Polymer Beads Increase Field Responses to Host Attractants in the Dengue Vector Aedes aegypti

• Published in: Journal of chemical ecology 2024-11, Vol.50 (11), p.654-662
• Main Authors: Adhiambo, Elizabeth F., Gouagna, Louis-Clement, Owino, Eunice A., Mutuku, Francis, Getahun, Merid N., Torto, Baldwyn, Tchouassi, David P.
• Format: Article
• Language: English
• Subjects: Acyclic Monoterpenes - pharmacology; Aedes - drug effects; Aedes - physiology; Aedes aegypti; Agriculture; Animals; Aquatic insects; Attractants; Biochemistry; Biological Microscopy; Biomedical and Life Sciences; Carbon dioxide; Control programs; Cyclohexanone; Dengue - transmission; Dengue fever; Ecology; Effectiveness; Entomology; Experiments; Female; Females; Formulations; Gravimetric analysis; Hexanes; Kenya; Ketones; Life Sciences; Linalool; Male; Mosquito Control; Mosquito Vectors - drug effects; Mosquito Vectors - physiology; Mosquitoes; Olfactory stimuli; Pheromones - pharmacology; Polymers; Polymers - chemistry; Polymers - pharmacology; Solvents; Trapping; Traps; Vector-borne diseases
• ISSN: 0098-0331; 1573-1561; 1573-1561
• DOI: 10.1007/s10886-024-01489-8

This study investigates the efficacy of three different olfactory cues - cyclohexanone, linalool oxide (LO), and 6-methyl-5-heptan-2-one (sulcatone) - in attracting Aedes aegypti , the primary vector of dengue, using BG sentinel traps in a dengue-endemic area (urban Ukunda) in coastal Kenya. Two experiments were conducted. Experiment 1 compared solid formulations of the compounds in polymer beads against liquid formulations with hexane as the solvent. CO 2 -baited traps served as controls. In Experiment 2, traps were baited with each compound in the polymer beads, commercial BG-Lure, and CO 2 . Our results indicate that CO 2 -baited traps recorded the greatest Ae. aegypti captures in both Experiment 1 and 2, whereas trap captures with polymer beads and solvent-based treatments were comparable. In experiment 2, polymer bead-based treatments yielded significantly greater female captures, each recording ~ 2-fold more captures than traps baited with the BG-Lure. There was no significant difference, however, between the treatments. Female Ae. aegypti captured in CO 2 -baited traps were mainly unfed (91%), with fewer gravid mosquitoes (6.4%) compared to traps with test compounds (range; 12.7–21.1%). Male captures were lower in LO and BG-Lure baited traps compared to other treatments. Gravimetric analysis showed LO had a slower release rate compared to other compounds. The findings suggest that host-associated compounds loaded on polymer beads are more effective in trapping Ae. aegypti than commercial BG-Lure and reveal sex-specific differences in mosquito responses. These results have implications for mosquito surveillance and control programs, highlighting the potential for selective trapping strategies.