Water striders of the subfamily Eotrechinae from the Phetchabun Mountain Range can be found at the margins of rock pools and puddles, and in hygropetric habitats including waterfalls. Twenty-two species in three genera are known from Thailand. In the Phetchabun Mountain Range, 12 species representing all three genera were recorded from over a decade of collections (2002–2012). This paper provides taxonomic, biological, and ecological information for taxa of the Phetchabun Mountain Range in Thailand and a taxonomic key to all known species from Thailand.

The species composition of aquatic (Nepomorpha) and semiaquatic (Gerromorpha) Heteroptera were examined from protected and unprotected study sites in three streams associated with Kaeng Krachan National Park. At each stream, both quantitative and qualitative sampling methods were used during seven collecting events (November 2018 to June 2020). A total of 11 families, representing 33 genera and 60 species, were collected in this study, with more Nepomorpha families but higher species richness in Gerromorpha. The species richness of both protected and unprotected sampling sites were lowest during the fifth sampling event. Nevertheless, there was no significant difference in richness between protected and unprotected sampling sites for any sampling event based on a paired t-test analysis. Based on an nMDS analysis, the patterns of species composition of aquatic and semiaquatic heteropterans were unclear among protected and unprotected sampling sites. The use of aquatic and semiaquatic Heteroptera as bioindicators for habitat quality is still uncertain. Additional physiochemical characters of the water and physical characters of the stream may lead to a clearer picture of the relationship between aquatic and semiaquatic Heteroptera and stream habitat quality.

Most Thai rivers have not yet reached "good" ecological status. Furthermore, the scientific community is deeply concerned about the existence and abundance of microplastics (MPs) in freshwater. The live weirs' river health status was assessed using water quality and a variety of aquatic insect species. The research was conducted along Khlong-La, which was compared in the absence (R1, R2) and presence of living weirs (LWs) (M71, M62, M4, and M2). In 2023, aquatic insects and water samples were gathered during two months: January (rainy season) and July (dry season). The results revealed that the six sampling sites had similar physical and chemical properties, with the exception of total dissolved solids, which varied significantly. A total of 658 aquatic insects from 25 families and 6 orders were identified. The Hydropsychidae dominated the aquatic insect fauna at the LWs locations, followed by Chironomidae, Naucoridae, and Caenidae. Ten genera were discovered at the reference site (R1), whereas 16, 21, 24, and 19 were discovered at LWs (M71, M62, M4, M2), and 16 at the reference site (R2). The results of CCA ordination revealed that the most important factors influencing aquatic insect diversity were dissolved oxygen, water temperature, pH, electrical conductivity, and ammonia nitrogen. This study suggests that because of their significant responses to environmental factors, the species richness of aquatic insects may indicate the conservation value of habitats. The BMWPTHAI score was 41, 51, 57, 58, 73, 54, and the ASPTTHAI score was 5.12, 5.10, 5.18, 5.27, 4.86, and 5.40, respectively. Shannon-Weiner diversity index (Hʼ) values were 2.059, 2.461, 2.839, 2.777, and 2.587, respectively. The results showed that the water quality was average. The physicochemical data, as well as the BMWP and ASPT, revealed that the water at the living well was slightly polluted. Furthermore, larger MPs (>500 µm) were found in the largest concentrations, in the shape of fibers, and primarily in the color violet.

Although the human consumption of aquatic insects is prevalent in many regions, the nutritional composition of the insects has not been comprehensively determined. The proximate composition of Pantala sp. was shown to be a good source of protein (49.45 ± 0.32 g/100 g DW), as well as of minerals such as sodium, calcium, potassium, phosphorus, zinc, and iron. All nine essential amino acids are present in this species, with valine being the most abundant. The major fatty acids are palmitic acid (1.19 ± 0.02 g/100 g DW), oleic acid (0.63 ± 0.02 g/100 g DW), and linoleic acid (0.55 ± 0.01 g/100 g DW). Lead (Pb), arsenic (As), and cadmium (Cd) showed a value of 0.18 ± 0.01 mg·kg⁻¹, 3.51 ± 0.12 mg·kg⁻¹, and 0.17 ± 0.00 mg·kg⁻¹, respectively. Furthermore, microplastic (MP) contamination in odonate larvae (419 individuals belonging to three identified families) was found in varying shapes, e.g., fibers, fragments, and rods. FTIR analysis revealed the following MP polymers, polyethylene terephthalate, polyvinyl acetate, bis(2-ethylhexyl), polybutadiene, poly(methyl methacrylate-co-methacrylic acid); P(MMA-co-MA), poly(ethylene glycol) tetrahydrofurfuryl ether, poly(acrylonitrile-co-butadiene), and polypropylene glycol. The results of this work could be a nutritional reference for food security and the risk of eating insects.

Thai rhaphidophorid species of the genus Eurhaphidophora Gorochov 1999 are reviewed. Previously, two species and one subspecies (E. bispina Gorochov 2010; E. pawangkhananti Dawwrueng, Gorochov & Suwannapoom 2020; E. tarasovi doitungensis Dawwrueng, Gorochov & Suwannapoom 2020) were reported from Thailand. In this study, a new additional species (E. apicoexcisa sp. nov.) from Ratchaburi Province is described. Males of this new large-sized species are easily recognized from other males of Eurhaphidophora by an almost straight and lamellar posteromedian process of the ninth abdominal tergite, the presence of a small but rather deep and rounded apical excision on this process, and a long apical part of the epiproct. Females of the new species also can be distinguished from other Thailand congeners by the presence of a small rounded posteromedian projection on the both eighth and ninth abdominal tergites, and a shortly triangular subgenital plate. An updated species catalogue of all known species and taxonomic keys to Thailand Eurhaphidophora species for males and females are provided.

The Gerromorpha assemblages in mangroves located in the central and eastern regions of Thailand were examined, and a total of nine species belonging to six genera and three families were discovered. Four of the recorded species are new records for Thailand. Asclepios annandalei Distant, 1915 was the most common species and widely distributed throughout the study area. The most diverse genus was Xenobates, which consisted of Xenobates argentatus Andersen, 2000, Xenobates mandai Andersen, 2000, Xenobates murphyi Andersen, 2000, and Xenobates singaporensis Andersen, 2000. Three of these species are new country records. Here, we present taxonomic and ecological information of mangrove gerromorphans in the central and eastern regions of Thailand.