The Silent Threat: How Climate Change Fuels Pest Invasions in Agriculture

Food goes a long journey before it reaches our plate. An immense supply chain is involved throughout the whole process. But the base is always agriculture! Agriculture is vital as it supports livelihoods, provides raw materials for food and other products and it is a strong component in the global economy. If agriculture is adversely affected, undoubtedly all these vital sectors will be threatened. Climate change, the trendiest topic ever, is a significant factor that impacts agriculture.

The United Nations states that climate change is long-term shifts in temperatures and weather patterns. Such shifts can be natural, due to changes in the sun’s activity or large volcanic eruptions (Climate change is an entirely natural phenomenon. But now it has been a pressing issue as climate change has accelerated to unprecedented levels due to anthropogenic activities. The last decade was the hottest decade of the entire human history. The global average temperature has increased by approximately 0.2°C per decade since the late 1970s.

Climate change and agriculture are inextricably linked. You might have heard how climate change is adversely affecting agriculture through extreme weather events like floods and droughts. A recent incident, the massive crop destruction in China, one of the biggest food producing countries in the world as a result of unprecedented flash floods in summer, 2023 is a perfect example.

The effect of droughts, floods and heat waves occurred due to climate change on agriculture is quite obvious. But climate change has its silent threats. What if I say the codling moth infestation in the apple tree in your orchard could be a result of climate change? Yes, there is a possibility! Recently, certain incidents were recorded worldwide associated with massive pest -related crop destruction. Climate scientists predict that these incidents have clear linkage with change of weather patterns occurred due to climate change.

In Summer, 2020 the sky of south Africa was covered with hundreds and thousands of dessert locusts. The swarms of locusts flew across farmlands and vegetation in Kenya, Somalia and Ethiopia eating everything and leaving nothing. Each generation of the Locust swarms grew larger in size, destroying hectares of farmlands and severely affecting the economy of African regions. The majority of the communities lost their earnings from their major livelihood which is agriculture (According to the statistics in 2021, 42.5 % of total employment in Africa belongs to agricultural sector) and the children were left hungry.

Dessert locusts are quite interesting creatures. Let us peep into the life cycle of dessert locusts. They are scientifically known as Schistocerca gregaria. These insects form huge swarms under heavy rains. Often these swarms are incredibly large. Each swarm can contain around 80 million locusts and can spread up to several hundred square kilometers! Even if they do not attack animals, they are considered dangerous migratory pests because of the immense destruction they are doing to the vegetation.

Wait. But what does this have to do with climate change? Yes, there is a direct distinct correlation between climate change and the massive spread of desert locusts. The extreme weather events generated by climate change including flooding, cyclones and heavy rainfall generate ideal breeding conditions for the locusts. Two cyclones emerged in 2018 and 2019 caused a rapid rise in locust populations. Entomologists have identified that the soil moistened by heavy rains is perfect for the desert locusts to lay eggs.
Not only that, but the warmer temperatures accelerate the development of locusts through increasing the number of life cycles per year. That means the warmer the temperature, the higher the number of generations per year. Moreover, the previously too cold areas for locusts to lay eggs now have converted into regions with warmer climate thanks to global warming further enhancing the spread of desert locusts. Not only in African regions but also in Asian regions are under the threat of desert locusts.
Let me bring another pest invasion accelerated by climate change that had a severe impact on agriculture. Fall armyworm or scientifically known as Spodoptera frugiperda and were initially recognized around 2015 in African region. The armyworm has a wide range of hosts including maize, rice, sugarcane and numerous vegetable crops. Armyworm larvae feed on the leaves and the stem causing significant damage to plants. They have the ability to defoliate a crop field within a few days. Maize is recognized as the most vulnerable crop plant to the fall Amyworm attack. Since Maize is a staple food for many countries in the world including sub- Saharan regions the threat to food security by fall armyworms is remarkable.

The effect of climate change on the spread of fall armyworm is quite similar to the scenario of dessert locusts. Increased rainfall will create favorable conditions for the development of the larvae providing adequate food. Moreover, when drought conditions occur the plants will be weakened and will be more prone to the fall armyworm attack. The frequent occurrence of cyclones and storms has enhanced the rapid geographical distribution of the pest.

We cannot risk our food security and economies for the sake of climate change. Therefore, mitigating and adapting to climate change is essential to ensure the sustainability of agriculture and global food security. We can not stop climate change ad hoc. Yet we can take several steps towards a sustainable journey to combat climate emergencies.

Implementing climate-resilient agricultural practices, like developing drought-resistant crop varieties, adopting efficient water management systems, and utilizing integrated pest management strategies, can help mitigate the adverse effects. Furthermore, investing in early warning systems and climate-smart technologies can enhance the ability to take proactive actions to respond to extreme weather.

You might not be able to do all those big things. Probably, you do not need to do them because you are not a farmer! But what if you can reduce your carbon footprint through a small change to your daily lifestyle Then you will be giving your contribution to tackling climate change. One day, your modest contribution will definitely help to lower the pest invasions in agriculture. Think about it. You will be taking a step forward to eliminate world hunger.

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