Survival of Immature Anopheles Arabiensis (Diptera: Culicidae) in Aquatic Habitats in Mwea rice Irrigation Scheme, Central Kenya

dc.contributor.authorShililu, J. I.
dc.date.accessioned2014-02-04T09:12:40Z
dc.date.available2014-02-04T09:12:40Z
dc.date.issued2006
dc.descriptionDOI: 10.1186/1475-2875-5-114en_US
dc.description.abstractBackground The survivorship and distribution of Anopheles arabiensis larvae and pupae was examined in a rice agro-ecosystem in Mwea Irrigation Scheme, central Kenya, from August 2005 to April 2006, prior to implementation of larval control programme. Methods Horizontal life tables were constructed for immatures in semi-field condition. The time spent in the various immature stages was determined and survival established. Vertical life tables were obtained from five paddies sampled by standard dipping technique. Results Pre-adult developmental time for An. arabiensis in the trays in the experimental set up in the screen house was 11.85 days from eclosion to emergence. The mean duration of each instar stage was estimated to be 1.40 days for first instars, 2.90 days for second instars, 1.85 days for third instars, 3.80 days for fourth instars and 1.90 days for pupae. A total of 590 individuals emerged into adults, giving an overall survivorship from L1 to adult emergence of 69.4%. A total of 4,956 An. arabiensis immatures were collected in 1,400 dips throughout the sampling period. Of these, 55.9% were collected during the tillering stage, 42.5% during the transplanting period and 1.6% during the land preparation stage. There was a significant difference in the An. arabiensis larval densities among the five stages. Also there was significant variation in immature stage composition for each day's collection in each paddy. These results indicate that the survival of the immatures was higher in some paddies than others. The mortality rate during the transplanting was 99.9% and at tillering was 96.6%, while the overall mortality was 98.3%. Conclusion The survival of An. arabiensis immatures was better during the tillering stage of rice growth. Further the survival of immatures in rice fields is influenced by the rice agronomic activities including addition of nitrogenous fertilizers and pesticides. For effective integrated vector management, the application of larvicides should target An. arabiensis larvae at the tillering stage (early vegetative stage of rice) when their survival in the aquatic habitats is high to significantly reduce them and the larvicides should be long-lasting to have a significant impact on the malaria vector productivity on the habitatsen_US
dc.identifier.citationMalaria Journal November 2006, 5:114en_US
dc.identifier.issn1475-2875
dc.identifier.urihttp://ir-library.ku.ac.ke/handle/123456789/8922
dc.language.isoenen_US
dc.publisherBioMed Centralen_US
dc.titleSurvival of Immature Anopheles Arabiensis (Diptera: Culicidae) in Aquatic Habitats in Mwea rice Irrigation Scheme, Central Kenyaen_US
dc.typeArticleen_US
Files
Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Survival of immature Anopheles....pdf
Size:
246.13 KB
Format:
Adobe Portable Document Format
Description:
Full Text Article
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description: