Elucidating the behavior of desert locust survival in the desert 

― Realization of predicting behavior using a constructed model ―

JIRCAS, in collaboration with the Mauritanian National Desert Locust Centre (CNLA), the French Agricultural Research Center for International Development (CIRAD) and the University of Melbourne, has clarified previously unknown behavior of desert locust to survive in harsh desert environments, and used the results to construct a model that can estimate the body temperature and predict the behavior of desert locust.

The body temperature and the surface temperature of the surroundings were measured at various times using a thermal infrared camera for desert locusts that were actively moving in groups. At low temperature, it was clarified that the gregarious nymphs tend to aggregate and bask in the sun to raise the body temperature, whereas at high temperature, they tend to move  away from the hot ground surface to regulate the body temperature. When the temperature is low, gregarious nymphs maintain a higher body temperature than the surroundings. It is thought that digestion can be promoted by maintaining about 40°C even when the temperature is high. An investigation of the condition of the feeding pattern showed that the foreguts of the locusts on the move were almost full of food. We therefore assumed that food is digested quickly so the migratory bands tend to starve easily and can efficiently forage and promote growth by using new feeding areas while moving. Furthermore, we constructed a biophysical model of thermoregulatory behavior that incorporates the relationship between the obtained body temperature and activity at a remote site, and confirmed that it is possible to estimate the body temperature and predict the behavior of desert locust using globally available weather information. These results will be useful in predicting the behavior of desert locust and improving the accuracy of locust outbreak prediction.

　The results were published in the online version of the journal Ecological Applications on April 7, 2021.

Authors

Maeno, K.O., Piou, C., Kearney, M.R., Ould Ely, S., Ould Mohamed, S., Jaavar,M.E.H and Ould Babah Ebbe, M.A.

Title

A general model of the thermal constraints on the world’s most destructive locust, Schistocerca gregaria

Journal

Ecological Applications, DOI: https://doi.org/10.1002/eap.2310

JIRCAS President: KOYAMA Osamu
Program Director: NAKASHIMA Kazuo    
Researcher-in-charge：MAENO Kotaro (Crop, Livestock and Environment Division) 
Press Coordinator：OMORI Keisuke (Head, Information and Public Relations Office) 
E-mail：koho-jircas@ml.affrc.go.jp