BITING ARTHROPODS: INTEGRATED PEST MANAGEMENT
Location: Mosquito and Fly Research Unit
Title: Laboratory evaluation techniques to investigate the spatial potential of repellents for push & pull mosquito control systems
Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 19, 2012
Publication Date: November 1, 2012
Citation: Obermayr, U., Ruther, J., Bernier, U.R., Rose, A., Geier, M. 2012. Laboratory evaluation techniques to investigate the spatial potential of repellents for push & pull mosquito control systems. Journal of Medical Entomology. 49(6):1387-1397.
Interpretive Summary: Scientists at the USDA-ARS, Center for Medical, Agricultural, and Veterinary Entomology in Gainesville, FL, in collaboration with scientists from the University of Regensburg, Germany and BioGents in Germany, have developed a way to test repellents that prevent humans and other animals from being bitten. The study was performed on ARS-patented chemicals called “attraction-inhibitors” and on catnip oil to find out if they can hide people from attack by mosquitoes. It was determined that the attraction-inhibitors did work in laboratory tests and therefore may be useful in a “push and pull” strategy to protect people and divert the mosquitoes and other biting flies to traps. This information will be useful to mosquito researchers and groups that are developing new technologies to protect humans and other animals form arthropods that spread disease.
A protocol has been developed for the indoor evaluation of candidate spatial repellents intended for use in push and pull systems. Single treatments (catnip oil, 1-methylpiperazine and homopiperazine) and a mixture of catnip oil and homopiperazine were tested with yellow-fever mosquitoes (Aedes aegypti) in Y-tube olfactometers to determine (a) if these compounds inhibited mosquito host-seeking at short distances and (b) if results obtained in olfactometer tests can be correlated with a larger scale set-up, i.e., a room test. All test materials significantly decreased the ability of mosquitoes to find host odors (from a human finger) by up to 96.7% (2.5% catnip & homopiperazine mix). Similar effects could be observed within a new room test set-up, which involved a repellent dispensing system and an attractive trap (BG-SentinelTM). Mosquitoes captured by the BGS trap had to fly through a treatment-containing air curtain created by the dispensing system. Compared to the use of a control (ethanol solvent without candidate repellent), trap catch rates were significantly reduced when 5% catnip, 5% 1-methylpiperazine and 5% homopiperazine were dispensed. Homopiperazine produced the greatest level of host-seeking inhibition with a 95% reduction in the trap catches. The experimental set-up was modified to test the viability of those technologies in a simple push & pull situation. The combination of BGS trap and a 10% mix of catnip and homopiperazine helped to reduce human landing rates by up to 44.2% with a volunteer sitting behind the air curtain and the trap running in front of the curtain.