Need to Know: Meet the bug killing the world's orange groves

Florida is the largest producer of oranges in the U.S., and its groves are under attack. This week on “TechKnow,” contributor Marita Davison travels to Florida to see how one bug has spread a disease known as “citrus greening” from Asia to the U.S.

Citrus greening disease infects orange trees and causes their fruit grow half-green and misshapen. Most importantly, the misshapen oranges taste sour, making the citrus impossible to sell.

Scientists had long suspected that one particular bug could be behind transmitting this disease: the Asian citrus psyllid. In 1971, researchers successfully confirmed that a bacteria in the psyllid’s digestive system spreads to the leaves of orange trees when they feed, infecting them. The bacteria alters the nutrient flow in citrus trees and inhibits their growth.

Citrus greening originated in Asia. It was first reported in China in 1923 and was first detected in the U.S. in 2005 in Florida. By 2012, it had made its way across the country to Southern California, too.

Davison visited River Country Citrus in Florida to get a first-hand look at how the Asian citrus psyllid changes orange growth. Travis E. Murphy, Jr., the president of River Country Citrus, said that the disease has now compromised 100 percent of his citrus groves.

"[It worries me] daily -- at night,” Murphy told Davison. “There’ll probably be a spot in my bed where it’s worn pretty good from sleepless nights."

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