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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

Stericlin repellent sachet attached to the FFS with the permeable side facing the fans.
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pone.0129878.g002: Stericlin repellent sachet attached to the FFS with the permeable side facing the fans.

Mentions: Prior to the start of a test, a repellent sachet was hung into the frame with its permeable Tyvek-side facing the row of fans (Fig 2). Mosquitoes were released immediately after the system was switched on. In all experiments, a BGS trap fitted with a BG-Lure dispenser was used as a proxy for a human target and placed inside the tent to attract host-seeking Ae. aegypti. Those mosquitoes that passed the air curtain were captured by the trap. For each individual test, 10 mosquitoes were released into the room at the side furthest away from the tent and allowed to respond for 15 min. Preliminary room tests had revealed that this was the maximum time period needed for all mosquitoes to be caught by the BGS trap and/or volunteer At the end of the test time, the investigator entered the room and documented the trap catch rate. Still free flying mosquitoes were aspirated with a modified hand-held vaccuum cleaner. Mosquitoes that did not approach the investigator or that were still sitting inside the transport cage were recorded as inactive. For each dispensing system, 10 replicates were conducted per treatment (repellent and control). Treatments were tested in a randomized order. To avoid an accumulation of the volatile stimuli, the room was aerated for 30 min before the next test was conducted.


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)

Stericlin repellent sachet attached to the FFS with the permeable side facing the fans.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0129878.g002: Stericlin repellent sachet attached to the FFS with the permeable side facing the fans.
Mentions: Prior to the start of a test, a repellent sachet was hung into the frame with its permeable Tyvek-side facing the row of fans (Fig 2). Mosquitoes were released immediately after the system was switched on. In all experiments, a BGS trap fitted with a BG-Lure dispenser was used as a proxy for a human target and placed inside the tent to attract host-seeking Ae. aegypti. Those mosquitoes that passed the air curtain were captured by the trap. For each individual test, 10 mosquitoes were released into the room at the side furthest away from the tent and allowed to respond for 15 min. Preliminary room tests had revealed that this was the maximum time period needed for all mosquitoes to be caught by the BGS trap and/or volunteer At the end of the test time, the investigator entered the room and documented the trap catch rate. Still free flying mosquitoes were aspirated with a modified hand-held vaccuum cleaner. Mosquitoes that did not approach the investigator or that were still sitting inside the transport cage were recorded as inactive. For each dispensing system, 10 replicates were conducted per treatment (repellent and control). Treatments were tested in a randomized order. To avoid an accumulation of the volatile stimuli, the room was aerated for 30 min before the next test was conducted.

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