Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “INSECTICIDES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,603 records · Page 89Linked to original sources
PubMed2003

Effects of the agricultural insecticide lambda-cyhalothrin (Warrior) on mosquitofish (Gambusia affinis).

Because agricultural insecticides have potential to disrupt biological control of mosquitoes, we quantified whether an insecticide used in rice fields causes mortality of mosquitofish. Laboratory studies have shown that lambda-cyhalothrin (Warrior) is toxic to fish; however, some studies report low field toxicities of pyrethroids to fish because they degrade rapidly and adsorb to soil. We tested whether Warrior kills mosquitofish under field conditions. Replicated enclosures in a rice field were either sprayed with Warrior at 5.8 g active ingredient/ha or were untreated. Mosquitofish were either added before the spray, or 7 days later. Of those added before the spray, none survived. Most fish added 7 days later survived.

Animals↗
PubMed2003

Efficacy of microencapsulated insecticides against the sandfly, Phlebotomus papatasi Scopoli.

The baseline and residual activity of micro-encapsulated insecticides was assessed on a sandfly colony originating in the Jordan Valley, Israel. Lethal doses were calculated for formulations of the pyrethroids permethrin and cypermethrin and the organophosphates diazinon and chlorpyrifos. Cypermethrin was found to be more toxic than permethrin and chlorpyrifos was more toxic than diazinon. Accordingly, the residual activity of chlorpyrifos and cypermethrin was tested after 1 and 4 wk exposure of impregnated filter papers under three environmental conditions: Jerusalem-indoors, Jerusalem-outdoors and semi-arid conditions. The results showed that environmental and climatic conditions play a major role in the persistence of toxicity of micro-encapsulated insecticides. A significant loss of toxicity for both compounds was noted after 4 wk of exposure under semi-arid conditions.

Animals↗
PubMed2004

Child mortality in a West African population protected with insecticide-treated curtains for a period of up to 6 years.

OBJECTIVES: To determine the impact of insecticide-treated curtains (ITC) on all-cause child mortality (6-59 months) over a period of six years. To determine whether initial reductions in child mortality following the implementation of ITC are sustained over the longer term or whether "delayed" mortality occurs. METHODS: A rural population of ca 100 000 living in an area with high, seasonal Plasmodium falciparum transmission was studied in Burkina Faso. Annual censuses were conducted from 1993 to 2000 to measure child mortality. ITC to cover doors, windows, and eaves were provided to half the population in 1994 with the remainder receiving ITC in 1996. Curtains were re-treated or, if necessary, replaced annually. FINDINGS: Over six years of implementation of ITC, no evidence of the shift in child mortality from younger to older children was observed. Estimates of the reduction in child mortality associated with ITC ranged from 19% to 24%. CONCLUSIONS: In our population there was no evidence to suggest that initial reduction in child mortality associated with the introduction of insecticide-treated materials was subsequently compromised by a shift in child mortality to older-aged children. Estimates of the impact of ITC on child mortality in this population range from 19% to 24%.

Animals↗
PubMedDate not supplied

[Monitoring of the insecticidal resistance of main malaria vectors in Uzbekistan].

In the Fergana valley, the sensitivity of Anopheles maculipennis to DDT was moderate (82.5% death rates) and that to carbamate agents (bendiocarb, 43.5%, and propoxur, 13.0%) was decreased. There was its high sensitivity to pyrethroidal insecticides, such as deltamethrin, lambdacigalothrin, and cifluthrin (100% death rates). The population was moderately resistant to carbamates: bendiocarb and propoxur (69.3 and 77.2% death rates, respectively). In the piedmont and mountainous districts of the Surkhandarya Region, A. superpictus is highly sensitive to all tested drugs. In the plain area of the Samarkand Area, the sensitivity of A. maculipennis to the insecticides, such as fenitrothion, propoxur, and permethrin, was 98.3, 92.3, and 97.0% death rates, respectively; the Tashkent, Dzhizak, and Surkhandaryinsk A. pulcherrimus population retained a normal sensitivity to all tested agents (94.4-100% death rates). The diapausing female A. superpictus mosquitoes in the population from the Fergana valley were found to be resistant to DDT (82.8% death rates) and highly resistant to malathion (43.8%), fenitrothion (38.8%), bendiocarb (2.7%), and propoxur (7.0%); the Tashkent and Surkhandaryinsk populations were also considerably resistant to these agents (35.3-89.6% death rates).

