Abstract

In Singapore, indoor space spraying, such as ultra-low-volume (ULV) treatment, is used to control adult mosquitoes during vector-borne disease outbreaks. This study assessed the efficacy of Mirakn® GX, a pyrethroid-based insecticide formulation combining d,d-trans-cyphenothrin with desiccated carbon dioxide as a propellant. The implications of these findings for operational use will be discussed. Mirakn® GX was evaluated against confined field and laboratory strains of Aedes aegypti, Ae. albopictus and Culex quinquefasciatus under semi-field conditions, following World Health Organization (WHO) guidelines. This study was conducted within an occupied residential apartment unit. An additional evaluation focusing on Ae. aegypti, designed to mimic operational practice, was performed using a reduced exposure duration of 10 min. At an application rate of 1 g/m3 with 60 min exposure, 100% knockdown and 99.79–100% mortality were observed across all three mosquito species. A shortened 10 min exposure also resulted in complete knockdown and mortality in both laboratory and field strains of Ae. aegypti, supporting operational feasibility. Under semi-field conditions, the insecticide formulation showed good penetration into enclosed spaces, indicating its potential use for scenarios where timely management of indoor adult mosquitoes is required, including during outbreaks to kill infected mosquitoes.

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