An annotated list of 39 species in 25 genera and seven subfamilies of the pygmy grasshoppers (Orthoptera: Tetrididae) from Thailand is given; from these 18 species are recorded from this country for the first time. Five new species are described: Cotysoides gaponi sp. nov. (subfamily Metrodorinae), Eucriotettix anisyutkini sp. nov., Gavialidium bufocrocodil sp. nov., Scelimena bellula sp. nov. (subfamily Scelimeninae) and Phaesticus uvarovi sp. nov. (subfamily Discotettiginae). One species is transferred from Scelimena to Amphibotettix and a new combination is proposed: Scelimena hafizhaii Mahmmod, Idris et Salman, 2007 = Amphibotettix hafizhaii (Mahmmod, Idris et Salman, 2007), comb. nov. The previously unknown male of Falconius tschernovi Storozhenko, 2014 is described.

Mimadiestra gen. nov. (type species: M. biloba sp. nov.) is described from Thailand. Megadiestramima Storozhenko et Gorochov, 1992 and Leodiestramima Storozhenko, 2009, stat. nov. are considered as separate genera, therefore, three new combinations are proposed: Leodiestramima exculta (Gorochov, 1998), comb. nov., L. lecta (Gorochov, 1998), comb. nov., L. orlovi (Gorochov, 1994), comb. nov. A key to genera of the tribe Diestramimini is given.

Sakaerat Biosphere Reserve is one of the four Biosphere Reserves in Thailand. It is situated at Khorat Plateau and comprises of mainly dry evergreen forest and dry dipterocarp forest. Despite studies that document its rich biodiversity, there was no concerted study on the orthopteran diversity. Recent sampling by the authors in Sakaerat led to the discovery of numerous undescribed species. A checklist, first for the place, is also reported here, each species represented with a habitus photograph. In total, 128 species of Orthoptera from 11 families were recorded. Caelifera (grasshoppers) were represented with five families and Ensifera (crickets and katydids) were represented with six families, making up 10 of the 16 lineages in the orthoptera phylogeny.

The pygmy grasshopper subfamily Cladonotinae and genera Epitettix Hancock, 1907, Pseudepitettix Zheng, 1995 and Tuberfemurus Zheng, 1992 are firstly recorded from Thailand. Three new species, namely Epitettixobtusus obtusus sp. nov. from provinces Nakhon Ratchasima and Chiang Mai, Pseudepitettix pimkarnae sp. nov. from province Saraburi and Tuberfemurus kanokwanae sp. nov. from province Saraburi, are described.

Three new species of scaly crickets are described: Ornebius xinyao sp. n. from Singapore; Ornebius dowwiangkanae sp. n. and Terraplistes ingrischi sp. n. from Thailand. Ornebius insculptus Tan & Ingrisch, 2013 from Singapore is also corrected for nomenclatural error from the original name Ornebius insculpta.