Big Island papaya growers have increased pesticide sprayings to combat the white peach scale — a tiny insect that damages trees. Peter Follett • U.S. Dept. of Agriculture

Belmes uses two tractors and spraying crews for three days at a time to spray insecticide. The chore must be repeated as often as every two weeks.

"It reaches the fruit. If they go on the top, then you cannot sell the things," Belmes said. "It's extra money for us to take care of the thing."

The scale feeds on tree sap, and is known for damaging peach and plum trees in other parts of the world. In severe cases it can reduce crop yields or kill the trees. If left unchecked in papaya fields, white peach scale nymphs will travel up the trunk to the fruit, forcing farmers to clean the fruit before it can be sold. Papaya exporters will reject the fruit if the scale is visible.

Extra pesticide spraying and scrubbing harvested fruit are additional costs in an industry that doesn't need more problems, farmers said. Papaya growers have struggled with diseases such as ringspot virus and blackspot fungus as well as swings in crop prices and other factors that drove many out of business.

On the Big Island, which accounts for about 85 percent of the state's papaya production, the number of papaya farms and the acreage planted both dropped by more than a third since 1998, to about 2,320 acres last year. Hawai'i papaya farmers grew almost 43 million pounds of fruit last year, a harvest worth about $13.5 million.

Reach Kevin Dayton at kdayton@honoluluadvertiser.com or (808) 935-3916.