Shade Grown Coffee Keeps Coffee Berry Borer at Bay
By Gregory Gough
Birds, ants…and now beetles. Add one more taxon to the list of animals that are more biodiverse in shaded coffee farms as opposed to sun coffee farms. Scientists found 293 species of beetles in a study of coffee farms in Chiapas, Mexico.
Beetles, as a whole, are more common in sun coffee farms, but there are fewer species. Unfortunately for the coffee farmer, one of the more abundant beetles in a sun coffee farm is the coffee berry borer, a pest.
Shade coffee farms offer a sanctuary for a variety of tropical organisms and are important in maintaining biodiversity.
This article summarizes the information in this publication:
Gordon, Caleb E., McGill, Brian, Ibarra-Nunez, Guillermo, Greenberg, Russell S. and Perfecto, Ivette 2009. Simplification of a coffee foliage-dwelling beetle community under low-shade management. Basic and Applied Ecology, 10: 246-254.
Coffee agroforests may be structurally and floristically complex and may contain a significant fraction of species from biodiverse and threatened tropical montane forest biotas; hence, understanding the dynamics of tropical forest biodiversity in coffee agroecosystems has emerged as a centrally important area of tropical conservation biology research. We conducted a morphospecies analysis on foliage-dwelling beetles collected from coffee plants on four coffee farms in southern Chiapas, Mexico, to characterize variation in the abundance, species richness, and species composition of this mega-diverse taxon in relation to coffee cultivation system, spatio-temporal variation, and predator removal. We constructed thirty-two cages to exclude birds and bats on four farms, each enclosing 7–10 coffee plants and paired with an adjacent uncaged control plot, and then collected beetles from coffee foliage with D-Vac aspirators in each plot once every 3 months for one year. We classified the 2662 beetles collected into 293 morphospecies, representing 42 families of beetles. Extrapolation and interpolation analyses revealed a very high level of species richness, with no plateau and only a slight leveling trend observed in our species accumulation curves. We found that low-shade systems contain equal or higher beetle abundance, lower species richness, more highly homogenized species composition, and higher abundance of coffee berry borer pests on coffee foliage than do high-shade systems. We observed no effect of flying vertebrate exclusion on the coffee foliage beetle assemblage, but did find significant variation in abundance, species richness, and species composition of coffee foliage beetles across seasons and study sites. The increased beetle biodiversity of high-shade coffee cultivation systems has important implications both for the preservation of native biodiversity in coffee growing regions and for the control of agricultural pests such as the coffee berry borer.
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