Animals↗
PubMed2004

Parasitism increases and decreases the costs of insecticide resistance in mosquitoes.

Adaptations conferring resistance to xenobiotics (antibiotics, insecticides, herbicides, etc.) are often costly to the organism's fitness in the absence of the selecting agent. In such conditions, and unless other mutations compensate for the costs of resistance, sensitive individuals are expected to out-reproduce resistant individuals and drive resistance alleles to a low frequency, with the rate and magnitude of this decline being proportional to the costs of resistance. However, this evolutionary dynamic is open to modification by other sources of selection acting on the relative fitness of susceptible and resistant individuals. Here we show parasitism not only as a source of selection capable of modifying the costs of organophosphate insecticide resistance in mosquitoes, but also that qualitatively different interactions (increasing or decreasing the relative fitness of resistant individuals) occurred depending on the particular form of resistance involved. As estimates of the parasite's fitness also varied according to its host's form of resistance, our data illustrate the potential for epidemiological feedbacks to influence the strength and direction of selection acting on resistance mutations in untreated environments.

Adaptation, Physiological↗
PubMed2003

Testing the efficacy of different insecticides to control onion thrips (Thrips tabaci Lindeman, Thysanoptera, Thripidae) in onion crops.

Onion thrips (Thrips tabaci) has become important pest in onion crops in Slovenia. Because it is a polyphagous species, it causes damage also in vegetable production in general (leek, cabbage, ornamentals etc.). The group of efficient insecticides for thrips control in Slovenia is limited, because its misusage in the past caused the development of resistance of this pest. In 2002, eight different insecticides based on four active substances was tested in Goriska region. The results of field experiments showed the highest efficiency of active substances Spinosad and Abamectine for control of Thrips tabaci. Unfortunatelly, they are not registrated in Slovenia for this purpose as yet.

Animals↗
PubMed2003

Insecticidal activity of the plant Phyllanthus amarus against Tribolium castaneum.

The plant Phyllanthus amarus is used as folk medicine since the year 1800 and has been established for its important medicinal properties particularly for liver ailments. The present communication explores the insecticidal activity of ethanolic extract of aerial and root parts of this plant against stored grain pest Tribolium castaneum. LC 50 values of ethanolic aerial part were 895.77, 473.91, 279.89 and 260.85 microg/cm2, while 512.62, 376.96, 248.88 and 209.79 microg/cm2 for ethanolic root part at the exposure of 3, 5, 7, 9 and 11 days respectively. Ethanolic root extract possessed significant insecticidal activity against T. castaneum.

Animals↗
PubMed2004

Space spraying of bacterial and chemical insecticides against Anopheles balabacensis Baisas for the control of malaria in Sabah, East Malaysia.

A pilot study was undertaken to determine the effectiveness of space application of insecticides for the control of malaria in Ranau, a district in Sabah. A village each was treated monthly: with chemical adulticide--alpha cypermethrin (Fendona SC(R)/10SC(R)) at 2 g a.i./10,000 m2 in Pahu; with biological larvicides--Bacillus thuringiensis israelensis (Vectobac 12AS(R)) at 500 ml/10,000 m2 or B. sphaericus (Vectolex WG(R)) at 500 g/10,000 m2 in Pinawantai; and with a mixture of chemical adulticide and biological larvicide in Togop Laut. All sprayings were conducted using a portable mist blower. During the study period all villages, including Tarawas the untreated village, received the conventional malaria control measures. Entomological and epidemiological surveillance was used to measure the effectiveness of the space application. The entomological surveillance indicated that the An. balabacensis population was significantly reduced by alpha cypermethrin in Pahu and Togop Laut and B. sphaericus in Pinawantai; but was not reduced by B.t.i. in Pinawantai. There was a significant reduction in the number of malaria cases and in the slide positivity rate in the treated villages during the study period. The pilot study does indicate that space application of larvicides/adulticides or a mixture of both is able to reduce the malaria vector population and the malaria transmission. A larger scale study needs to be undertaken in a malarious village/province to determine whether space application of insecticides together with other malaria control measures will be able to eradicate malaria.

