Build a better mosquito trap – a scientist thinks he's done: NPR

The Asian tiger mosquito Aedes albopictus, usually lay its eggs in stagnant water.

James Gathany / AP

hide the legend

toggle the legend

James Gathany / AP

The Asian tiger mosquito Aedes albopictus, usually lay its eggs in stagnant water.

James Gathany / AP

A simple trap called GAT can help neighborhoods get rid of the Asian tiger mosquito, an aggressive mordant.

Joe Palca

hide the legend

toggle the legend

Joe Palca

A simple trap called GAT can help neighborhoods get rid of the Asian tiger mosquito, an aggressive mordant.

Joe Palca

An Australian scientist has developed an insecticide-free method to control a particularly irritating mosquito species.

The approach involves two things: deploying a decisively low mosquito trap called GAT technology and getting to know your neighbors.

GAT stands for Gravid Aedes Trap. Aedes is the abbreviation of Aedes albopictus, familiarly known as the Asian tiger mosquito, which bites aggressively night and day.

The trap does not seem particularly impressive: three plastic buckets are stacked on top of each other. The upper and lower buckets are black. Mosquitoes fly in the trap through a hole in the upper bucket, but they seem to have trouble flying through the hole. To make matters worse (for the mosquito), you can hang a piece of sticky paper in the upper bucket to catch a wayward pest that gets there.

The bottom bucket contains water and rotten grass that floats there. Aedes Mosquitoes usually lay their eggs in standing water. The middle bucket has a net for trapping mosquitoes that hatch into the water.

This is a simple setup, but the scientist who invented the GAT, Scott Ritchie of the Australian Institute of Tropical Health and Medicine at James Cook University, says that there is many reasons why it is effective.

"Most mosquitoes are naturally attracted to black," says Ritchie, so that's what attracts them.

Female mosquitoes are the ones that sting people, and once they are filled with blood, they are eager to lay eggs.

"Then we have the darkness that brings them to the trap, and we then have stagnant water inside the trap where they can not escape," says Ritchie. "If you catch enough laying mosquitoes, there will be no eggs in the wild, so the population will crush them."

But traps alone are not enough to get rid of the mosquito. Ritchie says it's important that homeowners eliminate puddles of stagnant water. Abandoned tires, for example, are known to collect water after the rain, but even an inverted bottle cap can hold enough water for Aedes mosquito to lay eggs.

There is another key to controlling the mosquito population in a community: everyone must intervene. If your neighbors do not use traps and remove stagnant water, mosquitoes are likely to grow and snack.

But there is good news. "These mosquitoes do not fly very far," says Dina Fonseca, a mosquito expert at Rutgers University. "So, basically, if most of your neighbors are using this approach and are aware of what they have to do to control this mosquito, you are in good shape."

Then she adds with a smile: "It requires talking to neighbors."

There is already scientific evidence that traps can be effective. Fonseca works with several communities in and around Washington to see if the control program is working. Anecdotally, locals tell him that the number of mosquito bites has decreased in areas where people use the traps and eliminates stagnant water. The scientific proof is still far away.