Collection and quantification of Permanone^® 31-66 deposited during mosquito Culex quinquefasciatus field bioassays towards improving survival probability models

Monday, November 14, 2022

10:54 AM – 11:06 AM PT

Location: Vancouver Convention Centre, Meeting Room 201

Presenting Author(s)

Han-Jung Lee

PhD candidate
Texas A&M University
College Station, Texas

Co-Author(s)

MS

Michael R. Shields

Texas A&M University
College Station, Texas
MS

Miguel A. Saldaña

Harris County Public Health
Houston, Texas
CF

Chris Fredregill

Harris County Public Health
Houston, Texas
Patricia V. Pietrantonio

Professor
Texas A&M University
College Station, Texas

Several factors contribute to the success or failure of mosquito control in the field. Permanone^®, a pyrethroid-based pesticide, is applied by Harris County Public Health (HCPH) to control Culex quinquefasciatus when West Nile and/or other arboviruses are detected. To assess the efficacy of Permanone^®, HCPH performs seasonal field tests with mosquito females in cages simulating the field application. In our previous analyses, a linear regression model identified the “distance from the pesticide source” and the “subsamples within the same distance” as two of the factors affecting the survival probabilities of mosquitoes in these tests. We now hypothesized that Permanone^® quantities deposited in the testing area are heterogeneous, which causes variable control efficacy at different tested distances, and in subsamples within the same distance. To test this hypothesis, we developed a methodology to collect/quantify Permanone^® deposited during the field test. Permanone^® was collected in aluminum weighing boats hung on three poles at each of the distances. After the Permanone^® application the boats were collected and ethyl acetate was used to recover Permanone^® for GC/MS analyses. This method had a high extraction efficiency for Permanone^® ranging from 80 to 110%. The quantities of pesticide deposited decreased as the distance from the pesticide spraying source increased up to 91.2 m. Knowledge of Permanone^® distribution in the field using this method will improve the interpretation field bioassays, the models to predict survival probability and also contribute to the estimation of field resistance ratios.

Collection and quantification of Permanone® 31-66 deposited during mosquito Culex quinquefasciatus field bioassays towards improving survival probability models

Presenting Author(s)

Co-Author(s)

Collection and quantification of Permanone^® 31-66 deposited during mosquito Culex quinquefasciatus field bioassays towards improving survival probability models