The climate is changing in all corners of the planet on a scale unprecedented in decades, causing changes that will be irreversible for hundreds of thousands of years. An example of these effects is in the spread of increasingly destructive pests. But how does the environmental situation affect the proliferation of insect pests?
The Increased temperature, humidity and greenhouse gases are three circumstances of climate change that favor the growth and proliferation of fungi, insects and pests that affect not only populations, but also crops or agriculture.
In August 2018, a study published by the journal Science warned that andhe increase in plant pests will cause global crop losses of rice, corn and wheat in the next 20 years between 10% and 25% for every degree Celsius that average surface temperatures rise in the world. Currently, pests destroy up to 40% of global crop production each year, according to estimates by the Food and Agriculture Organization of the United Nations (FAO). And the situation is not looking to improve.
According to the latest report of the Intergovernmental Panel on Climate Change, published last August, greenhouse gas emissions from human activities are responsible for a global warming of 1.1º C, since the period 1850-1900 to the present.
And what is worse, the global temperature is expected to reach or exceed 1.5º C or more of warming in the next 20 years. According to this document, with an increase of 1.5 degrees there will be more heat waves, the hot seasons will be longer and the cold ones shorter. With two more degrees, episodes of extreme heat would be even more frequent and critical tolerance levels for health and agriculture would be reached.
More heat, more insect generation
Climate change is not only a matter of temperature, but this is undoubtedly one of the factors that has the most influence on the behavior, geographic distribution, development, survival and reproduction of urban pests. In the case of insects, for example, it could be argued that the influence of temperature greatly exceeds all other environmental factors.
Insects are cold-blooded organisms and cannot regulate their body temperature, which is roughly the same as that of their immediate environment.
“If the temperature increases, the life cycle of many insects is shortened, that is, they develop faster, passing from one state to another in less time, which means that there are more generations of that insect throughout the year,” explains Ignacio Santamarta, director of EZSA, one of the main companies in the country dedicated to insect control.
Warmer summers and milder winters lengthen the seasons of activity, for example, of arthropods such as mosquitoes, termites, ticks or fliesand cause changes in its geographical distribution.
In addition, although they normally develop and live well in high temperatures, when these are already very high, the insects opt for more temperate areas that allow them to live better, so that they colonize new areas where these pests did not exist until now.
Another consequence is the polarization of the situation between the pests themselves. Climate change tends to strengthen the most resistant insects, weakening those who until now acted as phytosanitary protecting the balance in agriculture.
“Global warming is introducing important effects on the growth, development and distribution of most pests, which are increasingly destructive. It remains to be seen how we will deal with the new scenario of prevention and fight against these pests because it is clear that the rules of the game are changing”, warns Ignacio Santamarta.
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