Cyclic ketoenols: Acaricides and insecticides with a novel mode of action

Abstract

Modern crop protection industry puts great efforts into the investigation and development of pesticides (insecticides, acaricides) with a novel mode of action, primarily because of increasingly important problem of resistance of pest organisms to pesticides. Resistance of many pest arthropod species (insects and mites) to insecticides and/or acaricides became a global phenomenon in the last decades. Therefore, pest management heavily relies on constant introduction of novel active ingredients in use, i.e. on the alternative use of a number of compounds with different modes of action in order to save the longevity of newly developed products. Among pest arthropods, according to the potential for resistance development and a number of documented cases, spider mites (Acari: Tetranychidae), especially species Tetranychus urticae and Panonychus ulmi, as well as certain species of whiteflies and leaf aphids (Homoptra: Aleyrodidae, Aphididae) stand out. In 2002, the company Bayer CropScience introduced spirodiclofen, a tetronic acid derivative and the first cyclic ketoenol, acaricide with a wide spectrum and a novel mode of action - inhibition of acetyl-CoA-carboxylase. Soon after, spiromesifen was introduced, also a derivative of tetronic acid, acaricide and insecticide intended for control of phytophagus mites and whiteflies. Spirotetramat, a tetramic acid derivative, and the third member of the ketoenol group, was recently commercialised as an insecticide efficient against whiteflies, leaf aphids and other harmful Homoptera. In this paper are presented the most significant properties of cyclic ketoenols, aiming at pointing to the possibilities and prospects of their use, but also to potential problems and limitations.