Animals↗
PubMed1992

Pyrethroid insecticide-induced alterations in mammalian synaptic membrane potential.

The neuroexcitatory actions of two toxicologically distinct classes of pyrethroid insecticides were characterized in rat brain synaptosomes using [3H]tetraphenylphosphonium to measure changes in synaptosomal membrane potential and by measuring the release of [3H]acetylcholine. Both type I (permethrin) and type II (deltamethrin, cypermethrin and fenvalerate) pyrethroids produced a concentration-dependent tetrodotoxin-sensitive membrane depolarization which was stereospecific for the neurotoxic isomer of each pyrethroid. Deltamethrin was the most potent and efficacious pyrethroid in these studies, with an EC50 of 30 nM and a maximal estimated membrane depolarization of 27 mV, followed by cypermethrin, fenvalerate and permethrin. The phenoxybenzyl pyrethroids also increased the spontaneous release of [3H]acetylcholine from rat brain synaptosomes, further supporting a depolarizing action of these insecticides on nerve terminal membranes. Pyrethroid-induced release of [3H]acetylcholine was tetrodotoxin-sensitive and occurred over the same concentration range as membrane depolarization. These data indicate that type I and type II phenoxybenzyl pyrethroids act potently and stereoselectively on the voltage-sensitive sodium channel to increase sodium influx into synaptic terminals producing membrane depolarization and neurotransmitter release. Furthermore, they show that pyrethroid-induced alterations in synaptosomal membrane potential is a sensitive measure of pyrethroid action on the sodium channel and of pyrethroid toxicity.

Animals↗
PubMed1999

Organochlorine insecticides and PCB residues in fat tissues of autopsied trauma victims in Israel: 1984 to 1986.

Between the 1950s and the 1970s, large quantities of organochlorines were used as insecticides in Israel's cowsheds, causing massive contamination of Israel's milk supply. In 32 of 40 autopsied Israeli trauma victims who died between 1984 to 1986, we found three or more types of organochlorines in adipose tissue, and at least one organochlorine residue in all 40 individuals. The cumulative mean organochlorine levels (ppm) in men and women were as follows: DDE = 5.73 and 4.36; DDT = 0.12 and 0.30; HCB = 0.31 and 0.11; beta-HCH = 0.53 and 0.43; PCB = 0.10 and 0.08, respectively. PCB residue levels in fat tissue were lower than those noted in other countries and below the adverse levels associated with health effects. The cumulative mean organochlorine levels in adipose tissue were higher in men than in women in all cases except for DDT. Mean levels for DDE + DDT combined was higher in older than younger people, and all persons' DDT/DDE ratios were less than 1. The DDE levels in adipose tissue were higher than the levels reported in many other countries during the 1970s, 1980s, and 1990s. Our findings suggest that population-wide exposures to organochlorine insecticides come not only from contaminated milk products but other food products as well. The amounts of organochlorines in adipose tissue are compatible with those found in food residue samples during the same period.

Accidents, Traffic↗
PubMed2004

Influence of the organophosphorus insecticide phosphamidon on lentic water.

