New state and host records are provided for 28 species of Buprestidae collected in Morelos, Mexico in the following genera: Acmaeodera Eschscholtz 1829, Actenodes Dejean 1833, Agrilus Curtis 1825, Brachys Dejean 1833, Chrysobothris Eschscholtz 1829, Leiopleura Deyrolle 1864, Lius Deyrolle 1864, Pachyschelus Solier 1833, and Tetragonoschema Thomson 1857.

The present study was conducted to determine the species composition of the family Coccinellidae (Coleoptera) in the tropical deciduous forest of Huautla, Morelos, Mexico in the south-central part of the Sierra de Huautla Biosphere Reserve (REBIOSH) during the period 2018–2019. Richness and abundance were quantified, and the expected richness was calculated with estimators. A total of 1,743 specimens belonging to two subfamilies, 12 tribes, 25 genera, and 52 species were recorded. The rainy season, particularly in August, was the most diverse, while the most abundant month was March (dry season). Several new state records for Morelos were found: Scymnobius flavifrons (Melsheimer), Scymnobius sordidus (Horn), Scymnus (Pullus) bryanti Gordon, Scymnus (Pullus) dozieri Gordon, Scymnus (Pullus) enochrus Gordon, Scymnus (Pullus) fraternus LeConte, Scymnus (Pullus) gilae Gordon, Brachiacantha indubitabilis Crotch, Brachiacantha quadrillum LeConte, Hyperaspis conspirans Casey, Hyperaspis globula Casey, Thalassa montezumae Mulsant, Diomus texanus Gordon, Paraneda viridescens Timberlake, Psyllobora renifer Casey. The following are reported additionally as new country records for Mexico: Scymnus (Pullus) mimoides Gordon, Calloeneis angelica Gordon and Hanley, Hyperaspis dobzhanskyi Gordon, Hyperaspis esclavium Dobzhansky, Hyperaspis oculifera Casey, Decadiomus austrinus (Gordon).

A checklist with 246 species, three subspecies, 37 genera, 19 tribes, and four subfamilies of Buprestidae and their distribution in the state of Oaxaca is provided. Acmaeodera crossi Barr, 1992, Chrysobothris viridiimpressa Gory & Laporte, 1837 and Melanophila atra Gory, 1841 are recorded for the first time in the state. Leucaena esculenta (DC.) Benth and Vachellia pennatula (Schltdl. & Cham.) Seigler & Ebinger, are recorded as new adult host plants for two buprestid species in Mexico.

DNA barcode sequences remain unavailable for many species of Mexican Coleoptera. This study presents the first COI barcode records for four saproxylophagous beetle species (Coleoptera: Buprestidae, Cerambycidae) from the Central Valleys of Oaxaca, Mexico: Acmaeodera scalaris, Placosternus erythropus, Parevander xanthomelas, and Stenaspis castaneipennis. The sequences, together with their associated metadata, were deposited in the Barcode of Life Data System (BOLD) under the project Oaxaca Central Valley Insect Diversity (OCVID). A. scalaris is newly barcoded for Mexico, while the other three species are newly represented in global barcode databases. The P. xanthomelas barcode differs by approximately 8% from a GenBank sequence labeled with the same name, suggesting either a misidentified reference or a cryptic mitochondrial lineage. These data expand the molecular reference coverage for Neotropical Buprestidae and Cerambycidae and highlight the need for additional taxonomic work to refine species boundaries within Cerambycidae.