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Sample records for mosquito repellent plants

  1. Toxicity of a plant based mosquito repellent/killer.

    PubMed

    Singh, Bhoopendra; Singh, Prakash Raj; Mohanty, Manoj Kumar

    2012-12-01

    The mission to make humans less attractive to mosquitoes has fuelled decades of scientific research on mosquito behaviour and control. The search for the perfect topical insect repellent/killer continues. This analysis was conducted to review and explore the scientific information on toxicity produced by the ingredients/contents of a herbal product. In this process of systemic review the following methodology was applied. By doing a MEDLINE search with key words of selected plants, plant based insect repellents/killers pertinent articles published in journals and authentic books were reviewed. The World Wide Web and the Extension Toxicity Network database (IPCS-ITOX) were also searched for toxicology data and other pertinent information. Repellents do not all share a single mode of action and surprisingly little is known about how repellents act on their target insects. Moreover, different mosquito species may react differently to the same repellent. After analysis of available data and information on the ingredient, of the product in relation to medicinal uses, acute and chronic toxicity of the selected medicinal plants, it can be concluded that the ingredients included in the herbal product can be used as active agents against mosquitoes. If the product which contains the powder of the above said plants is applied with care and safety, it is suitable fo use as a mosquito repellent/killer.

  2. Toxicity of a plant based mosquito repellent/killer

    PubMed Central

    Singh, Prakash Raj; Mohanty, Manoj Kumar

    2012-01-01

    The mission to make humans less attractive to mosquitoes has fuelled decades of scientific research on mosquito behaviour and control. The search for the perfect topical insect repellent/killer continues. This analysis was conducted to review and explore the scientific information on toxicity produced by the ingredients/contents of a herbal product. In this process of systemic review the following methodology was applied. By doing a MEDLINE search with key words of selected plants, plant based insect repellents/killers pertinent articles published in journals and authentic books were reviewed. The World Wide Web and the Extension Toxicity Network database (IPCS-ITOX) were also searched for toxicology data and other pertinent information. Repellents do not all share a single mode of action and surprisingly little is known about how repellents act on their target insects. Moreover, different mosquito species may react differently to the same repellent. After analysis of available data and information on the ingredient, of the product in relation to medicinal uses, acute and chronic toxicity of the selected medicinal plants, it can be concluded that the ingredients included in the herbal product can be used as active agents against mosquitoes. If the product which contains the powder of the above said plants is applied with care and safety, it is suitable fo use as a mosquito repellent/killer. PMID:23554562

  3. Mosquito repellent activity of volatile oils from selected aromatic plants.

    PubMed

    Lalthazuali; Mathew, Nisha

    2017-02-01

    Essential oils from fresh leaves of four aromatic plants viz., Ocimum sanctum, Mentha piperita, Eucalyptus globulus and Plectranthus amboinicus were extracted by hydrodistillation. The test solutions were prepared as 20% essential oil in ethanol and positive control as 20% DEET in ethanol. Essential oil blend was prepared as 5% concentration. Nulliparous, 3-5-day-old female adult Aedes aegypti mosquitoes were used for repellency screening as per ICMR protocol. The study showed that the repellency of 20% essential oil of O. sanctum, M. piperita and P. amboinicus were comparable with that of the standard DEET (20%) as no mosquito landing on the test was observed up to 6 h. The E. globulus oil exhibited mosquito repellency only upto 1½ h. Considerable mosquito landing and feeding was displayed in negative control. In the case of the oil blend, no landing of mosquitoes was seen up to 6 h as that of positive control. The results showed that the essential oil blend from O. sanctum, M. piperita, E. globulus and P. amboinicus could repel Ae. aegypti mosquitoes or prevent from feeding as in the case of DEET even at a lower concentration of 5%. This study demonstrates the potential of essential oils from O. sanctum, M. piperita, E. globulus and P. amboinicus and their blend as mosquito repellents against Ae. aegypti, the vector of dengue, chikungunya and yellow fever.

  4. Plants traditionally used as mosquito repellents and the implication for their use in vector control.

    PubMed

    Tisgratog, Rungarun; Sanguanpong, Unchalee; Grieco, John P; Ngoen-Kluan, Ratchadawan; Chareonviriyaphap, Theeraphap

    2016-05-01

    Numerous plants with insect repelling properties are native to the tropics where they are produced for a wide range of medicinal purposes. In Thailand, these native plant species have a history of use for personal protection against biting insects. From our investigation we identified 37 plant species within 14 plant families that showed some mosquito repellent properties. Of these, 9 plant species were characterized using an excito-repellency test system against several Thai mosquito species. Results from these studies revealed that five essential oils extracted from plants demonstrated promising insect repellent activity. These active ingredients show promise for further development into formulations that may serve as alternatives to DEET or possibly be used as natural bio-pesticides to kill mosquitoes. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Mosquito repellent activity of essential oils of aromatic plants growing in Argentina.

    PubMed

    Gillij, Y G; Gleiser, R M; Zygadlo, J A

    2008-05-01

    Mosquitoes are important vectors of diseases and nuisance pests. Repellents minimize contact with mosquitoes. Repellents based on essential oils (EO) are being developed as an alternative to DEET (N,N-diethyl-m-methylbenzamide), an effective compound that has disadvantages including toxic reactions, and damage to plastic and synthetic fabric. This work evaluated the repellency against Aedes aegypti of EO from aromatic plants that grow in Argentina: Acantholippia seriphioides, Achyrocline satureioides, Aloysia citriodora, Anemia tomentosa, Baccharis spartioides, Chenopodium ambrosioides, Eucalyptus saligna, Hyptis mutabilis, Minthostachys mollis, Rosmarinus officinalis, Tagetes minuta and Tagetes pusilla. Most EO were effective. Variations depending on geographic origin of the plant were detected. At a 90% EO concentration, A. satureoides and T. pusilla were the least repellent. At concentrations of 12.5% B. spartioides, R. officinalis and A. citriodora showed the longest repellency times. Comparisons of the principal components of each EO suggest that limonene and camphor were the main components responsible for the repellent effects.

  6. Are commercially available essential oils from Australian native plants repellent to mosquitoes?

    PubMed

    Maguranyi, Suzann K; Webb, Cameron E; Mansfield, Sarah; Russell, Richard C

    2009-09-01

    While the use of topical insect repellents, particularly those containing synthetic active ingredients such as deet (N,N-diethyl-3-methylbenzamide), are a mainstay in personal protection strategies emphasized in public health messages, there is a growing demand in the community for alternative repellents, particularly those of botanical origin and thus deemed to be "natural." This study evaluated the repellency of essential oils from 11 Australian native plants in 5% v/v formulations against Aedes aegypti, Culex quinquefasciatus, and Culex annulirostris under laboratory conditions. A blend of the top 3 performing oils was then compared with deet and a commercially available botanical insect repellent. All essential oils provided at least some protection against the 3 mosquito species, with the longest protection time (110 min) afforded by Prostanthera melissifolia against Cx. quinquefasciatus. Mean protection times against Ae. aegypti were substantially lower than those for the Culex spp. tested. Deet provided significantly longer protection against Ae. aegypti than both the 5% v/v blend of Leptospermum petersonii, Prostanthera melissifolia, and Melaleuca alternifolia (the 3 most effective oils) and the commercial botanical repellent. The results of this study indicate that these essential oils from Australian native plants offer limited protection against biting mosquitoes and that a blend of essential oils holds may offer commercial potential as a short-period repellent or under conditions of low mosquito abundance. However, it is important that public health messages continue to emphasize the greater effectiveness of deet-based repellents in areas with risks of mosquito-borne disease.

  7. "Singing in the Tube"--audiovisual assay of plant oil repellent activity against mosquitoes (Culex pipiens).

    PubMed

    Adams, Temitope F; Wongchai, Chatchawal; Chaidee, Anchalee; Pfeiffer, Wolfgang

    2016-01-01

    Plant essential oils have been suggested as a promising alternative to the established mosquito repellent DEET (N,N-diethyl-meta-toluamide). Searching for an assay with generally available equipment, we designed a new audiovisual assay of repellent activity against mosquitoes "Singing in the Tube," testing single mosquitoes in Drosophila cultivation tubes. Statistics with regression analysis should compensate for limitations of simple hardware. The assay was established with female Culex pipiens mosquitoes in 60 experiments, 120-h audio recording, and 2580 estimations of the distance between mosquito sitting position and the chemical. Correlations between parameters of sitting position, flight activity pattern, and flight tone spectrum were analyzed. Regression analysis of psycho-acoustic data of audio files (dB[A]) used a squared and modified sinus function determining wing beat frequency WBF ± SD (357 ± 47 Hz). Application of logistic regression defined the repelling velocity constant. The repelling velocity constant showed a decreasing order of efficiency of plant essential oils: rosemary (Rosmarinus officinalis), eucalyptus (Eucalyptus globulus), lavender (Lavandula angustifolia), citronella (Cymbopogon nardus), tea tree (Melaleuca alternifolia), clove (Syzygium aromaticum), lemon (Citrus limon), patchouli (Pogostemon cablin), DEET, cedar wood (Cedrus atlantica). In conclusion, we suggest (1) disease vector control (e.g., impregnation of bed nets) by eight plant essential oils with repelling velocity superior to DEET, (2) simple mosquito repellency testing in Drosophila cultivation tubes, (3) automated approaches and room surveillance by generally available audio equipment (dB[A]: ISO standard 226), and (4) quantification of repellent activity by parameters of the audiovisual assay defined by correlation and regression analyses.

  8. Mosquito (Diptera: Culicidae) repellency field tests of essential oils from plants traditionally used in Laos.

    PubMed

    Vongsombath, Chanda; Pålsson, Katinka; Björk, Lars; Borg-Karlson, Anna-Karin; Jaenson, Thomas G T

    2012-11-01

    Essential oils of Hyptis suaveolens (Lamiaceae), Croton roxburghii (Euphorbiaceae), and Litsea cubeba (Lauraceae) were tested in the field near Vientiane city, Lao PDR, on humans for repellent activity against mosquitoes. Landing mosquitoes were collected and later identified. The most abundant mosquitoes captured belonged to the genera Armigeres, Culex, and Aedes. All the plant oils tested at concentrations of 1.7 microg/cm(2), 3.3 microg/cm(2), and 6.3 microg/cm(2) were significantly more mosquito repellent than the negative control. Croton oil was significantly repellent against mosquitoes of the three genera at the highest (6.3 microg/cm(2)) concentration tested. Litsea oil was significantly repellent against Armigeres at all (1.7 microg/cm(2), 3.3 microg/cm(2), and 6.3 microg/cm(2)) concentrations tested. Hyptis oil was significantly repellent against Armigeres at 3.3 microg/cm(2) and 6.3 microg/cm(2) and against Culex at 1.7 microg/cm(2) and 6.3 microg/cm(2). The oils were analyzed for chemical content of volatiles, mainly terpenes. Main constituents were beta-pinene, sabinene, and 1,8-cineol from oils of the green parts of H. suaveolens; alpha-pinene, beta-pinene, and alpha-phellandrene from fresh bark of C. roxburghii; and alpha-pinene, beta-phellandrene, sabinene, and 1,8-cineol from fresh fruits of L. cubeba.

