Climate and the risk of pests and disease Primary research activities in this area:

1. Climate and the risk of pests and disease • Primary research activities in this area: • Participatory evaluations of risk for potato tuber moth and Andean potato weevil in relation to climate parameters in the Altiplano • Evaluation of climate and the utility of crop diversification for disease management • Integrated predictions of future risk for potato tuber moth and potato late blight based on climate change predictions

2. Climate and the risk of pests and disease • Primary research activities in this area: • Participatory evaluations of risk for potato tuber moth and Andean potato weevil in relation to climate parameters in the Altiplano • Evaluation of climate and the utility of crop diversification for disease management • Integrated predictions of future risk for potato tuber moth and potato late blight based on climate change predictions

3. From the LTRA-4 participatory community assessment: Farmers in our study area of the Bolivian altiplano perceive pest problems to be increasing, along with increasing resistance to pesticides They identified potato tuber moth and Andean potato weevil as priority constraints to production

4. Objectives: Estimate Andean potato weevil and potato tuber moth risk in three communities in each of Umala and Ancoraimes, Bolivia (expanding to Puno, Peru) Link pest risk with climate and socioeconomic factors

5. Methods: Measure pest populations in a study field in each of three communities in each of two regions across three years Use a ‘windows’ approach to evaluate time intervals that impact pest population growth in the field Evaluate the relationship between risk and climate variables across years using the site-year combinations as replicates

6. Pitfall traps used for sampling Andean potato weevil

7. Pheromone traps used for sampling potato tuber moth

8. Example data set from one community: Andean potato weevil 2006-2007 in the community Jatuquira: Number of adults of two species with maximum temperature and minimum temperature

9. Andean potato weevil 2006-2007 in three communities in Umala: The average number of adults retrieved from traps

10. Climate and pest populations As we gather more site-year observations and compare summary statistics, we are populating this figure for different combinations of climate statistics Associated socioeconomic and management data will provide context Each point indicates the result from one community in one season Population for one season Climate summary statistic for one season

11. Climate and the risk of pests and disease • Primary research activities in this area: • Participatory evaluations of risk for potato tuber moth and Andean potato weevil in relation to climate parameters in the Altiplano • Evaluation of climate and the utility of crop diversification for disease management • Integrated predictions of future risk for potato tuber moth and potato late blight based on climate change predictions

12. How does season length influence disease risk? Analysis in collaboration with the International Potato Center Garrett et al., in revision for Ecological Applications

13. Use of potato cultivar mixtures can reduce the risk of potato late blight Time Garrett and Mundt 2000

14. What is the effect of season length on the utility of potato mixtures to manage disease? RMR <1 indicates a benefit from mixtures Increasing season length Garrett et al., in revision

15. Climate and the risk of pests and disease • Primary research activities in this area: • Participatory evaluations of risk for potato tuber moth and Andean potato weevil in relation to climate parameters in the Altiplano • Evaluation of climate and the utility of crop diversification for disease management • Integrated predictions of future risk for potato tuber moth and potato late blight based on climate change predictions

16. We are using GIS to map risk predicted from disease and pest risk forecasting models Estimates of potato late blight risk in the altiplano 1995-1998: No disease predicted 2001-2004: …

18. Estimates of disease and pest risk in the altiplano We are developing risk maps for late blight under climate change scenarios based on existing models of the relationship between climate variables and epidemiology There are also models of weather effects on potato tuber moth that we will draw on for modeling that system

19. Sporleder et al. 2004 Potato tuber moth response to temperature in controlled environment experiments: Development rates for larvae and pupae

20. Developing a conceptual framework for the impacts of global change on cropping system constraints... to guide strategies... An early version of assessment of biological relationships follows – this might function as one component of a more complete model – even limited to biology, there are interactions across all scales

21. Garrett et al. 2006

22. Garrett et al. 2006

23. Evaluation of thresholds, interactions, and positive feedback loops A small change in temperature or precipitation does not necessarily imply a small change in disease risk Examples from epidemics follow Also need to consider interactions between changes in disease and pest risk and human capabilities for management Garrett 2008

24. The local inoculum load builds during the period of conducive weather Because plant disease pressure often increases following a compound interest model, increasing the length of the growing season slightly can have a very large impact on inoculum load Percentage inoculum saturation

25. An Allee effect may produce thresholds for pathogen reproduction (Allee effect = lower per capita reproduction in small populations) Allee thresholds may produce larger impacts from climate shifts than would be anticipated with partial knowledge Per capita reproduction Pathogen population size Garrett and Bowden 2002

26. Feedback loops for disease management • Management based on controlling local inoculum production becomes less useful as regional inoculum loads rise • Field sanitation • Intercropping and mixtures • Resistance based on lower inoculum production Utility of local management Regional inoculum load

27. Responding to climate change We are developing an integrated framework for evaluating responses to climate change for any given disease or pest Characterization of resources and needs in areas such as the following, at all relevant scales: -Plant genetic resources for resistance and issues for their deployment -Producer knowledge and resources, and training systems -Historic and predicted population characteristics for pathogens, vectors, and biocontrol agents -Historic and predicted climate characteristics -The nature of interactions between these areas Then: Validating the conceptual model