Scarabaeinae are sensitive to structural habitat changes caused by disturbance. We compared copronecrophagous beetle (Scarabaeinae) community structure in three differently managed zones within an agroecosystem of the northern Yucatan Peninsula, Mexico. We placed dung and carrion traps once a month from June 2004 through May 2005. The beetle community included 17 species from the genera Canthon, Canthidium, Deltochilum, Pseudocanthon, Malagoniella, Onthophagus, Phanaeus, Copris, Uroxys, Sisyphus and Ateuchus. The secondary vegetation had a higher beetle diversity than the other two zones. Species richness was highest in the Brosimum alicastrum plantation. The pasture had the lowest species diversity and richness, but exhibited the highest abundance of Scarabaeinae in the dry season. The two zones with extensive tree cover were the most diverse. Roller beetles were dominant over burrower species and small-sized species outnumbered large species. Our data show two important issues: beetle species in the pasture extended their activity to the beginning of the dry season, while abundances dropped in the other, unirrigated zones; and the possibility that the Scarabaeinae living in neotropical forests are opportunistic saprophages and have specialized habits for resources other than dung. The B. alicastrum plantation is beneficial to the entire ranch production system because it functions as a dispersion and development area for stenotopic species limited to tree cover.

Se presenta un estudio faunístico de las especies de Melolonthidae y Passalidae que habitan en el bosque tropical caducifolio y comunidades secundarias ubicadas entre los 9 y 70 m de altitud en los municipios de Tzucacab y Conkal, Yucatán. Durante 74 días de colecta distribuidos entre 2001 y 2002 se obtuvieron 6,378 ejemplares que representan a 49 especies de los géneros Phyllophaga, Diplotaxis, Anomala, Chasmodia, Macraspis, Plesiorutela, Pelidnota, Cyclocephala, Ligyrus, Strategus, Coelosis, Phileurus, Gymnetis, Cotinis, Hoplopyga, Balsameda, Amithao, Euphoria, Trigonopeltastes, Passalus, Heliscus y Verres. La abundancia de estas especies fue mayor durante los meses de abril, mayo y junio. La mayoría de los ejemplares procede de Conkal, pero la riqueza de especies fue más elevada en Tzucacab. Dieciocho especies se registran por primera vez para el estado de Yucatán, y se confirma la presencia en México de Hoplopyga ocellata G. & P. y Euphoria subguttata Burmeister. Se incluye una clave para separar las 49 especies, se comparan la fauna de Conkal con la de Tzucacab y con otras localidades tropicales de México, y se discuten algunos aspectos biogeográficos, agropecuarios y de conservación relacionados con la coleopterofauna yucateca.

<p><strong>Background</strong>. Macrocyclic lactones (ML) are effective in controlling endo- and ectoparasites in livestock. ML, specially ivermectin and moxidectin, have a typical pharmacokinetic profile of lipophilic molecules with slow degradation and when administered to livestock are excreted in the faeces almost unaltered. ML released into the environment, can cause lethal and sublethal effects on dung beetles (DB). <strong>Objective. </strong>To document the main scientific contributions of our research group to the awareness of the adverse effect of ML on DB associated with livestock environments under grazing systems. <strong>Methodology. </strong>The compilation of scientific articles from the studies carried out by a research group in the first 50 years of the FMVZ-UADY was carried out. <strong>Results. </strong>The studies have shown that ML (IVM-1%, IVM-3.15%, MOX-10%) in dung from cattle treated with injectable formulations had a sublethal effect on DB. For the species <em>Canthon indigaceus chevrolati </em>dung from cattle treated with injectable formulations of IVM (1% and 3.15%) and MOX (1% and 10%) do not produce lethal and sublethal effects. Faecal ivermectin residues may induce changes in attraction of some neotropical DB species to dung pats. <strong>Implications.</strong> Current ML application methods may have negative effects on the environmental services provided by dung beetles, and therefore need to be modified to minimize any impacts they might have on these vital members of tropical livestock systems. <strong>Conclusions.</strong> The review shows the adverse effects of ML on DB in the Mexican tropics; however, for the <em>C. i. chevrolati</em>, dung from cattle treated with IVM and MOX, do not produce lethal and sublethal effects, which suggests some type of tolerance</p>