Location: Arthropod-borne Animal Diseases Research
Project Number: 3020-32000-018-016-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 1, 2022
End Date: Jun 30, 2025
Objective 1: Determine effects of insecticide resistance on house fly behavior. Objective 2: Assess effects of insecticide resistance on house fly susceptibility to alternate control methods. Objective 3: Uncover molecular-genetic mechanisms of insecticide resistance and detoxification in house flies.
House flies are one of the most climate- and niche-adaptable insects on earth, with global distribution across urban, suburban, agricultural, and sylvatic habitats. In these areas they acquire, harbor, and transmit numerous types of pathogens, especially bacteria, that threaten human and animal health. Wild populations of house flies have shown remarkable resistance to every class of insecticides currently formulated for their control. Resistance is mediated primarily by metabolic detoxification (e.g., enzymes) and through mutations at the target site of the chemical. There is convincing evidence that some of these resistance mechanisms have fitness costs that manifest as detrimental modifications to behavior and physiology, especially in ways that make dealing with environmental stressors more difficult. These fitness costs may be exploitable to increase control efficacy using approaches other than traditional chemicals. The approach of this project includes (1) conducting behavioral assays to determine the effects of existing insecticide resistance on house fly response to stimuli such as cold, heat, and other neurosensory mediated activities, (2) testing efficacy of alternate control mechanisms such as entomopathogens on insecticide-resistant flies via dose-response and susceptibility assays, (3) Exploring the underlying genotypes and molecular phenotypes of insecticide resistant house flies through short- and long-read gene sequencing and gene expression analyses (e.g. qRTPCR, comparative transcriptomics). ARS and the Cooperator maintain insecticide resistant and susceptible colonies of house flies and also have access to natural populations with varied levels of susceptibility to insecticide classes that will be used in the assays described above.