Greg Sword on flying drones and a locust plague in Australia in 2010
A team of scientists in Australia is developing aerial drones – small, unmanned aircraft – to track the movements of what’s expected to be an unusually large plague of locusts this year.
Greg Sword: One of the things that makes locusts a very important crop pest, is that they’re mobile and they travel in these groups in the ground and in the air as swarms.
EarthSky spoke with Greg Sword of the University of Sydney. His team is using aerial drones designed to track tiny reflective pieces of glass that have been attached to the backs of individual locusts with a drop of glue. Sword’s team plans to create models of how the locusts move in groups.
Greg Sword: We’re developing mathematical models based on collective movement, what’s called collective movement dynamics, where we can predict where the locusts are going to go.
They plan to track newly-hatched locusts. Sword explained that juvenile locusts are easier to control. They don’t yet have wings, and travel on foot in what he calls “migratory bands,” eating grasses and crops as they go.
Greg Sword: If we can predict where these bands are going to travel, we can be much more precise in our application of pesticides to control them. We don’t have to blanket-spray.
Australian plague locusts attack farmers’ fields almost every year, and an especially large outbreak is expected in 2010, after months of rain provided ideal breeding conditions for locusts. In fact, scientists are warning that Australia will experience the worst plague of locusts in up to 75 years, starting in September 2010. Dr. Sword explained that heavy rains all in 2009, after a period of prolonged drought, and a warmer than usual fall allowed the native Australian plague locusts to lay unusually large numbers of eggs.
Greg Sword: The conditions in the previous year have created what some are describing as conditions for the perfect swarm.
This year’s outbreak is expected to affect areas across the eastern half of Australia.
Greg Sword: They will be feeding in pastures, taking out grass that would be intended for livestock or native animals. But they also can do severe damage to crops.
He added that locusts are driven by their own propensity to eat each other.
Greg Sword: The locusts are all looking for food resources, and they need to move to find new resources, but at the same time they are also highly cannibalistic. They’re more than happy to feed on each other. So they have to keep moving to avoid being eaten by hungry locusts approaching from behind. So these migratory bands are essentially a forced march of locusts driven by cannibalism.