The Growing Impact of Climate Change on Insect Populations
The Growing Impact of Climate Change on Insect Populations | Insights and Solutions
Introduction
As human-caused climate change continues to raise global temperatures, its effects on the natural world become increasingly severe and apparent. One of the most significant problems is the effect of excessive heat on insect populations. These include destructive pests that can infest crops and cause substantial yield losses and essential beneficial insects like pollinators that play a vital role in maintaining ecosystem balance and ensuring food production.
Insect Pests on the Move
Many economically significant pest species are expanding their geographic ranges (invasive species) due to increasing temperatures, often moving toward the poles and higher elevations. For instance, the cotton bollworm (Helicoverpa armigera), a major pest of cotton, corn, and other crops, has gradually shifted northward across Europe in recent years, benefiting from warmer climates.
As these pests spread to new areas, they can cause much damage to crops that are not prepared to confront them. Recent projections show that due to climate change, there might be a 10-25% decrease in global crop production by 2050 because of an increase in crop pest pressure. This will have significant impacts on both the economy and food security.
Higher temperatures also cause changes in the timing of pest life cycles and the number of generations per season, which means that many species can reproduce faster and grow their populations. If this continues, they will soon outnumber the natural predators, and the control methods farmers use will no longer be effective (development of resistance to pesticides, etc).
One example that is particularly concerning is the autumn armyworm (Spodoptera frugiperda). This invasive pest has quickly spread across Africa, Asia, and the Middle East in the past decade, presumably due to climate change. It is now considered one of the most destructive pests for cultivated plants worldwide, leading to billions of dollars in losses annually.
Pollinator Decline Accelerates
Climate change is also negatively affecting insect pollinators. These insects, such as bees, butterflies, moths, wasps, and others, play a vital role in the reproduction of numerous flowering plants, including essential crops. Unfortunately, their numbers have declined rapidly in recent decades due to the uncautious use of pesticides, the loss of biodiversity, and the effects of climate change (e.g., early heat waves, etc).
The delicate relationship between plants and their pollinators is being affected by extreme weather events, shifting rainfall patterns, and increasing temperatures. Changes in the flowering time can disrupt pollinators’ life cycles, causing them to emerge earlier or later than usual. At the same time, as the climate changes globally, pollinators are also being forced to leave their traditional habitats.
For example, many bumble bee species in North America and Europe have experienced a major reduction in their range as they approach the poles because they cannot withstand higher and drier temperatures. The rusty patched bumble bee (Bombus affinis), once widespread throughout the eastern United States and Canada, has vanished from most of its previous habitat.
Since pollination by animals (like bees) is believed necessary for 75% of the world’s food crop production, the decline in pollinator diversity and abundance seriously threatens crop yields and global food security. The harm caused by habitat loss and pesticide use is made worse because many wild pollinators are already under stress.
A Multifaceted Response – How to control the problem
Managing the effects of climate change on the insect (and, as a result, crop population) will require the following actions. Cover crops, the use of different and diverse crop varieties, and integrated pest control measures will increase crop strength and resilience to climate fluctuations.
To preserve and restore natural habitats, pollinator populations must be safeguarded. Ensure a reliable source of food by providing a range of blooming flowers throughout the growing season. The other thing is the reduction and stringent control of harmful pesticides.
To act now and fast globally to cut emissions and fight climate change is the need of the hour. The Paris Agreement says to keep global warming under 1.5°C from pre-industrial levels to avoid severe damage. Focusing on stopping deforestation, protecting carbon sinks, and using more renewable energy is important.
The future of insects is at risk. The world has to come together to save these important animals and the crucial services they provide before any permanent ecological damage occurs.
References:
- Parmesan, C. (2006). Ecol. Evol. Syst. 37, 637. https://doi.org/10.1146/annurev.ecolsys.37.091305.110100
- Deutsch et al. (2018). Science 361, 916. https://doi.org/10.1126/science.aat3466
- Goergen et al. (2016). PLoS ONE 11, e0165632. https://doi.org/10.1371/journal.pone.0165632
- Kerr et al. (2015). Science 349, 177. https://doi.org/10.1126/science.aaa7031
- Klein et al. (2007). Proc. R. Soc. B 274, 303. https://doi.org/10.1098/rspb.2006.3721
Further reading:
Plant Parasitic Nematodes and Strategies for Crop Protection
Field margin management to enhance wild pollinators in agroecosystems
Why are pollinators important to agriculture?
Integrated Pest (Disease & Weed) Management (IPM): Principles, Practices and Advantages
The importance of a pollinator-friendly garden and how to create one
