Do sexual gonadic maturity and age determine habitat occupancy of Canthon cyanellus LeConte, 1859 (Coleoptera: Scarabaeidae)?

High-quality habitats presumably have the resources required to sustain relatively high rates of survival and reproduction. We assessed how habitat type and local environmental conditions determine the distribution of individuals of Canthon cyanellus (Coleoptera: Scarabaeidae), an eurytopic dung beetle, according to age category and sexual gonadic maturity. Beetles were surveyed in forest fragments, live fences, and pastures in Mexico. Individuals were categorised into six age categories according to the glandular volumes in males and oocyte number and length in females. Mature females in forest fragments were the most abundant females found among the habitats. Air humidity and soil hardness were positively and negatively related to mature female abundance, respectively. Mature beetles were the most abundant among males, and higher abundance of males occurred in forest fragments than in live fences and pastures. Light quantity was negatively related to the abundance of young males. Compared to forest fragments, females in pastures had larger oocytes. However, sites with higher soil hardness and air humidity had females with lower numbers of oocytes. Our results demonstrate that, although C. cyanellus occurs across a wide range of habitats, forest habitats might host sexually mature individuals, which translates into more effective individual dispersion and potential reproduction.

Cassia grandis (pink shower).

C. grandis is an element of lowland and riparian, semideciduous forests, occurring naturally from Mexico to South America. The species is usually 10-15 m high, and is very ornamental, especially due to its pink flowers which appear when the tree is partially defoliate and cover the entire crown. It is used in landscape design and urban arborization in tropical America, although in some cases its use is restricted due to the size of its fruits, which can reach 40-60 cm long. The species is recommended for live fences and revegetation in gallery forests in periodically flooded areas, but it is also adapted to a more or less pronounced dry season. C. grandis can be planted under direct sunlight in mixed tree systems, in fertile soils. The species has agroforestry potential for dry zones, especially in Central America, and is recommended for arborization of perennial crops and pastures, the fruits are highly appreciated by the cattle. C. grandis requires periodical pruning, however this may cause early decay and rot. The wood is used in construction, especially for carpentry, joinery, flooring, posts, beams, also for rustic furniture, tool handles, small bridges and boats. It is considered good for charcoal and fuelwood, and inadequate for cellulose and paper. In Central America, especially in Costa Rica, the membrane which surrounds the seeds is used as a substitute for chocolate, and is also used in many countries due to its medicinal properties. Researches have shown that extracts from this plant exhibit activity against the most common dermatophytes.

Prosopis juliflora (mesquite).

P. juliflora, known commonly as mesquite or algarrobo in its native neotropical region, is a tough and resilient tree providing fuelwood in arid lands world-wide. As a tree it will grow to about 13 m (-20 m) in height, and produce robust, hard and strong timber suitable for construction purposes and fine furniture production. It can grow on any type of soil, including highly alkaline and saline soils. It requires very little rainfall (it can survive on 70 mm per year). The pods provide a valuable fodder and human food crop, and are nutritious and palatable. The foliage, however, is not palatable, even to camels and goats, except the tips of very tender twigs; thus, the species is suitable for use in hedges and live fences. It has been used in reclamation reforestation of mining spoil, wastelands and sand dunes (Hocking, 1993).

FOOD SELECTION AND USE OF SPACE BY DIDELPHIS PERNIGRA (DIDELPHIDAE: MAMMALIA) IN AN ANDEAN SUBURBAN ENVIRONMENT

Cities have grown throughout the Andes and we know little about the ecology of those species that tolerate them, limiting our options to do conservation. We applied optimal foraging theory to examine the behavior of the Andean White-eared Opossum (Didelphis pernigra), in a suburban area in Bogotá, Colombia. We used the giving-up density technique, which uses the amount of food left in a feeding patch, to evaluate whether the opossum’s foraging costs were affected by the height of food from the ground, and the quality and quantity of food. We also evaluated whether the spatial heterogeneity of the study site affected the opossum’s foraging. We used an artificial feeding patch to test these ideas. When food was either concentrated and, in less amount, (concentrated food) or diluted and more amount (diluted food), the opossums preferred to forage at 2 m than at 0.5 m, but concentrated food at 0.5 m was not significantly different from diluted food at 2 m. The opossums’ habitat use was affected by the spatial heterogeneity at the study site and animals preferred foraging along metal fences than on live fences made of trees. When a cable allowed connection between the metallic and live fences, the value of food patches at the live fence appeared to increase. Thus, although the opossums need resources associated with natural environments, our results suggest that there are human modifications that can benefit them, such as those that reduce the risk of predation and favor their mobility in suburban environments.

