and petiole anatomy of eight species of Canthium, one species of Canthiumera K.M.Wong & Mahyuni, three species of Meyna Roxb. ex Link, and three species of Psydrax Gaertn. were analyzed using the transverse sections, epidermal peels, and scanning electron microscopy (SEM). Anatomical characters were evaluated using Principal Component Analysis (PCA) and Unweighted Pair Group Method Algorithm (UPGMA). The anatomical analysis indicates that the genera can be distinguished based on the number of palisade mesophyll layers, the presence or absence of stomata on the leaf surface, and the presence or absence of an adaxial parenchymatous hypodermis. Anatomical features support the recognition of Canthium in a narrow sense: Canthium, Canthiumera, Meyna, and Psydrax. These findings emphasize the potential of leaf anatomical characters as a reliable tool for taxonomic classification.

Plant Growth Promoting Rhizobacteria (PGPR) are commonly used to produce biofertilizers. As such, the purpose of the present research was to develop a PGPR biofertilizer formulation from four Streptomyces strains isolated from millipede fecal pellets and to select suitable carriers for them. The four Streptomyces isolates were Streptomyces sp. KLS-AC04, S. zaomyceticus KLD-AC02-1, S. zaomyceticus KLD-AC16 and S. zaomyceticus KLD-AC30. Their compatibility was tested on Actinomycetes isolation agar by the cross-streak method and the results showed that the four isolates can coexist. A viability test was done with three different types of carriers: coconut coir, cow dung and peat moss. The best carrier for all isolates was peat moss (viability: 5.3 x 104 − 8.5 x 105 cfu/g). The isolate that exhibited the highest survival rate across the three carriers was Streptomyces sp. KLS-AC04. Seven PGPR biofertilizer formulations were developed, of which formulation 6 (cow dung: peat moss: KLS-AC04: KLD-AC02-1: KLD-AC16: KLD-AC30) showed the highest viability (6 x 105 cfu/g). The effects of the PGPR biofertilizer formulations on plant growth were explored on Chinese kale. This showed that the use of the four Streptomyces strains had a significant positive effect on germination percentage (range 47.5% − 80.0%), fresh weight (range 0.060 − 0.086 g), shoot length (range 36.1 − 60.4 mm), and root length (range 15.3 − 30.8 mm).

Human-elephant conflict (HEC) poses serious threats to humans and to elephants, and while HEC in Southeast Asia is increasing, mitigation effectiveness data are lacking. Previous assessments of available mitigation options have not compared relative benefits and impacts of each on a practical level to identify which factors should be considered by local agricultural communities and/or other stakeholders when choosing among mitigation options. Understanding which mitigation approach to apply in a given context is crucial for effective mitigation planning and can aid in the development of more holistic methods. We reviewed the literature regarding the strengths and weaknesses of 14 currently applied HEC mitigation methods in Southeast Asia, considering five key factors for each mitigation option: 1) effectiveness at reducing crop damage, 2) initial start-up costs, 3) maintenance/long-term costs, 4) potential impacts on humans and 5) potential impacts on elephants. Our results suggest there are considerable tradeoffs among these five factors for any given mitigation option and that none of the available mitigation methods are simultaneously highly effective in preventing crop damage and low cost while presenting minimal impact to people and elephants. Although our metric of comparison is not comprehensive, it may offer an initial set of guidelines for decision making.

Commelinceae subtribe Cyanotinae, which contains one species of Belosynapsis Hassk. and five species of Cyanotis D. Don in Thailand, are described based on morphological data. Keys to the genera and species are presented. Morphological descriptions of both genera are provided, as well as information on each species' distribution, ecology, conservation status, vernacular names, and additional notes. Cyanotis barbata D. Don, Tradescantia ciliata Blume, and T. capitata Blume have also been lectotypified.