Knockdown metofluthrin

Metofluthrin has high knockdown activity against mosquitoes and has an excellent mammalian safety profile. Metofluthrin is suitable for use not only in various... 

Metofluthrin is a suitable active ingredient for various formulations and devices due to its high lethal/knockdown activity against pest insects (especially mosquitoes), as well as having low mammalian toxicity and favorable physicochemical properties. This report summarizes its outstanding efficacy in various mosquito control formulations in both laboratory tests and field trials [2],... 

Table 2 Knockdown efficacy of Metofluthrin coil against Culex pipiens pallens (laboratory strain) by large chamber free-flying method...

Table 4 Knockdown efficacy of Metofluthrin coils against Culex quinquefasciatus (Bogor, Indonesia, field strain) using the large chamber free-flying method, 1 -h pre-fumigation...

Fig. 4 Knockdown efficacy of Metofluthrin(=160 mg) fan vaporizer against Culex pipiens pallens (susceptible strain) compared to commercial liquid vaporizer (prallethrin = 600 mg)...

One of the major characteristics of metofluthrin is its vapor activity at room temperature, which is not seen in the majority of knockdown pyrethroids, such as d-allethrin and prallethrin. We will describe a fan-type formulation where a motor turns a fan and the active ingredient is vaporized by the airflow from it at room temperature and a no-fan vaporizing formulation where the active ingredient is held in a paper, resin or other carrier without heating and without any motive force being provided. 

Table III. Knockdown efficacy of metofluthrin fan vaporizer against Culexpipiens (laboratory strain).

Thresholds exist for when and how insects respond to these chemical actions. These thresholds are governed by intrinsic factors related to the mode of action of the chemical and the insects susceptibility, as well as by extrinsic factors that modify those effects. Among the extrinsic factors, the physical environment, humidity, air movement, and temperature can affect the volatility of the active ingredient. The dose-dependent order in which thresholds are exceeded determines whether the primary mode of chemical action is repellent, irritant, or toxicant. Some pyrethroids can produce excitorepellency with possible mortality as a result of the exposure. Other pyrethroids with sufficiently high vapor phase concentration, for example, metofluthrin and transfluthrin, can result in a spatial repellent (barrier) effect regardless of knockdown and mortality of insects. 

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