Infection of the malaria mosquito, <it>Anopheles gambiae</it>, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence
<p>Abstract</p> <p>Background</p> <p>Entomopathogenic fungi <it>Metarhizium anisopliae </it>and <it>Beauveria bassiana </it>isolates have been shown to infect and reduce the survival of mosquito vectors.</p> <p>Methods</p> <p...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2009-12-01
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| Series: | Malaria Journal |
| Online Access: | http://www.malariajournal.com/content/8/1/309 |
| _version_ | 1819137976783863808 |
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| author | Lwetoijera Dickson W Kirby Matthew J Mnyone Ladslaus L Mpingwa Monica W Knols Bart GJ Takken Willem Russell Tanya L |
| author_facet | Lwetoijera Dickson W Kirby Matthew J Mnyone Ladslaus L Mpingwa Monica W Knols Bart GJ Takken Willem Russell Tanya L |
| author_sort | Lwetoijera Dickson W |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Entomopathogenic fungi <it>Metarhizium anisopliae </it>and <it>Beauveria bassiana </it>isolates have been shown to infect and reduce the survival of mosquito vectors.</p> <p>Methods</p> <p>Here four different bioassays were conducted to study the effect of conidia concentration, co-formulation, exposure time and persistence of the isolates <it>M. anisopliae </it>ICIPE-30 and <it>B. bassiana </it>I93-925 on infection and survival rates of female <it>Anopheles gambiae sensu stricto</it>. Test concentrations and exposure times ranged between 1 × 10<sup>7 </sup>- 4 × 10<sup>10 </sup>conidia m<sup>-2 </sup>and 15 min - 6 h. In co-formulations, 2 × 10<sup>10 </sup>conidia m<sup>-2 </sup>of both fungus isolates were mixed at ratios of 4:1, 2:1, 1:1,1:0, 0:1, 1:2 and 1:4. To determine persistence, mosquitoes were exposed to surfaces treated 1, 14 or 28 d previously, with conidia concentrations of 2 × 10<sup>9</sup>, 2 × 10<sup>10 </sup>or 4 × 10<sup>10</sup>.</p> <p>Results</p> <p>Mosquito survival varied with conidia concentration; 2 × 10<sup>10 </sup>conidia m<sup>-2 </sup>was the concentration above which no further reductions in survival were detectable for both isolates of fungus. The survival of mosquitoes exposed to single and co-formulated treatments was similar and no synergistic or additive effects were observed. Mosquitoes were infected within 30 min and longer exposure times did not result in a more rapid killing effect. Fifteen min exposure still achieved considerable mortality rates (100% mortality by 14 d) of mosquitoes, but at lower speed than with 30 min exposure (100% mortality by 9 d). Conidia remained infective up to 28 d post-application but higher concentrations did not increase persistence.</p> <p>Conclusion</p> <p>Both fungus isolates are effective and persistent at low concentrations and short exposure times.</p> |
| first_indexed | 2024-12-22T10:59:26Z |
| format | Article |
| id | doaj.art-50e87e71290e446ea092600095ed028a |
| institution | Directory Open Access Journal |
| issn | 1475-2875 |
| language | English |
| last_indexed | 2024-12-22T10:59:26Z |
| publishDate | 2009-12-01 |
| publisher | BMC |
| record_format | Article |
| series | Malaria Journal |
| spelling | doaj.art-50e87e71290e446ea092600095ed028a2022-12-21T18:28:32ZengBMCMalaria Journal1475-28752009-12-018130910.1186/1475-2875-8-309Infection of the malaria mosquito, <it>Anopheles gambiae</it>, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistenceLwetoijera Dickson WKirby Matthew JMnyone Ladslaus LMpingwa Monica WKnols Bart GJTakken WillemRussell Tanya L<p>Abstract</p> <p>Background</p> <p>Entomopathogenic fungi <it>Metarhizium anisopliae </it>and <it>Beauveria bassiana </it>isolates have been shown to infect and reduce the survival of mosquito vectors.</p> <p>Methods</p> <p>Here four different bioassays were conducted to study the effect of conidia concentration, co-formulation, exposure time and persistence of the isolates <it>M. anisopliae </it>ICIPE-30 and <it>B. bassiana </it>I93-925 on infection and survival rates of female <it>Anopheles gambiae sensu stricto</it>. Test concentrations and exposure times ranged between 1 × 10<sup>7 </sup>- 4 × 10<sup>10 </sup>conidia m<sup>-2 </sup>and 15 min - 6 h. In co-formulations, 2 × 10<sup>10 </sup>conidia m<sup>-2 </sup>of both fungus isolates were mixed at ratios of 4:1, 2:1, 1:1,1:0, 0:1, 1:2 and 1:4. To determine persistence, mosquitoes were exposed to surfaces treated 1, 14 or 28 d previously, with conidia concentrations of 2 × 10<sup>9</sup>, 2 × 10<sup>10 </sup>or 4 × 10<sup>10</sup>.</p> <p>Results</p> <p>Mosquito survival varied with conidia concentration; 2 × 10<sup>10 </sup>conidia m<sup>-2 </sup>was the concentration above which no further reductions in survival were detectable for both isolates of fungus. The survival of mosquitoes exposed to single and co-formulated treatments was similar and no synergistic or additive effects were observed. Mosquitoes were infected within 30 min and longer exposure times did not result in a more rapid killing effect. Fifteen min exposure still achieved considerable mortality rates (100% mortality by 14 d) of mosquitoes, but at lower speed than with 30 min exposure (100% mortality by 9 d). Conidia remained infective up to 28 d post-application but higher concentrations did not increase persistence.</p> <p>Conclusion</p> <p>Both fungus isolates are effective and persistent at low concentrations and short exposure times.</p>http://www.malariajournal.com/content/8/1/309 |
| spellingShingle | Lwetoijera Dickson W Kirby Matthew J Mnyone Ladslaus L Mpingwa Monica W Knols Bart GJ Takken Willem Russell Tanya L Infection of the malaria mosquito, <it>Anopheles gambiae</it>, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence Malaria Journal |
| title | Infection of the malaria mosquito, <it>Anopheles gambiae</it>, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence |
| title_full | Infection of the malaria mosquito, <it>Anopheles gambiae</it>, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence |
| title_fullStr | Infection of the malaria mosquito, <it>Anopheles gambiae</it>, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence |
| title_full_unstemmed | Infection of the malaria mosquito, <it>Anopheles gambiae</it>, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence |
| title_short | Infection of the malaria mosquito, <it>Anopheles gambiae</it>, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence |
| title_sort | infection of the malaria mosquito it anopheles gambiae it with two species of entomopathogenic fungi effects of concentration co formulation exposure time and persistence |
| url | http://www.malariajournal.com/content/8/1/309 |
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