  9. An evaluation of mosquito repellents and essential plant oils as deterrents of Asian citrus psyllid

    USDA-ARS?s Scientific Manuscript database

    This study objectives were to evaluate mosquito repellents against Asian citrus psyllid (ACP) and to expand our knowledge of the potential of essential plant oils as deterrents of adult infestations. Twenty-two candidate deterrents were tested as 20% solutions in methanol using a laboratory assay. G...

  10. Repellent properties of Cardiospermum halicacabum Linn. (Family: Sapindaceae) plant leaf extracts against three important vector mosquitoes

    PubMed Central

    Govindarajan, M; Sivakumar, R

    2012-01-01

    Objective To determine repellent activity of hexane, ethyl acetate, benzene, chloroform and methanol extract of Cardiospermum halicacabum (C. halicacabum) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi). Methods Evaluation was carried out in a net cage (45 cm×30 cm×25 cm) containing 100 blood starved female mosquitoes of three mosquito species and were assayed in the laboratory condition by using the protocol of WHO 2005; The plant leaf crude extracts of C. halicacabum was applied at 1.0, 2.5, and 5.0 mg/cm2 separately in the exposed area of the fore arm. Only ethanol served as control. Results In this observation, the plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity was dependent on the strength of the plant extracts. The tested plant crude extracts had exerted promising repellent against all the three mosquitoes. Conclusions From the results it can be concluded the crude extract of C. halicacabum was potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes. PMID:23569979

  11. Patent literature on mosquito repellent inventions which contain plant essential oils--a review.

    PubMed

    Pohlit, Adrian Martin; Lopes, Norberto Peporine; Gama, Renata Antonaci; Tadei, Wanderli Pedro; Neto, Valter Ferreira de Andrade

    2011-04-01

    Bites Bites of mosquitoes belonging to the genera Anopheles Meigen, Aedes Meigen, Culex L. and Haemagogus L. are a general nuisance and are responsible for the transmission of important tropical diseases such as malaria, hemorrhagic dengue and yellow fevers and filariasis (elephantiasis). Plants are traditional sources of mosquito repelling essential oils (EOs), glyceridic oils and repellent and synergistic chemicals. A Chemical Abstracts search on mosquito repellent inventions containing plant-derived EOs revealed 144 active patents mostly from Asia. Chinese, Japanese and Korean language patents and those of India (in English) accounted for roughly 3/4 of all patents. Since 1998 patents on EO-containing mosquito repellent inventions have almost doubled about every 4 years. In general, these patents describe repellent compositions for use in topical agents, cosmetic products, incense, fumigants, indoor and outdoor sprays, fibers, textiles among other applications. 67 EOs and 9 glyceridic oils were individually cited in at least 2 patents. Over 1/2 of all patents named just one EO. Citronella [Cymbopogon nardus (L.) Rendle, C.winterianus Jowitt ex Bor] and eucalyptus (Eucalyptus LʼHér. spp.) EOs were each cited in approximately 1/3 of all patents. Camphor [Cinnamomum camphora (L.) J. Presl], cinnamon (Cinnamomum zeylanicum Blume), clove [Syzygium aromaticum (L.) Merr. & L.M. Perry], geranium (Pelargonium graveolens LʼHér.), lavender (Lavandula angustifolia Mill.), lemon [Citrus × limon (L.) Osbeck], lemongrass [Cymbopogon citratus (DC.) Stapf] and peppermint (Mentha × piperita L.) EOs were each cited in > 10% of patents. Repellent chemicals present in EO compositions or added as pure “natural” ingredients such as geraniol, limonene, p-menthane-3,8-diol, nepetalactone and vanillin were described in approximately 40% of all patents. About 25% of EO-containing inventions included or were made to be used with synthetic insect control agents having mosquito

  12. Ethnobotanical study of some of mosquito repellent plants in north-eastern Tanzania

    PubMed Central

    Kweka, Eliningaya J; Mosha, Franklin; Lowassa, Asanterabi; Mahande, Aneth M; Kitau, Jovin; Matowo, Johnson; Mahande, Michael J; Massenga, Charles P; Tenu, Filemoni; Feston, Emmanuel; Lyatuu, Ester E; Mboya, Michael A; Mndeme, Rajabu; Chuwa, Grace; Temu, Emmanuel A

    2008-01-01

    Background The use of plant repellents against nuisance biting insects is common and its potential for malaria vector control requires evaluation in areas with different level of malaria endemicity. The essential oils of Ocimum suave and Ocimum kilimandscharicum were evaluated against malaria vectors in north-eastern Tanzania. Methodology An ethnobotanical study was conducted at Moshi in Kilimanjaro region north-eastern Tanzania, through interviews, to investigate the range of species of plants used as insect repellents. Also, bioassays were used to evaluate the protective potential of selected plants extracts against mosquitoes. Results The plant species mostly used as repellent at night are: fresh or smoke of the leaves of O. suave and O. kilimandscharicum (Lamiaceae), Azadirachta indica (Meliaceae), Eucalyptus globules (Myrtaceae) and Lantana camara (Verbenaceae). The most popular repellents were O. kilimandscharicum (OK) and O. suave (OS) used by 67% out of 120 households interviewed. Bioassay of essential oils of the two Ocimum plants was compared with citronella and DEET to study the repellence and feeding inhibition of untreated and treated arms of volunteers. Using filter papers impregnated with Ocimum extracts, knockdown effects and mortality was investigated on malaria mosquito Anopheles arabiensis and Anopheles gambiae, including a nuisance mosquito, Culex quinquefasciatus. High biting protection (83% to 91%) and feeding inhibition (71.2% to 92.5%) was observed against three species of mosquitoes. Likewise the extracts of Ocimum plants induced KD90 of longer time in mosquitoes than citronella, a standard botanical repellent. Mortality induced by standard dosage of 30 mg/m2 on filter papers, scored after 24 hours was 47.3% for OK and 57% for OS, compared with 67.7% for citronella. Conclusion The use of whole plants and their products as insect repellents is common among village communities of north-eastern Tanzania and the results indicate that the use of

