Drones and dogs battle beetle to save guacamole

A tiny beetle is threatening America's supply of guacamole, not to mention Florida's $100 million avocado industry. The Asian ambrosia beetle is attacking avocado trees and spreading a deadly fungus called laurel wilt.

"This is, no question, the biggest threat to the commercial avocado industry in Florida. We have never faced anything this devastating."

Jonathan Crane is a Tropical Fruit Crop Specialist at the University of Florida. He and a team of researchers in South Florida are developing strategies to prevent the fungus from spreading.

So far, a little more than 1% of Florida's commercial avocado crop has been hit, but Crane says the disease is moving thirty-to-fifty miles a day through wild laurel trees.

"There was a grove where we found one (avocado) tree infected. We recommended the owner remove and destroy the tree. The owner opted not to do that. Six months later ninety-five trees were dead. There's about ninety-five trees in one acre so you're losing an acre per month if you do nothing."

Crane says one of the main difficulties in stopping the beetle and containing the fungus is the fact that humans cannot detect symptoms of the disease. Once the tree shows signs of stress, it's too late to save it.

However, canines and camera-carrying drones can detect the disease in its early stages. First the heat-sensing drones fly above groves, locating the sections with stressed trees. Then, the dogs are sent in to sniff out the infected trees, many of which show no visible signs of infection.

Once the dogs locate an infected tree, the farmer can remove or burn it, and then inject nearby trees with fungicide to protect them. The fungicide is still in its experimental phase. Also, it can be expensive for farmers to use.

Crane says the dog-drone detection work has been progressing well. "They look very promising. I'd say we're going to know much more definitively within the next six months. My feeling is they're going to be successful."

But, the researchers are working against time. The Ambrosia beetle is moving west. Crane says the worst case scenario is if it hits the state that produces ninety per cent of America's avocados.

"California, as you may know, has about 70 000 or so acres of commercial avocados and theirs is about ten times larger than ours. So we're putting at risk a $400 million industry."