Insecticides Mode of Action in Relation to Their Toxicity to (original) (raw)

Insecticides with Novel Modes of Action: An Overview

Conventional insecticides such as chlorinated hydrocarbons, organophosphates, carbamates and pyrethroids were successful in controlling insect pests during the past five decades, minimizing thereby losses in agricultural yields. Unfortunately, many of these chemicals are harmful to man and beneficial organisms and cause ecological disturbances. Although considerable efforts have been made to minimize the adverse environmental impact of pesticides and to maximize food production and health of the human population and domestic animals, there is today a great demand for safer and more selective insecticides affecting specifically harmful pests, while sparing beneficial insect species and other organisms. Furthermore, the rapidly developing resistance to conventional insecticides provides the impetus to study new alternatives and more ecologically acceptable methods of insect control as part of integrated pest management (IPM) programs.

Toxicological Parameters and Risk Assessment of Some Novel Insecticides

Advances in Environmental Engineering and Green Technologies, 2023

Pesticides are widely used in agriculture, horticulture, and public health to protect crops and control pests. However, pesticides can also pose a significant risk to human health and the environment, especially when used improperly or in excessive amounts. The toxicity of a pesticide is often expressed in terms of its lethal dose (LD) or lethal concentration (LC) values, which provide an estimate of the amount of the pesticide that can cause death in a specified population. In this chapter, the authors review the LD and LC values and explore the different factors that influence pesticide toxicity, such as the mode of action and formulation. Additionally, they present the toxicity ranges of selected pesticides commonly used in agriculture and public health and discuss the health effects associated with acute and chronic exposure to these chemicals. The chapter will conclude with a discussion of the regulatory frameworks governing pesticide use and the need for sustainable and integr...

The Sublethal Effects of Insecticides in Insects

Biological Control of Pest and Vector Insects, 2017

Studies related to the effect of insecticides on insect pests and nontarget organisms, such as natural enemies, are traditionally accessed by the estimative of lethal effects, through mortality data. Due to the limitations of the traditional methods, recent studies in the past three decades are assessing the sublethal effects of insecticides upon several important biological traits of insect pests and natural enemies. Besides mortality, the sublethal dose/concentrations of an insecticide can affect insect biology, physiology, behavior and demographic parameters. In this chapter, many sublethal effects of insecticides were addressed for several chemical groups, such as botanical insecticides, carbamate, diamide, insect growth regulators, neonicotinoid, organochlorides, organophosphates, pyrethroid and others. An accurate assessment of these effects is crucial to acquire knowledge on the overall insecticide efficacy in the management of pest insect populations, as well as on their selectivity toward nontarget organisms.

Impact and Selectivity of Insecticides to Predators and Parasitoids

EntomoBrasilis, 2010

Problems with the use of insecticides has brought losses, such as, negative impact on natural enemies. When these beneficial insects reduce cause the eruption of pests and resurgence it’s more common. Thus principles of conservation these arthropods are extremely important in the biological natural control of pests, so that these enemies may present a high performance. Because of the negative impacts caused by insecticides on agriculture and their harmful effects on natural enemies, the objective of this article is to approach two important subjects, divided into three parts. Part I relates to the description of the main crop pests and their natural enemies; Part II involves the impact of insecticides on predators and parasitoids and Part III focuses on the selectivity of several groups of insecticides to natural enemies. Before spraying insecticides, it is necessary to choose a product that is efficient to pests and selective to natural enemies. So, it is indispensable to identify ...

The need for the application of modern chemical insecticides and environmental consequences of their use: a mini review

Journal of Plant Protection Research, 2018

Currently, the use of insecticides is an acute problem. Due to rapid population growth, the primary task is to increase food production. Beyond abiotic factors (drought, soil salinity, etc.) that reduce crop yields, farmers face problems with insect pests that can decrease crop productivity up to 60%. Also, insects are carriers of severe viral and protozoan human diseases. The need for application of insecticides is not questioned but many of them cause resistance of insect pests to them. This, in turn, leads to the necessity to invent new insecticides that are safe and more effective for long-term use. Preparations based on conservative parts of nucleic acids, particularly contact DNA insecticides, could be used to solve insecticide resistance problem as control agents which are well-tailored to target insect pests. This mini review is devoted to these issues.

Insecticides with novel modes of action: Mechanism, selectivity and cross-resistance

Entomological Research, 2007

Efforts have been made during the past two decades to develop insecticides with selective properties that act specifically on biochemical sites present in particular insect groups, but whose properties differ from other insecticides. This approach has led to the discovery of compounds that affect the hormonal regulation of molting and developmental processes in insects; for example, ecdysone agonists, juvenile hormone mimics and chitin synthesis inhibitors. In addition, compounds that selectively interact with the insect nicotinic acetylcholine receptor, such as imidacloprid, acetamiprid and thiamethoxam, have been introduced for the control of aphids, whiteflies and other insect species. Natural products acting selectively on insect pests, such as avermectins, spinosad and azadirachtin, have been introduced for controlling selected groups of insect pests. Compounds acting on the nervous site that controls the sucking pump of aphids and whiteflies, such as pymetrozine, or respiration, such as diafenthiuron, have been introduced for controlling sucking pests. All the above compounds are important components in pest and resistance management programs.

Lethal and sublethal effects of seven insecticides on three beneficial insects in laboratory assays and field trials

Chemosphere, 2016

Lethal and sublethal effects of insecticides on target and non-target arthropods are a concern of pest management programs. Cycloneda sanguinea, Orius insidiosus and Chauliognathus flavipes are important biological control agents for aphids, whitefly, lepidopterus eggs, thrips and mites. All three test species were subjected to a toxicity study using the insecticides acephate, bifenthrin, chlorantraniliprole, chlorpyrifos, deltamethrin, imidacloprid, and thiamethoxam. Experiments were done in the lab and field. In the laboratory we evaluated the mortality and sublethal effects of the concentration that killed 20% of the population (LC20) on feeding, repellence and reproduction of the species tested. The lethal effects of these insecticides at the recommended doses was evaluated in the field. Concentration-response bioassays indicated chlorantraniliprole had the lowest toxicity, while chlorpyrifos and acephate were the most toxic. Test species exposed to filter paper surfaces treated ...