Investigaciones recientes sobre Toxorhynchites rutilus (Diptera: Culicidae) con referencia al control biológico de mosquitos habitantes en recipientes

Esta revisión provee actualización de las investigaciones sobre Toxorhynchites rutilus, un depredador utilizado para el control de mosquitos. Una investigación a largo plazo en Florida (EUA) demostró reducción de mosquitos en huecos de árboles que fue atribuida a depredación por esta especie. Extinciones locales del vector potencial Aedes triseriatus no estuvieron asociadas con la presencia de T. rutilus en huecos. La disminución en el consumo durante la diapause debe explicar parcialmente la reducción del impacto de T. rutilus en el invierno. La sobrevivencia de T. rutilus en huecos y llantas, indican que la mortalidad es mayor en el primer estadio y que la proporción relativa de muertes es alta en el cuarto, debido al canibalismo. La diversidad de presas observadas en disecciones de T. rutilus coleccionados del campo fue amplia, y los mosquitos no fueron las presas más frecuentes. Artrópodos terrestres aparentemente capturados desde la superficie del agua, fueron comunes en la dieta, especialmente en depredadores del tercero y cuarto estadio. Juliano y Gravel (en prensa) demostraron que A. triseriatus expuestos a T. rutilus, son sujetos a una rápida selección de comportamiento(s) anti-depredador. En la naturaleza, esta presión de selección es débil, resultando en una distribución heterogénea de comportamientos anti-depredador en distintas poblaciones geográficas. En experimentos en internodos de bambú, la especie invasiva Aedes albopictus evitó la depredacion de T. rutilus mejor que la especie nativa A. triseriatus. En este trabajo, discutimos el significado de estos resultados para el control biológico de mosquitos por T. rutilus.Fil: Lounibos, Phil. University of Florida; Estados UnidosFil: Campos, Raul Ernesto. University of Florida; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología ; Argentin

Evaluating the Long-Term Metacommunity Dynamics of Tree Hole Mosquitoes

Four different conceptual models of metacommunities have been proposed, termed “patch dynamics,” “species sorting,” “mass effect,” and “neutral.” These models simplify thinking about metacommunities and improve our understanding of the role of spatial dynamics both in structuring communities and in determining local and regional diversity. We tested whether mosquito communities inhabiting water-filled tree holes in southeastern Florida, USA, displayed any of the characteristics and dynamics predicted by the four models. The densities of the five most common species in 3–8 tree holes were monitored every two weeks during 1978–2003. We tested relationships between habitat variables and species densities, spatial synchrony, the presence of life history trade-offs, and species turnover. Dynamics showed strong elements of species sorting, but with considerable turnover, as predicted by the patch dynamics model. Consistent with patch dynamics, there was substantial asynchrony in dynamics for different tree holes, substantial species turnover in space and time, and an occupancy/colonization trade-off. Substantial correlations of density and occupancy with tree hole volume were consistent with the species-sorting model, but unlike this model, species did not have permanent refuges. No evidence of mass effects was found, and correlations between habitat variables and dynamics were inconsistent with neutral models. Our results did not match a single model and therefore caution against overly simplifying metacommunity dynamics by using one dynamical characteristic to select a particular metacommunity perspective

Recent investigations on Toxorhynchites rutilus (Diptera: Culicidae) with reference to the biological control of mosquitos inhabiting containers

Esta revisión provee actualización de las investigaciones sobre Toxorhynchites rutilus, un depredador utilizado para el control de mosquitos. Una investigación a largo plazo en Florida (EUA) demostró reducción de mosquitos en huecos de árboles que fue atribuida a depredación por esta especie. Extinciones locales del vector potencial Aedes triseriatus no estuvieron asociadas con la presencia de T. rutilus en huecos. La disminución en el consumo durante la diapause debe explicar parcialmente la reducción del impacto de T. rutilus en el invierno. La sobrevivencia de T. rutilus en huecos y llantas, indican que la mortalidad es mayor en el primer estadio y que la proporción relativa de muertes es alta en el cuarto, debido al canibalismo. La diversidad de presas observadas en disecciones de T. rutilus coleccionados del campo fue amplia, y los mosquitos no fueron las presas más frecuentes. Artrópodos terrestres aparentemente capturados desde la superficie del agua, fueron comunes en la dieta, especialmente en depredadores del tercero y cuarto estadio. Juliano y Gravel (en prensa) demostraron que A. triseriatus expuestos a T. rutilus, son sujetos a una rápida selección de comportamiento(s) anti-depredador. En la naturaleza, esta presión de selección es débil, resultando en una distribución heterogénea de comportamientos anti-depredador en distintas poblaciones geográficas. En experimentos en internodos de bambú, la especie invasiva Aedes albopictus evitó la depredacion de T. rutilus mejor que la especie nativa A. triseriatus. En este trabajo, discutimos el significado de estos resultados para el control biológico de mosquitos por T. rutilus.This review describes research on Toxorhynchites rutilus, a predator used for mosquito control. A long-term investigation in Florida (USA) demonstrated a reduction in treehole mosquitoes attributable to predation by this species. Local extinctions of the potential vector Aedes triseriatus were not associated with the presence of T. rutilus in treeholes. A decline in prey consumption during diapause may partially explain the reduced winter impact of T. rutilus in the long-term data. Survivorship of T. rutilus in treeholes and discarded tires indicates that the mortality rate is highest in the first instar and that the relative proportion of deaths is also high in the fourth stage, owing to cannibalism. In dissected T. rutilus collected from the field, a broad diversity of prey types was observed, and mosquitoes were not the most common prey. Terrestrial arthropods, apparently captured from the water surface, were common in the diet, especially of third and fourth instars. Juliano and Gravel (in press) demonstrated that A. triseriatus exposed to T. rutilus experience rapid selection for anti-predator behavior(s). This selective pressure is weak in nature, resulting in a heterogeneous distribution of anti-predator behaviors in distinct geographic populations. In experiments conducted in bamboo sections, the invasive species Aedes albopictus escaped predation by T. rutilus better than A. triseriatus. We discuss the significance of these results for the biological control of mosquitoes by T. rutilusInstituto de Limnología "Dr. Raúl A. Ringuelet

