The Greater Everglades Region of South Florida is one of the largest natural wetlands and the only subtropical ecosystem found in the continental United States. Mosquitoes are seasonally abundant in the Everglades where several potentially pathogenic mosquito-borne arboviruses are maintained in natural transmission cycles involving vector-competent mosquitoes and reservoir-competent vertebrate hosts. The fragile nature of this ecosystem is vulnerable to many sources of environmental change, including a wetlands restoration project, climate change, invasive species and residential development. In this study, we obtained baseline data on the distribution and abundance of both mosquitos and arboviruses occurring in the southern Everglades region during the summer months of 2013, when water levels were high, and in 2014, when water levels were low. A total of 367,060 mosquitoes were collected with CO2-baited CDC light traps at 105 collection sites stratified among the major landscape features found in Everglades National Park, Big Cypress National Preserve, Fakahatchee State Park Preserve and Picayune State Forest, an area already undergoing restoration. A total of 2,010 pools of taxonomically identified mosquitoes were cultured for arbovirus isolation and identification. Seven vertebrate arboviruses were isolated: Everglades virus, Tensaw virus, Shark River virus, Gumbo Limbo virus, Mahogany Hammock virus, Keystone virus, and St. Louis encephalitis virus. Except for Tensaw virus, which was absent in 2013, the remaining viruses were found to be most prevalent in hardwood hammocks and in Fakahatchee, less prevalent in mangroves and pinelands, and absent in cypress and sawgrass. In contrast, in the summer of 2014 when water levels were lower, these arboviruses were far less prevalent and only found in hardwood hammocks, but Tensaw virus was present in cypress, sawgrass, pinelands, and a recently burned site. Major environmental changes are anticipated in the Everglades, many of which will result in increased water levels. How these might lead to the emergence of arboviruses potentially pathogenic to both humans and wildlife is discussed.

Specimens of a mosquito new to the continental USA, Aedes pertinax, were retrospectively identified from 2 collections made in 2011 in Indian River County, FL. Routine mosquito surveillance in subsequent years yielded more than 700 specimens appearing in 100 collections. The distribution of this mosquito in Florida and the United States is currently unknown, and recognition of the adult female is likely hampered by morphological similarities to Ae. atlanticus and Ae. tormentor.

Mosquitoes have profoundly affected human history and continue to threaten human health through the transmission of a diverse array of viruses and pathogens. Because mosquitoes are also highly diverse and globally widespread, their phylogeny has remained either little known or difficult to discern. Here, we used phylogenomic analysis of 709 orthologous nuclear gene sequences from 256 mosquito species to produce a strongly supported phylogeny that resolves the position of the major disease vector species and the major mosquito lineages. Our tree supports an origin of mosquitoes in the early Triassic (~217 mya) with species diversification and host-use patterns within major lineages coinciding in earth history both with major geologic events and with the diversification of vertebrate classes.

No abstract

The first report of Mansonia dyari on Saint Croix, United States Virgin Islands (USVI), is confirmed. Adult and larval specimens were collected in 2018 and 2019 through adult surveillance and larval collections. Specimens were identified by microscopic methods, and a representative specimen was confirmed by DNA sequencing (mitochondrial cytochrome c oxidase subunit I). Morphological features are reviewed and compared with Mansonia flaveola, a species previously reported in the USVI. Notes are provided on the locations, collection methods, and mosquito associates found with Ma. dyari in the USVI.