Abstract Chlorpyrifos is an organophosphate insecticide. It has low aqueous solubility, volatile and non-mobile, moderately persistent in soil, highly toxic to mammals, acetylcholinesterase inhibitor. The main use of chlorpyrifos control various types agricultural pests. This study aims determine the absorption residues maize plants. was conducted July-December 2019. Experimental research at Ja...

Insensitive acetylcholinesterase (AChE) has been shown to be responsible for resistance to organophosphates and carbamates in a number of arthropod species. Some arthropod genomes contain a single Ace gene, while others including mosquitoes contain two genes, but only one confers insecticide resistance. Here we report the isolation of the full-length cDNA and characterization of the complete ge...

Toxicity tests using early life stages of fish are of great importance in assessing risks to growth, reproduction and survival in polluted environments and are important tools for good environmental monitoring. However, a small number of standard bioassays of this type have been developed in Brazil. Curimbatá (Prochilodus lineatus) is an abundant South American characid fish of great commercial...

Oximes are well known as acetylcholinesterase reactivators and are used in organophosphorus poisoning to reactivate inhibited acetylcholinesterase. Therapeutically available oximes, namely, pralidoxime (2-PAM), obidoxime, trimedoxime and Hagedorn oxime (HI-6), have no broad-spectrum activity against structurally different kinds of organophosphorus anticholinesterases. The widely used oxime, 2-P...

Resistance in a dual malathionand permethrin-resistant head louse strain (BR-HL) was studied. BR-HL was 3.6and 3.7-fold more resistant to malathion and permethrin, respectively, compared to insecticide-susceptible EC-HL. S,S,S-Tributylphosphorotrithioate synergized malathion toxicity by 2.1-fold but not permethrin toxicity in BR-HL. Piperonyl butoxide did not synergize malathion or permethrin t...

The in vitro effect of a widely used organophosphorus insecticide, chlorpyrifos (CPP), on the acetylcholinesterase (AChE) activity was studied in vitro. The kinetic constants Km and Vmax and the bimolecular constant k(j) were determined in vitro. The in vitro AChE study indicated that CPP is neurotoxic and that it alters the apparent Km values widely in a concentration-dependent manner, resulti...

We compared biological functions of two acetylcholinesterase genes (TcAce1 and TcAce2) in Tribolium castaneum, a globally distributed major pest of stored grain products and an emerging model organism, by using RNA interference. Although both genes expressed at all developmental stages and mainly in the brain, the transcript level of TcAce1 was 1.2- to 8.7-fold higher than that of TcAce2, depen...

TheAsiancitruspsyllid,Diaphorina citriKuwayama, is aworldwidepest of citrus,which vectors the putative causal pathogen of huanglongbing. Current management practices warrant continuous monitoring of Þeld populations for insecticide resistance. Baseline activities of acetylcholinesterase (AChE), general esterase, and glutathione S-transferase as well as sensitivity of AChE to selected organophos...

High insecticide resistance resulting from insensitive acetylcholinesterase (AChE) has emerged in mosquitoes. A single mutation (G119S of the ace-1 gene) explains this high resistance in Culex pipiens and in Anopheles gambiae. In order to provide better documentation of the ace-1 gene and the effect of the G119S mutation, we present a three-dimension structure model of AChE, showing that this u...