  13. Mosquito repellents in frog skin

    PubMed Central

    Williams, C.R; Smith, B.P.C; Best, S.M; Tyler, M.J

    2006-01-01

    The search for novel insect repellents has been driven by health concerns over established synthetic compounds such as diethyl-m-toluamide (DEET). Given the diversity of compounds known from frog skin and records of mosquito bite and ectoparasite infestation, the presence of mosquito repellents in frogs seemed plausible. We investigated frog skin secretions to confirm the existence of mosquito repellent properties. Litoria caerulea secretions were assessed for mosquito repellency by topical application on mice. The secretions provided protection against host-seeking Culex annulirostris mosquitoes. Olfactometer tests using aqueous washes of skin secretions from L. caerulea and four other frog species were conducted to determine whether volatile components were responsible for repellency. Volatiles from Litoria rubella and Uperoleia mjobergi secretions were repellent to C. annulirostris, albeit not as repellent as a DEET control. The demonstration of endogenous insect repellents in amphibians is novel, and demonstrates that many aspects of frog chemical ecology remain unexplored. PMID:17148373

  14. Adult repellency and larvicidal activity of five plant essential oils against mosquitoes.

    PubMed

    Zhu, Junwei; Zeng, Xiaopeng; Yanma; Liu, Ting; Qian, Kuen; Han, Yuhua; Xue, Suqin; Tucker, Brad; Schultz, Gretchen; Coats, Joel; Rowley, Wayne; Zhang, Aijun

    2006-09-01

    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.

  15. Laboratory evaluation of Indian medicinal plants as repellents against malaria, dengue, and filariasis vector mosquitoes.

    PubMed

    Govindarajan, Marimuthu; Sivakumar, Rajamohan

    2015-02-01

    Mosquito-borne diseases have an economic impact, including loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates; however, no part of the world is free from vector-borne diseases. Mosquitoes are the carriers of severe and well-known illnesses such as malaria, arboviral encephalitis, dengue fever, chikungunya fever, West Nile virus, and yellow fever. These diseases produce significant morbidity and mortality in humans and livestock around the world. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticides, in the present study, the repellent activity of crude hexane, ethyl acetate, benzene, chloroform, and methanol extracts of leaf of Erythrina indica and root of Asparagus racemosus were assayed for their repellency against three important vector mosquitoes, viz., Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The crude extract was applied on a membrane used for membrane feeding of unfed mosquitoes in a 1-ft cage. About 50 unfed 3-4-day-old laboratory-reared pathogen-free strains of A. stephensi, A. aegypti, and C. quinquefasciatus were introduced in a 1-ft cage fitted with a membrane with blood for feeding with temperature maintained at 37 °C through circulating water bath maintained at 40-45 °C. Three concentrations (1.0, 2.0, and 5.0 mg/cm(2)) of the crude extracts were evaluated. Repellents in E. indica afforded longer protection time against A. stephensi, A. aegypti, and C. quinquefasciatus than those in A. racemosus at 5.0 mg/cm(2) concentration, and the mean complete protection time ranged from 120 to 210 min with the different extracts tested. In this observation, these two plant crude extracts gave protection against mosquito bites; also, the repellent activity is dependent on the strength of the plant extracts. These results suggest that the leaf extract of E. indica and root extract of A. racemosus have the potential to

  16. Repellent activity of selected plant essential oils against the malarial fever mosquito Anopheles stephensi.

    PubMed

    Rajkumar, S; Jebanesan, A

    2007-12-01

    In recent years, use of environment friendly and biodegradable natural insecticides of plant origin have received renewed attention as agents for vector control. In this study, essential oils extracted by steam distillation from leaves of five plant species Centella asiatica L., Ipomoea cairica L., Momordica charantia L., Psidium guajava L. and Tridax procumbens L. were evaluated for their topical repellency effects against malarial vector Anopheles stephensi in mosquito cages. All essential oils were tested at three different concentrations (2, 4 and 6%). Of these, the essential oils of I. cairica, M. charantia and T. procumbens exhibited relatively high repellency effect (>300 minutes at 6% concentration), followed by C. asiatica and P. guajava which showed less effective (< 150 minutes at 6 % concentration). However, the ethanol applied arm served as control provided maximum 8.0 minutes repellency in this study. In general, clear dose-response relationships were established in all essential oils, with the highest concentration of 6% provided high repellency effect. The results obtained from this study suggest that essential oils of I. cairica, M. charantia and T. procumbens are promising as repellents at 6% concentration against An. stephensi and could be useful in the search for new natural repellent compounds.

  17. Laboratory evaluation of traditional insect/mosquito repellent plants against Anopheles arabiensis, the predominant malaria vector in Ethiopia.

