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At least 19 recordsLinked to original sources
PubMed1976

Toxicity of natural pyrethrins and five pyrethroids to fish.

The toxicity of natural pyrethrins and five pyrethroids was determined with coho salmon (Oncorhynchus kisutch), steelhead trout (Salmo gairdneri), fathead minnow (Pimephales promelas), channel catfish (Icatlurus punctatus), bluegill (Lepomis macrochirus), and yellow perch (Perca flavescens). The 96-hour LC50's in static tests at 12 degrees C ranged from 24.6 to 114 mug/l of natural pyrethrins and from 0.110 to 1,140 mug/l of pyrethroids. Two pyrethroids, RU-11679 and SBP-1382 (R), were over 10 times more toxic than pyrethrum extract in the flow-through tests. Coldwater species of fish were more sensitive than warmwater species to all the compunds. Temperature (12-22 degrees C) influences the toxicity of natural pyrethrin and the pyrethroids. The natural pyrethrin was more toxic to fish in pH 6.5 than in pH 9.5 water, but the toxicity of pyrethroids was not influenced in the pH range. The two most toxic pyrethroids, RU-11679 and SBP-1382, Were deactivated more rapidly in water solutions than natural pyrethrins, S-bioallethrin, dimethrin, and d-trans allethrin.

Animals↗
PubMed1991

Neurotoxicology of pyrethrin and the pyrethroid insecticides.

Natural pyrethrin and synthetic pyrethroid insecticides have been considered among the safest classes of insecticides available. Pyrethrins and pyrethroids are classified on the basis of their chemical structures and their toxicologic, neurophysiologic and pharmacologic effects. Cellular effects of pyrethrin and pyrethroid insecticides have been postulated to involve interactions with sodium channels, receptor-ionophore complexes, neurotransmitters, and ATPases. Toxicity is a function of chemical structure, metabolism, route of exposure, and the presence or absence of synergists. Pyrethroid insecticides are neurotoxic, and the development and severity of clinical signs is proportional to the nervous tissue pyrethroid concentration. Type I pyrethroid poisoning in mice and rats produces a syndrome characterized by tremors, prostration and altered startle reflexes. Type II pyrethroid poisoning in mice and rats causes ataxia, convulsions, hyperactivity, choreoathetosis and profuse salivation. A presumptive diagnosis of pyrethrin/pyrethroid poisoning is based upon history of exposure, development of appropriate clinical signs, and chemical analysis for insecticide residues. Treatment of pyrethrin and pyrethroid toxicosis involves basic life support, seizure control when needed, and the prevention of further insecticide absorption.

Animals↗
PubMedDate not supplied

Treatment of infestation with Phthirus pubis: comparative efficacies of synergized pyrethrins and gamma-benzene hexachloride.

In recent years there has been a steady increase in the incidence of infestation with Phthirus pubis, a sexually transmitted louse. A recently introduced nonprescription liquid pediculicide, whose major ingredient is 0.3% pyrethrins synergized by 3.0% piperonyl butoxide (RiD), was compared for efficacy and safety with a prescription-only pediculicidal lotion whose major ingredient is 1% gamma-benzene hexachloride (Kwell). Thirty adult man and women with P. pubis infestation were assigned randomly to treatment with either the synergized pyrethrins or gamma-benzene hexachloride. A single 10-min application of the synergized-pyrethrin liquid produced the same results as a single 12-hr application of the gamma-benze hexachloride lotion: total eradication of adult lice and nymphs, cessation of pruritus, and no treatment-induced side effect. A follow-up visit a week after treatment verified all eradications.

Adolescent↗
PubMed1991

Trap perches to assess the activity of pyrethrins against the poultry red mite Dermanyssus gallinae in cage birds.

