Survey of Invasive Mosquito Surveillance and Control Capacity in Southeastern USA Reveals Training and Resource Needs.

Several invasive mosquito species that are nuisances or of medical and veterinary importance have been introduced into the Southeastern region of the USA, posing a threat to other species and the local ecosystems and/or increasing the risk of pathogen transmission to people, livestock, and domestic pets. Prompt and effective monitoring and control of invasive species is essential to prevent them from spreading and causing harmful effects. However, the capacity for invasive mosquito species surveillance is highly variable among mosquito control programs in the Southeast, depending on a combination of factors such as regional geography and climate, access to resources, and the ability to interact with other programs. To facilitate the development of invasive mosquito surveillance in the region, we, the Mosquito BEACONS (Biodiversity Enhancement and Control of Non-native Species) working group, conducted a survey on the capacities of various public health agencies and pest control agencies engaged in mosquito surveillance and control in seven Southeastern states (Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, and South Carolina). Ninety control programs completed the survey, representing an overall response rate of 25.8%. We report key findings from our survey, emphasizing the training and resource needs, and discuss their implications for future invasive mosquito surveillance and control capacity building. By increasing communication and collaboration opportunities (e.g., real-time sharing of collection records, coordinated multistate programs), the establishment of Mosquito BEACONS and the implementation of this survey can accelerate knowledge transfer and improve decision support capacity in response to or in preparation for invasive mosquito surveillance and can establish infrastructure that can be used to inform programs around the world.

Complete mitogenome sequence of Aedes (Hulecoeteomyia) japonicus japonicus from Hawai'i Island.

We report the first complete mitogenome (Mt) sequence of Aedes japonicus japonicus (Diptera: Culicidae). The sequence was extracted from one adult from the Big Island of Hawai'i Island. The length of the Ae. japonicus japonicus Mt was 16,528bp with 78.1% AT content. Its sequence is most similar to the Mt sequence of Aedes koreicus with 90.81% sequence identity. This is the first full Mt sequence available for this species and provides important genetic resource for studying population genetics and dynamics of this important invasive mosquito species.

Aedes pertinax, Anopheles perplexens, Culex declarator, and Cx. interrogator: An Update of Mosquito Species Records for Charlotte County, Florida.

Understanding the geographic occurrence of mosquito species is an important element to addressing public health and nuisance mosquito-related issues, particularly as changing climates and increased global connectivity is likely to facilitate changes in the distribution of mosquitoes and other species. In Charlotte County, FL, routine surveillance of mosquito species for public health in 2019-21 identified 4 mosquito species not previously documented in the county. Aedes pertinax, Anopheles perplexens, Culex declarator, and Cx. interrogator adults were collected and verified to species level. Aedes pertinax and Cx. declarator and were collected in 2019, whereas An. perplexens and Cx. interrogator were documented from collections in 2021. All 4 species were initially visually identified by external morphology and confirmed by sequencing the DNA barcoding region of the cytochrome c oxidase subunit I gene. Apart from native An. perplexens, in which only 1 specimen has been confirmed to date, the 3 newly documented nonnative species are now recognized throughout the county.

West Nile Virus Surveillance in Sentinel Chickens and Mosquitoes in Panama City Beach, Florida, from 2014 To 2020.

Over 20 years since its introduction, the West Nile virus (WNV) continues to be the leading cause of arboviral disease in the USA. In Panama City Beach (Bay County, FL), WNV transmission is monitored using sentinel chickens and testing mosquito pools for presence of viral RNA. In the current work, we monitored WNV transmission from 2014 to 2020 through weekly serology sampling of sentinel chickens; mosquito populations through biweekly mosquito collections by suction traps (1 m and 9 m) and weekly gravid trap collections; and mosquito infection rates using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Samples were sent to the Bureau of Public Health Laboratories (Tampa, FL) for testing presence/absence of WNV via RT-PCR assay. Our results indicated that canopy surveillance could augment ground collections, providing greater proportions of Culex mosquitoes with less bycatch compared with ground collections. Serology indicated 94 seroconversions to WNV in the study area from 2014 to 2020. The most active year was 2016, which accounted for 32% (n = 30) of all seroconversions reported during the study period. We detected 20 WNV-positive mosquito pools from Culex quinquefasciatus during 2014-17; mosquito infection rates ranged from 2.02 to 23.81 per thousand (95% CI). Climate data indicated anomalously high precipitation in 2014-19 preceding WNV transmission. Data analyzed herein indicate utility in year-round continuous and diversified surveillance methodologies. This information is needed to properly calibrate future models that could assist with predicting transmission events of WNV in Panama City Beach, FL.

Mosquito Control Priorities in Florida-Survey Results from Florida Mosquito Control Districts.

