Testing ant predation on the coffee berry borer in shaded and sun coffee plantations in Colombia

Soil‐dwelling ants, many of which are generalist predators, are more diverse in shaded than in sun coffee plantations without trees. We compared ant predation on the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) in three shaded and three sun coffee plantations in Apía, Colombia, in both the wet and the dry seasons. We found that H. hampei adults exposed to ants for 5 days suffered higher removal in shaded plantations and in the wet season. In the laboratory, we observed that ants killed 74–99% of H. hampei adults over the course of 5 days. Ants appear to be important predators of H. hampei, particularly in shaded coffee plantations and in the wet season.     

Assessment of indicator species of butterfly assemblages in coffee–banana farming system in central Uganda

Butterflies are believed to be important pollinators because they are nectar/pollen feeders of both wild and cultivated plant species occurring in natural and managed systems. However, there exist very little knowledge about their spatio‐temporal distribution and diversity in agricultural systems of Sub‐Sahara Africa and in Uganda. There are no protocols to monitor the status of good pollinator species in these systems. The main aim of this study was to collect baseline information about indicator species of butterfly community in coffee–banana farming systems of central Uganda. Data were collected for 1 year (2006) using banana fruit‐bait traps, transect walk‐and‐counts and hand‐nets sampling methods. Indicator species of farmland habitats were identified using indicator value method. Species that emerged as significant (P < 0.05) suitable indicators were Catopsilia florella, Junonia sophia, Bicyclus safitza, Acraea acerata, Eurema hecabe, Ypthima albida, Zizula hylax, Acraea ventura, Eurema brigitta, Neptidopsis ophione, Junonia eonone, Zizeeria kynsna, Cupidopsis cissus, Junonia chorimene and Acrae uvui. These ubiquitous species were recommended to monitoring programmes as indicator species of butterfly communities delivering pollination services to cultivated and wild plants in farmland environments of central Uganda. Transect count was proposed as the best sampling technique to monitor butterfly species that may be involved in successful pollination activities in farmlands. There is a need to develop strategies to protect linear and nonlinear natural and semi‐natural habitats to offer sufficient refugia and breeding sites to butterflies inhabiting farmlands.     

Conservation of Vascular Epiphyte Diversity in Shade Cacao Plantations in the Chocó Region of Ecuador

To assess the contributions of rustic shade cacao plantations to vascular epiphyte conservation, we compared epiphyte species richness, abundance, composition, and vertical distributions on shade trees and in the understories of six plantations and adjacent natural forests. On three phorophytes and three 10 × 10 m understory plots in each of the agroforestry plantations and natural forests, 54 and 77 species were observed, respectively. Individual-based rarefaction curves revealed that epiphyte species richness was significantly higher on forest phorophytes than on cacao farm shade trees; detailed analyses showed that the differences were confined to the inner and outer crown zones of the phorophytes. No differences in epiphyte species richness were found in understories. Araceae, Piperaceae, and Pteridophyta were less species-rich in plantations than in forests, while there were no differences in Orchidaceae and Bromeliaceae. Regression analysis revealed that epiphyte species richness on trunks varied with canopy cover, while abundance was more closely related to soil pH, canopy cover, and phorophyte height. For crown epiphytes, phorophyte diameter at breast height (dbh) explained much of the variation in species richness and abundance. There were also pronounced downward shifts in the vertical distributions of epiphyte species in agroforests relative to natural forests. The results confirm that epiphyte diversity, composition, and vertical distributions are useful indicators of human disturbance and showed that while the studied plantations serve to preserve portions of epiphyte diversity in the landscape, their presence does not fully compensate for the loss of forests.     

Influence of functional traits on foraging behaviour and pollination efficiency of wild social and solitary bees visiting coffee (Coffea canephora) flowers in Uganda

An on-farm pollination experiment was conducted during the June–August and November–February blooming seasons of 2007 to 2008, in 30 small-scale coffee fields characterised by different habitat and vegetation types. The study was conducted in order to determine the best pollinator groups for coffee in Uganda and to collect relevant field information and determine the pollination efficiency of different bee species. Results indicate that across blooming seasons, coffee flowers were visited by 24–36 bee species. Hypotrigona gribodoi was the most frequent flower visitor, comprising over 60% of 5941 bee-visits recorded. Foraging rate and pollination speed varied among bee species. Solitary bees foraged on more flowers than social bees, but they spent less time per flower visited. Solitary bees visited more coffee trees and fields, but deposited less pollen, whereas social bees visited less trees and coffee fields in the landscape, but deposited more pollen on flowers. Fruit set was of 87%, 64% and 0.9%, respectively, in hand-cross pollination, open pollination and controlled-pollination treatments. Fruit abortion due to self-pollination was insignificant in this study. There was variability in pollination efficiency of different bee species. Pollination efficiency varied more significantly with sociality than with other bee functional traits and was not significantly influenced by tongue length and bee body size. Single-flower visits by social and solitary bees resulted in 89.7% and 68.14% fruit set, respectively. The most efficient bee species was Meliponula ferruginea (98.3%) followed by Meliponula nebulata (97.1%). Thus, very good pollinator species were wild social bees (mainly stingless bees) as opposed to honeybees and solitary bees that were previously reported to be the best pollinators of coffee in Panama and Indonesia. Morphological and anatomical characteristics of the bee pollen storage features may explain the difference in foraging behaviour activities and in pollination efficiency of social and solitary afrotropical bee species visiting lowland coffee in Uganda. In addition, pollination efficiency was influenced by land-use intensity, field management systems and habitat types found in the immediate surroundings of coffee fields, but not by coffee field size, coffee genotypes and mass blooming wild vegetation. It is recommended to farmers to adopt pollinator-friendly conservation and farming practices such as keeping an uncultivated portion (25%–30%) of their farms as pollinator reservoirs, protecting semi-natural habitats found in the vicinity of coffee fields, as well as promoting high on-farm tree cover to benefit a functionally diverse pollinator community.