A study analyzes the temperature and behavior of locusts for a more effective application of biopesticides

Locusts are pests that can cause a lot of damage to crops and pastures, and are found on every continent except Antarctica. To control them, chemical pesticides have been used, but these can harm the environment and biodiversity. In recent years, biopesticides like entomopathogenic fungi have been promoted as an alternative. These fungi infect and kill insects, but work better on insects with lower body temperatures. To make sure the fungus is effective, it's important to apply it at the right time. A study in the journal Frontiers in Physiology suggests that the best time to apply the fungus is when the locusts are young, around 20 days after hatching.

The best time to apply biopesticides, specifically entomopathogenic fungi, to eliminate locusts is when they are young, around 20 days after hatching. This is because at this stage of development, the locusts are in their third phase and have optimal temperature and behavior conditions that guarantee the effectiveness of the biopesticide. Locusts cannot regulate their internal temperature by themselves, so they modify their behavior to find suitable temperature zones. This information comes from a study published in the journal Frontiers in Physiology by an international team that included researcher Pablo González, who has studied the eastern migratory locust at the Department of Forest Engineering at UCO.

The study looked at almost 1,000 eastern migratory locusts in China and found that in their third phase of development, the locusts have a lower temperature than in other stages. This is because they are usually close to the ground and more vulnerable. As they get older and move to warmer areas, their temperature increases. This means that the best time to apply the fungus is during their third phase, when they have a lower temperature and are more susceptible to it.

Applying the fungus during the third phase of the locust's growth is ideal because during this phase, the locusts are located close to the ground, which makes them more vulnerable, and their body temperature is lower, which makes them more susceptible to the fungus. Additionally, applying the fungus during this phase gives enough time for it to work before the locust reaches its adult stage, when it can fly and cause damage to crops.

Monitoring the population of locusts is an important task for authorities in areas where locusts are known to cause damage. By identifying the best time to apply the biopesticide, it may be possible to better control the infestation of locusts.

The study was conducted in China, but the results can be applied to other regions as well. The research was funded by the United Kingdom and China and was led by researchers from CABI, an international NGO focused on providing solutions to agricultural and environmental problems. The study also involved researchers from Zhejiang University, the national agricultural extension service of China, and the University of Córdoba in Spain.

Reference

Li H, Zhu J, Cheng Y, Zhuo F, Liu Y, Huang J, Taylor B, Luke B, Wang M and González-Moreno P (2023) Daily activity patterns and body temperature of the Oriental migratory locust, Locusta migratoriamanilensis (Meyen), in natural habitat. Frontiers in Physiology. 14:1110998. doi: https://doi.org/10.3389/fphys.2023.1110998.