Two types of locusts
Among locusts, the enemy lurks within their own ranks. That iswhy they mostly avoid each other and spread out over extensivetracts of land to search for food. But when the population densityincreases so does the risk of cannibalization. As soon as thepopulation density exceeds a critical value, the locusts form adevastating swarms. In desert locusts, the differences between thetwo types of locusts are so great that it was long thought thatthey were two different species. Not least because thesolitary individuals are green while the ones in swarms have ayellow-brown pattern.
The ‘minimum cannibalism algorithm’
The scientists from Max Planck, Princeton, the Indian Instituteof Science, Sydney and Texas A&M, designed a computer modelthat simulates the movement of the locusts. They designed analgorithm that matches the natural behavior of locusts, minimizing contacts among locusts and thus the risk ofcannibalism.
Prevent the formation of swarms
When the locust density decreases, they return to behaving likesolitary individuals and stay well clear of each other.Interestingly the threshold value for this behavioral changewas much lower than that for swarm formation. “So, to disperse anexisting swarm again, the locusts must be severely decimated,” saysresearcher Pawel Romanczuk. Today, usually the destructive swarmsare combated first. “But it makes sense to keep the locustpopulation small from the outset, avoiding swarm formation in thefirst place”. Which would be a cheaper and more sustainable way totackle locust plagues.