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Evaluation of a Push-Pull Approach for Aedes aegypti (L.) Using a Novel Dispensing System for Spatial Repellents in the Laboratory and in a Semi-Field Environment.

Obermayr U, Ruther J, Bernier UR, Rose A, Geier M - PLoS ONE (2015)

Bottom Line: A push-pull strategy might also significantly reduce human-vector contacts and augment existing mosquito control strategies, e.g. through the combination of an attractive trapping system and a potent spatial repellent.To impart a deterrent effect on mosquitoes at a distance, a homogenous and continuous dispersal of volatile repellent compounds is crucial.Nepetalactone, the main constituent of the oil, was detected in air at a concentration range of 80 to 100 μg/m3 and the amounts were comparable at all four sampling positions.

View Article: PubMed Central - PubMed

Affiliation: Biogents AG, Weissenburgstrasse 22, D-93055, Regensburg, Germany.

ABSTRACT
The increase in insecticide resistant mosquito populations necessitates the exploration of novel vector control intervention measures. Push-pull strategies for insect control have been successful when used in integrated crop pest management. Through the combinatory use of deterring and attracting stimuli, the abundance of insect pests can be changed in a given area. A push-pull strategy might also significantly reduce human-vector contacts and augment existing mosquito control strategies, e.g. through the combination of an attractive trapping system and a potent spatial repellent. Our approach includes the BG-Sentinel (BGS) trap in combination with catnip oil (Nepeta cataria), a known spatial repellent for Aedes aegypti. To impart a deterrent effect on mosquitoes at a distance, a homogenous and continuous dispersal of volatile repellent compounds is crucial. We have developed a repellent dispensing system that is easy to use and provides a homogenous dispersal of repellent in an air curtain. The use of five 9 V fans and custom-made repellent sachets containing 10% catnip essential oil created a repellent loaded air curtain that provided coverage of an area of 2 m2 (1.2 x 1.65 m). Air was sampled at four different heights in the curtain and analysed via thermal desorption (TD) and consecutive gas chromatography-mass spectrometry (GC-MS). Nepetalactone, the main constituent of the oil, was detected in air at a concentration range of 80 to 100 μg/m3 and the amounts were comparable at all four sampling positions. When a human volunteer was sitting behind the repellent curtain and a BGS trap was installed in front of the curtain in laboratory push-pull trials, Ae. aegypti landing collections decreased significantly by 50% compared to repellent-free controls. However, in a semi-field environment, comparable protective effects could not be achieved and further research on suitable repellent concentrations for outdoor implementation will be required.

No MeSH data available.


Related in: MedlinePlus

Semi-field set-up showing the tent inside the outdoor cage, BGS trap and FFS.
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pone.0129878.g003: Semi-field set-up showing the tent inside the outdoor cage, BGS trap and FFS.

Mentions: Due to the limited time outdoor test facilities were available, two experimental set-ups were used in semi field trials: [1] A BGS trap fitted with a BG lure dispenser was installed inside the tent as an attracting stimulus (Fig 3). Trap catch rates were documented in the presence of catnip and compared to control trials with paraffin oil only. [2] A human volunteer sat inside the tent to attract mosquitoes to fly through the air curtain while one BGS trap was installed outside (= push-pull set-up). Compared to laboratory trials, the greater space provided by the semi-field set-up necessitated a longer testing period. Mosquitoes were released at the far end of the cage and allowed for 1 h to respond to the test stimuli, following the USDA standard testing procedure for semi-field trials involving traps (Daniel L. Kline, personal communication). Mosquitoes approaching the volunteer were aspirated into collection tubes attached to a modified hand-held vacuum cleaner. At the end of a test, BGS catch bags and collection tubes were removed and stored at -20° for later counting. A total of 10 replicates were performed per treatment (repellent and control).


Evaluation of a Push-Pull Approach for Aedes aegypti (L.) Using a Novel Dispensing System for Spatial Repellents in the Laboratory and in a Semi-Field Environment.

Obermayr U, Ruther J, Bernier UR, Rose A, Geier M - PLoS ONE (2015)

Semi-field set-up showing the tent inside the outdoor cage, BGS trap and FFS.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482593&req=5

pone.0129878.g003: Semi-field set-up showing the tent inside the outdoor cage, BGS trap and FFS.
Mentions: Due to the limited time outdoor test facilities were available, two experimental set-ups were used in semi field trials: [1] A BGS trap fitted with a BG lure dispenser was installed inside the tent as an attracting stimulus (Fig 3). Trap catch rates were documented in the presence of catnip and compared to control trials with paraffin oil only. [2] A human volunteer sat inside the tent to attract mosquitoes to fly through the air curtain while one BGS trap was installed outside (= push-pull set-up). Compared to laboratory trials, the greater space provided by the semi-field set-up necessitated a longer testing period. Mosquitoes were released at the far end of the cage and allowed for 1 h to respond to the test stimuli, following the USDA standard testing procedure for semi-field trials involving traps (Daniel L. Kline, personal communication). Mosquitoes approaching the volunteer were aspirated into collection tubes attached to a modified hand-held vacuum cleaner. At the end of a test, BGS catch bags and collection tubes were removed and stored at -20° for later counting. A total of 10 replicates were performed per treatment (repellent and control).

Bottom Line: A push-pull strategy might also significantly reduce human-vector contacts and augment existing mosquito control strategies, e.g. through the combination of an attractive trapping system and a potent spatial repellent.To impart a deterrent effect on mosquitoes at a distance, a homogenous and continuous dispersal of volatile repellent compounds is crucial.Nepetalactone, the main constituent of the oil, was detected in air at a concentration range of 80 to 100 μg/m3 and the amounts were comparable at all four sampling positions.

View Article: PubMed Central - PubMed

Affiliation: Biogents AG, Weissenburgstrasse 22, D-93055, Regensburg, Germany.

ABSTRACT
The increase in insecticide resistant mosquito populations necessitates the exploration of novel vector control intervention measures. Push-pull strategies for insect control have been successful when used in integrated crop pest management. Through the combinatory use of deterring and attracting stimuli, the abundance of insect pests can be changed in a given area. A push-pull strategy might also significantly reduce human-vector contacts and augment existing mosquito control strategies, e.g. through the combination of an attractive trapping system and a potent spatial repellent. Our approach includes the BG-Sentinel (BGS) trap in combination with catnip oil (Nepeta cataria), a known spatial repellent for Aedes aegypti. To impart a deterrent effect on mosquitoes at a distance, a homogenous and continuous dispersal of volatile repellent compounds is crucial. We have developed a repellent dispensing system that is easy to use and provides a homogenous dispersal of repellent in an air curtain. The use of five 9 V fans and custom-made repellent sachets containing 10% catnip essential oil created a repellent loaded air curtain that provided coverage of an area of 2 m2 (1.2 x 1.65 m). Air was sampled at four different heights in the curtain and analysed via thermal desorption (TD) and consecutive gas chromatography-mass spectrometry (GC-MS). Nepetalactone, the main constituent of the oil, was detected in air at a concentration range of 80 to 100 μg/m3 and the amounts were comparable at all four sampling positions. When a human volunteer was sitting behind the repellent curtain and a BGS trap was installed in front of the curtain in laboratory push-pull trials, Ae. aegypti landing collections decreased significantly by 50% compared to repellent-free controls. However, in a semi-field environment, comparable protective effects could not be achieved and further research on suitable repellent concentrations for outdoor implementation will be required.

No MeSH data available.


Related in: MedlinePlus