Chemistry, Biological Activities and In Silico Bioprospection of Sterols and Triterpenes from Mexican Columnar Cactaceae

The Cactaceae family is an important source of triterpenes and sterols. The wide uses of those plants include food, gathering, medicinal, and live fences. Several studies have led to the isolation and characterization of many bioactive compounds. This review is focused on the chemistry and biological properties of sterols and triterpenes isolated mainly from some species with columnar and arborescent growth forms of Mexican Cactaceae. Regarding the biological properties of those compounds, apart from a few cases, their molecular mechanisms displayed are not still fully understand. To contribute to the above, computational chemistry tools have given a boost to traditional methods used in natural products research, allowing a more comprehensive exploration of chemistry and biological activities of isolated compounds and extracts. From this information an in silico bioprospection was carried out. The results suggest that sterols and triterpenoids present in Cactaceae have interesting substitution patterns that allow them to interact with some bio targets related to inflammation, metabolic diseases, and neurodegenerative processes. Thus, they should be considered as attractive leads for the development of drugs for the management of chronic degenerative diseases.

The genus Agave in agroforestry systems of Mexico

<p><strong>Background:</strong> The genus <em>Agave</em> L. is recognized for its wide distribution in Mexican ecosystems. Species have been described as multipurpose as part of agroforestry systems (AFS). There has not been a systematized, detailed analysis about its richness in AFS nor their ecological, economic and cultural relevance.</p><p><strong>Questions</strong>: What is the <em>Agave</em> richness in Mexican AFS? What is their ecological, agronomical, economic and cultural relevance? What are the risks and perspectives for strengthening their role in AFS?</p><p><strong>Species studied</strong>: 31 <em>Agave</em> species in Mexican AFS.</p><p><strong>Study site and dates</strong>: AFS throughout Mexican territory. January to august 2018.</p><p><strong>Methods</strong>: Systematization of published information, scientific reports, repositories, and our fieldwork, was performed. The data base “The genus <em>Agave</em> in AFS of Mexico” was created, containing information about <em>Agave</em> richness in AFS, ecological, economic and cultural relevance, as well as the current and future perspectives of the AFS they are included in.</p><p><strong>Results</strong>: We recorded 31 species with 22 uses that were part of AFS practices (hedgerows, boundaries and live fences), in homegardens, terraces and agroforests in temperate, semiarid and sub-humid regions, managed by 12 cultural groups. The main benefits of agaves are soil retention, infiltration of water and satisfaction of socio-economic and cultural needs. The decrease of multipurpose species and functions was observed in relation with the commercialization of mezcal.</p><strong>Conclusions</strong>: There has been ample recognition of AFS as settings for conservation and use of <em>Agave,</em> as well as the importance of the knowledge and management practices associated to agave species in AFS.

Cercas vivas en sistemas de producción tropicales: una revisión mundial de los usos y percepciones

Live fences in tropical production systems: a global review of uses and perceptions. The expansion of agricultural and livestock production has been a key factor in deforestation in the world and especially in the tropical region. Currently, more than half of the Earth’s surface is used for the establishment of production systems; in this context, live fences can generate positive effects on the environment and provide environmental goods and services. In this work, we reviewed the effects of live fences on production systems from the tropical regions of America, Africa, Asia and Australia, analyzing the uses and perceptions of farmers that have made use of these fences. It was found that live fences were mainly related to the delimitation of farms and pastures. However, their uses and benefits are manifold, among which we found: provide forage, wood extraction, fruit supply, windbreaks, medicinal, to avoid soil erosion, moisture retention and nutritional support. In addition, other positive perceptions were: increasing landscape connectivity, increasing economic incomes, reducing production costs, reducing pressure on remaining vegetation, keeping maintenance costs down, contributing to pest control, and improving fertility. However, negative perceptions included the excessive work in repairing or pruning them, shade negative impact on agricultural production, lack of information discourages establishment, high establishment costs, generation of property conflicts and management difficulty. It was found that the uses by farmers are focused on improving the yields of productive systems, but also on the conservation of natural resources especially soil and biodiversity. We proposed research topics for the future, as determining the criteria in the selection of native species to establish and enrich living fences valuing ecological and socioeconomic aspects; in additionally, we must deepen the benefits they produce on the yields of productive systems. We suggest the development of live fences studies in the tropical region of Australasia, because no data was found for this region, in order to know the biodiversity and services status that they provide to the rural communities. As a conclusion, it will be important to generate initiatives that encourage the formulation of rural policies, the creation of programs that encourage the establishment of live fences, whether through payments for environmental services, tax compensation or other mechanisms. Providing adequate information to farmers and livestock farmers is a key aspect on dynamizing the establishment of live fences. Rev. Biol. Trop. 66(2): 739-753. Epub 2018 June 01.