Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Insect Repellents”

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 1,531 records · Page 85Linked to original sources
PubMed2006

Tracing pollinator footprints on natural flowers.

Many insects are known to leave lipid footprints while walking on smooth surfaces. Presumably, the deposited substances improve tarsal adhesion. In bumblebees, footprint hydrocarbons also function as scent marks that allow detection and avoidance of recently depleted flowers. I used GC-MS to detect hydrocarbons deposited by bumblebee (Bombus pascuorum) on flowers of Lamium maculatum. In addition to the plants' own cuticular lipids, extracts of corollas that had been visited by bumblebees contained odd-numbered alkenes. The amount of pentacosenes (C25H50) on corollas was linearly related to the number of bumblebee visits, with workers depositing approximately 16 ng per visit (extrapolated to a total of 65 ng of bumblebee cuticular hydrocarbons). Pentacosenes were retained on visited flowers without loss for 2 hr, and probably longer. This and results from flight cage experiments suggest that flower epicuticles retain a chemical record of pollinator visitation, including information on visiting bee species. Continuous footprint accumulation necessitates new explanations concerning the reversibility of "repellent scent marks" of bumblebees.

Animals↗
PubMed1997

The Drosophila protein Wunen repels migrating germ cells.

In Drosophila, germ cells migrate in embryonic development from the lumen of the developing gut towards the overlying mesoderm, where they enter the gonads. The gene wunen is responsible for guiding the germ cells early in this process. Here we report that the protein Wunen has two properties that allow it to use repulsion to guide the germ cells. Wunen can transform a permissive cellular environment into a repulsive one, and is expressed in the gut in a pattern that guides germ cells towards the mesoderm. Wunen shows strong similarity to the enzyme type 2 phosphatidic acid phophatase (PAP2)4, suggesting that it is involved in lipid metabolism.

Amino Acid Sequence↗
PubMed2004

Delayed toxicity as a critical factor in the efficacy of aqueous baits for controlling Argentine ants (Hymenoptera: Formicidae).

Boric acid, imidacloprid, and thiamethoxam in sucrose aqueous baits had different delayed toxicities to worker Argentine ants, Linepithema humile (Mayr). The concentrations required to produce an LT50 (time required to produce 50% mortality) within 1-4 d were 3.63-0.55% boric acid, 9.2 x 10(-3) to 7.1 x 10(-4)% imidacloprid, and 3 x 10(-4) to 2 x 10(-5)% thiamethoxam. The three toxicants were not repellent. Other laboratory trials showed that 1% boric acid, 5 x 10(-4) to 5 x 10(-3)% imidacloprid, and 1 x 10(-5) to 1 x 10(-3)% thiamethoxam had delayed toxic effects, whereas 0.5% boric acid and < 5 x 10(-3)% imidacloprid did not. Baits that provided an LT50 between days 1 and 4 were considered to have delayed toxic effects. The utility of aqueous sucrose baits and toxicants soluble in such systems and the negative impact of fast-acting toxicants on trail following, recruitment, trophallaxis, and control of Argentine ants are discussed.

Animals↗
PubMed1999

[Historical study on the moth repellent, "Fujisawa Camphor" (1)].

"Fujisawa Camphor" was introduced for sale as a moth repellent for home use in 1897. As a background that camphor was produced on a commercial basis, the following were studied: (1) Camphor was already used as a moth repellent by some people in the Endo Period. (2) With the Sino-Japanese War as a turning point, armaments were increased and they made military uniforms which were made of wool. It also made Western woolen clothes spread in general. (3) As people were in danger to catch infectious diseases in those days, they had a habit of avoiding bad odors and drifting fragrances like camphor were used in rooms to prevent the plague. (4) In those days, a technique for refining camphor was established, so white crystal-line camphor was produced on a commercial basis.

Animals↗
PubMed1995

Low-volume application by mist-blower compared with conventional compression sprayer treatment of houses with residual pyrethroid to control the malaria vector Anopheles albimanus in Mexico.

