Expected impacts of climate change on insect pests
Societies in Africa are highly dependent on agriculture, an activity traditionally vulnerable to unpredictable changes in climatic conditions. Any increase in temperature caused by climate change, coupled with a decline in rainfall, will have direct and indirect drastic effects on crop production and food security. This will exacerbate existing vulnerabilities of resource-constrained farmers who depend on agriculture for a living. On average, 30–50% of the yield losses in agricultural crops are caused by pests, despite the application of pesticides to control them. Climate, especially temperature, has a strong and direct influence on the development and growth of insect pest populations. A rise in temperature due to climate change may both increase or decrease pest development rates and related crop losses. Hence, an increase in temperature can potentially affect range expansion and outbreaks of many insect pests. Therefore, if adequate integrated pest management (IPM) strategies are not developed and made available to farmers, greater losses in crop yield and quality could ultimately result.
The framework under which the ‘Atlas’ was developed
The International Potato Center (CIP), based in Lima, Peru, seeks to reduce poverty and achieve food security on a sustained basis in developing countries through scientific research and related activities on potato (Solanum tuberosum L.), sweetpotato (Ipomoea batatas L. Poir.), and other root and tuber crops, and on the improved management of natural resources (www.cipotato.org). In its global pest management research efforts, CIP’s Agroecology/IPM program developed a scientific framework based on advanced pest phenology models and Geographic Information System risk mapping for better understanding of future pest risks on global, regional, and local scales and to use this information for adaptation planning.
The collaborative project “Predicting climate change-induced vulnerability of African agricultural systems to major insect pests through advanced insect phenology modeling and decision aid development for adaptation planning” was led by CIP and implemented in collaboration with the International Centre of Insect Physiology and Ecology (icipe) and the International Institute for Tropical Agriculture (IITA). In the project, pest risk assessments under potential future climates were conducted for a number of important insect pests of agricultural and horticultural crops in Africa (i.e., potato, sweetpotato, vegetables, maize, cassava, and fruit). Results of these assessments are presented in the Pest Distribution and Risk Atlas for Africa (Pest Risk Atlas for Africa, for short).
The structure of the ’Atlas’
The Pest Risk Atlas for Africa introduces the applied pest risk assessment framework and provides detailed information for pest risk analysis, applying the following structure in the discussion of each of the pests presented in chapter 4 and its individual sections (i.e., 4.1–4.4):
- Synonyms of pest scientific names, taxonomic position, common names, and host plants
- Detection and identification, morphology, and biology with an emphasis on temperature-dependent development
- Means of movement and dispersal, economic impact, geographical distribution, and phytosanitary risks
- Risk mapping under current and future climates: global risks and regional risks for Africa with individual country risk maps
- Phytosanitary measures and adaptation to risk avoidance at farm level.
For each of the pests, detailed information on the developed phenology models and simulated life-table parameters are given in related annexes.
Natural enemies play an important role in managing pests and are often used in classical biocontrol programs to manage invasive non-indigenous pests. It is important to better understand how climate change will affect this trophic level and how crop management can build and rely on biocontrol strategies. Hence, as part of the project, phenology models have also been developed for important parasitoids associated with pests to better understand their establishment potential and efficacy in different global and regional agro-ecologies. The obtained results are presented in the following structure in chapter 5:
- Synonyms of parasitoids scientific names, taxonomic position, and hosts
- Possible regions of origin and distribution
- Morphology, biology, and economic impact in pest control
- Potential establishment, distribution, and efficacy under current and future climates
- Potential release areas in Africa and risks to non-targets.
The publication of the ‘Atlas’
The Pest Risk Atlas for Africa is currently only made available online and not published as a printed book. This allows us to update information regularly and to add new sections that cover pest risk assessments for other pests or suitability studies for associated natural enemies not yet considered. Hence, the Pest Risk Atlas for Africa can be either directly downloaded as entire document for free or by selecting individual chapters or sections. Further, all information is accessible interactively to allow flexible use, zoom into maps, and quick searches for specific information. A publication as printed book might be considered at another stage of its development and if requested from our stakeholders.
How to make contributions to expand the pest range in the ‘Atlas’
Scientists working on life-table studies intending to develop phenology models and conduct pest risk mapping using ILCYM are encouraged to submit and publish their work in the Pest Risk Atlas for Africa. The information received, including original life-table data and phenology models, will be peer reviewed, after which authors will be invited to prepare a new pest section.
Intended users of the ‘Atlas’
We have designed the Pest Risk Atlas for Africa to benefit researchers and extension workers who are either currently involved in pest risk analysis or planning to start, to better understand future pest range expansions and increase of pest abundance and infestation. Those at international and national agricultural research institutions, national plant protection organizations, agricultural ministries, and universities will find the material presented here to be particularly useful. Ultimately, the information presented here will create better awareness of future pest risks under climate change and promote the inclusion of pest risk adaptation plans at country level. Consequently, it may lead to the adaptation of sustainable control methods that are not overly dependent on pesticides and therefore are best suited for farmers in Africa to improve their food security and daily lives under future climates.
Pest Distribution and Risk Atlas for Africa
Potential global and regional distribution and abundance of agricultural and horticultural pests and associated
biocontrol agents under current and future climates
Kroschel, J., N. Mujica, P. Carhuapoma, and M. Sporleder
International Potato Center (CIP)