Climate Change could mean more Intense Locust Outbreaks and Threaten Food Security

A new study by a research team from Arizona State University has found that climate change will dramatically increase the intensity of locust swarms, resulting in even more crops lost to insect pests and threatening food security.

The study, recently published in Ecological Monographs, outlines the results of considerable data gathered on the physiology of South American locusts, and demonstrates that species distribution models that consider physiology in addition to temperature may reshape what we can expect to see as climate change continues.

"One unique aspect of our study is that we combined many different research approaches, including field observations, laboratory experiments and computational modeling," said Jacob Youngblood, recent ASU Biology Ph.D. graduate and first author on the study.

"To combine these approaches, we assembled a diverse team of researchers, which included physiologists, ecologists, entomologists and agriculturists. Collaborating with such a diverse team enabled us to study the effects of climate change on multiple aspects of locust biology."

The international team included Youngblood and researchers from ASU's Global Locust Initiative: assistant professor Arianne Cease, President's Professor Michael Angilletta and professor Jon Harrison from the School of Life Sciences, and postdoc Stav Talal from the Global Institute of Sustainability and Innovation, as well as innovators and collaborators in South America.

Plagues of old

Since at least the days of the pharaohs of ancient Egypt in 3200 B.C., locusts have been erupting into massive swarms that descend upon crops and plant life, causing almost total devastation.

Why do these destructive swarms suddenly occur?

Just like people, locusts can be either shy or gregarious. For the most part, locust populations can spend several seasons in a low-density population, called a solitarious phase. The locusts are a cryptic brown or green—shy, solitary and relatively harmless on a global economic scale. However, when circumstances are just right, the locust numbers swell to overcrowding, triggering a drastic switch to a gregarious phase—social, brightly-colored and capable of forming migratory swarms of 80 million locusts per square kilometer.