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An improved autocidal gravid ovitrap for the control and surveillance of Aedes aegypti.

Mackay AJ, Amador M, Barrera R - Parasit Vectors (2013)

Bottom Line: We had developed an autocidal gravid ovitrap (AGO) as a simple, low-cost device for surveillance and control of Ae. aegypti without the use of pesticides that does not require servicing for an extended period of time.Semi-weekly collections of Ae. aegypti females in the AGO-B were significantly correlated with cumulative rainfall 8 to 28 days prior to sampling, whereas egg collections in paired conventional ovitraps were not.When vector abundance was low, the AGO-B provided greater sensitivity and precision as a surveillance device, compared with paired conventional ovitraps.

View Article: PubMed Central - HTML - PubMed

Affiliation: Entomology and Ecology Activity, Dengue Branch, Centers for Disease Control and Prevention, 1324 Calle Cañada, San Juan, Puerto Rico. amackay@illinois.edu

ABSTRACT

Background: Limited success has been achieved using traditional vector control methods to prevent the transmission of dengue viruses. Integrated control programs incorporating alternative tools, such as gravid ovitraps (lethal ovitraps and sticky ovitraps) may provide greater potential for monitoring and reducing vector populations and dengue virus transmission. We had developed an autocidal gravid ovitrap (AGO) as a simple, low-cost device for surveillance and control of Ae. aegypti without the use of pesticides that does not require servicing for an extended period of time. The purpose of our study was to improve the efficacy and efficiency of this device.

Methods: Competitive assays were performed in the laboratory and an outdoor cage to evaluate whether modifications to the structure and appearance of our original trap design (AGO-A), and the addition of an olfactory bait (hay infusion), improve trap function. The performance of a modified trap design (AGO-B) was then assessed and compared with conventional ovitraps in a series of field tests in San Juan City, Puerto Rico. Generalized linear mixed models were used to analyze adult Ae. aegypti capture data from the laboratory, outdoor cage and field experiments.

Results: Increasing the size of the trap entrance, altering the color of trap components, and increasing the volume/surface area of the aqueous bait significantly improved the performance of the AGO in the outdoor cage. In a subsequent field comparison, captures of Ae. aegypti females were 3.7 fold greater in the improved trap (AGO-B), compared with the original design (AGO-A). An infusion bait produced "in situ" significantly improved capture rates of the improved trap under both semi-natural and field conditions. Semi-weekly collections of Ae. aegypti females in the AGO-B were significantly correlated with cumulative rainfall 8 to 28 days prior to sampling, whereas egg collections in paired conventional ovitraps were not. When vector abundance was low, the AGO-B provided greater sensitivity and precision as a surveillance device, compared with paired conventional ovitraps.

Conclusions: The AGO-B can be used to efficiently attract and capture gravid Ae. aegypti females for more than 8 weeks without the need for trap maintenance.

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Related in: MedlinePlus

Field comparison of original (AGO-A) and improved (AGO-B) trap designs. Cumulative daily rainfall and average daily mean air temperature 8 to 28 days preceding sampling (a), and the average numbers of Aedes eggs collected in ovitrap pairs and Aedes aegypti adult females collected in AGOs (b), from 15 February to 18 April, 2011 (Field experiment 1).
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Figure 4: Field comparison of original (AGO-A) and improved (AGO-B) trap designs. Cumulative daily rainfall and average daily mean air temperature 8 to 28 days preceding sampling (a), and the average numbers of Aedes eggs collected in ovitrap pairs and Aedes aegypti adult females collected in AGOs (b), from 15 February to 18 April, 2011 (Field experiment 1).

Mentions: In the first field experiment, the mean numbers of Ae. aegypti females collected on each collection date were on average 3.7 fold greater in the AGO-B than in the original (AGO-A) trap design (Figure 4). In the second field experiment (Figure 5), traps with a partial replacement of the infusion bait (AGO-Bp), and traps with a complete bait replacement (AGO-B) captured similar numbers of Ae. aegypti females on most collection dates. In the third field experiment (Figure 6), the addition of hay increased the capture rate of Ae. aegypti females in the AGO-B by an average of 1.6 fold, compared with traps only baited with water (AGO-Bw).


