Excitability changes following a nerve impulse were studied in the rat tail. Supernormal nerve excitability in control animals was present, as in other vertebrate nerve fibres, from 4-30 ms and was followed by a period of subnormal excitability extending up to 100-200 ms. Two to seven hours after intravenous administration of 1.5 mg/kg deltamethrin, supernormality was increased in degree and pr...

Three organophosphorus compounds- malathion, folithion and temephos- and two synthetic pyrethroids- alphamethrin and deltamethrin- were used for monitoring the susceptibility status of larvae and adults of six vector mosquito species: Culex quinquefasciatus (Filariasis) and Aedes albopictus (Dengue) (both laboratory and field strains); laboratory strains of Aedes aegypti (Dengue), Anopheles ste...

Biochemical markers are measurable responses to the exposure of an organism to xenobiotics as well as very suitable biosensors of aquatic pollutants. Aquatic pollution can easily be detected through biomarkers, as enzymes provide one of the most reliable means of assessing the degree of exposure of animals to pollutants. Some of the biochemical alteration occurring in the body gives the first i...

(1R)-trans-Norchrysanthemic acid fluorobenzyl esters are synthesized and their structure-activity relationships are discussed. These esters show outstanding insecticidal activity against mosquitoes. In particular, the 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl analog (metofluthrin) exhibits the highest potency, being approximately forty times as potent as d-allethrin in a mosquito coil formulati...

Five phytoseiid mite species: Phytoseiulus persimilis Athias-Henriot, Neoseiulus californicus（McGregor）, womersleyi（Schicha）, Amblyseius eharai Amitai and Swirski, Euseius sojaensis（Ehara）（Acari: Phytoseiidae）were collected from commercial Japanese pear orchards in Shizuoka Prefecture. To evaluate the suppressive effect of generalist species on spider Tetranychus kanzawai Kishida（Acari: Tetrany...

b a ckground: the german cockroach, b lattella germanica is a major hygienic pest and mechanical vector for path- ogenic agents in hospitals and residential areas. the development of insecticide resistance is a serious problem in controlling of this pest. toxicity of four commonly used insecticides (permethrin, cypermethrin, malathion and chlorpyrifos) against two hospital- collected strains of...