    PubMed

    Karunamoorthi, Kaliyaperumal; Mulelam, Adane; Wassie, Fentahun

    2008-08-01

    Laboratory study was carried out to evaluate the repellent efficiency of most commonly known four traditional insect/mosquito repellent plants Wogert [vernacular name (local native language, Amharic); Silene macroserene], Kebercho [vernacular name (local native language, Amharic); Echinops sp.], Tinjut [vernacular name (local native language, Amharic); Ostostegia integrifolia], and Woira[vernacular name (local native language, Amharic); Olea europaea] against Anopheles arabiensis under the laboratory conditions. One hundred (4-5 days old) female A. arabiensis were introduced into the both 'control' and 'test' repellent chamber through the hole on top. Traditional charcoal stoves were used for direct burning. The experiment was conducted by applying the smoke into the repellent "test" mosquito cage by direct burning of 25 gm of dried plant materials (leaves and roots) until plant materials completely burned. The number of mosquitoes driving away from the "test" and "control" cage was recorded for every 5 min. In the present investigation, the results clearly revealed that the roots of S. macroserene has potent repellent efficiency (93.61%) and was the most effective. The leaves of Echinops sp. (92.47%), leaves of O. integrifolia (90.10%) and O. europaea (79.78%) were also effective. Roots of S. macroserene exhibited the highest repellent efficiency by direct burning. The present study identified these four traditional indigenous insect/mosquito repellent plant materials are very promising and can be used as safer alternative to modern synthetic chemical repellents against mosquito vectors of disease. Since people have been using these plants for some medicinal purposes, no side effects have been found.

  18. Repellency and toxicity of aromatic plant extracts against the mosquito Culex pipiens molestus (Diptera: Culicidae).

    PubMed

    Traboulsi, Abdallah F; El-Haj, Samih; Tueni, Marie; Taoubi, Khalil; Nader, Natalie Abi; Mrad, Abir

    2005-06-01

    The insecticidal activities of essential oil extracts from leaves, flowers and roots of aromatic plants against fourth-instar larvae of the mosquito Culex pipiens molestus Forskal were determined. Extracts of Foeniculum vulgare Mill were the most toxic, followed by those of Ferula hermonis Boiss, Citrus sinensis Osbeck, Pinus pinea L, Laurus nobilis L and Eucalyptus spp with LC50 values of 24.5, 44.0, 60.0, 75.0, 117.0 and 120.0 mg litre(-1), respectively. Combination tests between the LC50 and the maximum sub-lethal concentration (MSLC) were determined. Over 20 major components were identified in extracts from each plant species tested. Five essential oils and nine pure components were studied for their repellency against mosquito bites. Terpineol and 1,8-cineole were the most effective against Culex pipiens molestus bites offering complete protection for 1.6 and 2 h, respectively.

  19. Ethnobotanical survey of knowledge and usage custom of traditional insect/mosquito repellent plants among the Ethiopian Oromo ethnic group.

    PubMed

    Karunamoorthi, Kaliyaperumal; Ilango, Kandan; Endale, Aschalew

    2009-09-07

    Repellent plants usage is an integral part of Ethiopian tradition and has been practiced over many centuries. Hence, the aim of this study was to assess the knowledge and usage custom of traditional insect/mosquito repellent plants among the Oromo ethnic group in Ethiopia. The ethnobotanical survey was conducted between January and March 2009. All 276 household members were interviewed on knowledge and usage custom of traditional repellent plants, using a pre-tested questionnaire in Kofe kebele, Jimma zone, Ethiopia. 83.6% respondents had adequate knowledge and usage custom regarding insect/mosquito repellent plants. Application of smoke by burning the repellent plant materials was the most common practice. The chi-square test result revealed that there was no statistically significant association found between the knowledge about insect repellent plants and sex (p-value=0.8912), educational status (p-value=0.7504), and age (p-value=0.1631) of the respondents. However, usage custom of repellent plants was significantly associated with sex (p-value=0.0002) and average monthly income (p-value=0.0001) although not with educational status (p-value=0.5206) of the respondents. Repellent efficacy of these plants is undetermined and therefore the scientific validity should be evaluated by conducting further laboratory and field research. Majority of the repellent plants have been used as medicine to treat various ailments by the local community. Furthermore, they are easily available, accessible and affordable therefore usage of traditional repellent plants should be promoted among the local residents in order to reduce vector-borne disease prevalence.

  20. Repellent, irritant and toxic effects of 20 plant extracts on adults of the malaria vector Anopheles gambiae mosquito.

    PubMed

    Deletre, Emilie; Martin, Thibaud; Campagne, Pascal; Bourguet, Denis; Cadin, Andy; Menut, Chantal; Bonafos, Romain; Chandre, Fabrice

    2013-01-01

    Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic) of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, a primary vector of malaria. Their effects were compared to those of DEET and permethrin, used as positive controls. Most plant extracts had irritant, repellent and/or toxic effects on An. gambiae adults. The most promising extracts, i.e. those combining the three types of effects, were from Cymbopogon winterianus, Cinnamomum zeylanicum and Thymus vulgaris. The irritant, repellent and toxic effects occurred apparently independently of each other, and the behavioural response of adult An. gambiae was significantly influenced by the concentration of the plant extracts. Mechanisms underlying repellency might, therefore, differ from those underlying irritancy and toxicity. The utility of the efficient plant extracts for vector control as an alternative to pyrethroids may thus be envisaged.