An improved autocidal gravid ovitrap for the control and surveillance of Aedes aegypti.

Mackay AJ, Amador M, Barrera R - Parasit Vectors (2013)

Field comparison of original (AGO-A) and improved (AGO-B) trap designs. Cumulative daily rainfall and average daily mean air temperature 8 to 28 days preceding sampling (a), and the average numbers of Aedes eggs collected in ovitrap pairs and Aedes aegypti adult females collected in AGOs (b), from 15 February to 18 April, 2011 (Field experiment 1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750875&req=5

Figure 4: Field comparison of original (AGO-A) and improved (AGO-B) trap designs. Cumulative daily rainfall and average daily mean air temperature 8 to 28 days preceding sampling (a), and the average numbers of Aedes eggs collected in ovitrap pairs and Aedes aegypti adult females collected in AGOs (b), from 15 February to 18 April, 2011 (Field experiment 1).
Mentions: In the first field experiment, the mean numbers of Ae. aegypti females collected on each collection date were on average 3.7 fold greater in the AGO-B than in the original (AGO-A) trap design (Figure 4). In the second field experiment (Figure 5), traps with a partial replacement of the infusion bait (AGO-Bp), and traps with a complete bait replacement (AGO-B) captured similar numbers of Ae. aegypti females on most collection dates. In the third field experiment (Figure 6), the addition of hay increased the capture rate of Ae. aegypti females in the AGO-B by an average of 1.6 fold, compared with traps only baited with water (AGO-Bw).

Bottom Line: We had developed an autocidal gravid ovitrap (AGO) as a simple, low-cost device for surveillance and control of Ae. aegypti without the use of pesticides that does not require servicing for an extended period of time.Semi-weekly collections of Ae. aegypti females in the AGO-B were significantly correlated with cumulative rainfall 8 to 28 days prior to sampling, whereas egg collections in paired conventional ovitraps were not.When vector abundance was low, the AGO-B provided greater sensitivity and precision as a surveillance device, compared with paired conventional ovitraps.

View Article: PubMed Central - HTML - PubMed

Affiliation: Entomology and Ecology Activity, Dengue Branch, Centers for Disease Control and Prevention, 1324 Calle Cañada, San Juan, Puerto Rico. amackay@illinois.edu

ABSTRACT

Background: Limited success has been achieved using traditional vector control methods to prevent the transmission of dengue viruses. Integrated control programs incorporating alternative tools, such as gravid ovitraps (lethal ovitraps and sticky ovitraps) may provide greater potential for monitoring and reducing vector populations and dengue virus transmission. We had developed an autocidal gravid ovitrap (AGO) as a simple, low-cost device for surveillance and control of Ae. aegypti without the use of pesticides that does not require servicing for an extended period of time. The purpose of our study was to improve the efficacy and efficiency of this device.

Methods: Competitive assays were performed in the laboratory and an outdoor cage to evaluate whether modifications to the structure and appearance of our original trap design (AGO-A), and the addition of an olfactory bait (hay infusion), improve trap function. The performance of a modified trap design (AGO-B) was then assessed and compared with conventional ovitraps in a series of field tests in San Juan City, Puerto Rico. Generalized linear mixed models were used to analyze adult Ae. aegypti capture data from the laboratory, outdoor cage and field experiments.

Results: Increasing the size of the trap entrance, altering the color of trap components, and increasing the volume/surface area of the aqueous bait significantly improved the performance of the AGO in the outdoor cage. In a subsequent field comparison, captures of Ae. aegypti females were 3.7 fold greater in the improved trap (AGO-B), compared with the original design (AGO-A). An infusion bait produced "in situ" significantly improved capture rates of the improved trap under both semi-natural and field conditions. Semi-weekly collections of Ae. aegypti females in the AGO-B were significantly correlated with cumulative rainfall 8 to 28 days prior to sampling, whereas egg collections in paired conventional ovitraps were not. When vector abundance was low, the AGO-B provided greater sensitivity and precision as a surveillance device, compared with paired conventional ovitraps.

Conclusions: The AGO-B can be used to efficiently attract and capture gravid Ae. aegypti females for more than 8 weeks without the need for trap maintenance.

Show MeSH
Related in: MedlinePlus