First record of Aedes aegypti and Aedes albopictus in thirteen Panhandle region counties of Texas, U.S.A

A systematic review of climate-change driven range shifts in mosquito vectors

As global temperatures rise, concerns about shifting mosquito ranges-and accompanying changes in the transmission of malaria, dengue, and other diseases-are mounting. However, systematic evidence for climate-driven changes in mosquito ranges remains limited. We conducted a systematic review of studies documenting expansions or contractions in medically important mosquito species. In total, 178 studies on six continents identified range expansions in 118 mosquito species. While over a third of these studies cited warming as a driver, fewer than 10% performed statistical tests of the role of climate. Instead, most expansions were linked to human-aided dispersal (e.g., trade, travel), land-use changes, and urbanization. Although several studies reported poleward or upward expansions consistent with climate warming, none demonstrated warm-edge contractions driven by rising temperatures, which are theoretically predicted in some settings. Rather than expanding into newly suitable areas, many expansions appear to be filling preexisting thermally suitable habitats. Our findings highlight the need for long-term mosquito monitoring, rigorous climate-attribution methods, and better documentation of confounding factors like land-use change and vector control efforts to disentangle climate-driven changes from other anthropogenic factors.

Landscape and Anthropogenic Factors Associated with Adult Aedes aegypti and Aedes albopictus in Small Cities in the Southern Great Plains

Simple Summary

Mosquito-borne diseases are a growing human health concern in the United States. While recent studies have updated the distribution of Aedes aegypti in southern Great Plains, little is known about what factors can be used to predict where important mosquito species thrive in the region. The aim of the study assessed different factors associated with encountering adult container-breeding mosquitoes in small cities in southern Oklahoma. Collections using two types of traps were carried out over a ten week period from June to August 2017 along two geographical transects, each consisting of three cities, equally distant from the Red River/Texas border. After five rounds of collection, 6628 female mosquitoes were collected from 242 commercial or residential sites in six cities. Of the mosquitoes collected, 80% consisted of container-breeding species. Regionally, Ae. aegypti was most likely to be collected in cities closest to the Texas border while Aedes albopictus was spread throughout the region. In general, Ae. aegypti and Ae. albopictus were more associated with residential sites or sites featuring no or low vegetation. The study highlighted important factors involved in the distribution of Ae. aegypti and Ae. albopictus in small cities in the southern Great Plains.

Abstract

As mosquito-borne diseases are a growing human health concern in the United States, the distribution and potential arbovirus risk from container-breeding Aedes mosquitoes is understudied in the southern Great Plains. The aim of the study was to assess landscape and anthropogenic factors associated with encountering adult container-breeding mosquitoes in small cities in southern Oklahoma. Collections were carried out over a 10 week period from June to August 2017 along two geographical transects, each consisting of three cities, equally distant from the Red River/Texas border. Mosquitoes were collected weekly using two trap types along with data for 13 landscape, vegetation, and anthropogenic variables. After five rounds of collection, 6628 female mosquitoes were collected over 2110 trap-nights involving 242 commercial or residential sites in six cities. Of the mosquitoes collected, 80% consisted of container-breeding species: Aedes albopictus (72%), Culex pipiens complex (16%) and Aedes aegypti (8%). Regionally, Aedes aegypti was more likely present in cities closest to the Texas border while Ae. albopictus was spread throughout the region. In general, Ae. aegypti and Ae. albopictus were significantly more present in sites featuring no or low vegetation and residential sites. Variables associated with Ae. albopictus presence and abundance varied between cities and highlighted the urban nature of the species. The study highlighted the distribution of Ae. aegypti geographically and within the urban context, indicated potential habitat preferences of container-breeding mosquito species in small towns, and demonstrated the usefulness of Gravid Aedes traps (GAT) traps for monitoring Aedes populations in urban habitats in small cities.

The Influence of New Surveillance Data on Predictive Species Distribution Modeling of Aedes aegypti and Aedes albopictus in the United States

The recent emergence or reemergence of various vector-borne diseases makes the knowledge of disease vectors' presence and distribution of paramount concern for protecting national human and animal health. While several studies have modeled Aedes aegypti or Aedes albopictus distributions in the past five years, studies at a large scale can miss the complexities that contribute to a species' distribution. Many localities in the United States have lacked or had sporadic surveillance conducted for these two species. To address these gaps in the current knowledge of Ae. aegypti and Ae. albopictus distributions in the United States, surveillance was focused on areas in Texas at the margins of their known ranges and in localities that had little or no surveillance conducted in the past. This information was used with a global database of occurrence records to create a predictive model of these two species' distributions in the United States. Additionally, the surveillance data from Texas was used to determine the influence of new data from the margins of a species' known range on predicted species' suitability maps. This information is critical in determining where to focus resources for the future and continued surveillance for these two species of medical concern.