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Laboratory experiments have shown, that mosquitoes fly into eggs trap not only at eggs laying. Icon has not attractive and repellent to mosquitoes. In dose 0.5 g/m2 the effect of a icon is persisting during as a minimum of 100 days. Icon is suitable for use in eggs trap for Culex pipiens.
Five species of ixodid ticks that frequently feed on humans, Ixodes dammini, I. scapularis, I. pacificus I. ricinus, and I. persulcatus, are competent vectors of B. burgdorferi. Collectively, these species are distributed over vast areas of North America, Europe, and Asia. Lyme disease is becoming prevalent because of increased human exposure to infected ticks. Chemical and environmental methods of controlling these ticks over large areas will be difficult because none of these species is concentrated in a particular habitat. In relatively small local areas and special habitats such as islands, ticks may be reduced significantly by application of chemicals or by altering the environment. For example, areas surrounding homes may be successfully treated with timely applications of chemicals; reductions in ticks may be achieved by eliminating significant host animals, such as deer. Satisfactory biologic methods of control are presently unavailable. Personal protection efforts taken by the individual, such as using repellents on clothing or skin, wearing clothing that prevents ticks from easily gaining access to skin, and locating and removing attached ticks promptly, may be the most effective measures that can be taken to reduce risk of contracting Lyme disease.
Patch and skin bioassays were used in laboratory and indoor tests to evaluate the repellency of (E)-cinnamaldehyde, identified in Cinnamomum cassia Blume bark and essential oil, and a cream containing 5% (w/w) cassia oil against Aedes aegypti (L.) females. Results were compared with those of a known C. cassia compound cinnamyl alcohol, N,N-diethyl-m-toluamide (DEET) and two commercial repellents: MeiMei cream containing citronella and geranium oils and Repellan S aerosol containing 19% DEET. In patch bioassay tests with A. aegypti females, (E)-cinnamaldehyde at 0.153 mg cm(-2) and DEET at 0.051 mg cm(-2) provided 93 and 89% protection at 40 min after exposure. In skin bioassay tests, (E)-cinnamaldehyde at 0.051 mg cm(-2) and DEET at 0.025 mg cm(-2) provided 87 and 95% protection at 30 min after application. (E)-Cinnamaldehyde was significantly more effective than cinnamyl alcohol in both bioassays. In indoor tests with four human volunteers, 5% cassia oil cream provided 94, 83 and 61% protection against A. aegypti females exposed for 30, 50 and 70 min after application respectively. Cassia oil cream was a slightly less effective repellent than MeiMei cream. Repellan S aerosol provided 91% repellency at 120 min after application. Products containing cassia oil merit further study as potential repellents for the protection of humans and domestic animals from blood-feeding vectors and the diseases they transmit.
A topical formulation of amitraz (Mitaban Liquid Concentrate, The Upjohn Company, Kalamazoo, Michigan, U.S.A.) was evaluated as a tick repellent and detachment agent, and flea repellent. The diluted liquid concentrate (250 p.p.m. active drug) was topically applied as a single treatment to dogs; the concentration was identical to the rate recommended for treatment of demodicosis and scabies. Brown dog tick (Rhipicephalus sanguineus) and American dog tick (Dermacentor variabilis) populations were eliminated and repelled. Repellent activity (92-95%) was observed against R. sanguineus for 2 weeks post-treatment; the treatment was moderately active (63%) during the third week, and at 4 weeks post-treatment the drug was inactive. Established R. sanguineus populations were also treated, and the diluted liquid concentrate had 100% tick-detachment efficacy. Repellent activity (99%) was also detected against D. variabilis; the activity was monitored for only 7 days. The ectoparasiticide had low to moderate flea (Ctenocephalides felis) repellent activity (42%) for 4 days post-treatment; thereafter the treatment was ineffective. Side-effects were not observed in any of the dogs treated with amitraz, or the placebo.
In our search for new bioactive products against mosquito vectors, we reported the slightly larvicidal and adulticidal potency, but remarkable repellency of Apium graveolens both in laboratory and field conditions. Repellency of the ethanolic preparation of hexane-extracted A. graveolens was, therefore, investigated and compared with those of 15 commercial mosquito repellents including the most widely used, DEET. Hexane-extracted A. graveolens showed a significant degree of repellency in a dose-dependent manner with vanillin added. Ethanolic A. graveolens formulations (10-25% with and without vanillin) provided 2-5 h protection against female Aedes aegypti. Repellency that derived from the most effective repellent, 25% of hexane-extracted A. graveolens with the addition of 5% vanillin, was comparable to the value obtained from 25% of DEET with 5% vanillin added. Moreover, commercial repellents, except formulations of DEET, showed lower repellency than that of A. graveolens extract. When applied on human skin under field conditions, the hexane-extracted A. graveolens plus 5% vanillin showed a strong repellent action against a wide range of mosquito species belonging to various genera. It had a protective effect against Aedes gardnerii, Aedes lineatopennis, Anopheles barbirostris, Armigeres subalbatus, Culex tritaeniorhynchus, Culex gelidus, Culex vishnui group and Mansonia uniformis. The hexane-extracted A. graveolens did not cause a burning sensation or dermal irritation when applied to human skin. No adverse effects were observed on the skin or other parts of the human volunteers' body during 6 months of the study period or in the following 3 months, after which time observations ceased. Therefore, A. graveolens can be a potential candidate for use in the development of commercial repellents that may be an alternative to conventional synthetic chemicals, particularly in community vector control applications.
