Se describen 36 especies nuevas de Photinus y 1 de Paraphotinus. Las nuevas especies proceden de la Ciudad de México (2), Estado de México (15), Hidalgo (6), Morelos (2), Puebla (11) y Tlaxcala (1). Se actualiza la información de 64 especies del centro de México de los géneros Aorphalus Zaragoza-Caballero y Gutiérrez-Carranza, Aspisoma Laporte, Aspisomoides Zaragoza-Caballero, Bicellonycha Motschulsky, Cratomorphus Motschulsky, Lucidota Laporte,Paraphotinus Zaragoza-Caballero nov. est., Phaenolis Gorham, Photinus Laporte, Photuris Dejean, Pleotomus LeConte, Pyractomena Melsheimer, Pyropyga LeConte y Pyropygodes Zaragoza-Caballero. Se presenta una clavepara identificar tribus, géneros y especies de esta región, así como una diagnosis para el reconocimiento de los géneros y especies. Las diagnosis genéricas se complementan con la mención de la especie tipo, quién la designó, literatura donde se ha hecho mención del género y las especies que se han registrado en los estados mencionados, así como su distribución en el país. Además, se proponen los siguientes cambios nomenclaturales: nuevos estatus: Paraphotinus aulophallus (Zaragoza-Caballero y Gutiérrez-Carranza, 2018b), P. furcatus (Zaragoza-Caballero, 2000a), P. tlapacoyaensis (Zaragoza-Caballero, 1996) y P. tuxtlaensis (Zaragoza-Caballero, 1995a); nueva combinación: Photinus palaciosi comb. nov. = Macrolampis palaciosi Zaragoza-Caballero, 2015; y combinaciones restauradas: Photinus lunicollis Gorham, 1880 y Photinus producta Gorham 1881.

A morphology-based phylogenetic analysis of the family Phengodidae (Coleoptera) is given. Thirty-six terminals, six genera and 60 morphological characters are included. To test the monophyly of phengodid subfamilies the terminals that belong to superfamily Elateroidea Drilocephalus Pic (Dascillidae), Pterotus LeConte (incertae sedis), Vesperelater Costa (Elateridae), Photinus Laporte (Lampyridae), Pseudotelegeusis Wittmer and Telegeusis Horn (Telegeusidae) are used as outgroups, with the remaining 30 terminals corresponding to 26 specific and four generic levels. The matrix was analyzed under a parsimony criterion under a heuristic search performed in TNT v. 2.0. One parsimonious tree was obtained. In this study two principal groups are recognized in the family Phengodidae. This study suggests for the first time a close relationship between the Telegeusidae and the subfamily Penicillophorinae.

An updated checklist of fireflies (Coleoptera: Lampyridae) from Mexico is presented. The checklist includes the following valid taxa: the subfamilies Amydetinae Olivier in Wytsman, 1907, Chespiritoinae Ferreira, Keller and Branham, 2020, Photurinae Lacordaire, 1857, Pterotinae LeConte, 1861, and Lampyrinae Rafinesque, 1815, in addition to 8 tribes (including incertae sedis), 2 subtribes, 25 genera, and 232 species. We also propose Photinus cubilguitzi Pérez-Hernández & Zaragoza-Caballero nom. nov. as a replacement name for Photinus moestus (Gorham, 1884) nec Photinus moestus (Perty, 1830). At least 152 documented species (65.6% of the total) are restricted to Mexico, another 21 have also been recorded in Canada and the United States of America, and 59 in different Latin American countries. Remarkably, Photinini contains 64.6% (150 species) of the Mexican lampyrid fauna, and at least 54.7% (127 species) belong to the Photinus genus. The Mexican Transition Zone had higher Lampyridae species richness and endemism than the Nearctic and Neotropical biogeographic regions in the country, while the Transmexican Volcanic Belt, Veracruzan and Balsas Basin biogeographic provinces harbor the highest overall species richness and endemism. Veracruz and Oaxaca are the richest states in terms of lampyrid genera and species, while Aguascalientes, Querétaro and Zacatecas have only one or no species recorded each. To date, 10% of the global firefly fauna has been recorded in Mexico, and the country has a large number of endemic species. It is essential to intensify the study and fieldwork throughout the country to increase our knowledge of the group, with special focus on poorly explored regions and endemic species, and from other perspectives in addition to taxonomy.

Stenodrilus gen. nov., Stenodrilus rodolfoi sp. nov., Platydrilus gen. nov., and Platydrilus magaliae sp. nov. from Chiapas, Mexico, are described and illustrated. A key for identification of the genera of Telegeusidae is presented.

Cleicosta, a new genus of Phengodidae containing two new species, C. equatoreana sp. nov., and C. monaguense sp. nov., are described. Additionally, a new combination for Cenophengus breviplumatus Wittmer, 1976 is included. Cleicosta gen. nov., is the thirty-eighth genus assigned to the beetle family Phengodidae in the new world and is also the most morphologically similar to Cenophengus LeConte, 1881. Both genera exhibit clearly separated tentorial pits, vertical frons and simple tarsomeres. In Cleicosta gen. nov., however, the antennal rami are 1.5 times longer than the corresponding antennomere, the pronotum is subquadrate and the elytra are short, reaching the first or second abdominal segment. In addition, it presents an aedeagus with lateral lobes slender, parallel exteriorly, narrowed medially to toothless apex.

Se sintetiza la información de luciérnagas de la región norte-occidente de México, que abarca los estados de Baja California, Baja California Sur, Sonora, Chihuahua, Coahuila, Nuevo León, Sinaloa, Durango, Zacatecas, San Luis Potosí, Nayarit, Jalisco, Aguascalientes, Guanajuato, Querétaro, Colima y Michoacán. Se comentan 67 especies de las 69 registradas, que corresponden a los géneros Ankonophallus Zaragoza-Caballero y Navarrete-Heredia, 2014 (2), Aspisoma Laporte, 1833 (4), Aspisomoides Zaragoza-Caballero, 1995 (2), Bicellonycha Motschulsky, 1853 (5), Chespirito Ferreira, Keller y Branham, 2020 (1), Cratomorphus Motschulsky, 1853 (3), Microphotus LeConte, 1866 (7), Nelsonphotus Cicero,2006 (1), Paracratomorphus Zaragoza-Caballero, 2013 (1), Photinoides McDermott, 1963 (1), Photinus Laporte, 1833 (25), Photuris Dejean, 1833 (2), Pleotomus LeConte, 1861 (3), Prolutacea Cicero, 2006 (1), Pterotus LeConte, 1859 (1), Pyractomena Melsheimer, 1846 (1), Pyropyga Motschulsky, 1852 (8) y Tenaspis LeConte, 1881(1). Se describen e ilustran 48 especies nuevas pertenecientes al género Photinus, incluyendo por primera vez una especie de luciérnaga para Zacatecas. Se presentan 2 claves, una para la identificación de los géneros de Lampyridae y otra para el reconocimiento de las especies de Photinus de la región. Además, se reportan registros nuevos estatales para 9 especies. Se reconoce a México como un centro de diversificación del género Photinus.