Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.

BACKGROUND:The developmental time of vector insects is important in population dynamics, evolutionary biology, epidemiology and in their responses to global climatic change. In the triatomines (Triatominae, Reduviidae), vectors of Chagas disease, evolutionary ecology concepts, which may allow for a...

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Main Authors: Frédéric Menu, Marine Ginoux, Etienne Rajon, Claudio R Lazzari, Jorge E Rabinovich
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2010-05-01
Series:PLoS Neglected Tropical Diseases
Online Access:http://europepmc.org/articles/PMC2876115?pdf=render
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author Frédéric Menu
Marine Ginoux
Etienne Rajon
Claudio R Lazzari
Jorge E Rabinovich
author_facet Frédéric Menu
Marine Ginoux
Etienne Rajon
Claudio R Lazzari
Jorge E Rabinovich
author_sort Frédéric Menu
collection DOAJ
description BACKGROUND:The developmental time of vector insects is important in population dynamics, evolutionary biology, epidemiology and in their responses to global climatic change. In the triatomines (Triatominae, Reduviidae), vectors of Chagas disease, evolutionary ecology concepts, which may allow for a better understanding of their biology, have not been applied. Despite delay in the molting in some individuals observed in triatomines, no effort was made to explain this variability. METHODOLOGY:We applied four methods: (1) an e-mail survey sent to 30 researchers with experience in triatomines, (2) a statistical description of the developmental time of eleven triatomine species, (3) a relationship between development time pattern and climatic inter-annual variability, (4) a mathematical optimization model of evolution of developmental delay (diapause). PRINCIPAL FINDINGS:85.6% of responses informed on prolonged developmental times in 5(th) instar nymphs, with 20 species identified with remarkable developmental delays. The developmental time analysis showed some degree of bi-modal pattern of the development time of the 5(th) instars in nine out of eleven species but no trend between development time pattern and climatic inter-annual variability was observed. Our optimization model predicts that the developmental delays could be due to an adaptive risk-spreading diapause strategy, only if survival throughout the diapause period and the probability of random occurrence of "bad" environmental conditions are sufficiently high. CONCLUSIONS/SIGNIFICANCE:Developmental delay may not be a simple non-adaptive phenotypic plasticity in development time, and could be a form of adaptive diapause associated to a physiological mechanism related to the postponement of the initiation of reproduction, as an adaptation to environmental stochasticity through a spreading of risk (bet-hedging) strategy. We identify a series of parameters that can be measured in the field and laboratory to test this hypothesis. The importance of these findings is discussed in terms of global climatic change and epidemiological consequences.
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spelling doaj.art-b2511036a5f94b79b37a6e97f60ddc5f2022-12-22T01:56:16ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352010-05-0145e69110.1371/journal.pntd.0000691Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.Frédéric MenuMarine GinouxEtienne RajonClaudio R LazzariJorge E RabinovichBACKGROUND:The developmental time of vector insects is important in population dynamics, evolutionary biology, epidemiology and in their responses to global climatic change. In the triatomines (Triatominae, Reduviidae), vectors of Chagas disease, evolutionary ecology concepts, which may allow for a better understanding of their biology, have not been applied. Despite delay in the molting in some individuals observed in triatomines, no effort was made to explain this variability. METHODOLOGY:We applied four methods: (1) an e-mail survey sent to 30 researchers with experience in triatomines, (2) a statistical description of the developmental time of eleven triatomine species, (3) a relationship between development time pattern and climatic inter-annual variability, (4) a mathematical optimization model of evolution of developmental delay (diapause). PRINCIPAL FINDINGS:85.6% of responses informed on prolonged developmental times in 5(th) instar nymphs, with 20 species identified with remarkable developmental delays. The developmental time analysis showed some degree of bi-modal pattern of the development time of the 5(th) instars in nine out of eleven species but no trend between development time pattern and climatic inter-annual variability was observed. Our optimization model predicts that the developmental delays could be due to an adaptive risk-spreading diapause strategy, only if survival throughout the diapause period and the probability of random occurrence of "bad" environmental conditions are sufficiently high. CONCLUSIONS/SIGNIFICANCE:Developmental delay may not be a simple non-adaptive phenotypic plasticity in development time, and could be a form of adaptive diapause associated to a physiological mechanism related to the postponement of the initiation of reproduction, as an adaptation to environmental stochasticity through a spreading of risk (bet-hedging) strategy. We identify a series of parameters that can be measured in the field and laboratory to test this hypothesis. The importance of these findings is discussed in terms of global climatic change and epidemiological consequences.http://europepmc.org/articles/PMC2876115?pdf=render
spellingShingle Frédéric Menu
Marine Ginoux
Etienne Rajon
Claudio R Lazzari
Jorge E Rabinovich
Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.
PLoS Neglected Tropical Diseases
title Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.
title_full Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.
title_fullStr Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.
title_full_unstemmed Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.
title_short Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.
title_sort adaptive developmental delay in chagas disease vectors an evolutionary ecology approach
url http://europepmc.org/articles/PMC2876115?pdf=render
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