What’s the biggest enemy to Miami-Dade County’s $1.6 billion agriculture industry? A little fruit fly. Specifically, the Bactrocera dorsalis, or oriental fruit fly.

The flies, described by Florida’s Agriculture Department as one of the industry’s “most devastating pests,” were first spotted in the county on Aug. 26. Since then, a total of 159 of the insects have been detected in Miami-Dade County, according to the agency. Most of them have been found in Redland, home to a high concentration of groves.

The fruit fly, firmly established in various Asian countries, is considered especially economically harmful because it infests so many different kinds of plants. Female flies lay eggs in more than 430 varieties of tropical fruits, vegetables and nuts, including avocados, mangoes, bananas and papayas. The larvae feast on the produce.

“If it becomes established in the continental U.S., it will ravage commercial agriculture and make it difficult and expensive for you to grow fruits, nuts, and vegetables in your backyard,” reads a fact sheet from the Miami-Dade Oriental Fruit Fly Program.

The infestation is one of Florida’s largest, and raises nationwide concern as the area provides produce during winter months.

Florida’s Agriculture Commissioner Adam Putnam declared a state of agricultural emergency earlier this month and an 85-square-mile area was quarantined, meaning growers were restricted from moving fruits and vegetables. Many in Redland had to halt production just as they were harvesting.

“We estimated that we have mamey alone about 500,000 pounds left on the trees,” J&C Tropicals operations manager Salvador Fernandez told NPR. “As for dragon fruit, that leaves 20 million pounds on the trees potentially.”

The state agriculture department issued a statement Tuesday, saying that “efforts to eradicate the pest are working.” In addition to the quarantine, workers are applying pest treatments to areas where each fly is found, removing fruits from host trees and set out traps to find any more flies.

But officials are still weighing whether to start aerially spraying pesticides in South Florida. Putnam told a town hall of growers Monday that spraying GF-120 would be the next step if a pregnant female, larvae or more flies in traps are found, the Miami Herald reported.

The particular pesticide is approved for organic farming and Putnam called it the “last, best bullet in the gun,” the paper reported. Organic farmers voiced worry about another pesticide that the state is seeking federal clearance to use, a chemical that could invalidate their organic status, the Herald reported.

According to an agency spokeswoman, clearance to use that chemical is being sought only for growers who want to voluntarily hand-spray their crops. Organic growers wouldn’t be required to use it, and none would risk losing certification, the spokeswoman added.

The state has called upon growers to sign compliance agreements, which signal their willingness to abide by eradication efforts.

Meanwhile, thousands of pounds of produce have been bagged and destroyed, rather than shipped off to market. The quarantine will lift in January, as long as no additional flies turn up.