BRAZIL-SCREW WORM IN CATTLE.
Two hundred million irradiated flies are being released over cattle farms in the Brazil-Uruguay border region as part of an experimental project to eradicate the screw-worm, a parasite that causes yearly losses of US$1.7 billion in the Brazilian cattle industry and US$210 million in Uruguay.
The insects are being released in an area 100 km wide in the two countries. The female flies have been exposed to radiation, rendering them infertile. They are expected to mate and produce eggs that will not hatch, thus causing a decrease in the fly population.
The screw-worm fly deposits its eggs in wounds in the flesh of cattle and other warm-blooded animals. When the eggs hatch, the maggots feed on the animal’s flesh, causing severe tissue damage and leaving it vulnerable to infection. The fly typically occurs in countries in the Americas, but has been eradicated in the US and Mexico using irradiated flies.