Village-scale trials were carried out in southern Mexico to compare the efficacy of indoor-spraying of the pyrethroid insecticide lambda-cyhalothrin applied either as low-volume (LV) aqueous emulsion or as wettable-powder (WP) aqueous suspension for residual control of the principal coastal malaria vector Anopheles albimanus. Three indoor spray rounds were conducted at 3-month intervals using back-pack mist-blowers to apply lambda-cyhalothrin 12.5 mg a.i./m2 by LV, whereas the WP was applied by conventional compression sprayer at a mean rate of 26.5 mg a.i./m2. Both treatments caused mosquito mortality indoors and outdoors (collected inside house curtains) as a result of contact with treated surfaces before and after feeding, but had no significant impact on overall population density of An. albimanus resting indoors or assessed by human bait collections. Contact bioassays showed that WP and LV treatments with lambda-cyhalothrin were effective for 12-20 weeks (> 75% mortality) without causing excito-repellency. Compared to the WP treatment (8 houses/man/day), LV treatment (25 houses/man/day) was more than 3 times quicker per house, potentially saving 68% of labour costs. This is offset, however, by the much lower unit price of a compression sprayer (e.g. Hudson 'X-pert' at US$120) than a mist-blower (e.g. 'Super Jolly' at US$350), and higher running costs for LV applications. It was calculated, therefore, that LV becomes more economical than WP after 18.8 treatments/100 houses/10 men at equivalent rates of application, or after 7.6 spray rounds with half-rate LV applications.

Animals↗
PubMed1983

Chemiosmotic potassium ion pump of insect epithelia.

Transporting epithelia of insects are unlike most vertebrate epithelia in that they lack a serosa and possess septate junctions. The Na+/K+ pump is absent and an electrogenic K+ uniport pump is present in such insect epithelia as lepidopteran midgut, dipteran salivary glands, and many Malpighian tubules. The K+ pump is located in the apical plasma membrane and pumps K+ out of the cells. In midgut the transepithelial K+ transport is against a potential difference (PD) in excess of 120 mV and against a 10-fold K+ concentration difference in vivo. The pump uses a K+-modulated ATPase thought to be located in particles called K+ portasomes, which resemble the F1-F0 ATPase of phosphorylating membranes. Like F1-F0 particles the K+ portasomes are located on the cation input, electronegative, ATP-binding side of the membrane and appear to pump two cations for each MgATP2- hydrolyzed. We propose that in K+-transporting epithelia and in phosphorylating membranes running backwards the portasomes orient the binding of ATP with respect to a cation-gated channel in such a way that when MgATP2- is hydrolyzed P-i is separated from MgADP-; the 2 K+ or 2 H+ ions are no longer neutralized and are repelled from the channel to the opposite side of the membrane. We have isolated the K+ portasome-containing goblet cell apical membrane from larval Manduca sexta midgut and are attempting to isolate the K+ portasomes and K+-ATPase.

Animals↗
PubMed1997

Compliance with malaria chemoprophylaxis and preventative measures against mosquito bites among Dutch travellers.

Self-reported compliance with a malaria chemoprophylaxis regimen of proguanil (PG) plus chloroquine (CQ) was assessed in a cohort of 547 Dutch travellers who visited a single travel clinic when travelling to various areas endemic for falciparum malaria. 503 (92%) had taken PG/CQ prophylaxis, but only 326 (60%) reported regular and uninterrupted use throughout the journey and 4 weeks afterwards. Compliance differed by travel destination and was 45% in South America, 52% in West Africa, 53% in South-east Asia, 60% in the Indian Subcontinent and 78% in East Africa. Parasitologically confirmed falciparum malaria occurred in 5 travellers (0.9%), including 3 of 24 non-compliant travellers to West Africa (12.5%). Apart from destination, independent risk factors for non-compliance were young age, extensive travel experience and adventurous travel. Compliance with protection against mosquito bites was 80% for wearing long-sleeved shirts and long-legged trousers after sunset, 73% for use of repellents, 56% for sleeping under bed nets and 37% for keeping the sleeping quarters free of mosquitoes. Although 440 travellers (80%) reported to have taken two or more of these measures at least once, only 88 (16%) had done so on a daily basis. Daily use of bed nets was reported more frequently among subjects who were non-compliant with chemoprophylaxis. Compliance regarding malaria chemoprophylaxis should be improved, particularly in high-risk areas such as Sub-saharan Africa, with extra attention to young, adventurous travellers. More emphasis should be placed on prevention of Anopheles bites.

Adult↗
PubMed2006

Evaluation of the efficacy of a topically administered combination of imidacloprid and permethrin against Phlebotomus perniciosus in dog.

