Fish For Moquito Control

NEW ORLEANS - Steve Sackett knelt beside the concrete fountain and peered into its algae-stained depths.

"Yep, we've got pupae," Sackett said. "Hundreds of 'em. In another 24 hours, they'll hatch and be ready for a bloodbath."

Mosquito larvae are the bane of Sackett's existence, as research entomologist for the New Orleans Mosquito and Termite Control Board.

The stagnant water he was checking out, in a weed-infested yard along Bayou St. John, was one of thousands of abandoned pools and ponds in the New Orleans area, each of them transformed by post-Katrina neglect into a mosquito-breeding tank.

The pools and ponds are the most daunting challenge Sackett has faced in his 26 years with the mosquito board.

Fortunately, he has found allies in his battle against mosquitoes. Volunteers with Operation Blessing, a faith-based nonprofit agency that has established a headquarters in Slidell, accompanied him on his rounds. Allies of another sort swam in a water-filled plastic bag hanging from his right hand: the mosquitofish.

The slender guppylike fish are the most effective biological mosquito control agents on Earth. Each minnow can gobble as many 100 mosquito larvae a day.

Gambusia affinis has been used to control mosquito populations since the late 1930s. The fish are native to Louisiana waters and generally require no feeding and little care. As surface-breathing fish, they are able to survive in polluted waters with low levels of dissolved oxygen and wide ranges of temperatures. Their primary food source is mosquito larvae, and they are voracious predators. If no mosquito larvae are present, they can live off algae. What's more, they are prolific breeders, bearing 50 to 100 young per brood.

"They have been one of the most effective, noninsecticidal and nonchemical methods of controlling mosquitoes," said Dan Suttle, the owner-operator of Suttle Fish Farm in Laurel, Miss., which supplies the fish for transplantation. "Normally, we think of fish as food. But these fish save lives."