Some like it hot: the influence and implications of climate change on coffee berry borer (Hypothenemus hampei) and coffee production in East Africa

Abstract

The negative effects of climate change are already evident for many of the 25 million coffee farmers across the tropics and the 90 billion dollar (US) coffee industry. The coffee berry borer (Hypothenemus hampei), the most important pest of coffee worldwide, has already benefited from the temperature rise in East Africa: increased damage to coffee crops and expansion in its distribution range have been reported. In order to anticipate threats and prioritize management actions for H. hampei we present here, maps on future distributions of H. hampei in coffee producing areas of East Africa. Using the CLIMEX model we relate present-day insect distributions to current climate and then project the fitted climatic envelopes under future scenarios A2A and B2B (for HADCM3 model). In both scenarios, the situation with H. hampei is forecasted to worsen in the current Coffea arabica producing areas of Ethiopia, the Ugandan part of the Lake Victoria and Mt. Elgon regions, Mt. Kenya and the Kenyan side of Mt. Elgon, and most of Rwanda and Burundi. The calculated hypothetical number of generations per year of H. hampei is predicted to increase in all C. arabica-producing areas from five to ten. These outcomes will have serious implications for C. arabica production and livelihoods in East Africa. We suggest that the best way to adapt to a rise of temperatures in coffee plantations could be via the introduction of shade trees in sun grown plantations. The aims of this study are to fill knowledge gaps existing in the coffee industry, and to draft an outline for the development of an adaptation strategy package for climate change on coffee production. An abstract in Spanish is provided as Abstract S1.

Figure 1. Distribution of the coffee berry borer (Hypothenemus hampei) in Eastern Africa under current climate, the map was constructed using the ecoclimatic indices (EI) obtained from CLIMEX parameters in Table 1 .

The EI values (0–100), indicates unsuitability of the location's climate (0), and a ‘perfect’ climate for the given species (100).

Figure 2. Climate suitability (EI) for the coffee berry borer (Hypothenemus hampei) in Eastern Africa under the climate conditions according to the HadCM3-SRES A2 scenario in 2050.

The EI values (0–100), indicates unsuitability of the location's climate (0), and a ‘perfect’ climate for the given species (100).

Figure 3. Distribution of the coffee berry borer (Hypothenemus hampei) illustrating species range shifts in Eastern Africa under climate change scenario A2A*.

* The map was developed from the difference between the values EI for the predicted future Hypothenemus hampei distribution obtained when applying scenario A2A criteria (Figure 3) and the distribution under current climate in Eastern Africa (Figure 1).

Figure 4. Climate suitability (EI) for the coffee berry borer (Hypothenemus hampei) in Eastern Africa under the climate conditions according to the HadCM3-SRES B2 scenario in 2050.

The EI values (0–100), indicates unsuitability of the location's climate (0), and a ‘perfect’ climate for the given species (100).

Figure 5. Distribution of the coffee berry borer (Hypothenemus hampei) illustrating species range shifts Eastern Africa under climate change scenario B2A*.

* The map was developed from the difference between the values EI for the predicted future Hypothenemus hampei distribution obtained when applying scenario B2A criteria (Figure 4) and the distribution under current climate in Eastern Africa (Figure 1).

Figure 6. Spatial patterns in the number of coffee berry borer (Hypothenemus hampei) generations per year in Eastern Africa under current climate.

Figure 7. Spatial patterns in the number of coffee berry borer (Hypothenemus hampei) generations per year in Eastern Africa under the climate conditions according to the HadCM3-SRES A2 scenario in 2050.

Figure 8. Spatial patterns in the number of coffee berry borer (Hypothenemus hampei) generations per year in Eastern Africa under the climate conditions according to the HadCM3-SRES B2 scenario in 2050.

Figure 9. Number of coffee berry borer (Hypothenemus hampei) generations per year along an altitudinal transect around Lake Victoria (Tanzania, Uganda and Kenya) under current climate and according to the HadCM3-SRES A2 and B2 scenarios in 2050.