Florida lies within a subtropical region where the climate allows diverse mosquito species including invasive species to thrive year-round. As of 2021, there are currently 66 state-approved Florida Mosquito Control Districts, which are major stakeholders for Florida public universities engaged in mosquito research. Florida is one of the few states with extensive organized mosquito control programs. The Florida State Government and Florida Mosquito Control Districts have long histories of collaboration with research institutions. During fall 2020, we carried out a survey to collect baseline data on the current control priorities from Florida Mosquito Control Districts relating to (1) priority control species, (2) common adult and larval control methods, and (3) major research questions to address that will improve their control and surveillance programs. The survey data showed that a total of 17 distinct mosquito species were considered to be priority control targets, with many of these species being understudied. The most common control approaches included truck-mounted ultra-low-volume adulticiding and biopesticide-based larviciding. The districts held interest in diverse research questions, with many prioritizing studies on basic science questions to help develop evidence-based control strategies. Our data highlight the fact that mosquito control approaches and priorities differ greatly between districts and provide an important point of comparison for other regions investing in mosquito control, particularly those with similar ecological settings, and great diversity of potential mosquito vectors, such as in Florida. Our findings highlight a need for greater alignment of research priorities between mosquito control and mosquito research. In particular, we note a need to prioritize filling knowledge gaps relating to understudied mosquito species that have been implicated in arbovirus transmission.

Distribution of Culex coronator in the USA.

In 1920, Culex coronator was reported from San Benito, Texas, and later in Arizona, New Mexico, and Oklahoma. In 2005, this species was reported to be spreading across the southeastern USA. Now reported in 14 states, it has been found as far north as northern Oklahoma; Memphis, TN; and Suffolk, VA. The public health significance of Cx. coronator is not firmly established, even though it has been implicated as a potential vector of several arboviral diseases. This study aims to document additional Cx. coronator county-level records, to provide information about its continued expansion across the southern USA, and to provide a short research update into its vector potential. Data acquired through multistate collaborations and author collections resulted in 146 new county records from Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, and Texas. No new county records were presented for Arizona, New Mexico, Tennessee, or Virginia, which had previously reported this species. With these new data, this species has been documented in 386 counties in 14 states of the continental USA.

Modelling distributions of Aedes aegypti and Aedes albopictus using climate, host density and interspecies competition.

Florida faces the challenge of repeated introduction and autochthonous transmission of arboviruses transmitted by Aedes aegypti and Aedes albopictus. Empirically-based predictive models of the spatial distribution of these species would aid surveillance and vector control efforts. To predict the occurrence and abundance of these species, we fit a mixed-effects zero-inflated negative binomial regression to a mosquito surveillance dataset with records from more than 200,000 trap days, representative of 53% of the land area and ranging from 2004 to 2018 in Florida. We found an asymmetrical competitive interaction between adult populations of Aedes aegypti and Aedes albopictus for the sampled sites. Wind speed was negatively associated with the occurrence and abundance of both vectors. Our model predictions show high accuracy (72.9% to 94.5%) in validation tests leaving out a random 10% subset of sites and data since 2017, suggesting a potential for predicting the distribution of the two Aedes vectors.

Field Observations of Invasive Species Aedes japonicus and Larval Contemporaries in Escambia County, Florida.

The Asian bush mosquito, Aedes japonicus, is an invasive species that is well established in North America and Europe. Though it is considered a temperate species, we have observed an established population of Ae. japonicus in the subtropical climate of northwestern Florida. To evaluate the temporal patterns of Ae. japonicus abundance, mosquito larvae were collected from 15 artificial containers in Escambia County, FL, from August 2019 to July 2020, with the prediction that Ae. japonicus abundance would peak in the winter months and decline with increasing ambient temperatures. Aedes japonicus larvae were collected in low abundances during each month except for February (n = 51), with no clear temporal patterns of abundance. Larval contemporaries belonging to other species were considered in sampling of containers and were also cataloged. We demonstrate monthly observance of this temperate species at a single site in the Florida panhandle, exemplifying the persistence of Ae. japonicus through all seasons in a subtropical climate.

AN UPDATE OF THE MOSQUITO RECORDS OF FLORIDA COUNTIES, USA.

In the last 2 decades, many new Florida county mosquito records have been discovered. The intent of this report is to establish unpublished county records to update the known distribution of mosquito species in Florida. We report 92 new county records from 5 major sources collected during 1989-2019.

First Record of Aedes japonicus In Florida.

The presence of Aedes j. japonicus in Florida is reported for the first time. Four adult females were collected by a Mosquito Magnet® X trap baited with pressurized CO2 in Okaloosa County, FL, in August 2012 and later identified as Ae. japonicus in 2014. Additional adult and larval specimens were collected during 2014-17 from Bay, Leon, Okaloosa, Santa Rosa, or Walton counties, Florida. Notes are provided on the location, general habitats, and mosquito associates that may be found with Ae. japonicus in northwestern Florida. The role of Ae. japonicus in arbovirus transmission within Florida is currently unknown and should be further explored.

Molecular identification of Aedes triseriatus and Aedes hendersoni by a novel duplex polymerase chain reaction assay.

Aedes triseriatus is the principal vector of La Crosse virus (LACv), which is the most common cause of pediatric arboviral encephalitis in North America. Here we report a novel species-specific polymerase chain reaction (PCR) assay that differentially identifies Ae. triseriatus and Ae. hendersoni. Because these 2 sibling species differ in their abilities to transmit LACv, accurate identification is critical for surveillance, research, and control programs. This duplex assay can detect the presence of both species in a single PCR reaction and is therefore simpler and faster than previously reported methods.