The phlebotomine sand fly Phlebotomus perniciosus is one of the main vectors of Leishmania infantum, responsible for human and canine leishmaniasis in the Mediterranean Basin. The objective of this study was to evaluate the repellent and insecticidal efficacy of imidacloprid 10% (w/v)/permethrin 50% (w/v) spot-on against sand flies (P. perniciosus) on dogs. The dogs used in this trial were laboratory-bred beagles: eight were impregnated with the solution (treated group), while the other eight were left untreated (control group). On day 0 the animals in the treatment group received 0.1 ml/kg body weight of the combination imidacloprid/permethrin spot-on. Dogs were exposed for 1h to about 100 female sand flies at weekly intervals for a period of 4 weeks, on day 1, 7, 14, 21, and 28 after applying the product. The repellency criterion was based on the feeding rate of sand flies in the treated compared to the untreated group. The insecticidal efficacy criterion was based on comparison of the survival rate of sand flies between the two groups. The product had an insecticidal efficacy on female sand flies of 53.2% (day 1), 49.4% (day 7), 15.1% (day 14), 13.2% (day 22), and 2.9% (day 29). The product showed a repellent effect of 97.7% (day 1), 96.3% (day 7), 96.5% (day 14), 92.7% (day 22), and 74.0% (day 29). Within the first week of application the insecticidal effect was significant; however it did not surpass 50%. On the other hand, the product showed a potent anti-feeding effect of over 90% during the first 3 weeks of this trial. Therefore, the application of this product every 3 weeks would be a good tool to significantly reduce sand fly bites over the period of transmission of vectorial diseases such as leishmaniasis and several arbovirosis such as Toscana virus.

Animals↗
PubMed1998

[Electronic repellents against mosquitoes: the propaganda and the reality].

A bibliographic review about the use of electroacoustic devices with a supposed repellent action on the females of different species of hematophagous mosquitoes is presented. 15 direct references and 2 indirect ones are given, in which it is concluded that these devices do not protect those who have them from the stings of mosquitoes. The names of 9 of the tested devices as well as of 16 of the main species of mosquitoes present in the field tests are mentioned. These tests have been carried out in very different ecological conditions from Alaska to Equatorial Africa. It is also stressed that the high intensity ultrasonic frequencies emitted by these devices produces a potentially harmful effect on man.

Acoustics↗
PubMed2002

Antimicrobial activity of exocrine glandular secretion of Chrysomela larvae.

The exocrine glandular secretions of leaf beetle larvae of the taxon Chrysomela are well-known defensive devices used against some generalist predators. Salicylaldehyde is the major repellent component of secretions emitted by larvae of Chrysomela vigintipunctata and C. lapponica, which feed on salicin-rich Salicaceae. In this study, we examined whether salicylaldehyde is also active against the entomopathogenic fungus Metarhizium anisopliae. The germination and growth of this fungus was strongly inhibited when salicylaldehyde was applied directly onto the blastospores. The salicylaldehyde concentration of the larval secretions of the tested willow feeding Chrsysomela larvae was much higher than the one necessary to display this antifungal activity. Additionally, salicylaldehyde was shown to reduce germination and growth of M. anisopliae via the gas phase over a distance of 45 mm. Further studies on the antimicrobial activity of the salicylaldehyde-containing secretions of Chrysomela larvae revealed that they act nonspecifically against prokaryotic (Escherichia coli) and eukaryotic cells (Saccharomyces cerevisiae and Trichoplusia ni). All antimicrobial and cytotoxic effects detected proved to be due to salicylaldehyde. The larval secretions of the birch-feeding allospecies of C. lapponica, that do not contain salicylaldehyde, but mainly carboxylic acids and their esters, showed no detectable effects on bacteria or fungi and no cytotoxic effects against insect cells. The results are discussed with respect to their ecological relevance.

Aldehydes↗
PubMed2003

[Effect of plant alcohol extracts on vegetable aphids and their parasitoids].

The repelling and controlling effect of alcohol extracts from 8 common plant species on 3 major vegetable aphids (Myzus persicae, Aphis gossypii and Lipaphis erysimi) were studied in the laboratory, and the effect on their parasitoid was also studied. The results showed that the test 8 plant species had some effects on 3 aphids. The plant alcohol extracts from Tephrosia vogelli and Cinnamomum camphora had the most effect. The deterrent rate on Myzus persicae, Aphis gossypii and Lipaphis erysimi was 0.414, 0.729, 0.547 and 0.549, 0.690, 0.729, respectively. These 2 plants had the most controlling effect on 3 aphids, too. The alcohol extract of Cinnamomum camphora was safely for parasitoids (Aphidius gifuensis and Diaeretiella rapae).

Animals↗
PubMed2005

World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of ectoparasiticides against biting and nuisance flies on ruminants.

These guidelines have been prepared to assist in the planning, conduct and interpretation of studies for the assessment of the efficacy of ectoparasiticides (excluding repellents) against the biting and nuisance dipteran flies of ruminants. Information is provided on the selection of animals, dose determination and dose confirmation studies, field studies, record keeping and result interpretation. These guidelines advocate the use of pen facilities for dose determination and dose confirmation studies. These guidelines also are intended to assist investigators on how to conduct specific studies, to provide specific information for registration authorities involved in the decision-making process, to assist in the approval and registration of new ectoparasiticides, and to facilitate the worldwide adoption of standard procedures.

