Giant water scavenger beetles Hydrophilus subgenus Dibolocelus (Coleoptera: Hydrophilidae) from Mexico with description of two new species.

The Hydrophilus (Dibolocelus) Bedel species from Mexico and adjacent areas are treated on the basis of the study of 142 adult specimens and published data. Two new species are herein recognized and described: H. (D.) nucleoensis Arce-Prez Arriaga-Varela sp. nov. from Mexico, Guatemala and Nicaragua, H. (D.) pseudovatus Arce-Prez Arriaga-Varela sp. nov. from Mexico. Three already known species are re-described and their geographical distribution is updated, H. (D.) ovatus Gemminger Harold and H. (D.) pollens Sharp and H. (D.) violaceonitens Jacquelin du Val, a species resurrected as distinct to H. (D.) smaragdinus. Hydrophylus (D.) cf. purpurascens (Rgimbart) is also redescribed but their identity is questionable. The lectotype of H. (D.) pollens Sharp is designated. Within Mexico, the state with the highest known diversity is Veracruz with five species. A key to the species of Hydrophilus (Dibolocelus) from Mexico and Central America is provided.

Two new species of Megarthrus (Coleoptera, Staphylinidae, Proteininae) from Mexican Cloud Forests.

Two new species of Megarthrus are described from cloud forests of the Mexican state of Veracruz: M. cavianae Rodríguez, Navarrete-Heredia Arriaga-Varela sp. nov., and Chiapas:  M. chiapas Cuccodoro sp. nov. They differ from the two hitherto known Mexican species M. altivagans Bernhauer, 1929, and M. alatorreorum Rodríguez Navarrete-Heredia, 2015, both from temperate forests of the Transmexican Volcanic Belt, by having synapomorphic features of the M. inaequalis-supergroup of species. This lineage includes all the Central and South American members of the genus, with the inclusion of these species, the distribution of the group is extend by more than 5 degree of latitude to the North. Within this lineage, the two new species share a very peculiar morphology of the male abdominal sternite VIII found elsewhere in the genus only in M. flavosignatus Bierig, 1940, and M. zunilensis Sharp, 1887, with which they form the M. zunilensis-group of species defined here.

Hylaperdina squamosa, a new species of Neotropical Lycoperdininae (Coleoptera, Endomychidae) from Brazil.

Endomychidae or Handsome Fungus Beetles are a moderately large family of mycophagous beetles distributed worldwide but with the highest diversity in the tropics (Shockley et al. 2009a, b). The concept of the family (e.g. Lawrence & Newton 1995; Tomaszewska 2000, 2010; Shockley et al. 2009a) has recently been restricted by an elevation of former subfamilies Eupsilobiinae, Mycetaeinae and Anamorphinae to the level of independent families in the newly recognized superfamily Coccinelloidea (Robertson et al. 2015).

Electribius relictus, a new extant species of Artematopodidae (Coleoptera: Elateroidea) from Veracruz, Mexico.

Electribius relictus sp. nov. (Artematopodidae) is described from a cloud forest fragment in central Veracruz, Mexico. This species is distinguished from the other extant species known, E. crowsoni Lawrence (Mexico) and E. similis Lawrence (El Salvador), by the pronotum and elytra completely black, pronotum with margins crenulate at base, fifth abdominal ventrite with distinct median ridge, and the shape of aedeagus. The new species is illustrated and a key for the identification of extant species of the genus and ecological data for the collecting site are provided.

Preliminary review of the genus Stenotarsus Perty (Coleoptera: Endomychidae) from México, Guatemala and Belize, with descriptions of twelve new species.

A preliminary review of the species of Stenotarsus Perty from México, Guatemala and Belize is presented. Twenty-seven species are recorded from the region including 12 new species described here: Stenotarsus cortesi sp. nov. (Jalisco), S. incisus sp. nov. (Quetzaltenango, Chiapas, Oaxaca, Veracruz), S. kafkai sp. nov. (Veracruz), S. mesoamericanus sp. nov. (Chiapas, Puebla), S. mexicanus sp. nov. (Veracruz), S. molgorae sp. nov. (Jalisco), S. monterrosoi sp. nov. (Izabal), S. parallelicornis sp. nov. (Veracruz), S. raramuri sp. nov. (Durango, Jalisco), S. rulfoi sp. nov. (Jalisco), S. shockleyi sp. nov. (Veracruz), S. spiropenis sp. nov. (Jalisco). Stenotarsus circumdatus Gerstaecker, S. discipennis Gorham and S. tarsalis Gorham are synonymized with S. globosus Guérin-Méneville. Stenotarsus distinguendus Arrow is synonymized with S. sallaei Gorham. Stenotarsus pilatei Gorham is synonymized with S. militaris Gerstaecker. Lectotypes are designated for: Stenotarsus circumdatus Gerstaecker, Stenotarsus distinguendus Arrow, Stenotarsus exiguus Gorham, Stenotarsus globosus Guérin-Méneville, Stenotarsus guatemalae Arrow, Stenotarsus discipennis Gorham, Stenotarsus lemniscatus Gorham, Stenotarsus militaris Gerstaecker, Stenotarsus rubrocinctus Gerstaecker, Stenotarsus sallaei Gorham, Stenotarsus tarsalis Gorham, Stenotarsus thoracicus Gorham. A key to the species in this region is provided. Species are described in detail and illustrated, and habits and habitats are given when available.