The coffee leaf rust disease (CLR), caused by the fungus Hemileia vastatrix, is an economically significant phytopathogen of cultivated Coffea species. Since coffee plants with CLR drop their infected leaves, rain splash from infected leaf litter could be one way H. vastatrix spores are dispersed, but this mechanism has not been demonstrated. Here we experimentally verify that splash from leaf litter can lead to H. vastatrix dispersal and infection. In a semi-controlled experiment, we compared the infection rates of pairs of potted uninfected, susceptible C. arabica plants with leaf litter that was either infected with CLR (experimental treatment) or without CLR (control). Plants with CLR litter became infected sooner than control plants by a median difference of 2.5 weeks. On average, CLR litter treatment plants had 18% of their leaves infected, while control plants had 9% of leaves infected, though later patterns could reflect leaf turnover and reinfection. Future research should investigate the dynamics of leaf litter splash for CLR in the field. Possible management measures to limit the effect of splash from leaf litter could include planting cover crops or restoring natural groundcover, techniques known to provide additional benefits as understood in general practices of agroecology.

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As the extent of oil palm (Elaeis guineensis) cultivation has expanded at the expense of tropical rainforests, enriching conventional large-scale oil palm plantations with native trees has been proposed as a strategy for restoring biodiversity and ecosystem function. However, how tree enrichment affects insect-mediated ecosystem functions is unknown. We investigated impacts on insect herbivory and pollination in the fourth year of a plantation-scale, long-term oil palm biodiversity enrichment experiment in Jambi, Sumatra, Indonesia. Within 48 plots systematically varying in size (25-1600 m 2 ) and planted tree species richness (one to six species), we collected response data on vegetation structure, understory insect abundances, and pollinator and herbivore activity on chili plants (Capsicum annuum), which served as indicators of insect-mediated ecosystem functions. We examined the independent effects of plot size, tree species richness, and tree identity on these response variables, using the linear model for random partitions design. The experimental treatments were most associated with vegetation structure: tree identity mattered, as the species Peronema canescens strongly decreased (by approximately one standard deviation) both canopy openness and understory vegetation cover; whereas tree richness only decreased understory flower density. Further, the smallest plots had the lowest understory flower density and richness, presumably because of lower light availability and colonization rates, respectively.Enrichment influenced herbivorous insects and natural enemies in the understory to a lesser extent: both groups had higher abundances in plots with two enrichment species planted, possibly because higher associated tree mortality created more habitat, while herbivores decreased with increasing tree species richness, in line with the resource concentration hypothesis. Linking relationships in structural equation models showed that the negative association

Context There is great interest in land management practices for pollinators; however, a quantitative comparison of landscape and local effects on bee communities is necessary to determine if adding small habitat patches can increase bee abundance or species richness. The value of increasing floral abundance at a site is undoubtedly influenced by the phenology and magnitude of floral resources in the landscape, but due to the complexity of measuring landscape-scale resources, these factors have been understudied. Objectives To address this knowledge gap, we quantified the relative importance of local versus landscape scale resources for bee communities, identified the most important metrics of local and landscape quality, and evaluated how these relationships vary with season. Methods We studied season-specific relationships between local and landscape quality and wild-bee communities at 33 sites in the Finger Lakes region of New York, USA. We paired site surveys of wild bees, plants, and soil characteristics with a multi-dimensional assessment of landscape composition, configuration, insecticide toxic load, and a spatio-temporal evaluation of floral resources at local and landscape scales. Results We found that the most relevant spatial scale varied by season. Spring bees depended on landscape resources, but summer bees responded more to local quality, implying that site-level management is most likely to be successful in supporting summer bees. Semi-natural habitats, including forests, wetlands, and other aquatic habitats, were particularly important for spring bees. Conclusions By considering spatial and temporal variation in resources, we developed season-specific recommendations to improve habitat quality for wild bees and offset manifold stressors threatening these essential pollinators.