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.

Arboviral disease outbreaks, Aedes mosquitoes, and vector control efforts in the Pacific

Recurring outbreaks of mosquito-borne diseases, like dengue, in the Pacific region represent a major biosecurity risk to neighboring continents through potential introductions of disease-causing pathogens. Aedes mosquitoes, highly prevalent in this region, are extremely invasive and the predominant vectors of multiple viruses including causing dengue, chikungunya, and Zika. Due to the absence of vaccines for most of these diseases, Aedes control remains a high priority for public health. Currently, international organizations put their efforts into improving mosquito surveillance programs in the Pacific region. Also, a novel biocontrol method using Wolbachia has been tried in the Pacific region to control Aedes mosquito populations. A comprehensive understanding of mosquito biology is needed to assess the risk that mosquitoes might be introduced to neighboring islands in the region and how this might impact arboviral virus transmission. As such, we present a comprehensive review of arboviral disease outbreak records as well as Aedes mosquito biology research findings relevant to the Pacific region collected from both non-scientific and scientific sources.

Multiple Novel Clades of Anopheline Mosquitoes Caught Outdoors in Northern Zambia

Residual vector populations that do not come in contact with the most frequently utilized indoor-directed interventions present major challenges to global malaria eradication. Many of these residual populations are mosquito species about which little is known. As part of a study to assess the threat of outdoor exposure to malaria mosquitoes within the Southern and Central Africa International Centers of Excellence for Malaria Research, foraging female anophelines were collected outside households in Nchelenge District, northern Zambia. These anophelines proved to be more diverse than had previously been reported in the area. In order to further characterize the anopheline species, sequencing and phylogenetic approaches were utilized. Anopheline mosquitoes were collected from outdoor light traps, morphologically identified, and sent to Johns Hopkins Bloomberg School of Public Health for sequencing. Sanger sequencing from 115 field-derived samples yielded mitochondrial COI sequences, which were aligned with a homologous 488 bp gene segment from known anophelines (n = 140) retrieved from NCBI. Nuclear ITS2 sequences (n = 57) for at least one individual from each unique COI clade were generated and compared against NCBI’s nucleotide BLAST database to provide additional evidence for taxonomical identity and structure. Molecular and morphological data were combined for assignment of species or higher taxonomy. Twelve phylogenetic groups were characterized from the COI and ITS2 sequence data, including the primary vector species Anopheles funestus s.s. and An. gambiae s.s. An unexpectedly large proportion of the field collections were identified as An. coustani and An. sp. 6. Six phylogenetic groups remain unidentified to species-level. Outdoor collections of anopheline mosquitoes in areas frequented by people in Nchelenge, northern Zambia, proved to be extremely diverse. Morphological misidentification and underrepresentation of some anopheline species in sequence databases confound efforts to confirm identity of potential malaria vector species. The large number of unidentified anophelines could compromise the malaria vector surveillance and malaria control efforts not only in northern Zambia but other places where surveillance and control are focused on indoor-foraging and resting anophelines. Therefore, it is critical to continue development of methodologies that allow better identification of these populations and revisiting and cleaning current genomic databases.

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.