  1. Repellent, Irritant and Toxic Effects of 20 Plant Extracts on Adults of the Malaria Vector Anopheles gambiae Mosquito

    PubMed Central

    Deletre, Emilie; Martin, Thibaud; Campagne, Pascal; Bourguet, Denis; Cadin, Andy; Menut, Chantal; Bonafos, Romain; Chandre, Fabrice

    2013-01-01

    Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic) of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, a primary vector of malaria. Their effects were compared to those of DEET and permethrin, used as positive controls. Most plant extracts had irritant, repellent and/or toxic effects on An. gambiae adults. The most promising extracts, i.e. those combining the three types of effects, were from Cymbopogon winterianus, Cinnamomum zeylanicum and Thymus vulgaris. The irritant, repellent and toxic effects occurred apparently independently of each other, and the behavioural response of adult An. gambiae was significantly influenced by the concentration of the plant extracts. Mechanisms underlying repellency might, therefore, differ from those underlying irritancy and toxicity. The utility of the efficient plant extracts for vector control as an alternative to pyrethroids may thus be envisaged. PMID:24376515

  2. Natural product studies of U.S. endangered plants: Volatile components of Lindera melissifolia (Lauraceae) repel mosquitoes and ticks

    Treesearch

    Joonseok Oh; John J. Bowling; John F. Carroll; Betul Demirci; K. Hüsnü Can Baser; Theodor D. Leininger; Ulrich R. Berniere; Mark T. Hamann

    2012-01-01

    The number of endangered plant species in the U.S. is significant, yet studies aimed towards utilizing these plants are limited. Ticks and mosquitoes are vectors of significant pathogenic diseases of humans. Repellents are critical means of personal protection against biting arthropods and disease transmission. The essential oil and solvent extracts from ...

  3. Repelling mosquitoes with essential oils

    NASA Astrophysics Data System (ADS)

    Riley, L.

    2017-12-01

    Mosquitoes carry diseases than can lead to serious illness and death. According to the World Health Organization, mosquitoes infect over 300 million people a year with Malaria and Dengue Fever, two life threatening diseases vectored by mosquitoes. Although insecticides are the most effective way to control mosquitoes, they are not always environmentally friendly. Therefore, alternative tactics should be considered. In this study, we looked at the repellency of various essential oils on female Aedes aegypti through a series of laboratory assays.

  4. Performance of the plant-based repellent TT-4302 against mosquitoes in the laboratory and field and comparative efficacy to 16 mosquito repellents against Aedes aegypti (Diptera: Culicidae).

    PubMed

    Bissinger, B W; Schmidt, J P; Owens, J J; Mitchell, S M; Kennedy, M K

    2014-03-01

    Repellent efficacy of the plant-based repellent, TT-4302 (5% geraniol), was compared with 16 other products in laboratory arm-in-cage trials against Aedes aegypti (L). Eight repellents (Badger, BioUD, Burt's bees, California Baby, Cutter Natural, EcoSMART, Herbal Armor, and SkinSmart) exhibited a mean repellency below 90% to Ae. aegypti at 0.5 h after application. Three repellents (Buzz Away Extreme, Cutter Advanced, and OFF! Botanicals lotion) fell below 90% repellency 1.5 h after application. TT-4302 exhibited 94.7% repellency 5 h posttreatment, which was a longer duration than any of the other repellents tested. The positive control, 15% DEET (OFF! Active), was repellent for 3 h before activity dropped below 90%. Additional arm-in-cage trials comparing TT-4302 with 15% DEET were carried out against Anopheles quadrimaculatus Say. At 6 h after treatment, TT-4302 provided 95.2% repellency while DEET exhibited 72.2%. In North Carolina field trials, TT-4302 provided 100% repellency 5 h after application against Aedes albopictus Skuse while DEET provided 77.6% repellency. These results demonstrate that TT-4302 is an efficacious plant-based repellent that provides an extended duration of protection compared with many other commercially available products.

  5. An ethnobotanical survey of mosquito repellent plants in uMkhanyakude district, KwaZulu-Natal province, South Africa.

    PubMed

    Mavundza, E J; Maharaj, R; Finnie, J F; Kabera, G; Van Staden, J

    2011-10-11

    The aim of the study was to document plants traditionally used to repel mosquitoes in the uMkhanyakude district, KwaZulu-Natal, South Africa. The specific objectives of the study were to: (1) identify plant species and their parts being used; (2) determine the condition of plant material used and the method of application. Data was collected from 60 respondents in five villages in the district using standardised and pre-tested questionnaires. Thirteen plant species are used in the study area to repel mosquitoes. These species belong to 11 genera from 9 families. Meliaceae and Anacardiaceae were the most represented families with two species each. The most frequently recorded species were Lippia javanica (91.67%), followed by Aloe ferox (11.67%), Sclerocarya birrea (5%), Melia azedarach (3%), Balanite maughamii (3%) and Mangifera indica (3%). Leaves were the most (38%) common plant part used. The majority (82%) of the plant parts were used in a dry state. Burning of plant materials to make smoke was the most (92%) common method of application. Nine plant species, namely: A. ferox, Calausena anista, Croton menyharthii, S. birrea, B. maughamii, Olax dissitiflora, Trichilia emetic, M. indica, and Atalaya alata are documented for the first time as mosquito repellents. This documentation provides the basis for further studies in developing new, effective, safe and affordable plant-derived mosquito repellents especially for Africa where malaria is highly prevalent. The study also plays a part in documenting and conserving traditional knowledge of mosquito repellent plants for future use. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  6. Repellent activities of some Labiatae plant essential oils against the saltmarsh mosquito Ochlerotatus caspius (Pallas, 1771) (Diptera: Culicidae).

