Assessing insecticide resistance and potency directly on the mosquito central nervous system: a novel method

Authors: Norris, Edmund; BLOOMQUIST, JEFFREY - University Of Florida

Submitted to: American Mosquito Control Association
Publication Type: Abstract Only
Publication Acceptance Date: 11/3/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Resistance to currently utilized chemical insecticides and public push back against new insecticide registrations represent significant threats to public health and food security worldwide. Better understanding the neurophysiological effects of currently available and candidate insecticides is crucial in evaluating cross-resistance in wild arthropod populations and the utility of new compounds to control pests. Here we highlight a novel method of recording nerve firing from the central nervous system of fourth instar larvae from two medically relevant mosquito species, Aedes aegypti and Anopheles gambiae. In short, 1) mosquitoes were carefully dissected to provide access to the ventral nerve cord, 2) the nerve cord was then severed between the 2nd and 3rd abdominal ganglion, and 3) a recording suction electrode was connected directly to the descending connective in a novel way to record nerve firing in the ventral nerve cord. This method provided a high signal-to-noise ratio compared to previously attempted protocols needed to characterize drug effects. Using this method, we report the effects of various neuroactive compounds, ranging from neurotransmitters to insecticides. We also explore the potential of characterizing insecticide resistance using this new preparation at the level of the nerve by screening on both larvae from pyrethroid-susceptible and pyrethroid-resistant populations.