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Oviposition responses of Aedes mosquitoes to bacterial isolates from attractive bamboo infusions.

Ponnusamy L, Schal C, Wesson DM, Arellano C, Apperson CS - Parasit Vectors (2015)

Bottom Line: When we tested single bacterial isolates, seven isolates (B1, B2, B3, B5, B12, B13 and B14) were significantly attractive to Ae. aegypti, and six isolates (B1, B5, B7, B10, B13 and B14) significantly attracted Ae. albopictus.Our results show that at specific cell densities, some bacteria significantly influence the attraction of gravid Ae. aegypti and Ae. albopictus females to potential oviposition sites.Attractive bacterial isolates, when formulated for sustained release of attractants, could be coupled with an ovitrap containing a toxicant to achieve area-wide management of Aedes mosquitoes.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology and W. M. Keck Center for Behavioral Biology, North Carolina State University, Campus Box 7613, Raleigh, NC, 27695-7613, USA. loganathan_ponnusamy@ncsu.edu.

ABSTRACT

Background: The mosquitoes Aedes aegypti and Aedes albopictus are vectors of pathogenic viruses that cause major human illnesses including dengue, yellow fever and chikungunya. Both mosquito species are expanding their geographic distributions and now occur worldwide in temperate and tropical climates. Collection of eggs in oviposition traps (ovitraps) is commonly used for monitoring and surveillance of container-inhabiting Aedes populations by public health agencies charged with managing mosquito-transmitted illness. Addition of an organic infusion in these traps increases the number of eggs deposited. Gravid females are guided to ovitraps by volatile chemicals produced from the breakdown of organic matter by microbes.

Methods: We previously isolated and cultured 14 species of bacteria from attractive experimental infusions, made from the senescent leaves of canebrake bamboo (Arundinaria gigantea). Cultures were grown for 24 h at 28 °C with constant shaking (120 rpm) and cell densities were determined with a hemocytometer. Behavioral responses to single bacterial isolates and to a mix of isolates at different cell densities were evaluated using two-choice sticky-screen bioassay methods with gravid Ae. aegypti and Ae. albopictus.

Results: In behavioral assays of a mix of 14 bacterial isolates, significantly greater attraction responses were exhibited by Ae. aegypti and Ae. albopictus to bacterial densities of 10(7) and 10(8) cells/mL than to the control medium. When we tested single bacterial isolates, seven isolates (B1, B2, B3, B5, B12, B13 and B14) were significantly attractive to Ae. aegypti, and six isolates (B1, B5, B7, B10, B13 and B14) significantly attracted Ae. albopictus. Among all the isolates tested at three different cell densities, bacterial isolates B1, B5, B13 and B14 were highly attractive to both Aedes species.

Conclusions: Our results show that at specific cell densities, some bacteria significantly influence the attraction of gravid Ae. aegypti and Ae. albopictus females to potential oviposition sites. Attractive bacterial isolates, when formulated for sustained release of attractants, could be coupled with an ovitrap containing a toxicant to achieve area-wide management of Aedes mosquitoes.

No MeSH data available.


Related in: MedlinePlus

Results of 2-choice sticky screen attraction bioassays in which different bacterial species in MR2A liquid medium were tested for their attractiveness to Ae. aegypti against plain MR2A medium. Bars show the mean percentage of gravid females trapped on the sticky screens. Error bars represent half-width of a 95 % confidence intervals of the mean (SEM X 1.96). Each test consisted of 18 assays with 10 gravid females per assay. Bacterial isolates that did not elicit significant responses to any of the three cell densities and those that elicited significant responses to only one cell density are not shown in this figure. NR = not responding
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Fig1: Results of 2-choice sticky screen attraction bioassays in which different bacterial species in MR2A liquid medium were tested for their attractiveness to Ae. aegypti against plain MR2A medium. Bars show the mean percentage of gravid females trapped on the sticky screens. Error bars represent half-width of a 95 % confidence intervals of the mean (SEM X 1.96). Each test consisted of 18 assays with 10 gravid females per assay. Bacterial isolates that did not elicit significant responses to any of the three cell densities and those that elicited significant responses to only one cell density are not shown in this figure. NR = not responding

Mentions: Behavioral assays of each bacterial isolate indicated that seven isolates (B1, B2, B3, B5, B12, B13 and B14; see Table 1) elicited statistically significant attraction at two cell densities (Fig. 1, Table 3) . With these isolates, gravid mosquitoes were attracted to bacteria at 107 and 106 cells/mL, but responses to the highest bacterial cell density of 108 cells/mL were not significantly different from responses to MR2A medium alone (P > 0.05). Some bacterial isolates significantly attracted gravid females at only a single cell density, namely B4 (107 cells/mL, P = 0.0217), B6 (106 cells/mL, P = 0.0051), and B7 (106 cells/mL, P = 0.0407) (data not shown). Ae. aegypti females were repelled by one isolate at a cell density of 108 cells/mL (B11, P = 0.0407). Bacterial isolates B8, B9 and B10 did not elicit significant responses to any of the three cell densities tested (Table 3). Among all the isolates tested at three different cell densities, approximately 10 to 21 % of the Ae. aegypti females remained free in the test arena.Fig. 1


Oviposition responses of Aedes mosquitoes to bacterial isolates from attractive bamboo infusions.