Animals↗
PubMed2002

Do insecticide-treated bednets have an effect on malaria vectors?

The use of insecticide-treated bednets (ITNs) has been widely adopted as an important method for malaria control. Few data exist on effects of ITNs on mosquito biology and ecology, other than the development of insecticide resistance against the insecticides used. There is no hard evidence that the insecticide resistance recorded is the result of insecticidal use on bednets or from agricultural use. Resistance against pyrethroids, the preferred class of insecticides for ITN use, has been recorded from countries in Asia, Africa and South America. Resistance is expressed as reduced excito-repellency and mortality of mosquitoes exposed to insecticide-treated materials. In the absence of resistance, however, most studies on ITN effects report a reduced survival of adult mosquitoes as well as mass killing. Other effects are highly variable, and shifts in time of biting, feeding site and blood hosts have occasionally been reported, but not in proportion to the scale of ITN use. In general, a reduced sporozoite rate is recorded in ITN programmes. Because many of the anticipated behavioural effects caused by insecticidal use will be avoided by the use of untreated nets, studies on the efficacy of untreated nets are required. Examples are presented in which untreated nets provided a reasonable degree of protection against malaria.

Animals↗
PubMed1998

Epistatic interactions between smell-impaired loci in Drosophila melanogaster.

Odor-guided behavior is a polygenic trait determined by the concerted expression of multiple loci. Previously, P-element mutagenesis was used to identify single P[lArB] insertions, in a common isogenic background, with homozygous effects on olfactory behavior. Here, we have crossed 12 lines with these smell impaired (smi) mutations in a half-diallel design (excluding homozygous parental genotypes and reciprocal crosses) to produce all possible 66 doubly heterozygous hybrids with P[lArB] insertions at two distinct locations. The olfactory behavior of the transheterozygous progeny was measured using an assay that quantified the avoidance response to the repellent odorant benzaldehyde. There was significant variation in general combining abilities of avoidance scores among the smi mutants, indicating variation in heterozygous effects. Further, there was significant variation among specific combining abilities of each cross, indicating dependencies of heterozygous effects on the smi locus genotypes, i.e., epistasis. Significant epistatic interactions were identified for nine transheterozygote genotypes, involving 10 of the 12 smi loci. Eight of these loci form an interacting ensemble of genes that modulate expression of the behavioral phenotype. These observations illustrate the power of quantitative genetic analyses to detect subtle phenotypic effects and point to an extensive network of epistatic interactions among genes in the olfactory subgenome.

Animals↗
PubMed1983

Potassium ion transport ATPase in insect epithelia.

K+ transport by the epithelia of midgut, salivary glands, Malpighian tubules, sensory sensilla, possibly rectum, and other organs of certain insects appears to use a unique K+ ATPase. Ouabain inhibition of transport-related events has not been demonstrated in these epithelia. The K+ pump is unlike the Na-K;ump but resembles the H;ump of phosphorylating membranes in its transport orientation, efficient thermodynamics, speculated two K+ per one MgATP2- stoichiometry, electrogenicity, and structure. Older electrochemical, tracer flux, and conductance evidence suggested that the K+ pump was on the apical plasma membrane of transporting cells in these epithelia. New X-ray microanalytical studies (XMA), reveal that the K+ concentration in all cells is more than 100 mM. Together with new microelectrode data these XMA results confirm the apical K+ pump location, resolve the K+ transport sport route, and suggest that the goblet cell cavity facilitates the generation of a large apical PD which may be used in nutrient absorption and pH regulation. K+ portasomes, which resemble F1-Fo ATPase particles, stud these K+ transporting apical membranes and are though to be the unit of active K+ transport. We have suggested a K+ transport mechanism in which two cations (2K+) are abandoned in an isolated domain of the portasomes during ATP2-hydrolysis and are repelled to the opposite membrane side via a K+ channel. Small peptides hydrolysed from the delta-endotoxin of Bacillus thuringiensis inhibit the K+ transport and may be useful as K+ pump inhibitors, apical membrane probes and insecticides. Goblet cell apical membrane fragments (GCAM) as well as fragments from columnar cell apical membrane (CCAM), lateral membrane (LM) and basal membranes (BM) were isolated as clean fractions using ultrasound, aspiration, and both differential and density gradient centrifugation; purification was monitored by electron microscopy. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE) reveals that GCAM, CCAM, LM and BM have very different protein compositions. Preliminary enzymology is consistent with the K+ ATPase being on the apical plasma membrane of the goblet cells of midgut and enveloping cells of sensilla.

