Barcodes reveal insects’ hidden habits

march_insect_1

Barcodes that identify species from a short DNA sequence offer scientists a fast way to study the global spread and diet of insect pests, like the Asota caricae moth (above) that has a two-inch wingspan and a 2,500-mile distribution. “I’m concerned about how much biodiversity might be lost before we’ve had a chance to understand it. DNA barcoding helps to increase the pace of discovery,” says biologist George Weiblen. (Credit: Lauren Helgen/Smithsonian Institution)

U. MINNESOTA (US)—DNA barcoding is giving researchers a faster way to study where insects go and what they eat along the way.

An international team of researchers used the technique, which involves the identification of species from a short DNA sequence, to study populations of numerous moth and butterfly species across Papua New Guinea and discovered that migratory patterns and caterpillar diets are very dynamic.

In one case, for example, a tiny moth that is distributed from Taiwan to Australia, recently crossed thousands of miles of Pacific Ocean.

The research was published in the early online edition of Proceedings of the National Academy of Sciences.

“DNA barcoding was developed for rapid identification but it also provides information about the habits and history of species,” says George Weiblen, associate professor of plant biology at the University of Minnesota.

The technique is of particular interest in Papua New Guinea, a country slightly larger in size than California with an insect diversity more than three times that of the United States.

“New Guinea is one of those special places on Earth where we know very little about its biodiversity. This rich natural environment is increasingly threatened by economic development,” he says.

“I’m concerned about how much biodiversity might be lost before we’ve had a chance to understand it. DNA barcoding helps to increase the pace of discovery.”

DNA barcoding also plays an important role in studying the arrival of invasive species, such as the emerald ash borer, a species recently introduced from Asia.

“We need to understand the genetic history of invasion in order to combat the pests that threaten trees and crops,” Weiblen says.

“DNA barcoding can pinpoint the geographic source of an invading species and measure the distances over which pest species can travel.”

Researchers from the Smithsonian Institution, the University of Guelph in Ontario, Canada, and the University of South Bohemia, Czech Republic, contributed to the study.

University of Minnesota news: http://www1.umn.edu/news/