Trap perches were utilised to quantify mite recoveries during efficacy tests of pyrethrin formulations against experimental infestations of Dermanyssus gallinae (De Geer, 1778) in budgerigars and pigeons, and to monitor mite recoveries from untreated canaries. Pyrethrins applied topically before infestation significantly reduced the mean numbers of poultry red mites found in both budgerigar and pigeon trap perches, over those in untreated controls (P = less than 0.01). In untreated control budgerigars and pigeons, and in untreated canaries, the percentage recoveries after 48 h were 12.6 +/- 1.6, 4.1 +/- 1.9, and 32.6 +/- 1.6%, respectively (geometric mean +/- SD), and the blood engorgements rates were 71.5 +/- 1.7, 11.9 +/- 5.1, and 90.1 +/- 1.0% respectively. The recovery in trap perches of mites from canaries declined exponentially; 85% of the cumulative total recovered was collected 24 h after infestation, but small numbers were recovered daily up to 96 h (limit of observation). The use of the trap perches is discussed as a way of assessing the efficacy of acaricides, and as a laboratory tool in studies on mite aggregation behaviour or immune responses to mite infestation.

Administration, Topical↗
PubMed1977

Separation and analysis of the pyrethrins by combined gas-liquid chromatography-chemical ionization mass spectrometry.

Pyrethrins, the 6 naturally occurring insecticidal esters of pyrethrum extract, were analyzed by combined gas-liquid chromatography-chemical ionization mass spectrometry. Separation was best on an OV-25 column with temperature programming; The chemical ionization mass spectra for the 6 esters as well as for the thermally isomerized pyrethrins I and II are reported and discussed. Using selective ion monitoring, a lower limit of detectability of all 6 esters was 114 ng of total extract injected on the column.

Chromatography, Gas↗
PubMed1991

[The use of pesticides indoors with special reference to pyrethrins. Description of problems and attempts at solution from the viewpoint of ecological health protection].

One of the primary concerns of ecological health protection is to take of preventive health measures via the assessment of indoor toxic levels and the implementation of regulations governing the use of such toxics. Underlying this concern is the premise that the use of toxics should be minimised to the greatest possible extent. The use of pesticides indoors, which is often carried out without adequate expert knowledge and in excessive quantities, is a problem that affects all aspects of life but has thus far been addressed only insufficiently. Two recent incidents in Berlin involving the use of pesticides urgently point to the need of increasing our understanding of this complex subject. The incidents in Berlin involved the incorrect utilization of pesticides--mainly pyrethroids--in schools, leading to illness among pupils and school staff. After a short description of the problem of the use of pesticides indoors, potential means of solving this problem are discussed. In addition, individual recommendations regarding the use of specific pesticides are discussed with the aim of minimising the health risks associated with their application.

Animals↗
PubMed1991

Extended selections for pyrethroid resistance in the German cockroach (Dictyoptera: Blattellidae).

Selection experiments with a pyrethrins-susceptible and a pyrethrins-resistant strain of German cockroaches, Blattella germanica (L.), were conducted for 17 generations with either permethrin or fenvalerate as the selecting agent. Large nymphs were left on treated glass surfaces for extended periods of time each generation. Mortality was assessed at 24 h. The level of resistance was determined periodically by time-mortality testing. The VPI-susceptible strain served as the basis for comparison. The pyrethrins-susceptible strain developed resistance to pyrethrins early in the selection process; this strain ultimately became resistant to allethrin, phenothrin, permethrin, fenvalerate, cyfluthrin, and cypermethrin. Fenvalerate caused faster development of resistance than did permethrin. The pyrethrins-resistant strain, selected with fenvalerate, quickly became resistant to allethrin, permethrin, phenothrin, and fenvalerate. Ultimately, it developed resistance to all nine pyrethroids tested.

Animals↗
PubMed1990

[The appearance of insecticide resistance in Blattella germanica in the German Democratic Republic].

