Desert Locust Stopped by Tibetan Highlands during the 2020 Upsurge

Jun Liu,Long Zhang,Michel Lecoq

doi:10.3390/agronomy11112287

Abstract

Desert locust is an important pest to agriculture. In 2019–2020, a major upsurge originated in the southern Arabian Peninsula and gradually spread to east Africa, then to south-west Asia, as far as Pakistan and India, even reaching Nepal, resulting in major agricultural losses. For the first time, a few swarms entered southern Tibet. Using field observations and experiments, we studied their path to the Tibetan plateau and their behavior at these very high altitudes. The locusts moved up the Tibetan valleys from low-lying areas (1700 m) to much higher elevations (5400 m). The low temperatures and high humidity put them under severe stress; their activities were limited, and they did not survive long or produce local offspring. It is clear that the high-altitude environmental conditions in the Himalayan mountains provided an important natural barrier that limited the northward expansion of the desert locust populations.

Highlights

IntroductionSchistocerca gregaria (Forskål, 1775) is an important pest to agriculture for many countries in Africa, the Middle East, and SW Asia
Agronomy 2021, 11, 2287. https://Desert locust, Schistocerca gregaria (Forskål, 1775) is an important pest to agriculture for many countries in Africa, the Middle East, and SW Asia
The transition from a solitary to a gregarious phase is another characteristic of the desert locust that depends on population density, and locusts in the gregarious phase can migrate long distances in large swarms and cause huge crop losses [8,9,10,11]

Summary

Introduction

Schistocerca gregaria (Forskål, 1775) is an important pest to agriculture for many countries in Africa, the Middle East, and SW Asia This polyphagous insect can cause damage to almost all types of vegetation and crops [1,2,3]. Desert locusts can spread over larger territories (an invasion area of 31M km2 ) and reach the limits of the areas they can colonize, often unfavorable for breeding, but where they can still cause significant damage This is the case of the humid woodlands of Africa to the south, or the too cold and mountainous regions to the north. In the southern end of the range, if northern India and Nepal have sometimes been colonized, no swarms have ever been reported from Tibet.

Methods

Results

Conclusion