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Efficacy of neem chippings for mosquito larval control under field conditions.

Imbahale SS, Mukabana WR - BMC Ecol. (2015)

Bottom Line: Within treated habitats, early instar anopheline mosquitoes were recovered more from habitats provided with neem and fish compared to Bti treated habitats.All treated habitats recorded higher numbers of early instar larvae than late instars or pupae, indicating that gravid female mosquitoes still oviposited within treated habitats.Neem chippings are a good tool for mosquito larval source management under field conditions.

View Article: PubMed Central - PubMed

Affiliation: International Centre of Insect Physiology and Ecology, P.O. Box 30772 GPO, Nairobi, Kenya. sueimbahale@yahoo.com.

ABSTRACT

Background: An in depth understanding of mosquito breeding biology and factors regulating population sizes is fundamental for vector population control. This paper presents results from a survey of mosquito breeding habitats and the efficacy of neem chippings as a potential larvicide that can be integrated in mosquito control on Nyabondo Plateau in western Kenya.

Results: Six main mosquito habitat types namely artificial ponds, abandoned fish ponds, active fish ponds, open drains, temporary pools and swamps were found in Nyabondo. Early anopheline instars were mainly recovered from temporary pools, artificial ponds and abandoned fish ponds. The mosquitoes collected were Anopheles gambiae sensu lato (35%), An. coustani (46%) and Culex spp (19%). Both early and late instar larvae of anopheline and culicine mosquitoes were more abundant in the controls than in the Bti and neem treated habitats. Within treated habitats, early instar anopheline mosquitoes were recovered more from habitats provided with neem and fish compared to Bti treated habitats. All treated habitats recorded higher numbers of early instar larvae than late instars or pupae, indicating that gravid female mosquitoes still oviposited within treated habitats.

Conclusions: Neem chippings are a good tool for mosquito larval source management under field conditions. However, more research needs to be done to quantify the contribution of this tool to the overall mosquito borne disease transmission.

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Related in: MedlinePlus

Physical appearance of mosquito larval habitat types identified on Nyabondo plateau in western Kenya. The habitats included artificial ponds (A), open drains (B), swamps (C), active fish ponds (D), abandoned fish ponds (E) and temporal pools (F).
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Fig1: Physical appearance of mosquito larval habitat types identified on Nyabondo plateau in western Kenya. The habitats included artificial ponds (A), open drains (B), swamps (C), active fish ponds (D), abandoned fish ponds (E) and temporal pools (F).

Mentions: A total of 339 (N) potential habitats were identified among which 57% had mosquito larvae. The rest (43%) had no larvae. A total of six mosquito larval habitat types were identified (Figure 1). These included artificial ponds, open drains, swamps, active fish ponds, abandoned fish ponds and temporary pools (Table 1). Temporary pools were composed of foot/hoof prints, tire tracks, brick pits and ground pools. Temporary pools held water for approximately two weeks after rains and dried out when rains ceased. Permanent habitats held water for approximately 2–3 months after the rains. Majority of the habitats sampled were permanent (62%) in nature, with sizes ranging from 10 - 100 m in surface perimeter (72%) and occurring as a result of human activities (96%). Exploratory statistical analyses found the presence or absence of mosquito larvae inside habitats to be affected by habitat type (χ2 = 21.974; df = 5; P = 0.001), habitat stability i.e. whether the habitats were temporary or permanent (χ2 = 22.317; df = 1; P = 0.001), source of water (χ2 = 5.254; df = 1; P = 0.022), habitat size (χ2 = 9.822; df = 2; P = 0.007) and vegetation (χ2 = 12.547; df = 1; P = 0.001) (Table 2). Habitat origin i.e. whether natural or manmade (P = 0.350) and water movement within habitats (P = 0.381) had no effect on presence or absence of mosquito larvae (Table 2). Further analysis using binary logistic regression found habitat stability (temporary or permanent) to be the only significant determinant of the presence or absence of mosquito larvae in habitats (OR 0.353; C.I. 0.203 - 0.614; P = 0.001). Permanent habitats had a 65% higher chance of containing mosquito larvae than temporary habitats.Figure 1


Efficacy of neem chippings for mosquito larval control under field conditions.