The inland freshwater resources are being increasingly subjected to heavy stress as a result of indiscriminate dumping of industrial wastes, domestic sewage and agricultural run-off causing deterioration of the water quality and adverse impact on aquatic biota. Pesticides drained to the aquatic environment are primarily of agricultural origin. Phosphamidon (widely used organophosphate pesticide in paddy field) significantly reduced dissolved oxygen (DO) at 1.8 mg/l exposure and reduced alkalinity at 0.9 and 1.8 mg/l. Hardness also reduced gradually but not significantly. Free carbondioxide was increased significantly at 1.8 mg/l of the insecticide compared to control. The insecticide had no influence on pH and temperature. There was maximum reduction of phytoplankton and zooplankton population at 1.8 mg/l of phosphamidon. Though gradual reduction of plankton community was also noticed at different lower concentrations of pesticides but in case of phytoplankton an abrupt reduction (about 50% of the control) was observed. The normal behaviour and feeding rate of air breathing teleost, Channa punctatus was also hampered. Therefore, phosphamidon even at low concentrations may create disorders in the aquatic ecosystem.

Animals↗
PubMedDate not supplied

[Levels of resistance to insecticides and their mechanisms in 2 strains of Aedes aegypti from Panama].

The levels of susceptibility and/or resistance to insecticides in larvae and adults of Aedes aegypti from 2 localities of Panama (Rio Abajo and Victoriano Lorenzo) were determined. Among larvae, it was found resistance to methyl- pyrimifos in both localities; however, they were susceptible to the rest of the organophosphate insecticides (temephos, malathion, fenthion fenitrothion and clorpirifos) and to pyrethroids (deltamethrin, lambda-cyhalothrin, cypermethrin and cyfluthrin. In the trials carried out in adults, according to the categories of the World Health Organization, the 2 localities proved to be completely susceptible to deltamethrin, lambda-cyhalothrin, beta cypermethrin and cyfluthrin.

Aedes↗
PubMedDate not supplied

Determination of carbamate insecticides in Chinese medicinal herbs by gas chromatography with a nitrogen-phosphorus detector.

A simplified method for determining carbamate insecticides (including metolcarb, isoprocarb, fenobucarb, carbofuran, pirimicarb, and carbaryl) in Chinese medicinal herbs (White Peony Alba, Red Peony Root, and Baical Skullcap Root) is described. Standards were fortified into Chinese medicinal herbs at 3 levels (0.05-0.5 mg/kg). The carbamates were extracted with dichloromethane in a Soxhlet apparatus and analyzed by gas chromatography with a nitrogen-phosphorus detector. The results showed average recoveries between 80.77 and 104.56%. The method evidenced good robustness, accuracy, and precision for monitoring carbamates in Chinese medicinal herb samples, and it is a suitable alternative to replace the currently dedicated analytical systems. The minimum detectable amount ranged from 3.0 x 10(-10) to 5.0 x 10(-10)g, and the limit of quantification was 0.05 mg/kg. The method is rapid, simple, sensitive, and reproducible, and it can be conveniently used as a low-cost, rapid method for measuring the carbamate insecticide contamination of Chinese medicinal herbs.

Carbamates↗
PubMed2005

Field performance of cyphenothrin: an integrated insecticide strategy against German cockroaches (Dictyoptera: Blatellidae).

BACKGROUND & OBJECTIVES: Resistance to organophosphorous and carbamate insecticides amongst German cockroaches is widely reported. Cyphenothrin EC, a new synthetic pyrethroid was evaluated in cookhouses in an urban area, with the aim of exploring alternate control option against the German cockroach Blatella germanica. METHODS: Three cookhouses were selected by simple random sampling method, two for treatment and one as control. The impact of treatment on cockroach infestation was monitored weekly by visual assessment sampling technique. RESULTS: Cyphenothrin brought about 95 to 97.5% reduction in cockroach infestation by the end of six weeks post-treatment. INTERPRETATION & CONCLUSION: The study reports the efficacy of cyphenothrin in the control of German cockroaches and recommends an "Integrated insecticide strategy" for the control of cockroaches in urban cookhouses.

Animals↗
PubMed2004

Effects of onboard insecticide use on airline flight attendants.

