Unexpected high losses of Anopheles gambiae larvae due to rainfall.

BACKGROUND: Immature stages of the malaria mosquito Anopheles gambiae experience high mortality, but its cause is poorly understood. Here we study the impact of rainfall, one of the abiotic factors to which the immatures are frequently exposed, on their mortality. METHODOLOGY/PRINCIPAL FINDINGS: We...

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Main Authors: Krijn P Paaijmans, Moses O Wandago, Andrew K Githeko, Willem Takken
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2007-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC2063461?pdf=render
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author Krijn P Paaijmans
Moses O Wandago
Andrew K Githeko
Willem Takken
author_facet Krijn P Paaijmans
Moses O Wandago
Andrew K Githeko
Willem Takken
author_sort Krijn P Paaijmans
collection DOAJ
description BACKGROUND: Immature stages of the malaria mosquito Anopheles gambiae experience high mortality, but its cause is poorly understood. Here we study the impact of rainfall, one of the abiotic factors to which the immatures are frequently exposed, on their mortality. METHODOLOGY/PRINCIPAL FINDINGS: We show that rainfall significantly affected larval mosquitoes by flushing them out of their aquatic habitat and killing them. Outdoor experiments under natural conditions in Kenya revealed that the additional nightly loss of larvae caused by rainfall was on average 17.5% for the youngest (L1) larvae and 4.8% for the oldest (L4) larvae; an additional 10.5% (increase from 0.9 to 11.4%) of the L1 larvae and 3.3% (from 0.1 to 3.4%) of the L4 larvae were flushed away and larval mortality increased by 6.9% (from 4.6 to 11.5%) and 1.5% (from 4.1 to 5.6%) for L1 and L4 larvae, respectively, compared to nights without rain. On rainy nights, 1.3% and 0.7% of L1 and L4 larvae, respectively, were lost due to ejection from the breeding site. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that immature populations of malaria mosquitoes suffer high losses during rainfall events. As these populations are likely to experience several rain showers during their lifespan, rainfall will have a profound effect on the productivity of mosquito breeding sites and, as a result, on the transmission of malaria. These findings are discussed in the light of malaria risk and changing rainfall patterns in response to climate change.
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spelling doaj.art-4f48857546ff43019a48e3da138006732022-12-22T02:01:52ZengPublic Library of Science (PLoS)PLoS ONE1932-62032007-01-01211e114610.1371/journal.pone.0001146Unexpected high losses of Anopheles gambiae larvae due to rainfall.Krijn P PaaijmansMoses O WandagoAndrew K GithekoWillem TakkenBACKGROUND: Immature stages of the malaria mosquito Anopheles gambiae experience high mortality, but its cause is poorly understood. Here we study the impact of rainfall, one of the abiotic factors to which the immatures are frequently exposed, on their mortality. METHODOLOGY/PRINCIPAL FINDINGS: We show that rainfall significantly affected larval mosquitoes by flushing them out of their aquatic habitat and killing them. Outdoor experiments under natural conditions in Kenya revealed that the additional nightly loss of larvae caused by rainfall was on average 17.5% for the youngest (L1) larvae and 4.8% for the oldest (L4) larvae; an additional 10.5% (increase from 0.9 to 11.4%) of the L1 larvae and 3.3% (from 0.1 to 3.4%) of the L4 larvae were flushed away and larval mortality increased by 6.9% (from 4.6 to 11.5%) and 1.5% (from 4.1 to 5.6%) for L1 and L4 larvae, respectively, compared to nights without rain. On rainy nights, 1.3% and 0.7% of L1 and L4 larvae, respectively, were lost due to ejection from the breeding site. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that immature populations of malaria mosquitoes suffer high losses during rainfall events. As these populations are likely to experience several rain showers during their lifespan, rainfall will have a profound effect on the productivity of mosquito breeding sites and, as a result, on the transmission of malaria. These findings are discussed in the light of malaria risk and changing rainfall patterns in response to climate change.http://europepmc.org/articles/PMC2063461?pdf=render
spellingShingle Krijn P Paaijmans
Moses O Wandago
Andrew K Githeko
Willem Takken
Unexpected high losses of Anopheles gambiae larvae due to rainfall.
PLoS ONE
title Unexpected high losses of Anopheles gambiae larvae due to rainfall.
title_full Unexpected high losses of Anopheles gambiae larvae due to rainfall.
title_fullStr Unexpected high losses of Anopheles gambiae larvae due to rainfall.
title_full_unstemmed Unexpected high losses of Anopheles gambiae larvae due to rainfall.
title_short Unexpected high losses of Anopheles gambiae larvae due to rainfall.
title_sort unexpected high losses of anopheles gambiae larvae due to rainfall
url http://europepmc.org/articles/PMC2063461?pdf=render
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AT willemtakken unexpectedhighlossesofanophelesgambiaelarvaeduetorainfall