The effect of a non-host plant, Solanum myriacanthum , on ovarian dynamics and longevity of Leptinotarsa undecimlineata (Stål) (Coleoptera: Chrysomelidae) was studied under laboratory conditions. Females reared on the natural host, S. lanceolatum , served as controls . Female beetles did not accumulate eggs on the non-host. After continuous exposure to S. myriacanthum , the production of basal oocytes was diminished and oocytes were reabsorbed. Oocyte size, however, was not affected when compared to females fed with S. lanceolatum . In control females, the first mature eggs appeared at 34 days old. No eggs matured in females fed with the non-host in the 54-day duration of our experiment. Continuous exposure to the non-host resulted in significantly less resorption of reproductive resources than a stress period of 20 days on the non-host. Egg resorption was completely reversible after the preferred host was re-offered for another 20 days. Further studies under field conditions will be necessary to understand why this Leptinotarsa species uses only one of two sympatric Solanum species.

Reproductive phenology of organisms is modulated by biotic and abiotic factors, with direct effects on the demography. This study describes the annual reproductive phenology of Dichotomius satanas (Harold, 1867) (Coleoptera: Scarabaeidae, Scarabaeinae) of the cloud forest in eastern Mexico, through the morphological changes in the reproductive systems of individuals and their relationship with climatic conditions. Three stages of sexual maturity were recognised as occurring throughout the year: immature, maturing, and mature – with a higher occurrence of immature individuals. Abundance of immature and maturing females was explained by minimum temperature, but none of the environmental variables considered was related to mature females. Abundance of immature and maturing males was related to precipitation, while abundance of mature males was related to minimum temperature and precipitation. The phenology of D. satanas was markedly seasonal with a single peak of abundance corresponding to the reproductive period during the warm and rainy season, thus indicating a univoltine pattern of reproduction. Immature females were recorded before immature males, and no synchrony was observed between the maturing and mature males and females. We provide information pertaining to the reproductive biology of coprophagous beetles and highlight the importance of reproductive phenology as a tool with which to understand future environmental scenarios.

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In the present article, a summary and analysis of literature published in Mexico on the removal and burial of dung by dung beetles, a primary function that represents an ecosystem service of great importance for livestock production, is presented. Studies from distinct ecosystems are examined, emphasizing the findings in livestock pastures with active grazing in several different states of Mexico. In addition, the unpublished results of the authors obtained in pastures across an altitudinal gradient in central Veracruz are presented for a dung exposure time of 24 hours. No significant differences were found in species richness among sites. However, differences were found in the dung removal rate; higher values were found at the sites with higher elevation and lower values at sites with lower elevation. The species with the highest biomass included the 3 largest species and small but very abundant species. Nocturnal tunnelers reincorporated the largest quantity of dung over the first 24 hours; in contrast, rollers only removed dung at the lowest areas of the gradient (< 250 m asl). However, much more information is still required regarding the capacity of the different functional groups and dung beetle species for dung burial in the livestock production zones of Mexico.