A review is given on the situation of resistance in the German cockroach (Blattella germanica) to insecticides during the last 15 years in the GDR, and conclusions are drawn for the future. From 23 samples trapped in various localities and subsequently reared in the laboratory, susceptibilities were measured against lindane, pyrethrin + PBO, trichlorfon, dichlorvos, and propoxur, the most used insecticides against cockroaches in our country. Detection of resistance was done with discriminating doses and the degree of resistance was measured with the doses-mortality method in deposit tests. In no case we found any resistance to propoxur but, for the first time, strains with a low resistance to dichlorvos. There was a distinct increase in the resistance to lindane, trichlorfon and pyrethrins + PBO during the lost years. A strain selected with pyrethrins in the laboratory showed marked group resistance to all tested pyrethroids (permethrin, cyfluthrin, cypermethrin, tetramethrin, deltamethrin, bioresmethrin, bioallethrin), but no cross resistance to the other insecticides.

Animals↗
PubMed1979

Demographic study of head lice infestations in Sacramento County school children.

Head lice infestations have become a problem in school children in Sacramento County. An open study was conducted to determine how widespread head lice infestations were among preschool and elementary school children in Sacramento County and to see how effective a newly marked ever-the-counter pediculicide containing 0.3% pyrethrins synergized by 3.0% piperonyl butoxide was. The public health nurse for this study visited the homes of all reported patients infested with head lice. She verified and provided the pyrethrins-based treatment for 248 children, aged 6 months to 12 years. The children were Caucasian, Mexican-American, black and other ethnic backgrounds and from low, middle and upper income levels. All the patients were successfully treated, and the school children were able to return to their classs in a short time.

California↗
PubMed1991

Pesticides and the Third World.

Many developing countries are importing industrial processes that make use of toxic chemicals. By the same token, pesticides, which are toxic by design, are also used increasingly in agriculture and in public health programs to control pests and vector-borne diseases. Recent estimates suggest that pesticides account for more than 20,000 fatalities yearly, and that most of these will have occurred in developing countries. This may actually be a gross underreporting. Although organophosphate and carbamate insecticides are still responsible for many of those poisoning cases, herbicides such as paraquat are also increasingly being implicated in fatal poisoning cases. Newer pesticides such as the synthetic derivatives of pyrethrin, which were believed to be relatively safe to humans, now appear to be implicated in some serious cases of intoxication. Community-based pest control using locally available botanical pesticides could have severe consequences unless the toxicity of these compounds is carefully assessed relative to nontarget organisms. A high proportion of pesticide intoxications appear to be due to lack of knowledge, unsafe attitudes, and dangerous practices. The technology available to small farmers for pesticide application is often inappropriate: faulty sprayers, lack of protective equipment adapted to tropical conditions, nonexistent first-aid provisions. Agricultural extension is often not oriented to the transfer of information relative to the dangers inherent in the use of pesticides. The lack of information at all levels may be one of the most important causative factors of chemical intoxication in developing countries. Research should at this time concentrate on behaviors leading to chemical intoxication. This should be done concurrently with proper prospective and retrospective surveys of poisonings in developing country communities. More information should be sought relative to the decision processes of import, legislation, and licensing. Research and development efforts in appropriate technology and safety devices are also critically needed.

Animals↗
PubMed1992

Susceptibility of house flies (Diptera: Muscidae) and five pupal parasitoids (Hymenoptera: Pteromalidae) to abamectin and seven commercial insecticides.

