Technical Paper: Desert Locust and Climate: A Weather and Bio-climatic Case Study of Desert Locust Conditions in Northern Kenya



Changes in the climate system caused by anthropogenic climate change make locust plagues more likely. The 2019/2020 desert locust plague in Eastern Africa, the worst of its kind in more than 70 years, was likely exacerbated by shifts in rainfall patterns and intensity, as well as high cyclone activity in late 2019. Due to higher than usual average temperatures, conditions for desert locusts have become more conducive to plague development in recent years. This climate and desert locust study examines the interconnections between climate and weather parameters, locust breeding, and spread over Kenya. The initial context was that shifts in temperature and the hydrological cycle, already being observed and linked to a changing climate, are believed to create a more conducive environment for desert locusts. The key question addresses the conditions that allowed desert locust to thrive in Kenya from the end of 2019 to mid-2020. The analysis is thus based on the dekadals that show the highest frequency of sightings within the relevant time period (December 2019 - May 2020).

In light of different favorable growth and development conditions for each lifecycle stage (hoppers, adults, bands, swarms) and behavioral stage (solitarious vs. gregarious), the central finding of this analysis is that although many of the observed highest-frequency sightings are indeed within the favorable desert locust thresholds, there are noticeable deviations from literature that warrant further exploration. This study adds value to literature established by WMO and FAO by further exploring the relationship between soil moisture, cloud cover, NDVI, and locust sightings. Locusts were most observed in the counties of Turkana, Marsabit and Isiolo. Continued research of these counties could serve as an informative entry point for the development of an early warning system.
Keywords: Climate change, dekadals, desert locust, hydrological cycle, temperature .