Oils of Syzygium aromaticum (clove) and Zanthoxylum limonella (makaen), widely used essential oils for dental caries or flavoring of food in Thailand, were prepared as 10 experimental repellent products in gel or cream form against Aedes aegypti, Culex quinquefasciatus, and Anopheles dirus under laboratory conditions, using the human-arm-in-cage method. Two products that gave the longest-lasting complete protection were selected to examine their repellency against a variety of mosquito species under field conditions. In laboratory tests, 0.1 g of each product was applied to 3x10 cm of exposed area on a volunteer's forearm, while in field trials, 1.0 g was applied to each volunteer's leg (from knee to ankle). In the laboratory, the gel dosage form contained 20% clove oil (Gel B) or 10% clove plus 10% makaen oil mixture (Gel E) were promising plant-based repellents against three mosquito species and gave significantly longer complete protection times of 4-5 hours than all other developing products. Therefore, their efficacy in the field was evaluated. Under field conditions, Gel E showed complete protection for 4 hours and gave 95.7% repellency after 5 hours application, whereas Gel B and 20% deet (di-methyl benzamide) provided only 86.8 and 82.7% repellency after treatment, respectively against Ae. aegypti, daytime-biting mosquitos. For nighttime-biting, the 3 repellents under development yielded equally excellent (average 97.1%) repellency for 5 hours against the predominant Cx. quinquefasciatus and Mansonia uniformis, but they gave 89.0% repellency against Cx. tritaeniorhynchus and Cx. gelidus. This finding demonstrated the effectiveness of Gel B and Gel E products for possible use by low-income rural communities against various mosquito species.
Field trials on the spatial repellency of metofluthrin-impregnated plastic strips for mosquitoes present in shelters without walls (beruga) were carried out in Lombok, Indonesia. A major reduction in the incidence of human biting by Culex quinquefasciatus was achieved, and the use of two strips per beruga repelled >60% of the mosquitoes for at least 11 wk while four strips repelled >60% of the mosquitoes for more than 15 weeks. The technique was found to be a practical long-term solution for the prevention of mosquito bites without using electricity or heat to evaporate the metofluthrin.
Two controlled-release repellent formulations containing 33% (3M) and 42% (Biotek) deet and an Army repellent containing 75% deet were evaluated in 3 different climatic regimens (tropical forested, tropical open and basic hot environments). The 3 repellents provided similar protection for different time periods after application under all 3 climates against Aedes aegypti, Ae. taeniorhynchus and Anopheles stephensi whereas there was no difference in protection period against An. albimanus.
Deet (N,N-diethyl-3-methyl-benzamide), the lactone CIC-4 ([2-hydroxy-methyl-cyclohexyl] acetic acid lactone), the USDA Proprietary Chemicals AI3-37220 (1- [3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine) and ++[3-35765 (1-[3-cyclohexen-1-ylcarbonyl] piperidine), and the U.S. military extended duration repellent formulation (EDRF) of deet were evaluated for repellency in the laboratory and field against the black flies Prosimulium mixtum and P. fuscum. CIC-4, AI3-37220, and AI3-35765 were as effective as deet at repelling P. mixtum and P. fuscum in laboratory and field experiments. Only the EDRF provided significantly longer protection than the deet standard against these black flies in the field.
The larvicidal activity and repellency of 5 plant essential oils--thyme oil, catnip oil, amyris oil, eucalyptus oil, and cinnamon oil--were tested against 3 mosquito species: Aedes albopictus, Ae. aegypti, and Culex pipiens pallens. Larvicidal activity of these essentials oils was evaluated in the laboratory against 4th instars of each of the 3 mosquito species, and amyris oil demonstrated the greatest inhibitory effect with LC50 values in 24 h of 58 microg/ml (LC90 = 72 microg/ml) for Ae. aegypti, 78 microg/ml (LC90 = 130 microg/ml) for Ae. albopictus, and 77 microg/ml (LC90 = 123 microg/ml) for Cx. p. pallens. The topical repellency of these selected essential oils and deet against laboratory-reared female blood-starved Ae. albopictus was examined. Catnip oil seemed to be the most effective and provided 6-h protection at both concentrations tested (23 and 468 microg/ cm2). Thyme oil had the highest effectiveness in repelling this species, but the repellency duration was only 2 h. The applications using these natural product essential oils in mosquito control are discussed.
