Gone in 60 seconds: Sub-lethal Effects of Metofluthrin Vapors on Behavior and Fitness of Resistant and Field Strains of Aedes aegypti (Diptera: Culicidae).

Spatial repellents can reduce fecundity and interrupt oviposition behavior in Aedes aegypti. Yet, it is unclear if short exposure times, resistant phenotypes, and other aspects of spatial repellents can impact these effects on mosquito reproduction. To address these issues, pyrethroid susceptible, pyrethroid resistant, and field strains of Ae. aegypti were used to evaluate the extent to which fecundity and oviposition behavior are affected following metofluthrin exposure. Mosquitoes were exposed for 60 s to a sub-lethal dose (LC30) of metofluthrin before blood feeding and allowed 72 h to become gravid before evaluation in an oviposition bioassay for an additional 72 h. Metofluthrin-exposed susceptible, field, and to a lesser extent resistant strain Ae. aegypti showed oviposition across fewer containers, less egg yield, less egg viability, and reduced larval survivorship in hatched eggs compared to unexposed cohorts. Susceptible mosquitoes retained some eggs at dissection following bioassays, and in one case, melanized eggs retained in the female. Treated resistant and field strain F1 larvae hatched significantly earlier than unexposed cohorts and resulted in increased larval mortality in the first 3 d after oviposition. Upon laying, the treated field strain had incompletely melanized eggs mixed in with viable eggs. The treated field strain also had the lowest survivorship of larvae reared from bioassay eggs. These results indicate that metofluthrin could succeed in reducing mosquito populations via multiple mechanisms besides acute lethality. With the available safety data, pre-existing spatial repellent registration, and possibilities for other outdoor delivery methods, metofluthrin is a strong candidate for transition into broader mosquito abatement operations.

Bibbs CS ，Bloomquist JR ，Hahn DA ，Kaufman PE ，Xue RD ... -  《-》

Effects of sublethal exposure to metofluthrin on the fitness of Aedes aegypti in a domestic setting in Cairns, Queensland.

Buhagiar TS ，Devine GJ ，Ritchie SA 《Parasites & Vectors》

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

Bibbs CS ，Hahn DA ，Kaufman PE ，Xue RD ... -  《Parasites & Vectors》

Adulticidal Efficacy and Sublethal Effects of Metofluthrin in Residual Insecticide Blends Against Wild Aedes albopictus (Diptera: Culicidae).

Field development for optimizing the use patterns of spatial repellents are an ongoing research need. To investigate volatile pyrethroids in blends containing multiple active ingredients, metofluthrin was formulated into a vegetation spray for application to foliage and mosquito harborage. Metofluthrin was compared by itself and in combination with Sector (permethrin), Hyperion (sumithrin), Onslaught Fast Cap (s-fenvalerate, prallethrin), and against a benchmark for comparison, OneGuard (λ-cyhalothrin, prallethrin, pyriproxyfen). Field sites with established Aedes albopictus (Skuse) (Diptera: Culicidae) populations were allocated as control and treatment and surveilled with both adult traps and oviposition cups before and after treatment. Adult mosquito reductions were consistently higher over 4 wk in the combination treatments and were comparable to OneGuard. In contrast, efficacy provided by metofluthrin alone or the standalone existing product (Sector, Hyperion, Onslaught) by were consistently less effective than OneGuard and the comparative blends. Additionally, poorly melanized and collapsing eggs were identified from mosquito adults collected at treated field sites. A 20-50% significant decrease in nonviable mosquito eggs, a 50% or more reduction in total eggs and an 80% or more reduction in adult mosquitoes collected at the local field sites was demonstrated across all metofluthrin-containing treatments. Metofluthrin applications both supplemented the adulticidal control of the selected pyrethroid-containing products and provided significant reduction in egg laying frequency and viability during monitoring of areas adjacent to the treated vegetation. Metofluthrin, and possibly other volatile ingredients, appears to have complex interactions for mosquito control in the field and could be unique as a supporting ingredient to other insecticides.

Bibbs CS ，Kaufman PE ，Xue RD 《-》

Metofluthrin: investigations into the use of a volatile spatial pyrethroid in a global spread of dengue, chikungunya and Zika viruses.

Buhagiar TS ，Devine GJ ，Ritchie SA 《Parasites & Vectors》