Climate change weakens pest control strategies

Justus Monari, a farm manager at Kisii Agricultural Training Centre, sprays vegetables against pests. [Sammy Omingo,Standard]

To control the aggressive pests and diseases that have emerged in the wake of climate change and global warming, there is a need to relook at the current pest and management strategies. In a past presentation, International Crops Research Institute for the Semi-Arid Tropics (Icrisat) Principal Scientist, Entomology HC Sharma said the major fallouts of climate change, namely increased temperatures and ultraviolet radiation, and low relative humidity may render many established pest control strategies less effective.

According to International Maize and Wheat Improvement Centre climate change is driving the spread of pests and diseases across continents. The centre points out that climate change can affect the population size, survival rate and geographical distribution of pests; and the intensity, development and geographical distribution of diseases. 

As climate change hits harder, pests are also changing their behaviour patterns to cope. Icrisat adds that owing to climate change, insect pests presently confined to tropical and subtropical regions will move to temperate regions along with a shift in the areas of production of their host plants; while distribution and relative abundance of some insect species vulnerable to high temperatures in the temperate regions may decrease as a result of global warming.

To compound the problem, Science Direct, a science journal, observes that in the wake of climate change and global warming pest outbreaks will occur more frequently, particularly during extended periods of drought, followed by heavy rainfall.

With that background, Science Direct points out that some of the components of pest management such as host-plant resistance, biopesticides, natural enemies, and synthetic chemicals will be rendered less effective as a result of these drastic changes in pest behaviour patterns.

New ecological zones

Consequently, to win the war on crop pests and diseases there is therefore an urgent need to assess the efficacy of various Integrated Pest Management technologies. Pest control is a big deal because up to 40 per cent of food crops are lost to plant pests and diseases each year according to the Food and Agriculture Organisation.

- Hellen Miseda is an editor at the Standard Group and a journalist passionate about environmental conservation


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