CEPAVE   05420
CENTRO DE ESTUDIOS PARASITOLOGICOS Y DE VECTORES
Unidad Ejecutora - UE
artículos
Título:
Adaptive Developmental Delay in Chagas Disease Vectors: An Evolutionary Ecology Approach
Autor/es:
FRÉDÉRIC MENU, MARINE GINOUX, ETIENNE RAJON, CLAUDIO R. LAZZARI, AND JORGE E. RABINOVICH
Revista:
PLOS NEGLECTED TROPICAL DISEASES
Editorial:
PUBLIC LIBRARY SCIENCE
Referencias:
Año: 2010
ISSN:
1935-2735
Resumen:
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Background. The developmental time of 1 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 was 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 inter10 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 5th 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
5th instars in nine out of eleven species but no trend between development time
16 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, 18 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.