Species of the nivea group (genus Ditrichophora Cresson) are revised. The group now includes four species of which one, D. gulkana (Alaska and Mongolia), is newly described. The group is now known to have a Holarctic distribution with two species, D. gulkana and D. nivea, being the first reported from the Nearctic Region. Another Asian species, D. brunnicosa, previously placed in Diclasiopa, is transferred to this group (genus Ditrichophora) and is also reported from Mongolia. To facilitate identification of these rare species, we have included diagnoses of the tribe, genus, and species group and have also provided an annotated key to Holarctic genera of the tribe Discocerinini and to species of the nivea group within Ditrichophora. We also provide the first illustrations of male terminalia for all included species.

A new species of flat-headed mayflies (Heptageniidae) is described as Maccaffertium appaloosa, n. sp. The species is based on larvae taken from Tennessee, U.S.A. It is both morphologically and markedly unique within the genus, and is most conspicuous with respect to spotting on the abdominal sterna.

An annotated checklist consisting of 300 species is provided for the mayfly fauna of the southeastern United States [Alabama (139 spp.), Arkansas (118 spp.), Florida (77 spp.), Georgia (155 spp.), Kentucky (135 spp.), Louisiana (61 spp.), Mississippi (59 spp.), North Carolina (207 spp.), South Carolina (185 spp.), Tennessee (167 spp.), Virginia (170 spp.), West Virginia (119 spp.)]. The list is based on previously published and newly published collection data. Some 107 supported state records in the region are also provided based on 92 of the species. The Southeast is the richest region in North America in terms of mayfly biodiversity, but the states of Louisiana and Mississippi remain poorly known.

Megachile is one of the largest genus of the family Megachilidae widely distributed in temperate and tropical areas of the world. Megachile (Pseudocentron) gomphrenoides was described by Vachal (1908) based on three female collected in Buenos Aires. Recently in a work about nest building of bees, we obtained females and males of this species in trap-nest. In this paper, the original description of the female is enlarged and the first description of the male is provided. Additionally, floral host and new record geographical are presented.

Two new species, Eudorylas dicranus sp. nov. and E. atrigonius sp. nov., are described from Palaearctic China.

Two new species, Hybos guanmenshanus sp. nov. and H. latus sp. nov., are described from Hubei, China. Their relationships with the related species are discussed.

A new species, Oreogeton flavicoxa sp. nov., is described from Oriental China. A key to Palaearctic and Oriental species of the genus is presented.

Two new species, P. brevis sp. nov. and P. didymus sp. nov., of Platypalpus are described from Oriental China. These two new species belong to the longicornis species group.

Four species of the genus Ophthalmothrips Hood are recorded from Mainland China, including the descriptions of one new species. O. yunnanensis sp. nov. (Yunnan). Illustrations of the new species and a key to all species of genus Ophthalmothrips from Mainland China are provided, along with a checklist of the known species of the genus.

Three new species of Philonthus furvus species group with orange elytra are described: P. rufotibialis sp. nov. from Chiapas (Mexico) and San Marcos (Guatemala); P. pollens sp. nov. from Morelos (Mexico) and P. navarretei sp. nov. from Oaxaca (Mexico). Diagnostic features, new state and locality records for P. hoegei, P. testaceipennis and P. yaqui are included. Also, a key to identify the six species recorded from Mexico and the species shared with Guatemala is presented, with some schemes of the most important structures.

The genus Nanotopsis Schuster is revised. The two species currently included in the genus, Nanotopsis isolatrix Schuster, male, and N. malincha (Casal), female, are redescribed, and four new species are described: Nanotopsis delsinnei, male and female, from Paraguay and Argentina; N. leleji, male, from Argentina; N. paglianoi, male, from Guatemala; and N. panamae, male and female, from Panama. Additional records for N. isolatrix and N. malincha are given. Body and genitalia of males are illustrated for the first time. A key is provided for the six species of the genus Nanotopsis, species that have disjunct distributions in America: Guatemala, Panama, Brazil, Paraguay, and Argentina.

The genus Cardiodactylus Saussure, 1878 with one new species, Cardiodactylus hainanensis, sp. nov., is reported here from Hainan Island of China for the first time. This new genus record extends the range of Cardiodactylus westward from Taiwan Island, China. The new species can be distinguished from others mainly by its longer and higher dorsal ridge in the apical part of the pseudepiphallic, in lateral view, as well as the rectangle-shaped basal part of the ridge.

A chance find of a dead mole cricket is proved to be a new species, Gryllotalpa choui, sp. nov., from Yunnan, China. This species, described in the present paper, can be distinguished from all other mole crickets mainly by short abdomen (pronotum longer than half length of abdomen), tegmen nearly round when flattened, large proportional size proportion of the harp, c1 and c2, very short apical field as well as longitudinal veins in this field, vestigial hind wings and a foot-shaped ectophallus.

The genus Semelaspidus MacGillivray, 1921 is reviewed, and one new species, Semelaspidus multiporus sp. nov., from China, is described. In addition, photographs and illustrations of the new species, and a key to all species of the genus are provided.