Allethrin-Based Mosquito Control Device Causing Knockdown, Morbidity, and Mortality in Four Species of Field-Caught Mosquitoes (Diptera: Culicidae)

Abstract

A mosquito control device marketed for spatial repellency, the ThermaCELL Mosquito Repellent Appliance, was evaluated in semifield trials against multiple field-caught species of mosquito. Using paper and mesh cages, mosquito test groups of at least 30 mosquitoes were suspended in a 2,337 cubic foot outdoor space while two ThermaCELL repellent devices were active. After 30 min of treatment, cages were moved to the laboratory to observe knockdown, morbidity, and mortality for 24 h. Species tested included Aedes atlanticus Dyar and Knab (98% average mortality), Psorophora ferox Humboldt (97% average mortality), Psorophora columbiae Dyar and Knab (96% average mortality), and Aedes taeniorhynchus Wiedemann (84% average mortality). The repellent devices showed effectiveness with high knockdown and mortality across all species tested. Mosquito control devices like the ThermaCELL Mosquito Repellent Appliance may have further practical applications to help combat viral exposures by limiting host mosquitoes. Such devices may provide a functional alternative to DEET dependence in the current state of mosquito management.

Behavioral response of insecticide-resistant mosquitoes against spatial repellent: A modified self-propelled particle model simulation

“…However, spatial repellents, such as some coil products, use pyrethroids and other synthetic chemicals and plant products as major volatile ingredients to repel mosquitoes [23,25,[44][45][46]. These volatile chemicals prevent mosquitoes from feeding on humans through several mechanisms, including 1) knockdown and mortality; 2) deterrence (mosquitoes are prevented from entering human dwellings); 3) irritancy (mosquitoes enter houses but leave early); 4) excitorepellency (mosquitoes exit the house to avoid contacting airborne insecticides); and 5) feeding inhibition (mosquitoes are prevented from biting and getting blood meals) [23,25,35,37,40,[44][45][46][47][48][49][50]. Since malaria vectors have developed widespread resistance to insecticides, the efficacy of spatial repellents against these resistant mosquitoes is unknown.…”

Sublethal effects of a vapour-active pyrethroid, transfluthrin, on Aedes aegypti and Ae. albopictus (Diptera: Culicidae) fecundity and oviposition behaviour

“…Spatial repellent devices, such as ambient emanators, mosquito coils, vaporiser mats, and liquid vaporisers are an alternative to topical repellents that are frequently chosen by consumers [ 9 ]. Spatial repellents allow the dissemination of active ingredients on small scales, often serving as personal protection devices [ 11 – 13 ]. When such devices emit volatile pyrethroids, these tools can both reduce mosquito contact with humans [ 14 ] and kill mosquitoes outright [ 12 , 13 ].…”

“…Spatial repellents allow the dissemination of active ingredients on small scales, often serving as personal protection devices [ 11 – 13 ]. When such devices emit volatile pyrethroids, these tools can both reduce mosquito contact with humans [ 14 ] and kill mosquitoes outright [ 12 , 13 ]. This is due to the primary mode of action of pyrethroids, in which the active ingredient binds to the voltage-gated sodium channel (VGSC) as the primary mode of toxicity.…”

“…This property of inhalation is a clear benefit of some active ingredients, such as metofluthrin or transfluthrin, that lead to various acute and sub-acute outcomes. Because of the combined benefits of repellency and mortality, volatile pyrethroids have been advocated as a tool for urban vector management [ 12 , 13 ].…”

Behavioral response of insecticide-resistant mosquitoes against spatial repellent: a modified self-propelled particle model simulation

“…These volatile chemicals prevent mosquitoes from feeding on humans through several mechanisms, including 1) knockdown and mortality; 2) deterrence (mosquitoes are prevented from entering human dwellings); 3) irritancy (mosquitoes enter houses but leave early); 4) excito-repellency (mosquitoes exit the house to avoid contacting airborne insecticides); and 5) feeding inhibition (mosquitoes are prevented from biting and getting blood meals) [23,25,35,37,40,[44][45][46][47][48][49][50]. Since malaria vectors have developed widespread resistance to insecticides, the efficacy of spatial repellents against these resistant mosquitoes is unknown.…”