Armed with a glue gun and radio transmitters the size of a penny, a University of North Carolina scientist is trying to stop mass insect migrations that devastate ranches in the Mountain West.
Mormon crickets, also known as flightless katydids, travel in massive packs, devouring all surrounding terrain as they move. Packs of the bugs can cover more than a mile a day and devastate crops.
Scientists are trying to identify patterns the crickets follow so they can kill them or divert their paths with small distributions of pesticide, rather than the blanket applications now used against the pests.
Patrick Lorch, a postdoctoral fellow in biology at UNC-Chapel Hill, is among three scientists studying the crickets and their travels.
The trio – which also includes Gregory Sword, a research ecologist with the U.S. Department of Agriculture’s Agriculture Research Service, and Darryl Gwynne, a biology professor at the University of Toronto at Mississauga – do their research by gluing tiny radio transmitters to the backs of crickets, and then tracking the signals they emit as they travel.
The researchers spend weeks in the field each summer, usually in Utah and Colorado. Last June, the team spent 2 1/2 weeks working near Utah’s Dinosaur National Monument. Their research, in its third year, is funded by the Agriculture Department.
To understand why the insects travel in packs that can stretch several miles wide and 10 miles in length, the scientists separate individual crickets from the mass. Then they glue transmitters – each weighing less than half a gram – to the backs of their selected critters.
When separated, their research found,
50 to 60 percent of the crickets were killed by predators within two days. That led to the conclusion that pack travel is a survival mechanism for the crickets, a finding that could be applied to all mass migrating animals and insects, from locusts to wildebeests, Lorch said.
Although the theory that mass migrations help protect animals from predators has been proposed before, Lorch said this study is the first to quantify the benefits of such behavior
If the research eventually allows Lorch and his colleagues to predict migration patterns, the information could aid farmers in protecting crops and could ultimately reduce the cost of producing beef in certain parts of the country, Lorch said.