Factors which influence the knockdown effect of insecticide products

Abstract

Knockdown in insects following application of an insecticide may be defined as the state of intoxication and partial paralysis which usually precedes death. Pyrethroid insecticides cause knockdown within a few minutes in contrast to the slower action of other groups of compounds. Users throughout the world have varying interpretations of knockdown and may apply different emphasis depending upon the species involved and local application techniques. To obtain valid assessments it is necessary to carry out tests under the most realistic conditions possible and to see that the effects of variations in procedure are taken into full account. Some factors which influence knockdown are: single rapid dosing or continuous pick-up during the observation period ; size and distribution of spray droplets; size of test chamber; interaction in mixtures of synergist and insecticides; use of organic solvents or water-based formulations. Examples of these are given.

Biochemical and molecular analyses to determine pyrethroid resistance in Aedes aegypti

“…Pyrethroid insecticides cause knockdown within a few minutes [17]. The rapid knockdown induced by pyrethroids simply demonstrates their rapid action on the nervous system, suggesting their mode of entry through the spiracles under certain experimental conditions [18].…”

Characteristics and magnitude of acute pesticide‐related illnesses and injuries associated with pyrethrin and pyrethroid exposures—11 states, 2000–2008

“…Paresthesias have been reported to be more commonly caused by dermal exposure to Type II pyrethroids, but can occur from exposure to Type I pyrethroids [US EPA, ; Ray and Forshaw, ]. To enhance the insecticidal properties of pyrethrin/pyrethroid products, pesticide formulators added piperonyl butoxide or MGK‐264, which are synergists that inhibit pyrethroid metabolism in insects so as to increase the “knock down” effect (i.e., paralysis before death) [Wickman et al, ]. While human data are lacking, animal data suggest that the addition of synergists can also cause greater toxicity in humans due to pesticide concentrations persisting longer in the body [Bradberry et al, ].…”

Pengaruh Arah Pergerakan Nozzle dalam Penyemprotan Pestisida Terhadap Liputan dan Distribusi Butiran Semprot dan Efikasi Pestisida pada Tanaman Kentang

“…Distribusi butiran semprot perlu diketahui karena menurut Wickham et al (1974) parameter tersebut merupakan salah satu faktor yang memengaruhi efikasi pestisida. Pelaksanaan pengukuran menggunakan bantuan serbuk fluorescens.…”

“…Sebagian petani yang lain mengaplikasikan pestisida dengan posisi nozzle di bawah dan diayunkan ke arah tanaman dengan sudut 45 o (Gambar 1). Setiap cara aplikasi tersebut akan menghasilkan distribusi butiran semprot yang berbeda, yang akhirnya berpengaruh terhadap efikasi pestisida (Wickham et al 1974 …”