The Community Ecology of Herbivore Regulation in an Agroecosystem: Lessons from Complex Systems

AbstractWhether an ecological community is controlled from above or below remains a popular framework that continues generating interesting research questions and takes on especially important meaning in agroecosystems. We describe the regulation from above of three coffee herbivores, a leaf herbivore (the green coffee scale, Coccus viridis), a seed predator (the coffee berry borer, Hypothenemus hampei), and a plant pathogen (the coffee rust disease, caused by Hemelia vastatrix) by various natural enemies, emphasizing the remarkable complexity involved. We emphasize the intersection of this classical question of ecology with the burgeoning field of complex systems, including references to chaos, critical transitions, hysteresis, basin or boundary collision, and spatial self-organization, all aimed at the applied question of pest control in the coffee agroecosystem

Non-additive effects of multiple predators alter the biological control of the coffee leaf miner (Leucoptera coffeella)

Although most prey are attacked by multiple predators, much of the ecological theory on prey suppression focuses on the effects of a single predator. The presence of multiple predators can lead to complex interactions such as trait-mediated interactions (TMIIs) and intraguild predation which can influence the suppression of pest populations. Here we explore the effect of two predators, a native anole lizard species Anolis cristatellus (Squamata: Dactyloidae) and a non-native ant species Wasmannia auropunctata (Hymenoptera: Formicidae), on the coffee leaf miner, Leucoptera coffeella (Lepidoptera: Lyonetiidae) (CLM). In a laboratory experiment we examined the effects of these two predators in isolation and when co-occurring. Our results show that when each predator is alone, they are able to consume the CLM in a comparable way. However, when they are together, their effect is not greater than when alone. This indicates that there is a negative effect when both predators co-occur. The results from this experiment have practical implications since both predators are present in coffee agroecosystems in Puerto Rico, where the CLM is considered the main insect pest. Furthermore, these results demonstrate the potential dynamics among several predators in agroecosystems and the potential implications for herbivore regulation

High intermediary mutualist density provides consistent biological control in a tripartite mutualism

Understanding the ecology of mutualisms becomes a particularly important task when considering agroecosystems, as many ecosystem services are associated with mutualistic interactions. Here we report on experiments associated with an indirect pest control mutualism between the arboreal nesting ant Azteca sericeasur and coffee. This system is particularly interesting because the indirect Azteca-Coffea mutualism emerges from an Azteca-scale insect mutualism that takes place on the coffee plant. We describe this interaction structure as a mutualism-dependent mutualism and ask whether the density of intermediary mutualist (scale insects, Coccus) that benefits Azteca also influences the benefits provided to coffee plants. We found that indeed Azteca’s benefit to Coffea is consistent when Coccus density is high. Furthermore, we also found that at low Coccus density Azteca only benefits Coffea in the beginning of the rainy season, and this effect is likely due to the fact that Coccus produces less sugars with higher precipitation. We suggest a framework for thinking about context-dependency in agroecosystem mutualisms that may provide a more mechanistic way to tease apart the prevalent context-dependent results in ecological literature. Finally, we address some past recommendations as it pertains to the management of the Azteca-Coffea-Coccus complex in coffee agroecosystems

Mexico's Ants: Who are They and Where do They Live?

International audienc

Mexico ants: incidence and abundance along the Nearctic–Neotropical interface

International audienceto explore different aspects of the population and community research of ants at different spatial scales, and to aid in the establishment of conservation policies and actions. There are no copyright restrictions. Please cite this data paper when using its data for publications or teaching events