A new device may help the Department of Homeland Security monitor crops for signs of deliberate attacks against U.S. food supplies. Iowa State University plant pathologist Forrest Nutter designed balloons attached to devices that measure clouds of spores above fields and sniff for disease activity - both natural and manmade. Spores are microscopic structures that fungus uses to spread.

To test their new device, Nutter and his colleagues deliberately infected a wheat field and measured spore clouds that escaped from the diseased wheat.

The spore collector onboard the balloon has six samplers researchers can turn on remotely, allowing them to measure spore densities at different altitudes and calculate the size and density of the spore cloud. They analyze the data after they return the balloon to the lab.

Analyzing the spores genetically gives investigators information on their origin, Nutter said.

The balloon experiment is part of a larger DHS project in which officials could use a combination of balloon and satellite data to monitor food crops for suspicious activity - not just in the U.S., but in other countries as well. They can also use to data to study how natural diseases travel through fields and develop new ways to stop their spread.

If a field viewed from satellites has suspicious areas, we could provide the GPS coordinates to go look at them. This makes our warning system more accurate, Nutter said in a statement.