Researchers use DNA to quickly unravel relationship between plants and insects

March 25, 2013
This shows six of dozens of rolled leaf beetles collected in Costa Rica for the study. High-quality plant DNA was obtained from the gut contents of these beetles, revealing exactly which Zingiberales plants they had been eating. Credit: Charles Staines

It can take years of direct observation for a researcher to fully understand the diets of a community of herbivorous insects in a tropical rain forest. Now, five Smithsonian scientists are paving a fast track using the DNA found inside the insects' stomachs, potentially turning years of research into months. This method will help scientists understand the ecology and evolution of plant-herbivore interactions more efficiently.

Studying the relationship between plants and the insects that feed on them is an arduous task, as it must be done through direct observation. It can take years for a researcher to fully understand the diets of a community of in a . Now, five Smithsonian scientists are paving a fast track using the DNA found inside the insects' stomachs, potentially turning years of research into months. This method will help scientists understand the of plant-herbivore interactions more efficiently. Their findings are published in the journal PLOS ONE.

Plants and insects comprise about 50 percent of all known species on Earth, forming the critical foundation of biodiversity in most terrestrial ecosystems. This study focused on 20 species of rolled leaf beetles in Costa Rica and 33 species of flowering plants in the order Zingiberales that the beetles eat and lay eggs on almost exclusively.

This is the rolled leaf beetle C. alternans inside a Zingiberales leaf with its eggs in Costa Rica. Credit: Smithsonian

Using specialized DNA extraction methods the scientists obtained a mix of DNA both from the actual insect and from the insect's stomach contents. They used specific to animals to obtain DNA barcodes for each and markers specific to plants to identify the plant species in each insect's diet.

"What makes this study unique is that we developed DNA extraction techniques and full libraries that allowed us to identify host plants to the species level," said Carlos García-Robledo, a post-doctoral fellow at the Smithsonian and lead author of the study. "Another unique feature of this study is that we invested several years in the field identifying the diets of insect herbivores using direct observations. This baseline data allowed us for the first time to test the accuracy of DNA barcodes to identify insect diets."

This is Carlos García-Robledo in Costa Rica. Credit: Erin Kuprewicz

Matched against the data gathered from prior direct observation, the information derived from this DNA stomach-content study was nearly identical, yet had taken only fraction of the time and effort.

Explore further: Plants can grow quickly or ward off hungry insects, but not both: research

Related Stories

Six times more insects in tropical mountains

September 6, 2010

How many species of insects exist? Umea University researcher, Genoveva Rodriguez-Castaneda, found that in tropical mountains there are six times more insects than shown in global calculations. The insects in these areas ...

Barcodes refocus understanding of ecosystems

August 12, 2011

You're probably familiar with barcodes, those black and white stripes on most store items that bring about the familiar "beep" when scanned at checkout. They determine whether a scanned item is a gallon of milk or a can of ...

Genetic markers for tracking species

April 25, 2012

At the supermarket checkout, hardly anybody enters prices manually anymore. Using scanners that can read the barcodes is much faster. Biologists now want to use a similar procedure for identifying domestic animal and plant ...

Barcoding insects as a way to track and control them

May 2, 2012

Barcodes may bring to mind the sales tags and scanners found in supermarkets and other stores. But U.S. Department of Agriculture (USDA) scientists are using "DNA barcodes" to monitor insects that damage crops as diverse ...

Recommended for you

How bees naturally vaccinate their babies

July 31, 2015

When it comes to vaccinating their babies, bees don't have a choice—they naturally immunize their offspring against specific diseases found in their environments. And now for the first time, scientists have discovered how ...

Researchers design first artificial ribosome

July 29, 2015

Researchers at the University of Illinois at Chicago and Northwestern University have engineered a tethered ribosome that works nearly as well as the authentic cellular component, or organelle, that produces all the proteins ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.