Dose–Response Assay for Synthetic Mosquito (Diptera: Culicidae) Attractant Using a High-Throughput Screening System

Abstract

Natural volatile host cues play a critical role for mosquito orientation and locating a blood source for egg production. Similar olfactory activation responses have allowed the use and development of artificial chemical attractants to lure mosquitoes to trapping devices. Using a pre-formulated commercial product mixture of different attractant chemicals, a high-throughput screening system (HITSS) is used to screen varying doses of chemical required to activate behavioral responses. Two strains of Aedes aegypti (L.): permethrin-susceptible (USDA) and -resistant (Pu Teuy) phenotypes and one Culex quinquefasciatus Say. (NIH) laboratory strain were tested. Overall, mosquitoes showed repellency between 1.0 g and to 10.0 g dose of each compound. However, by progressively reducing the dose, Cx. quinquefasciatus showed a greater positive percent attraction (88.9%) at 0.025 g, whereas the USDA and Pu Teuy Ae. aegypti produced optimum attractant activation at 0.005 g (72.6% and 58.9%, respectively) without significant difference within species (p > 0.05). In parallel control assays, Cx. quinquefasciatus was significantly attracted to 1 g of dry ice (carbon dioxide) (76%) more than Ae. aegypti (USDA) (12.2%). The HITSS was originally designed to measure three chemical actions to sublethal concentrations of chemicals by mosquitoes: toxicity and the two primary behavior avoidance responses (contact excitation and spatial repellency). These findings demonstrate that the HITSS assay, with only minor modifications, allows comparison screening of candidate compounds as potential attractants for anemotactic responses under laboratory-controlled conditions. Further investigations will be required to equate measurements obtained from controlled laboratory assays to more varied field conditions for attracting natural mosquito populations.

Semi-field evaluation of novel chemical lures for Aedes aegypti, Culex quinquefasciatus, and Anopheles minimus (Diptera: Culicidae) in Thailand

“…In particular, economical and simple methodologies are critical for the development of mosquito attractants in less well-equipped laboratories. Recently, Kim et al [ 22 , 23 ] evaluated a potential tool for lure development, the HITSS assay. However, more data are needed to demonstrate its accuracy in larger-scale SFS house set ups.…”

“…quinquefasciatus was more strongly attracted by 0.1 g of dry ice than Ae. aegypti [ 23 ]. We also found that the amounts of the lure ingredients were among the most crucial factors for mosquito attraction and repellence.…”

“…Salaza et al [ 25 ] confirmed that there was no significant difference in the capture rate of BGS traps surrounding experimental huts between mosquitoes that had been previously exposed to the spatial repellent and those that had not. Furthermore, no meaningful relation between pesticide resistance and host-seeking behavior could be confirmed in laboratory experiments using the HITSS assay [ 22 , 23 ]. However, further study of the persistence of the chemical lures in the material to which they are applied should be considered.…”

“…aegypti were collected from natural or artificial breeding habitats in Pu Tuey Village, Kanchanaburi Province, Thailand (14°77′N, 99°11′E) in January 2019. This field population showed a high phenotypic resistance to 0.25% permethrin, with only 6% mortality, in the World Health Organization (WHO) tube bioassay [ 23 ]. Aquatic stages of Cx.…”

Development of an automated biomaterial platform to study mosquito feeding behavior

“…Although several assays have been proposed to screen mosquito attractants ( Kim et al, 2021a ; 2021b ) or repellents ( Grieco et al, 2005 ; Tisgratog et al, 2016 ; Kajla et al, 2019 ; Chauhan et al, 2021 ), creating a controlled environment to simultaneously test the impact of multiple variables such as temperature and blood type on mosquito feeding behavior remains challenging. Several recently published experimental platforms effectively quantify repellent effectiveness, but often rely on human volunteers or use spatially inefficient designs, thereby limiting their scalability ( Goodyer et al, 2020 ; Farooq et al, 2022 ).…”