The authors have declared that no competing interests exist.
Conceived and designed the experiments: IR DVN MLH AF. Performed the experiments: IR DVN MLH AF. Analyzed the data: IR DVN. Contributed reagents/materials/analysis tools: IR DVN MLH AF. Wrote the paper: IR DVN MLH AF.
The Asian tiger mosquito,
Mosquitoes are the single most important taxon of arthropods affecting human health globally
In North America,
Extraordinary invasion propensities and public health significance of the Asian tiger mosquito have attracted substantial attention in the United States since this species first became established in Texas in 1985
No specific permits were required for the collections of adult mosquitoes, which were conducted with homeowners assent by professional county mosquito control personnel. This study did not involve endangered or protected species.
Climatic and landscape variables used in this study are listed in
Variable | Abbreviation | Inclusion in the final model |
Annual Mean Temperature | bio1 | No, highly correlated with bio11 |
Mean Diurnal Range | bio2 | No, not significant based on AICc |
Isothermality | bio3 | No, not significant based on AICc |
Temperature Seasonality | bio4 | No, highly correlated with bio11 |
Max Temp of Warmest Month | bio5 | No, highly correlated with bio11 |
Min Temp of Coldest Month | bio6 | No, highly correlated with bio11 |
Temperature Annual Range | bio7 | No, highly correlated with bio11 |
Mean Tempe of Wettest Quarter | bio8 | No, not significant based on AICc |
Mean Temp of Driest Quarter | bio9 | No, highly correlated with bio11 |
Mean Temp of Warmest Quarter | bio10 | No, highly correlated with bio11 |
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Annual Precipitation | bio12 | No, highly correlated with bio17 and bio19 |
Precipitation of Wettest Month | bio13 | No, not significant based on AICc |
Precipitation of Driest Month | bio14 | No, highly correlated with bio17 and bio19 |
Precipitation Seasonality | bio15 | No, not significant based on AICc |
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Precipitation of Warmest Quarter | bio18 | No, not significant based on AICc |
Precipitation of Coldest Quarter | bio19 | No, poorer geographic goodness-of -fit |
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Elevation | alt | No, not significant based on AICc |
Statistical modeling was conducted using Maxent v3.3.3 k, a machine learning algorithm for modeling species distribution estimated from the presence data-only and from the environmental variables
Compared to other available algorithms, Maxent performance consistently ranked among the best
The modeling for this study was conducted in two steps. The first model was created with a small number of
Minimum convex polygons (MCP,
WorldClim temperature variables (bio1-bio11;
The final MCP model had AUCtest = 0.919 indicating very good model performance and the omission rate (proportion of test points not predicted) = 0.012, which was significantly better than random prediction at p<0.001 by binomial test. Mean temperature of coldest quarter was the most significant environmental factor defining the current range of
The MCP model was projected into current and future climatic conditions (
(
Under both B2 and A2 CO2 emission scenarios, significant expansions of the current
The models' outputs for the middle to last parts of the century were somewhat different in spatial extent, but showed similar trends of decelerating rates of expansion. The moderate CO2 emissions model B2 predicted the suitable
Under higher CO2 emissions model A2, similar changes would occur but at a more rapid pace.
Climatic factors likely represent the major constraints on the extent of
Despite its importance, winter temperature might not be sufficient to define the range of
Apart from climatic factors, landscape features also play an important role in mosquito distributions, especially weak fliers with very short dispersal distances such as
Two recent global modeling studies included predictions of the current
The second global modeling study by Medley
Our study differed from both Benedict et al.
Rising winter temperatures will drive the expansion of
The Northeastern region has a population of over 55 million people (about 18% of the USA total), and contains some of the country's major metropolitan areas such as those associated with New York City, Philadelphia and Boston. Before the arrival of WNV in New York City in1999, mosquito-borne diseases were not an important concern in Northeastern metropolitan areas or even in most suburbs, and relatively little attention was paid to mosquito control. For instance, in 1999, New York City had no organized mosquito control program and the initial response to the virus outbreak required acquisition of outside experts and pesticide application contractors
(
Compared to these more traditional mosquito control habitats, the rise of
If larval control becomes impractical in an area, adulticiding may be required. However, effective adulticiding of
Measures to control this species, therefore, can easily outstrip the resources available to mosquito control programs, especially since they are already stretched to deal with their traditional problem set. The problems faced by local public health agencies in many urban and rural areas of northeastern USA with no organized mosquito control programs will be even more challenging.
Anticipating areas of potential establishment while planning ahead and gathering sufficient resources will be the key for successful public health campaigns. A broad effort in community sanitation and education at all levels of government and the private sector is required. It may be appropriate to increase the role of private pest control operators offering mosquito control services to provide barrier treatments or other specialized and localized control that is currently beyond the means of public entities. The groundwork for possible large-scale adulticiding needs to be implemented as well, both in terms of identifying resources and putting plans in place to determine under what circumstances such control would be initiated. None of this will be easy, but unless improved strategies are developed to prevent infestations of
The Asian tiger mosquito,
(XLS)
This work would not have been possible without a large group of dedicated public health and vector control professionals who led the surveillance and control efforts. We are deeply indebted to the New Jersey State Mosquito Control Commission, the Center for Vector Biology at Rutgers University, personnel of all 21 county mosquito control programs in New Jersey, Scott R. Campbell and all Suffolk County Arthropod-Borne Disease Laboratory and the Division of Vector Control staff, and numerous mosquito control professionals in Pennsylvania who submitted specimens used in the analysis. We are also indebted to the primary investigators and review board of the Area-wide Management of the Asian tiger mosquito project for valuable input and discussions