The 8th Medical Brigade, deployed to Kuwait in January 2004 in support of Operation Iraqi Freedom provided theater-wide health service support and medical command and control. An historic "surge" of troops and equipment occurred during our deployment as 140,000 service members (SMs) redeployed out of theater and 110,000 arrived to take their place. The brigade's preventive medicine personnel conducted a questionnaire-based survey at military camps in northwestern Kuwait in mid-March to determine whether SMs had been provided with supplies and information to protect them against endemic vector-borne diseases. Of 1,200 questionnaires distributed, 870 (73%) were returned. In addition to military affiliation information, the survey contained specific questions related to the provision of n-diethyl-m-toluamide repellents, permethrin and treated uniforms, and medical threat briefings. On average, less than one-half of the SMs received these resources before their arrival in Kuwait. Significant differences of resource provision existed among service branches, components, and mobilization or deployment stations.
Litsea salicifolia is one of the many plants used as phytopesticide, traditionally by various tribes of Assam. Of the five extracts of L. salicifolia tested for the bioactivity against Aedes aegypti and Culex quinquefasciatus, the aqueous extract was more effective compared to other extracts exhibiting bioactivity at 72 ppm against A. aegypti. The hexane extract (2000 ppm) exhibited 70% repellent activity for 3 hr against A. aegypti and 46% activity for 3 hr against C. quinquefasciatus. This is the first report on the insecticidal properties of L. salicifolia which can be further developed as an eco-friendly biopesticides of the future.
Two to 3 ml of Neemos, when applied to the exposed body parts of human volunteers, provided protection for 8 h from the bites of all anopheline species in 2 villages of the Sucre municipality, Bolivar State, Venezuela. Neemos is safe and can be used for protection from malaria in endemic countries.
A collagen membrane technique, based on the membrane blood-feeding system of Cosgrove et al. (1994), was used to compare repellents against Aedes aegypti mosquitoes. Repellency was defined in terms of inhibition of probing (ED50 and ED90) after 5 min exposure. A direct comparison was made with repellency from probing after 5 min on five male volunteers. Four repellent products were compared with technical DEET as the standard. The liquid formulations tested were: Autan (20% deet; Bayer); Repel Plus (20% deet plus 0.05% permethrin; Boots); permethrin (Zeneca) and citronellal (Sigma). Membrane and arm tests gave similar results. Deet formulations required less active compound than citronellal for the same degree of repellency. Pure deet and Autan gave similar results, dose for dose. Permethrin was highly repellent at very low doses, but Repel Plus did not enhance the immediate repellency of deet. A technique using the same membrane system was developed to evaluate persistence of Autan, which declined to 75% after 1 h against Ae. aegypti, and to about 50% after 2-4 h.
A study was carried out in certain villages of Distt. Ghaziabad (U.P.) to evaluate the efficacy of commercially available mosquito repellent preparations and devices. Results revealed that none of the repellents tested provided absolute protection against mosquito bites. The protection varied from 38 to 98% with different species of mosquitoes. In general, better protection was provided against Anopheles bite than against Culex. Of ten repellents evaluated. Mylol oil and Tortoise coils were marginally superior to Odomos cream and Rooster coils. Among electrical devices, Good Bye and Casper were marginally superior to Good Knight and Knight Queen.
Ointment and cream formulations of lemongrass oil in different classes of base and the oil in liquid paraffin solution have been evaluated for mosquito repellency in a topical application. Mosquito repellency was tested by determining the bite-deterrence of product samples applied on an experimental bird's skin against a 2-day starved culture of Aedes aegypti L. mosquitoes. The 1%v/v solution and 15%v/w cream and ointment preparations of the oil exhibited > or =50% repellency lasting 2-3 h, which may be attributed to citral, a major oil constituent. This activity was comparable to that of a commercial mosquito repellent. Base properties of the lemongrass oil formulations influenced their effectiveness. The oil demonstrated efficacy from the different bases in the order of hydrophilic base > emulsion base > oleaginous base.
The behavioural response of Anopheles stephensi Liston (Diptera: Culicidae) to incubated host odours (from human and goat) and to human odour in combination with a repellent plant, Ocimum forskolei (Labiatae), or deet (N, N, diethyl-toluamide) (20%) was tested in a dual-port olfactometer. An. stephensi was significantly attracted to both host odours compared with air alone, but showed no preference when given a choice between both host odours simultaneously. In choice tests, the addition of deet to human odour did not significantly divert mosquitoes to human odour alone, but did divert them to goat odour. O. forskolei combined with human odour diverted mosquitoes to goat or human odour alone. Combinations of human odour and O. forskolei, and human odour and deet were both as unattractive as air alone, and attracted mosquitoes equally when offered simultaneously. The results indicate that use of O. forskolei as a repellent would be beneficial in reducing vector biting if used in communities in areas with partially zoophilic mosquito species such as An. stephensi, and where animals are present.
Two percent neem oil mixed in coconut oil, when applied to the exposed body parts of human volunteers, provided complete protection for 12 h from the bites of all anopheline species. Application of neem oil is safe and can be used for protection from malaria in endemic countries.