Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 22, 2005
Publication Date: February 1, 2006
Citation: Carlson, D.A., Hogsette Jr, J.A., Kline, D.L., Geden, C.J., Vander Meer, R.K. 2006. Prevention of mosquitoes and house flies from entering simulated aircraft with commercial air curtain units. Journal of Economic Entomology. 99(1):182-193. Interpretive Summary: Public health officials instituted aircraft disinsection in the 1930s out of concern that aircraft might transport mosquitoes that might be vectors of disease, and insecticide was sprayed with passengers and crew present, and later DDT was used. In 1979, the CDC dropped routine spraying of flights arriving in the United States on the basis that there are more effective ways to control mosquitoes. In 1993 questions about disinsection rose again and the DOT began urging nations to drop their requirements for disinsection. About 12 countries now require disinsection on arriving flights. Airline crews remain concerned about direct insecticide exposure, yet residues are also claimed to pose a health threat. As a result, DOT funded a study of air curtains in a simulated aircraft loading system, using off-the-shelf technology to minimize passenger contact and allow normal passenger flow into the aircraft. Scientists at the USDA's Center for Medical, Agricultural, and Veterinary Entomology carried out experiments in Gainesville, Florida that demonstrated excellent efficacy in excluding released mosquitoes and the common house fly. Two pairs of simulated aircraft cabin and passenger loading bridges were constructed and equipped with one horizontal overhead units and either 2 or 4 vertical units on either side of the doorway. Hungry mosquitoes (150) of three different species and flies (50) were released into the passenger bridge to see how many could enter the aircraft against the airflow, when 25 passengers were walking through the air curtain and into the aircraft cabin. The results showed exclusion of all but 5% percent of mosquitoes and houseflies at these high release numbers. When only 5 insects of each species were released, the results were even better with less than 1% of mosquitoes and no flies passing through. The trials showed that air curtains are very effective in keeping flying insects from entering aircraft and can do so without exposing passengers and crews to pesticides. We believe that this research validates the concept that the air curtain can be effective in keeping insects from entering aircraft, allowing systems to be developed that eliminate the pesticide treating of aircraft.
Technical Abstract: Commercially available air curtain units were used to create air barriers to prevent mosquitoes and house flies from entering a simulated aircraft doorway together with passengers. Two assemblies of simulated passenger bridge and aircraft were constructed and airflow measurements were recorded to confirm airflow characteristics for several combinations of commercial units. Three mosquito species were selected for different host-seeking characteristics, and house flies were selected to represent a large, strong flying insect. Batches of 5 or 50 insects were released into the passenger bridge just before 25 persons passed through the assembly, then insects that entered the aircraft cabin were recovered. Results showed that horizontal plus vertical or vertical mounted air curtain units with the airflow directed at a 45° angle into the passenger bridge were highly effective as barriers to mosquitoes, giving 95 to 99% exclusion and 95 to 100% of house flies, respectively. Airflows were measured and estimated to be effective if the mean was more than 4 m/s in the critical area in the center of the converging airflows. The study validates the concept that air barriers can effectively prevent the passage of flying insects into an aircraft.