I’ve been doing a bunch of reading up recently, and boy, things are going swimmingly. And by that I mean we’ll all be swimming by the end of the century. Jokes aside, things have been going downhill for a while now, or I suppose uphill along the temperature graph. As we all know, global temperatures are rising (NASA, 2020). And since this is a blog about pests, we shall focus specifically on how rising temperatures affect them.
Turns out there’s a general trend, but it’s complicated.
Recent research reveals that rice, maize, and wheat crops could be under threat in the coming years as warming global temperatures favor insect pests (Deutsch et al, 2018). According to the study, the temperate zone will be especially vulnerable, while the excessively-warm lowland tropics will see insect populations decline. Which I guess would be a good thing for crop-growers in the lowland tropics, if they can stand being uncomfortable and sweaty all the time. Even so, we’ll be bringing in 10 to 25% less of the staple crops whenever the temperature rises by 1 degree (Deutsch et al., 2018).
One possible limitation of the above study would be in its use of a generalised model of insect metabolism in its projection, which may not capture the nuances of individual species’ responses to environmental changes. Lehmann et al. (2020) echo this sentiment. Although they agree with the general predictions of Deutsch et al. (2018) regarding increasing pest severity, Lehmann et al. (2020) demonstrates that there is great variability to many species’ responses to warming depending on location. Additionally, their findings suggest that mid-latitude areas may be warming past pests’ optimal temperatures, as opposed to lowland regions as in the findings of Deutsch et al. (2018).
Lehmann et al. (2020) also propose that rapid evolution of pest species could cause unpredictability in these models. It’s unavoidable, but a challenge nonetheless.
So, clearly it’s not that simple, and there are some contradictory findings that need to be addressed. But either way, the evidence suggests that pest populations may grow in many parts of the world in the near future. Deutsch et al. (2018) postulates that pest population booms in intensive agriculture could lead to increasing pesticide use in order to protect crop yields. As a consequence, there would be an increased risk to environmental and human health, and of pesticide resistance (Deutsch et al., 2018). This would be a good segue to issues on pesticide use, but we’ll cover that in later posts.
Soooooo yeah. Keep it chill and stay safe, y’all.
References
1. NASA. (2020, July 16). Global Surface Temperature. Retrieved from https://climate.nasa.gov/vital-signs/global-temperature/
2. Deutsch, C. A., Tewksbury, J. J., Tigchelaar, M., Battisti, D. S., Merrill, S. C., Huey, R. B., & Naylor, R. L. (2018). Increase in crop losses to insect pests in a warming climate. Science, 361(6405), 916-919. doi:10.1126/science.aat3466
3. Lehmann, P. D., Ammunét, T. U., Barton, M. S., Battisti, A. U., Eigenbrode, S. U., Jepsen, J. U., . . . Björkman, C. U. (2020). Complex responses of global insect pests to climate warming. Frontiers in Ecology and the Environment, 18(3), 141-150. doi:10.1002/fee.2160
Images
Image of a cabbage whitefly by Amada44 / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0). Retrieved from https://commons.wikimedia.org/wiki/File:Cabbage_Whitefly_-_Aleyrodes_proletella_8618.jpg