Applied Mosquito Research Program
The Applied Mosquito Research program (AMRP) at FMEL conducts research of relevance to Florida mosquito control and public health agencies. Originally intended to address mosquito control pesticide issues, it has recently been expanded to include issues important to Florida mosquito control in general.
Presently, the AMRP has three principal components:
- Mosquito Identification and DNA Sequence-Based Tools for mosquito and pathogen surveillance.
- Pesticide reduction and non-pesticide mosquito control strategies.
- Pesticide development, testing, and application
Staff Scientist: Dr. Lawrence Reeves, Research Assistant Scientist
Project Synopsis: Focus is on the development of DNA barcode-based molecular approaches to surveilling mosquitoes and detecting pathogens, and investigating mosquito biology and ecology and translating these details to improved mosquito control strategies. A secondary focus, in collaboration with Dr. Nathan Burkett-Cadena, is the creation of an updated identification resource for the mosquitoes of Florida.
Primary Goals: Goals include (1) creation of a complete reference database of COI DNA barcoding gene sequences for all Florida and regional mosquito species, collected within the state and region. A publicly accessible molecular and specimen-based reference collection of sequence data will be created to enhance our ability to identify mosquitoes and recognize introductions of non-native species, and will be a user-friendly alternative to morphology-based ID. Creation of this database will facilitate next generation DNA sequencing and bioinformatic pipelines for the identification of bulk mosquito collections, environmental samples (e.g., water samples from potential larval habitats), and blood meals (2) which will provide efficient and straightforward methods for operational mosquito surveillance. I provide a DNA barcoding identification service to mosquito control districts to assist in the taxonomic identification of mosquito specimens that cannot be determined through the use of morphological keys (3). Please email email@example.com for details on specimen submission. In addition, Florida is a hotspot for non-native mosquito species, with ten new species detected in the state since 2000. Working with Dr. Burkett-Cadena, I am creating an updated morphological identification resource for the mosquitoes of Florida, including species missing from the current key (4).
Major Results to Date: This program initiated in August 2018 and my lab has begun collecting mosquito specimens for molecular processing. Creation of a complete reference database is prioritized, as specimens used to populate the database are also being used to illustrate the updated Mosquitoes of Florida. His lab is now set up to receive and identify mosquito specimens for mosquito control districts. Major results, below, are derived from work published in 2018, prior the establishment of my program.
Current activity: Since Darsie and Morris published the Keys to the Adult Females and Fourth Instar Larvae of the Mosquitoes of Florida (Diptera, Culicidae) in 2003, at least nine additional mosquito species have been reported from the state, some of them widespread and common. In collaboration with Dr. Nathan Burkett-Cadena, we are creating an updated and photographically illustrated resource for the morphological identification of Florida mosquitoes. While we expect this project to take approximately two years to compile photographs and prepare the text, I am preparing a review of the recently introduced mosquito species to Florida to immediately address the need to morphologically identify species that are not present in the current key. Coincident with this work, I am collecting molecular and morphological specimens to be used toward Goal 1 (above), prioritizing species groups that a preliminary analysis using GenBank-mined barcode sequences indicated were likely to yield undescribed cryptic species.
Staff Scientist: Dr. Dongyoung Shin, Research Assistant Professor
Project Synopsis: This program investigates the genomics and genetics of mosquitoes and determines any interactions between mosquitoes and mosquito-borne diseases at the molecular level.
Primary Goals: Developing novel, non-pesticide control strategies; investigating the development of insecticide resistance in Florida mosquito populations by investigating interactions between mosquito and mosquito-borne diseases; characterizing vector capacity (ability to transmit a pathogen) and the genes that are responsible for alteration of vector competence in pesticide-resistant mosquito populations.
Major Results to Date:
- Grated drain covers can serve as a barrier to Culex oviposition in storm drains: Mosquito breeding begins from oviposition. We tested two different physical structures with different types of openings. Most Culex mosquitoes were significantly disrupted from finding oviposition sites if the openings were divided into several small openings. This suggests that physical barriers with grating shape openings over mosquito breeding sites can be used as a method to decrease the number of Culex breeding sites
- Detection of Culex interrogator in multiple Florida counties, a non-native species morphologically similar to native species: Culex interrogator species, known to be abundant in Texas and Central America, were discovered for the first time in Florida. This species, like coronator or Culex declarator, appears to have come from Texas during the warm winter. This route can also be used by other mosquito species carrying vector-bone diseases. Thus, mosquito control needs to focus on this route to prevent invasive species and mosquito-borne diseases. Florida’s mosquito control districts should also be aware of the presence of this mosquito in the state as it is morphologically similar to Cx. restuans and Cx. quinquefasciatus, important vectors of several arboviruses.
- Identification of the esterase, Temsha-est1, as an indicator of insecticide resistance in Culex nigripalpus: An esterase (Temsha-est1) in a field population of nigripalpus was assessed as an inducible marker of organophosphate insecticide resistance. I developed a single vial bioassay to check the resistance levels of individual mosquitoes using individual mosquito RNA for further analysis. The expression level of Temsha-est1 showed a positive relation with the level of insecticide resistance. This process can be used as a tool for monitoring the level of the development of organophosphate resistance formation.
- Assessment of vectorial capacity in permethrin-selected population of Aedes aegypti: An elevated permethrin resistance level in Aedes aegypti populations collected in Florida cause them to become more susceptible to Dengue virus. The behavioral difference between the permethrin-resistant population and other susceptible populations has also been investigated. We show that in Florida population of aegypti there is a relation between permethrin resistance and target site mutation frequencies by using allele-specific PCR. This is also a good tool for monitoring the level of permethrin resistance of Ae. aegypti in Florida. This work also informs consequences of the elevated insecticide resistant status in various biological aspects of Florida mosquito population.
- Characterization of genes and signaling pathways in mosquito antiviral mechanisms: The genes or pathways that play a role in the mosquito’s defense against mosquito borne-pathogens have been investigated using different mosquito-pathogen models. This information will be used to develop techniques that interfere with the development of mosquito-mediated pathogens. Furthermore, these results can be used to suppress mosquito vector populations in Florida through the manipulation of these functions using molecular biological techniques.
Ae. aegypti and Ae. albopictus are known as the primary vector of the Zika virus to humans. A laboratory population of Cx. quinquefasciatus collected in Florida was infected with the Zika virus and the transmission ability of the Zika virus was proven by various analyses in mosquito saliva and body tissues. This discovery was significant since this species is one of the most common mosquitoes in Florida and has high host preference to humans. If Cx. quinquefasciatus is found to be an effective vector for Zika virus in the field, control strategies targeting this species should be considered in addition to those implemented against Ae. aegypti and Ae. albopictus. Currently, I am testing other Florida field populations of Cx. quinquefasciatus for their ability to transmit the Zika virus.
I am also combining conventional microbiological and insecticide resistance bioassays with current mid-throughput sequencing technologies to determine whether the microbial communities that inhabit the mosquito guts contribute to insecticide resistance using a permethrin-selected population.
Staff Scientist: Dr. Liming Zhao, Research Assistant Professor
Project Synopsis: Includes several projects addressing issues related to improved use of pesticides of importance to Florida mosquito control.
Primary Goals: development of novel pesticides using RNAi methods for application against mosquito larvae and adults, development of novel diagnostic tests for mosquito-borne pathogens to target dangerous mosquitoes, and characterization of mosquito pesticide response mechanisms to design strategies to reduce the development of insecticide resistance in mosquito populations.