Imbahale SS, Mukabana WR - BMC Ecol. (2015)

Physical appearance of mosquito larval habitat types identified on Nyabondo plateau in western Kenya. The habitats included artificial ponds (A), open drains (B), swamps (C), active fish ponds (D), abandoned fish ponds (E) and temporal pools (F).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4355977&req=5

Fig1: Physical appearance of mosquito larval habitat types identified on Nyabondo plateau in western Kenya. The habitats included artificial ponds (A), open drains (B), swamps (C), active fish ponds (D), abandoned fish ponds (E) and temporal pools (F).
Mentions: A total of 339 (N) potential habitats were identified among which 57% had mosquito larvae. The rest (43%) had no larvae. A total of six mosquito larval habitat types were identified (Figure 1). These included artificial ponds, open drains, swamps, active fish ponds, abandoned fish ponds and temporary pools (Table 1). Temporary pools were composed of foot/hoof prints, tire tracks, brick pits and ground pools. Temporary pools held water for approximately two weeks after rains and dried out when rains ceased. Permanent habitats held water for approximately 2–3 months after the rains. Majority of the habitats sampled were permanent (62%) in nature, with sizes ranging from 10 - 100 m in surface perimeter (72%) and occurring as a result of human activities (96%). Exploratory statistical analyses found the presence or absence of mosquito larvae inside habitats to be affected by habitat type (χ2 = 21.974; df = 5; P = 0.001), habitat stability i.e. whether the habitats were temporary or permanent (χ2 = 22.317; df = 1; P = 0.001), source of water (χ2 = 5.254; df = 1; P = 0.022), habitat size (χ2 = 9.822; df = 2; P = 0.007) and vegetation (χ2 = 12.547; df = 1; P = 0.001) (Table 2). Habitat origin i.e. whether natural or manmade (P = 0.350) and water movement within habitats (P = 0.381) had no effect on presence or absence of mosquito larvae (Table 2). Further analysis using binary logistic regression found habitat stability (temporary or permanent) to be the only significant determinant of the presence or absence of mosquito larvae in habitats (OR 0.353; C.I. 0.203 - 0.614; P = 0.001). Permanent habitats had a 65% higher chance of containing mosquito larvae than temporary habitats.Figure 1

Bottom Line: Within treated habitats, early instar anopheline mosquitoes were recovered more from habitats provided with neem and fish compared to Bti treated habitats.All treated habitats recorded higher numbers of early instar larvae than late instars or pupae, indicating that gravid female mosquitoes still oviposited within treated habitats.Neem chippings are a good tool for mosquito larval source management under field conditions.

View Article: PubMed Central - PubMed

Affiliation: International Centre of Insect Physiology and Ecology, P.O. Box 30772 GPO, Nairobi, Kenya. sueimbahale@yahoo.com.

ABSTRACT

Background: An in depth understanding of mosquito breeding biology and factors regulating population sizes is fundamental for vector population control. This paper presents results from a survey of mosquito breeding habitats and the efficacy of neem chippings as a potential larvicide that can be integrated in mosquito control on Nyabondo Plateau in western Kenya.

Results: Six main mosquito habitat types namely artificial ponds, abandoned fish ponds, active fish ponds, open drains, temporary pools and swamps were found in Nyabondo. Early anopheline instars were mainly recovered from temporary pools, artificial ponds and abandoned fish ponds. The mosquitoes collected were Anopheles gambiae sensu lato (35%), An. coustani (46%) and Culex spp (19%). Both early and late instar larvae of anopheline and culicine mosquitoes were more abundant in the controls than in the Bti and neem treated habitats. Within treated habitats, early instar anopheline mosquitoes were recovered more from habitats provided with neem and fish compared to Bti treated habitats. All treated habitats recorded higher numbers of early instar larvae than late instars or pupae, indicating that gravid female mosquitoes still oviposited within treated habitats.

Conclusions: Neem chippings are a good tool for mosquito larval source management under field conditions. However, more research needs to be done to quantify the contribution of this tool to the overall mosquito borne disease transmission.

Show MeSH
Related in: MedlinePlus