Ponnusamy L, Schal C, Wesson DM, Arellano C, Apperson CS - Parasit Vectors (2015)

Results of 2-choice sticky screen attraction bioassays in which different bacterial species in MR2A liquid medium were tested for their attractiveness to Ae. aegypti against plain MR2A medium. Bars show the mean percentage of gravid females trapped on the sticky screens. Error bars represent half-width of a 95 % confidence intervals of the mean (SEM X 1.96). Each test consisted of 18 assays with 10 gravid females per assay. Bacterial isolates that did not elicit significant responses to any of the three cell densities and those that elicited significant responses to only one cell density are not shown in this figure. NR = not responding
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4581471&req=5

Fig1: Results of 2-choice sticky screen attraction bioassays in which different bacterial species in MR2A liquid medium were tested for their attractiveness to Ae. aegypti against plain MR2A medium. Bars show the mean percentage of gravid females trapped on the sticky screens. Error bars represent half-width of a 95 % confidence intervals of the mean (SEM X 1.96). Each test consisted of 18 assays with 10 gravid females per assay. Bacterial isolates that did not elicit significant responses to any of the three cell densities and those that elicited significant responses to only one cell density are not shown in this figure. NR = not responding
Mentions: Behavioral assays of each bacterial isolate indicated that seven isolates (B1, B2, B3, B5, B12, B13 and B14; see Table 1) elicited statistically significant attraction at two cell densities (Fig. 1, Table 3) . With these isolates, gravid mosquitoes were attracted to bacteria at 107 and 106 cells/mL, but responses to the highest bacterial cell density of 108 cells/mL were not significantly different from responses to MR2A medium alone (P > 0.05). Some bacterial isolates significantly attracted gravid females at only a single cell density, namely B4 (107 cells/mL, P = 0.0217), B6 (106 cells/mL, P = 0.0051), and B7 (106 cells/mL, P = 0.0407) (data not shown). Ae. aegypti females were repelled by one isolate at a cell density of 108 cells/mL (B11, P = 0.0407). Bacterial isolates B8, B9 and B10 did not elicit significant responses to any of the three cell densities tested (Table 3). Among all the isolates tested at three different cell densities, approximately 10 to 21 % of the Ae. aegypti females remained free in the test arena.Fig. 1

Bottom Line: When we tested single bacterial isolates, seven isolates (B1, B2, B3, B5, B12, B13 and B14) were significantly attractive to Ae. aegypti, and six isolates (B1, B5, B7, B10, B13 and B14) significantly attracted Ae. albopictus.Our results show that at specific cell densities, some bacteria significantly influence the attraction of gravid Ae. aegypti and Ae. albopictus females to potential oviposition sites.Attractive bacterial isolates, when formulated for sustained release of attractants, could be coupled with an ovitrap containing a toxicant to achieve area-wide management of Aedes mosquitoes.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology and W. M. Keck Center for Behavioral Biology, North Carolina State University, Campus Box 7613, Raleigh, NC, 27695-7613, USA. loganathan_ponnusamy@ncsu.edu.

ABSTRACT

Background: The mosquitoes Aedes aegypti and Aedes albopictus are vectors of pathogenic viruses that cause major human illnesses including dengue, yellow fever and chikungunya. Both mosquito species are expanding their geographic distributions and now occur worldwide in temperate and tropical climates. Collection of eggs in oviposition traps (ovitraps) is commonly used for monitoring and surveillance of container-inhabiting Aedes populations by public health agencies charged with managing mosquito-transmitted illness. Addition of an organic infusion in these traps increases the number of eggs deposited. Gravid females are guided to ovitraps by volatile chemicals produced from the breakdown of organic matter by microbes.

Methods: We previously isolated and cultured 14 species of bacteria from attractive experimental infusions, made from the senescent leaves of canebrake bamboo (Arundinaria gigantea). Cultures were grown for 24 h at 28 °C with constant shaking (120 rpm) and cell densities were determined with a hemocytometer. Behavioral responses to single bacterial isolates and to a mix of isolates at different cell densities were evaluated using two-choice sticky-screen bioassay methods with gravid Ae. aegypti and Ae. albopictus.

Results: In behavioral assays of a mix of 14 bacterial isolates, significantly greater attraction responses were exhibited by Ae. aegypti and Ae. albopictus to bacterial densities of 10(7) and 10(8) cells/mL than to the control medium. When we tested single bacterial isolates, seven isolates (B1, B2, B3, B5, B12, B13 and B14) were significantly attractive to Ae. aegypti, and six isolates (B1, B5, B7, B10, B13 and B14) significantly attracted Ae. albopictus. Among all the isolates tested at three different cell densities, bacterial isolates B1, B5, B13 and B14 were highly attractive to both Aedes species.

Conclusions: Our results show that at specific cell densities, some bacteria significantly influence the attraction of gravid Ae. aegypti and Ae. albopictus females to potential oviposition sites. Attractive bacterial isolates, when formulated for sustained release of attractants, could be coupled with an ovitrap containing a toxicant to achieve area-wide management of Aedes mosquitoes.

No MeSH data available.


Related in: MedlinePlus