Fungus Taking a Bite out of Avocados Avocados are Florida's second largest crop, second only to citrus as one of the main agricultural exports of this agricultural powerhouse.  And like citrus, they are being threatened by a difficult to treat disease. The culprit is the redbay ambrosia beetle, an inadvertent import from Thailand that came in a shipment of wood over a decade ago.  The beetle attacks the roots of trees, and spreads easily from tree to tree within avocado groves. The ambrosia beetle carries a fungus that that leads to certain death for the tree. Unabated, the beetle is likely to spread to other avocado producing states, such as Texas and California.  For the state of Florida, annual avocado production is worth $20 to 30 million, and numerous jobs. To defeat the scourge, agricultural experts at Florida State University have tried two methods.  Trained dogs can sniff at the fungus at ground level, which helps detect infection.  From the air, FSU is turning to drones.  The flying detection can spot an unhealthy tree, which shows signs of thinning at its crown. Avocado trees are now dying at a rate of about 1% loss per year in Florida due to the fungus. s