Investigaciones recientes sobre Toxorhynchites rutilus (Diptera: Culicidae) con referencia al control biol\uf3gico de mosquitos habitantes en recipientes

Lounibos P, Campos RE. 2002. Recent investigations on Toxorhynchites rutilus (Diptera: Culicidae) with reference to the biological control of mosquitos inhabiting containers. Entomotropica 17(2):145-156. This review describes research on Toxorhynchites rutilus, a predator used for mosquito control. A long-term investigation in Florida (USA) demonstrated a reduction in treehole mosquitoes attributable to predation by this species. Local extinctions of the potential vector Aedes triseriatus were not associated with the presence of T. rutilus in treeholes. A decline in prey consumption during diapause may partially explain the reduced winter impact of T. rutilus in the long-term data. Survivorship of T. rutilus in treeholes and discarded tires indicates that the mortality rate is highest in the first instar and that the relative proportion of deaths is also high in the fourth stage, owing to cannibalism. In dissected T. rutilus collected from the field, a broad diversity of prey types was observed, and mosquitoes were not the most common prey. Terrestrial arthropods, apparently captured from the water surface, were common in the diet, especially of third and fourth instars. Juliano and Gravel (in press) demonstrated that A. triseriatus exposed to T. rutilus experience rapid selection for anti-predator behavior(s). This selective pressure is weak in nature, resulting in a heterogeneous distribution of anti-predator behaviors in distinct geographic populations. In experiments conducted in bamboo sections, the invasive species Aedes albopictus escaped predation by T. rutilus better than A. triseriatus. We discuss the significance of these results for the biological control of mosquitoes by T. rutilus.Lounibos P, Campos RE. 2002. Investigaciones recientes sobre Toxorhynchites rutilus (Diptera: Culicidae) con referencia al control biol\uf3gico de mosquitos habitantes en recipientes. Entomotropica 17(2):145-156. Esta revisi\uf3n provee actualizaci\uf3n de las investigaciones sobre Toxorhynchites rutilus, un depredador utilizado para el control de mosquitos. Una investigaci\uf3n a largo plazo en Florida (EUA) demostr\uf3 reducci\uf3n de mosquitos en huecos de \ue1rboles que fue atribuida a depredaci\uf3n por esta especie. Extinciones locales del vector potencial Aedes triseriatus no estuvieron asociadas con la presencia de T. rutilus en huecos. La disminuci\uf3n en el consumo durante la diapause debe explicar parcialmente la reducci\uf3n del impacto de T. rutilus en el invierno. La sobrevivencia de T. rutilus en huecos y llantas, indican que la mortalidad es mayor en el primer estad\uedo y que la proporci\uf3n relativa de muertes es alta en el cuarto, debido al canibalismo. La diversidad de presas observadas en disecciones de T. rutilus coleccionados del campo fue amplia, y los mosquitos no fueron las presas m\ue1s frecuentes. Artr\uf3podos terrestres aparentemente capturados desde la superficie del agua, fueron comunes en la dieta, especialmente en depredadores del tercero y cuarto estad\uedo. Juliano y Gravel (en prensa) demostraron que A. triseriatus expuestos a T. rutilus, son sujetos a una r\ue1pida selecci\uf3n de comportamiento(s) anti-depredador. En la naturaleza, esta presi\uf3n de selecci\uf3n es d\ue9bil, resultando en una distribuci\uf3n heterog\ue9nea de comportamientos anti-depredador en distintas poblaciones geogr\ue1ficas. En experimentos en internodos de bamb\ufa, la especie invasiva Aedes albopictus evit\uf3 la depredacion de T. rutilus mejor que la especie nativa A. triseriatus. En este trabajo, discutimos el significado de estos resultados para el control biol\uf3gico de mosquitos por T. rutilus

Ecology of invasive mosquitoes: effects on resident species and on human health.

