Keeping Locusts Away
When it comes to farmland, overgrazing is not just bad news for the land and livestock – it can encourage certain species of locusts to flourish.
Researchers have found that some locust species prefer to eat nutrient starved grasses that grow in overgrazed land.
Researchers found that intense grazing by livestock depletes nitrogen levels in the soil. While the resulting lower protein crop should limit the size of populations that feed on them, locusts thrive in these conditions.
Warmer temperatures also increase locust populations, with many species increasing in size and number at a temperature of 38 degrees and above. Recent warm springs and summers could result in an increase in the local locust population. The rise in temperature also allows the locust to colonise new species of plants and avoid predators and diseases that they would otherwise encounter.
Previous locust outbreaks have resulted in hundreds of millions of dollars worth of crop damage. While locusts are timid when alone, in a group they become aggressive destroyers of crops. The change in behaviour is driven by a surge in serotonin that occurs in group settings.
Pesticides can be used to curb locust infestations but there are also natural predators like certain wasps and even fungal diseases that can affect their numbers. Researchers are also considering a way to target the locust’s serotonin receptors to make them less aggressive.