Flight attendants (FAs) exposed to insecticide spray in an aircraft were compared with unexposed subjects for neurobehavioral function, pulmonary function, mood states, and symptoms. The 33 symptomatic FAs were self-selected, and 5 had retired for disability. Testing procedures included balance, reaction time, color discrimination, visual fields, grip strength, verbal recall, problem solving, attention and discrimination functions, and long-term memory functions. Measurements were expressed as a percentage of their predicted values (derived from unexposed controls), and the author compared the means of the percentage predicted values by analysis of variance. Symptom frequencies and Profile of Mood States (POMS) scores were assessed. FAs were significantly more impaired than controls with respect to balance with eyes closed, grip strength, and color discrimination. Nearly half had 3 or more abnormal neurobehavioral functions, after adjustment was made for age, sex, and education level. Neither elevated POMS scores nor frequencies of average symptoms correlated with their numbers of abnormal measurements. Occupational exposure to synthetic pyrethrin insecticides on airliners was associated with neurobehavioral impairment and disability retirement.

Adult↗
PubMed2006

[Toxicity of photoactivated insecticide K-01 to the larvae of Aedes albopictus].

OBJECTIVE: To evaluate the toxicity of photoactivated insecticide K-01 to the larvae of Aedes albopictus and observe the histopathological changes in the larvae. METHODS: The number of dead larvae was recorded after application of K-01 at different concentrations under different illumination conditions. The content variation of the midgut, malpighian tubules and fat bodies in the larvae was observed microscopically, and the genomic DNA of the larvae was extracted for electrophoresis to identify the target bands. RESULTS: The maximum larvae-killing effect was achieved with 50 mg/ml K-01 applied under sunlight (100% killing 24 hours after application). Optical microscopic observation of the killed larvae revealed severe damage of the mid-intestinal cells that showed disintegration and elongation. Distinct vacuoles were observed in the fat body cells, in which red droplets were seen to assemble around the cell nuclei. The result of 0.8% agarose gel electrophoresis of the larvae genomic DNA presented typical ladder patterns, suggesting the presence of cell apoptosis. CONCLUSION: K-01 is an effective photoactivated insecticide.

Aedes↗
PubMed2005

Comparative toxicity of three ecdysone agonist insecticides against the Mediterranean flour moth.

The Mediterranean flour moth, Ephestia Kuehniella Zeller (Lepidoptera: Pyralidae), is an important pest in stored products worldwide, and is one of the major pests in flour mills in Algeria. Because environmental consideration, alternative approaches to neurotoxic insecticides, as well as safe, effective, and sound integrated pest management strategies are developed pest control agents such as the insect growth regulator (IGRs). Among these IGRs, the bisacylhydrazine derivatives are nonsteroidal ecdysterold agonists that mimic the action of moulting hormones and induce a precocious and incomplete moult in several insect orders. In topical bioassays using the pupae of E. kuehniella, three ecdysteroid agonists: RH-5849, the first bisaclhydrazine ecdysone agonist and two analogs, RH-5992 (tebufenozide) and RH-0345 (halofenozide), were evaluated on the reproduction under laboratory conditions. In a first series of experiments, the efficacy of these compounds was tested. These compounds exhibited insecticidal activity and the duration of pupal development was reduced with a dose-response relationship. Among the three tested compounds, tebufenozide (LD50 = 0.005 microg) appeared the most potent ecdysteroid agonist against E. kuehniella (RH-5849: LD50 = 0.05 microg and RH-0345: LD50 = 5.10 microg). In a second series of experiments, the effects of the ecdysone agonists (LD50) were investigated on the reproduction. Data showed that the three compounds affected growth of ovaries as evidenced by morphometric measurements of the ovaries from newly emerged adult females. In addition, the thickness of the chorion from basal oocytes was reduced only by RH-5992 and RH-0345. However, electron microscopic observations revealed that the three compounds had no significant effect on the fine structure of chorion. Finally, measurements of ovarian ecdysteroids' production by an enzyme immunoassay showed an increase in the hormonal amounts recorded in treated series compared to control series.

Animals↗