Abstract Investigations of biological invasions focus on patterns and processes that are related to introduction, establishment, spread and impacts of introduced species. This review focuses on the ecological interactions operating during invasions by the most prominent group of insect vectors of disease, mosquitoes. First, we review characteristics of nonnative mosquito species that have established viable populations, and those invasive species that have spread widely and had major impacts, testing whether biotic characteristics are associated with the transition from established non-native to invasive. Second, we review the roles of interspecific competition, apparent competition, predation, intraguild predation and climatic limitation as causes of impacts on residents or as barriers to invasion. We concentrate on the best-studied invasive mosquito, Aedes albopictus, evaluating the application of basic ecological theory to invasions by Aedes albopictus. We develop a model based on observations of Aedes albopictus for effects of resource competition and predation as barriers to invasion, evaluating which community and ecosystem characteristics favour invasion. Third, we evaluate the ways in which invasive mosquitoes have contributed to outbreaks of human and animal disease, considering specifically whether invasive mosquitoes create novel health threats, or modify disease transmission for existing pathogen-host systems

Convergent habitat segregation of Aedes aegypti and Aedes albopictus (Diptera : Culicidae) in southeastern Brazil and Florida

During the rainy season of 2001, the incidence of the dengue vectors Aedes aegypti and Ae. albopictus was examined in different habitats of two cities (Rio de Janeiro and Nova Iguacu) in Rio de Janeiro State, Brazil, and in two cities (Palm Beach and Boca Raton) in Florida. Oviposition trap collections were performed in urban, suburban, and rural habitats in both areas. Our hypothesis that the abundances and frequencies of occurrence of Ae. aegypti and Ae albopictus are affected in opposite ways by increasing urbanization was only partially supported. City, habitat, and their interaction significantly affected the abundance of both species. Cities with high abundance of Ae. aegypti also had a high abundance of Ae. albopictus. The two species were most abundant in the cities of Rio de Janeiro state and the lowest in Boca Raton. Habitat bad a significant but opposite effect on the abundances of Ae. aegypti and Ae. albopictus. In general, Ae. aegypti was most prevalent in highly urbanized areas and Ae. albopictus in rural, suburban, and vegetated urban areas in Rio de Janeiro state and Florida. However, abundances of the two species were similar in most suburban areas. Analyses of frequencies of occurrence showed an unexpected high level of co-occurrence of both species in the same oviposition trap. Despite the different geographical origins of Ae. albopictus in Brazil and the United States, the habitats used by this recent invader are remarkably similar in the two countries

Population genomics of the Asian tiger mosquito, Aedes albopictus. Insights into the recent worldwide invasion

Aedes albopictus, the “Asian tiger mosquito,” is an aggressive biting mosquito native to Asia that has colonized all continents except Antarctica during the last ~30–40 years. The species is of great public health concern as it can transmit at least 26 arboviruses, including dengue, chikungunya, and Zika viruses. In this study, using double- digest Restriction site-Associated DNA (ddRAD) sequencing, we developed a panel of ~58,000 single nucleotide polymorphisms (SNPs) based on 20 worldwide Ae. albopic-tus populations representing both the invasive and the native range. We used this genomic- based approach to study the genetic structure and the differentiation of Ae. albopictus populations and to understand origin(s) and dynamics of the recent inva-sions. Our analyses indicated the existence of two major genetically differentiated population clusters, each one including both native and invasive populations. The de-tection of additional genetic structure within each major cluster supports that these SNPs can detect differentiation at a global and local scale, while the similar levels of genomic diversity between native and invasive range populations support the scenario of multiple invasions or colonization by a large number of propagules. Finally, our re-sults revealed the possible source(s) of the recent invasion in Americas, Europe, and Africa, a finding with important implications for vector- control strategies

The worldwide airline network and the dispersal of exotic species: 2007–2010

International air travel has played a significant role in driving recent increases in the rates of biological invasion and spread of infectious diseases. By providing high speed, busy transport links between spatially distant, but climatically similar regions of the world, the worldwide airline network (WAN) increases the risks of deliberate or accidental movements and establishment of climatically sensitive exotic organisms. With traffic levels continuing to rise and climates changing regionally, these risks will vary, both seasonally and year-by-year. Here, detailed estimates of air traffic trends and climate changes for the period 2007–2010 are used to examine the likely directions and magnitudes of changes in climatically sensitive organism invasion risk across the WAN. Analysis of over 144 million flights from 2007–2010 shows that by 2010, the WAN is likely to change little overall in terms of connecting regions with similar climates, but anticipated increases in traffic and local variations in climatic changes should increase the risks of exotic species movement on the WAN and establishment in new areas. These overall shifts mask spatially and temporally heterogenous changes across the WAN, where, for example, traffic increases and climatic convergence by July 2010 between parts of China and northern Europe and North America raise the likelihood of exotic species invasions, whereas anticipated climatic shifts may actually reduce invasion risks into much of eastern Europe