Keeping mosquitoes out of foreign airspace.

Mosquitoes can travel, although not always under their own power. Sometimes they hitch rides in commercial aircraft, and some countries, especially those with high levels of tourism, want assurances that any insects that may be on a plane when it arrives will not leave the aircraft.

Recently retired chemist Dave Carlson, entomologist Jerome Hogsette, and colleagues in the Mosquito and Fly Research Unit at the ARS Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida, have investigated an alternative control approach: the use of air curtains--the huge blowers used at entrances and exits of some commercial establishments--to keep insect pests from getting off planes after landing. The researchers have also tested use of air curtains to keep mosquitoes and other flying insects from getting onto planes.

Hogsette and colleagues tested the air curtains' ability to blow hitchhiking insects back into the cabin while passengers disembark. A minimum airflow of 6,000 cubic feet per minute is sufficient to prevent insects from passing through. In addition, placement of net curtains or screens impregnated with safe-to-handle pesticides across front and rear doors kills any insects that do attempt an escape. To control insects that may remain, aerosol sprays can be used after all crew and passengers have left the aircraft.

Health officials from several Caribbean countries have shown interest in using air curtains to prevent insect escapes from incoming flights. Currently, passengers, crew, and crew quarters are sprayed in flight to prevent accidental introduction of invasive species into some countries. It is hoped that air curtains can provide a viable alternative to chemical sprays that currently raise health concerns.