Larry Black kneels in the sandy soil beside a bushy orange tree flush with ripening fruit, his brow glistening in the hot Florida sun. He pinches a sprig of young leaves and pulls it in at eye level. “You see him?” Black says. “He’s tiny.” A grayish speck flutters off. It’s the Asian citrus psyllid — smaller than a grain of rice, but big enough to possibly destroy Florida’s citrus industry.

The tree’s yellow-blotched leaves betray a symptom citrus growers have come to expect. It’s sick. And so is nearly every mature citrus tree in the state.

Black’s family has raised oranges here since the 1850s. For five generations, they’ve faced hurricanes, frost and pests. But over the past decade or so, they’ve seen this tiny bug become their worst calamity, decimating the state’s iconic orange trees by ferrying a disease called citrus greening, or Huanglongbing (HLB) — the yellow dragon disease.

“Pre-HLB, a grower planted a grove of trees and expected them to live for a generation,” says Black, who runs Peace River Packing Co. in Fort Meade. “And that’s just not a reality anymore.”