AC-DC electropenetropgraphy for the study of probing and ingestion behaviors of Culex tarsalis mosquitoes on human hands

Authors: COOPER, ANASTASIA - Kansas State University; REIF, KATHRYIN - Kansas State University; Miesner, Tracy; Mitzel, Dana; SILVER, KRISTOPHER - Kansas State University

Submitted to: Journal of Visualized Experiments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2024
Publication Date: 11/29/2024
Citation: Cooper, A.M., Reif, K.E., Miesner, T.J., Mitzel, D.N., Silver, K.S. 2024. AC-DC electropenetrography for the study of probing and ingestion behaviors in mosquitoes and biting midges. Journal of Visualized Experiments. Article e66877. https://doi.org/10.3791/66877.
DOI: https://doi.org/10.3791/66877

Interpretive Summary: Viruses transmitted by insects continue to be a major concern for public and animal health. The transmission of these viruses occur in a natural cycle between vertebrate hosts and blood-feeding insects. However the feeding behaviors of these insects are poorly understood because the majority of the behaviors occur inside the host tissue. This manuscript describes a technique called electropenetropgrahy (EPG) that is used to quantify the different feeding behaviors of mosquitoes. In addition, this is the first manuscript to demonstrate the functionality of EPG on biting midges. EPG can be used to study the effects of pathogens and will provide insight into virus transmission and pathogenicity and will identify actions needed to break the transmission cycle.

Technical Abstract: Blood-feeding insects, such as mosquitoes and biting midges, transmit pathogens that negatively affect human and animal health. A greater understanding of blood-feeder biology and insect-host-pathogen interactions could be exploited to develop new targets for controlling vector-borne diseases. Unfortunately, probing (i.e., biting) behaviors of blood-feeding insects are poorly understood because they occur inside host tissues. Here, we describe a non-invasive procedure for using AC-DC Electropenetrography (EPG) to indirectly visualize and quantify those behaviors by recording changes in electrical signals generated during probing on human hands and mice. Thin gold wires are attached to the insects using conductive silver glue and connected to the EPG instrument. The human host holds a substrate voltage probe in their hand, or an anesthetized mouse is placed in sternal recumbency on the substrate voltage probe. When the insect contacts and probes the host, it completes the electrical circuit. The electrical signals are recorded on a computer in the form of “waveforms” that can then be measured and counted for analysis. A procedure for synchronizing video observations with the waveforms is provided to help elucidate the behaviors corresponding to each waveform. This methodology has been used to characterize probing and ingestion behaviors from Aedes and Culex mosquitoes and Culicoides biting midges and can be applied to a wide variety of blood-feeding arthropods, including vector and non-vector species. EPG can be used to study the effects of pathogens, insecticides, and other factors on probing and ingestion behaviors that occur during blood feeding.