Adenosine Triphosphatases↗
PubMed1997

Extended field trial of deltamethrin WDP for control of malaria at Jagdalpur, Madhya Pradesh, India.

The synthetic pyrethroid, deltamethrin 2.5% wdp, was evaluated at a dosage of 25 mg/sq m in a group of villages of tribal area around Jagdalpur, District Bastar (Madhya Pradesh). Study was carried out in three consecutive years from 1986 to 1988 with a total of five rounds of deltamethrin spray covering a population of approximately 10,000. The suspension of deltamethrin wdp was white in colour, odourless, non-irritant and the deposits were faintly visible on the surface of wall. A total of 3848 kg of 2.5% deltamethrin wdp was consumed during the trial. Insecticide was found effective in keeping the adult vector density An. culicifacies to a very low level for a period of 14-16 wks. Both anopheline and culicine mosquitoes were affected by the spray. The trial confirmed its long residual effectiveness from 15 to 16 wks on both mud and cement plastered surfaces. Deltamethrin spray shortened the average life span of vector mosquitoes. Observations indicated that insecticide although has an excito-repellent effect on mosquitoes, thus forcing exodus from treated area but with poor survival. Partial impact of deltamethrin spray was observed on the larval population confirm this. Deltamethrin spray did not exhibit any fumigant effect on mosquitoes. Significant decline in SPR from 17.93 to 4.26% was observed in areas sprayed with deltamethrin as compared to the comparison area. Similarly, SfR showed 81% reduction in experimental area while the control area showed increase by 42 per cent. No ill-effect of spray was noticed on the inhabitants, spray personnels, animal population and other non-target organisms of the area. The acceptability of the deltamethrin spray was found to be very high.

Animals↗
PubMed2003

[Prevention of malaria in the adult].

Great scourge of poor countries, malaria is the most important tropical parasitic disease. It is responsible for a large number of deaths in concerned countries and represents a real danger for travellers going to endemic regions. So, prophylactic measures are essential. On the one hand protective measures against mosquito bites, by wearing covering clothes, by using repellents and bed net (eventually impregnated with insecticide) will be useful. On the other hand, chemoprophylaxis is most often necessary, adapted to the possibility of chloroquine resistant P. falciparum, to the length or conditions of travel, and to the traveller's antecedents and age. Special concern about pregnant woman is necessary, due to potential severity of malaria. Chemoprophylaxis needs to be continued after coming back, for a duration depending on the drug used. Unfortunately, no prophylaxis is 100% effective, and the appearance of fever during the travel or two to three months after return requires medical advice. In some circumstances, it is necessary to prescribe a stand-by emergency treatment, if no quick medical advice is possible.

Adult↗
PubMed1994

Biology and control of tabanids, stable flies and horn flies.

Tabanids are among the most free-living adult flies which play a role as livestock pests. A single blood meal is used as a source of energy for egg production (100-1,000 eggs per meal), and females of certain species can oviposit before a blood meal is obtained (autogeny). Therefore, the maintenance of annual populations requires successful oviposition by only 2% of females. Wild animal blood sources are usually available to maintain annual tabanid populations. Larval habitats are also independent of domestic livestock. Thus, the use of repellents or partial repellents is the only effective chemical strategy to reduce the incidence of tabanids on livestock. Permanent traps (and possibly treated silhouette traps) can be employed to intercept flies. Selective grazing or confinement can also reduce the impact of tabanids. Stable fly adults are dependent on vertebrate blood for survival and reproduction, but the amount of time spent in contact with the host is relatively small. Stable fly larvae develop in manure, spilled feed and decaying vegetation. Management of larval habitats by sanitation is the key to stable fly control. Treatment of animals with residual insecticides can aid in control; thorough application to the lower body parts of livestock is important. Proper use of modified traps, using either treated targets or solar-powered electrocution grids, can be effective in reducing stable fly populations. Adult horn flies spend the major part of their time on the host, and the larvae are confined to bovid manure. Therefore, almost any form of topical insecticide application for livestock is effective against horn flies, in the absence of insecticide resistance. Treatments should be applied when economic benefit is possible; economic gains are associated with increased weaning weights and weight gains of yearling and growing cattle. Oral chemical treatments (insect growth regulators or insecticides) administered at appropriate rates via bolus, water, food or mineral mixtures can inhibit horn fly larval development. However, adult horn fly movement among cattle herds limits the use of larval control for horn fly population management. The augmentation of native parasites, predators and competitors has been attempted and even promoted for horn fly and stable fly control, but evidence for the success of such programmes is equivocal.

Animals↗