Assays of five commercial insecticides applied as residual sprays at label rates to plywood indicated the most toxic insecticide overall for pteromalid parasitoids of house flies, Musca domestica L., was Atroban (permethrin), followed by Ciodrin (crotoxyphos), Rabon (tetrachlorvinphos), Ectrin (fenvalerate), and Cygon (dimethoate). Insecticide-susceptible house flies were susceptible to all five insecticides (mortality, 62-100%). Flies that were recently colonized from populations on dairy farms in New York were susceptible only to Rabon. Urolepis rufipes (Ashmead) was the most susceptible parasitoid species overall to these insecticides, followed by Muscidifurax raptor Girault & Sanders, Nasonia vitripennis Walker, Pachycrepoideus vindemmiae (Rondani), and Spalangia cameroni Perkins. Compared with susceptible flies, newly colonized flies showed moderate resistance to avermectin B1a (abamectin). Abamectin was more toxic to all of the parasitoids except N. vitripennis and S. cameroni than to newly colonized house flies when exposed for 90 min to plywood boards treated with 0.001-0.1% abamectin. Space sprays with Vapona (dichlorvos) killed all of the parasitoids and susceptible flies and 64% of the newly colonized flies when insects were placed directly in the path of the spray; mortality was substantially lower among flies and parasitoids protected under 5 cm of wheat straw. Space sprays with Pyrenone (pyrethrins) killed greater than 86% of all insects exposed to the spray path except for the newly colonized flies (1% mortality); mortality of insects protected under straw was low (less than 12%) except for S. cameroni (76%). Because responses of the five parasitoids to the different insecticides varied considerably, general conclusions about parasitoid susceptibility to active ingredients, insecticide class, or method of application were not possible.

Animals↗
PubMed1991

Stimulation of vitellogenesis by pyrethroids in mated and virgin female adults, male adults, and fourth instar females of Ornithodoros moubata (Acari: Argasidae).

The effects of several pyrethroids on vitellogenesis, i.e., vitellogenin (Vg) synthesis and ovarian development in unfed mated female adults of Ornithodoros moubata were investigated. Survival of ticks treated with pyrethrin, resmethrin, and etophenprox was very low. Ticks treated with cypermethrin (CyM), fenvalerate (Fev), and flucythrinate (Flu) survived even when high concentrations were used. Vg titer in the hemolymph of unfed mated females was the same level on day 5 and about three times higher on day 10 after treatment with CyM, Fev, and Flu, as that of engorged adult females. CyM was the most effective in inducing vitellogenesis and was further evaluated in unfed virgin females, males, and fourth instars. CyM was shown to stimulate vitellogenesis in unfed virgin females adults. Oviposition did not occur but ovaries were well developed. CyM also was shown to stimulate Vg in the hemolymph of unfed and fed adult males; however, the Vg levels were very low compared to that of engorged adult females. Extremely high concentrations of Vg were observed in the hemolymph of female nymphs (fourth instar), particularly engorged nymphs, treated with CyM (10 micrograms). No ovarian development was observed in these nymphs. Vg stimulated by CyM was shown to be immunologically and electrophoretically the same as that of normal engorged females.

Animals↗
PubMed1976

Accudosetm aerosol--an effective house fly (Diptera; Muscidae: Musca domestica L.) adulticide control system for cage type poultry houses.

An automatic piped aerosol system (Accudose TM) using 0.7% synergized pyrethrin insecticide, was tested at a typical narrow cage poultry farm for the control of adult house flies, Musca domestica L. A similar narrow cage poultry farm was used as a control with all house fly control measures left up to the cooperating poultryman. AccudoseTM was compared with other house fly control methods at other similar farms which included three types of man-portable ultra volume (ULV) generators and an integrated (biological-chemical) program. Results of the five month test demonstrated that the AccudoseTM system suppressed house fly populations better than other control methods.

Aerosols↗
PubMed1990

Pediculosis.

Pediculosis can be caused by two distinctly different organisms, the head louse and the pubic louse. Although differing anatomically, they produce equivalent disorders, with itching, bites, and nits on the hairs. The head louse causes disease of the scalp, while the pubic louse lives in short hair in the pubic regions, the body, the axillae, the eyebrows, and the eyelashes. Both can be treated with gamma isomer of hexachlorobenzene, but various mixtures of pyrethrins seem more effective. The body louse, which exactly resembles the head louse, is the only one that can transmit disease. Treatment of body louse infestation is mainly cleanliness: washing the patient and changing his clothing.

Animals↗