    PubMed

    Koc, Samed; Oz, Emre; Cetin, Huseyin

    2012-06-01

    The repellent activities of the essential oils of two Thymus (Thymus sipyleus Boiss. subsp. sipyleus and Thymus revolutus Celak) and two Mentha (Mentha spicata L. subsp. spicata and Mentha longifolia L.) species against Ochlerotatus caspius (Pallas, 1771) (Diptera: Culicidae) are presented. The essential oils were obtained by hydrodistillation of the aerial parts of the plants in flowering period and repellency tests were done with a Y-tube olfactometer. All essential oils showed repellency in varying degrees and exhibited no significant time-dependent repellent activities. When all test oils compared for repellent activities there was no significant activity detected within 15 min exposure period. Mentha essential oils had better activity than Thymus essential oils, producing high repellency (73.8-84.2%) at 30th min on Oc. caspius. Mentha longifolia has the best mosquito repellent activity among the plants tested at the 25th min. Th. sipyleus subsp. sipyleus essential oil produced >85% repellent activity at the 15th min, but the effect decreased noticeably to 63.1% and 68% at 25th and 30th min, respectively.

  7. A natural agonist of mosquito TRPA1 from the medicinal plant Cinnamosma fragrans that is toxic, antifeedant, and repellent to the yellow fever mosquito Aedes aegypti.

    PubMed

    Inocente, Edna Alfaro; Shaya, Marguerite; Acosta, Nuris; Rakotondraibe, L Harinantenaina; Piermarini, Peter M

    2018-02-01

    Plants produce various secondary metabolites that offer a potential source of novel insecticides and repellents for the control of mosquito vectors. Plants of the genus Cinnamosma are endemic to, and widely-distributed throughout, the island of Madagascar. The barks of these species are commonly used in traditional medicines for treating a wide range of maladies. The therapeutic nature of the bark is thought to be associated with its enrichment of pungent drimane sesquiterpenes, which elicit antifeedant and toxic effects in some insects. Here we test the hypothesis that a bark extract of Cinnamosma fragrans (CINEX) and its major drimane sesquiterpenes are insecticidal, antifeedant, and repellent to Aedes aegypti, the principal mosquito vector of chikungunya, dengue, yellow fever, and Zika viruses. We demonstrate that CINEX is 1) toxic to larval and adult female mosquitoes, and 2) antifeedant and repellent to adult female mosquitoes. Moreover, we show that cinnamodial (CDIAL), a sesquiterpene dialdehyde isolated from CINEX, duplicates these bioactivities and exhibits similar toxic potency against pyrethroid-susceptible and -resistant strains of Ae. aegypti. Importantly, we show that CDIAL is an agonist of heterologously-expressed mosquito Transient Receptor Potential A1 (TRPA1) channels, and the antifeedant activity of CDIAL is dampened in a TRPA1-deficient strain of Ae. aegypti (TRPA1-/-). Intriguingly, TRPA1-/- mosquitoes do not exhibit toxic resistance to CDIAL. The data indicate that modulation of TRPA1 is required for the sensory detection and avoidance of CDIAL by mosquitoes, but not for inducing the molecule's toxicity. Our study suggests that CDIAL may serve as a novel chemical platform for the development of natural product-based insecticides and repellents for controlling mosquito vectors.

  8. Mosquito repellent attracts Culicoides imicola (Diptera: Ceratopogonidae).

    PubMed

    Braverman, Y; Chizov-Ginzburg, A; Mullens, B A

    1999-01-01

    A plant-derived mosquito repellent, based on the oil of Eucalyptus maculata var. citriodora Hook, was evaluated against the biting midge Culicoides imicola Kieffer. Suction black light-traps covered with repellent-impregnated polyester mesh and deployed near horses attracted large numbers of C. imicola, which were seen near the treated net within a few minutes of the start of the experiment. Initial collections in the traps were approximately 3 times as large as those in control traps with untreated mesh. Numbers collected in treated traps were similar to untreated control traps after 4 h. Traps with mesh treated with DEET or another plant-derived (Meliaceae) proprietary product, AG1000, acted as repellents relative to the control. The differential activity of repellents against blood-feeding Diptera is discussed.

  9. Identification of mosquito repellent odours from Ocimum forskolei

    PubMed Central

    2011-01-01

    Background Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD) with headspace extracts of crushed plants. Results EAD active compounds included (R)-(-)-linalool, (S)-(+)-1-octen-3-ol, trans-caryophyllene, naphthalene, methyl salicylate, (R)-(-)-α-copaene, methyl cinnamate and (E)-ocimene. Of these compounds (R)-(-)-linalool, methyl cinnamate and methyl salicylate reduced landing of female Aedes aegypti on human skin-odor baited tubes. The latter two are novel mosquito repellent compounds. Conclusions The identification of mosquito repellent compounds contributes to deciphering the mechanisms underlying repulsion, supporting the rational design of novel repellents. The three mosquito repellent compounds identified in this study are structurally dissimilar, which may indicate involvement of different sensory neurons in repulsion. Repulsion may well be enhanced through combining different repellent plants (or their synthetic mimics), and can be a locally sustainable part in mosquito control efforts. PMID:21936953

  10. Identification of mosquito repellent odours from Ocimum forskolei.

    PubMed

    Dekker, Teun; Ignell, Rickard; Ghebru, Maedot; Glinwood, Robert; Hopkins, Richard

    2011-09-22

    Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD) with headspace extracts of crushed plants. EAD active compounds included (R)-(-)-linalool, (S)-(+)-1-octen-3-ol, trans-caryophyllene, naphthalene, methyl salicylate, (R)-(-)-α-copaene, methyl cinnamate and (E)-ocimene. Of these compounds (R)-(-)-linalool, methyl cinnamate and methyl salicylate reduced landing of female Aedes aegypti on human skin-odor baited tubes. The latter two are novel mosquito repellent compounds. The identification of mosquito repellent compounds contributes to deciphering the mechanisms underlying repulsion, supporting the rational design of novel repellents. The three mosquito repellent compounds identified in this study are structurally dissimilar, which may indicate involvement of different sensory neurons in repulsion. Repulsion may well be enhanced through combining different repellent plants (or their synthetic mimics), and can be a locally sustainable part in mosquito control efforts.

