Puerto Rico’s Department of Agriculture will begin a ground fumigation operation against the Mediterranean fruit fly on Thursday, October 22, in the islet of San Juan from Paseo de la Princesa to El Escambrón, after 1,652 wild specimens of the pest were confirmed as of October 16. Agriculture Secretary Irving Rodríguez Torres said spraying complements the work brigades already do with traps, bait stations and removal of fruit that can harbor the insect.
The operation will be coordinated with the USDA Animal and Plant Health Inspection Service (USDA-APHIS) and consists of localized applications on trees and vegetation selected by technical staff, not aerial dispersal. Treatments will be repeated every seven days, weather permitting, using GF-120 NF Naturalyte Fruit Fly Bait, which contains 0.02% spinosad as its active ingredient and is applied with one-gallon manual pumps.
The product is registered with the federal the U.S. Environmental Protection Agency (EPA) and listed by the Organic Materials Review Institute for organic production. USDA-APHIS assessed human health risk as minimal if application instructions are followed. Residents and merchants were asked to stay away from treated points, allow brigade access and follow staff instructions.
The measures follow the fly’s initial detection on July 16 and a quarantine declared July 28. As of October 16, authorities maintained 889 traps and 945 bait stations in San Juan, and brigades had removed 14,934 pounds of host fruit. One specimen was detected in Ceiba on August 17, with no new findings since.
Sterile fly releases to disrupt reproduction began September 5-6 with about 1.5 million flies, and six release rounds had been completed by October 16, the first four totaling about 6.5 million. A September 30 operational map sets a 41.8-square-mile quarantine zone covering parts of the San Juan islet and other metropolitan areas. Agriculture reiterated that the fly does not bite or directly threaten human health but can damage produce and cause economic losses.