Degree

Doctor of Philosophy (PhD)

Department

Entomology

Document Type

Dissertation

Abstract

Abstract

Mosquitoes are a public nuisance and can vector pathogen causing diseases that affect both animal and human health. West Nile virus, vectored by Culex quinquefasciatus, the Southern House mosquito, made its entry into Louisiana early in the 21st century, causing serious morbidity and mortality. Effective use of insecticides can be useful to combat these mosquitoes and reduce transmission of disease, however use of insecticides can lead to insecticide resistance.

The objectives of this study were to: (1) to screen adult Cx. quinquefasciatus throughout Orleans Parish, Louisiana for insecticide resistance and explore target-site and metabolic mechanisms of resistance, (2) to investigate the impact of repeated exposure on field populations of Cx. quinquefasciatus via a barrier treatment, and (3) to survey the knowledge, attitude and practices of insecticide use by residents of New Orleans, Louisiana.

Both the topical and Centers for Disease Control and Prevention (CDC) bottle bioassay methods detected high frequencies of insecticide resistance in field populations of Cx. quinquefasciatus to bifenthrin, deltamethrin and malathion, however the results from the two assays were poorly correlated. Heightened activities of esterases, often associated with insecticide resistance, and high frequencies of a mutation (L1014F) associated with targe-site resistance were detected in these populations.

Bifenthrin was applied as a barrier treatment via monthly applications in a residential neighborhood in Orleans Parish. Topical and CDC bottle bioassays were used to screen for changes in susceptibility in field populations of Cx. quinquefasciatus, and mechanisms of resistance were evaluated. High frequencies of resistance to bifenthrin which were correlated with heightened esterase activities, were measured at both untreated and treated sites.

A questionnaire-based survey was disseminated to the residents of Orleans Parish. Results from the survey give insight into resident’s contribution to and understanding of mosquito control practices and can enable local mosquito abatement districts to develop more effective mosquito control awareness campaigns. Overall, the data collected through this study provide a better comprehension of the resistance profile of Cx. quinquefasciatus in New Orleans, LA and the mechanisms driving this resistance, as well as insight into the public’s perception of mosquito control.

Date

11-2-2023

Committee Chair

James Ottea

Download

Available for download on Sunday, November 01, 2026

Included in

Entomology Commons

Share

COinS