Enio B. Cano

THE IMPACT OF AVIAN INSECTIVORY ON ARTHROPODS AND LEAF DAMAGE IN SOME GUATEMALAN COFFEE PLANTATIONS

Experimental work has established that vertebrates can have a large impact on the abundance of arthropods in temperate forest and grasslands, as well as on tropical islands. The importance of vertebrate insectivory has only rarely been evaluated for mainland tropical ecosystems. In this study, we used exclosures to measure the impact of birds on arthropods in Guatemalan coffee plantations. Variation in shade management on coffee farms provides a gradient of similar habitats that vary in the complexity of vegetative structure and floristics. We hypothesized that shaded coffee plantations, which support a higher abundance of insectivorous birds, would experience relatively greater levels of predation than would the sun coffee farms. We found a reduction (64–80%) in the number of large (> 5 mm in length) but not small arthropods in both coffee types which was consistent across most taxonomic groups and ecological guilds. We also found a small but significant increase in the frequency of herbivore damage on leaves in the exclosures. This level of predation suggests that birds may help in reducing herbivore numbers and is also consistent with food limitation for birds in coffee agroecosystems. However, the presence of shade did not have an effect on levels of insectivory.

Dung beetle community (Coleoptera: Scarabaeidae: Scarabaeinae) in a tropical landscape at the Lachua Region, Guatemala

Biological diversity conservation within natural reserves has been prioritized, but conservation efforts outside protected areas (where most human activities take place) have been very little considered. In this scenario, an alternative agricultural practice that may reduce the impacts of fragmentation in outer landscapes is a perforation process, which involves conservation in agricultural fields surrounded by continuous forests. Such practices enhance the positive impact of ecological services on fields. In this study we analyzed the biological diversity state in perforation fields and their surrounding forests. The analysis was done using dung beetles as biological indicators. A nested pattern in dung beetles distribution was found, which ordered the surrounding continuous forest sites as the ones with the highest species richness, followed by the perforation fields, and placed the fragmentation practice fields (continuous agricultural fields surrounding forest patches) with the lowest one. Indicator species for perforation fields and surrounding continuous forests were chosen. In general, perforation practice fields differed in composition, based upon functional groups richness and identity; it also contained a higher species richness than the fragmentation practice. Agricultural practices that enhance biological diversity conservation such as perforation, should be recommended and considered in natural resource management by local communities in order to take advantage of ecological services that otherwise may be gradually lost.

What Can Scarabaeoidea Contribute to the Knowledge of the Biogeography of Guatemala

Abstract Scarabaeoidea is one of the biogeographically best known groups of organisms for Nuclear Central America, especially Guatemala. They have been used to determine areas of endemism for cloud forests of the region and to analyze relationships among these endemic areas. A major north-south division of these areas is described. Lowland scenarios are also given. This information was used for justifying the establishment of biological reserves in the area and is a tool available for prioritization of reserve establishment that could be adapted to other parts of the world as well.

A New Species of Petrejoides from Guatemala and Comments on Petrejoides michoacanae (Coleoptera: Passalidae)

Petrejoides caralae New Species is described from wet lowland forest of eastern Guatemala (450-950 m altitude). The aedeagus of Petrejoides michoacanae Schuster is described.

Phylogenetics of Ogyges Kaup and the biogeography of Nuclear Central America (Coleoptera, Passalidae)

Abstract A phylogenetic morphological analysis of the genus Ogyges Kaup, distributed in Nuclear Central America, from Chiapas, Mexico, to northwestern Nicaragua was undertaken. Five species of Proculejus Kaup, distributed north of the Isthmus of Tehuantepec in Mexico, were selected as outgroup. Ogyges was recovered as monophyletic with three species groups: championi, laevissimus, and crassulus. Each species group shows a distinct, generally allopatric distribution. The O. championi species group, with ten species, is distributed in the Maya block, more specifically in the mountainous system north of the Motozintla-Comaltitlán fault in Chiapas, and north of the dry valleys of the Cuilco and Motagua rivers in Guatemala. The two remaining species groups are distributed in the Chortis block. The O. laevissimus species group, including seven species, ranges mostly along the Pacific Volcanic Chain from Guatemala to El Salvador, and from southeastern Honduras to the northwestern area of Nicaragua. The O. crassulus species group, with ten species, is distributed from northeastern Guatemala (Merendón) to northern Honduras. The Isthmus of Tehuantepec in Mexico, the Motagua-Cuilco and Motozintla-Comaltitlán sutures zones in Chiapas and Guatemala, the lowland valleys of Colón and Comalí rivers between Nicaragua and Honduras (or, perhaps, the northern suture of the Siuna Terrane in Nicaragua), the Guayape fault system in Honduras, and the intricate dry valleys of Ulúa-Chamelecón-Olancho in Honduras, are hypothesized to have acted as barriers that affected the geographical distribution of Ogyges, as well as probably other montane organisms.

A new species of Oileus Kaup (Coleoptera, Passalidae) from Guatemala, with a key to the species of the genus.

Abstract Oileus gasparilomi sp. n. is described from nine specimens from the mountains of Quiché in Guatemala, from cloud forest at 1795 m elevation. This represents the second species of the genus for Guatemala, differing from the closely related Mexican species Oileus rimator (Truqui) in having a straight anterior clypeal border, the postocular sulcus divided by a keel and the pronotum almost straight (not clearly bilobed). A key to the species of Oileus is given.

Biodiversity and biogeographic significance of the Sierra Chinajá in Alta Verapaz, Guatemala: a first look.

A rapid biodiversity assessment was carried out in the Sierra Chinajá, Guatemala in order to support the conservation policies of the national agency for protected areas management. This study represents the first systematic account of the flora and fauna of the area. The floristic composition was surveyed using 21 Whitaker plots and non-systematic sampling of other vegetative strata. Bird communities were assessed using a system of point counts and mist nets. Bats were sampled with mist nets at 400 m and 600 m. For small terrestrial mammals, two transects with 90 traps each were established at low and high elevations. Reptiles and amphibians were collected through non-systematic walks through forest patches. Dung beetles were sampled with pitfall traps. A total of 309 plant species were found, including trees, orchids and bromeliads. The list of animal species includes 20 bats, four rodents, one marsupial, 110 birds, 24 reptiles, 14 amphibians, and 20 dung beetles. The results indicate that the Sierra Chinajá is an ecotone or transition zone from predominantly tropical lowland to a mix of montane environments.