Bugs in boxes are helping UC Davis researcher Alan Hastings improve scientific tools used to predict the spread of invasive plants and animals.

In the Sept. 21 edition of the journal Science, Hastings and a University of Colorado colleague report their latest findings from both a tightly controlled laboratory experiment and a mathematical model: When they released 600 identical beetles and let them spread at will through 30 identical landscapes over 13 generations, there was a surprising degree of difference in the outcome.

Some of the beetles went far and fast, traveling across 31 landscape patches in the 15-month experiment, while others went only a third as far. The rest fell somewhere in the middle.

Hastings said the results suggest that it will not be as easy as some had hoped to catalog all the factors that influence the spread of an invasion.

If it is difficult to predict the course of an invasion, it will be difficult to control it. And there are hundreds of destructive invaders in the U.S. alone, from kudzu to zebra mussels to the light brown apple moth.

“There appears to be this intrinsic variability, even in the simplest ecological settings, that means that difficulty in prediction is a basic feature of ecological systems,” said Hastings, a professor in the Department of Environmental Science and Policy.

Hastings’ collaborator and co-author Brett Melbourne was previously a postdoctoral scholar at UC Davis and is now an assistant professor at the University of Colorado, Boulder.