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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

Laboratory test set-up showing the tent structure, BGS trap and FFS (front view).
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pone.0129878.g001: Laboratory test set-up showing the tent structure, BGS trap and FFS (front view).

Mentions: The FFS consisted of a 120 x 15 x 30 cm wooden frame into which five 12 V DC fans were mounted equidistantly with the down flow facing the tent opening (Fig 1). The fans could be operated at 3, 4.5, 6, 7.5, 9 and 12 V, with each voltage creating different air speeds in the tent opening (S1 Table). Control tests were used to identify the speed that did not generate a mechanical barrier to the mosquitoes. Mosquitoes were able to overcome the air curtain at all tested speeds (S3 Fig), even at 0.8–2.0 m/s which were measured in the center of the opening when fans were operated at 12 V. The lowest variation was found at 9 V, when wind speeds in the center of the opening reached 0.8–1.4 m/s. Based on these findings, all consecutive trials were conducted with fans operating at 9 V. Smoke experiments (data not shown) indicated that the entire tent opening was uniformly covered (S4 Fig), the volume of the generated air curtain was estimated at approximately 0.24 m³ (1.7 x 1.2 x 0.12 m)


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)

Laboratory test set-up showing the tent structure, BGS trap and FFS (front view).
© Copyright Policy
Related In: Results  -  Collection

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

pone.0129878.g001: Laboratory test set-up showing the tent structure, BGS trap and FFS (front view).
Mentions: The FFS consisted of a 120 x 15 x 30 cm wooden frame into which five 12 V DC fans were mounted equidistantly with the down flow facing the tent opening (Fig 1). The fans could be operated at 3, 4.5, 6, 7.5, 9 and 12 V, with each voltage creating different air speeds in the tent opening (S1 Table). Control tests were used to identify the speed that did not generate a mechanical barrier to the mosquitoes. Mosquitoes were able to overcome the air curtain at all tested speeds (S3 Fig), even at 0.8–2.0 m/s which were measured in the center of the opening when fans were operated at 12 V. The lowest variation was found at 9 V, when wind speeds in the center of the opening reached 0.8–1.4 m/s. Based on these findings, all consecutive trials were conducted with fans operating at 9 V. Smoke experiments (data not shown) indicated that the entire tent opening was uniformly covered (S4 Fig), the volume of the generated air curtain was estimated at approximately 0.24 m³ (1.7 x 1.2 x 0.12 m)

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