About 3.5 million sterile male flies have arrived in Libya as part of a U.S.-backed campaign to eradicate the screwworm, a deadly flesh-eating parasite that threatens livestock throughout Africa.

The flies are the first shipment to arrive from a joint U.S.-Mexican plant at Chiapo de Corso in Mexico. They reached Tripoli airport Sunday, the official Libyan news agency JANA said Monday.The campaign organizers will start releasing the flies from planes Tuesday over an experimental area of 2,700 square miles, it added.

The idea is that the sterile males will outnumber the fertile males born in Libya. When they mate with the females, the eggs will be infertile, breaking the reproduction chain.