The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is considered one of the most economically damaging pests of citrus orchards in Spain. Insecticide treatments for the control of this pest are mainly based on aerial and ground treatments with malathion bait sprays. However, the frequency of insecticide treatments has been increased in some areas of the Comunida...

Introduction: Antioxidant defense components protect insects by scavenging reactive oxygen species, leading to oxidative stress. We therefore investigated the effect of an organophosphate insecticide, dichlorvos, on superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione S-transferase (GST) and glutathione reductase (GR) as antioxidative biomarkers in silk worm, Bo...

OBJECTIVE To study the susceptibility status of Aedes aegypti to the organophosphate insecticide temephos. METHODS Samples of Ae. aegypti larvae were obtained, using ovitraps, from eight cities of the Federal District, central Brazil, in 2000 and 2001. Larvae were submitted to the diagnostic dose of 0.012 mg/l temephos, as recommended by standard World Health Organization methodology. Field p...

Rachel Carson's 1962 Silent Spring exposed both observed and potential environmental and health externalities of the increasing organochlorine and organophosphate insecticide use in the United States post-World War II. Silent Spring was a critical component in a popular movement that resulted in increased regulation and the development of safer pesticides. Most changes in pesticide use in the g...

Electrophysiological studies in suicidal patients with organophosphate poisoning are reported. Patients often developed muscular weakness of variable severity owing to diplorisation block at nicotinic receptors. During such paralysis nerve conduction velocity and distal latencies were normal even in severely paralysed patients. The amplitude of the compound action potential was smaller than in ...

Resistance to methyl-parathion among Nebraska western corn rootworm, Diabrotica virgifera virgifera LeConte, populations is associated with increased hydrolytic metabolism of an organophosphate insecticide substrate. An electrophoretic method to identify resistant individuals based on the staining intensity of esterase isozymes on nondenaturing polyacrylamide gels was developed. Three groups of...

Pesticides are known to affect insects metabolic rate and CO2 release patterns. In the presented paper metabolic rate and mortality of mealworms Tenebrio molitor L. exposed to four different insecticides was evaluated, to find out whether there is a relationship between mealworms sensitivity to pesticides and their metabolic rate. Tenebrio molitor mortality was determined after intoxication wit...

The sublethal stress of the organophosphate insecticide chlorpyrifos was investigated in different tissues of the freshwater crab (Barytelphusa guerini). Crabs were exposed to 1/3 of LC50 concentrations for 7, 14, 21, and 28 days. After 28 days, they were released into fresh water and kept for 18 days for recovery. The study was conducted by estimating total proteins, amino acids, ammonia, urea...

Insecticide resistance genes have developed in a wide variety of insects in response to heavy chemical application. Few of these examples of adaptation in response to rapid environmental change have been studied both at the population level and at the gene level. One of these is the evolution of the overproduced esterases that are involved in resistance to organophosphate insecticides in the mo...

A rugged and sensitive method was developed to monitor urinary concentrations of O,S-dimethyl hydrogen phosphorothioate (O,S-DMPT), a specific biomarker of exposure to the organophosphate insecticide methamidophos. After pH adjustment and C18 solid phase extraction column cleanup, the urine was lyophilized at a low temperature to prevent loss of possibly highly volatile and unstable O,S-DMPT me...