  11. Mosquito repellents for malaria prevention

    PubMed Central

    Maia, Marta F; Kliner, Merav; Richardson, Marty; Lengeler, Christian; Moore, Sarah J

    2018-01-01

    Background Malaria is an important cause of illness and death across endemic regions. Considerable success against malaria has been achieved within the past decade mainly through long-lasting insecticide-treated nets (LLINs). However, elimination of the disease is proving difficult as current control methods do not protect against mosquitoes biting outdoors and when people are active. Repellents may provide a personal protection solution during these times. Objectives To assess the impact of topical repellents, insecticide-treated clothing, and spatial repellents on malaria transmission. Search methods We searched the following databases up to 26 June 2017: the Cochrane Infectious Diseases Group Specialized Register; the Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE; Embase; US AFPMB; CAB Abstracts; and LILACS. We also searched trial registration platforms and conference proceedings; and contacted organizations and companies for ongoing and unpublished trials. Selection criteria We included randomized controlled trials (RCTs) and cluster-randomized controlled trials of topical repellents proven to repel mosquitoes; permethrin-treated clothing; and spatial repellents such as mosquito coils. We included trials that investigated the use of repellents with or without LLINs, referred to as insecticide-treated nets. Data collection and analysis Two review authors independently reviewed trials for inclusion, extracted the data, and assessed the risk of bias. A third review author resolved any discrepancies. We analysed data by conducting meta-analysis and stratified by whether the trials had included LLINs. We combined results from cRCTs with individually RCTs by adjusting for clustering and presented results using forest plots. We used GRADE to assess the certainty of the evidence. Main results Eight cRCTs and two RCTs met the inclusion criteria. Six trials investigated topical repellents, two trials investigated insecticide

  12. Prevention of Dengue fever through plant based mosquito repellent Clausena dentata (Willd.) M. Roem (Family: Rutaceae) essential oil against Aedes aegypti l. (Diptera: Culicidae) mosquito.

    PubMed

    Rajkumar, S; Jebanesan, A

    2010-03-01

    Plant based repellent against mosquito borne diseases are used recently because synthetic repellents cause side effects like breathing problem, eye irritation, head ache, cough, etc. The use of natural products for dengue control would protect the environment, reduce dependence on expensive synthetic repellents and also generate local employment. Essential oil was isolated by steam distillation which was used against the bites of Aedes aegypti and duration of protection period was assessed. Skin-irritant potential test was also conducted on 25 healthy volunteers by using four-point scale. The increase in the concentrations of essential oil increased the mean protection time against the bites of Aedes aegypti. The lowest mean protection time was 180.0 min for 2.5% and highest time of 255.0 min for 10%. The mean score of zero for skin-irritant potential test for all the concentrations indicated that the essential oil did not cause irritation to human skin. Results indicated that the use of plant based repellent for the control of dengue fever would replace the currently used synthetic repellents which causes many side effects.

  13. Extract of the seeds of the plant Vitex agnus castus proven to be highly efficacious as a repellent against ticks, fleas, mosquitoes and biting flies.

    PubMed

    Mehlhorn, Heinz; Schmahl, Günter; Schmidt, Jürgen

    2005-03-01

    About 70 plant extracts were tested for their ability to repel the attacks of blood-sucking arthropods. It was found that a CO2 extract of the seeds of the Mediterranean plant Vitex agnus castus (monk's pepper) can be used as a spray to keep away especially Ixodes ricinus and Rhipicephalus sanguineus ticks from animals and humans for at least 6 h. In addition mosquitoes, biting flies and fleas are also repelled for about 6 h.

  14. Assessment of knowledge and usage custom of traditional insect/mosquito repellent plants in Addis Zemen Town, South Gonder, North Western Ethiopia.

    PubMed

    Karunamoorthi, Kaliyaperumal; Mulelam, Adane; Wassie, Fentahun

    2009-01-12

    A cross-sectional descriptive study was carried out to assess the knowledge and usage custom of traditional insect/mosquitoes repellent plants among the inhabitants in Addis Zemen Town, Ethiopia. Stratified, systematic random sampling was used for selection of 393 households from the total of 5161 households. One adult from each household was interviewed. The ethnobotonical survey was carried out during the period February 2007 to March 2007. Data analysis was carried out using SPSS, version 9.0. Range and mean were analysed and appropriate tables, graphs and percentage were displayed. Level of significance also determined by using 95% of confidence intervals and p-value. Overall, 97.2% of the respondents had ample knowledge and usage custom concerning traditional insect/mosquito repellent plants. Application of smoke (91.55%) was one of the most commonly well-known methods amongst local community by burning the plant parts such as leaves, stems and roots. Leaves were used by 90.2% for the application smoke. Knowledge and usage custom of traditional insect/mosquito repellent plants had significantly associated with sex (p=0.013) and lower income of respondents (p=0.002). In spite of this, knowledge and usage custom had no significant association with age and educational status. Furthermore, the survey also indicated that most commonly known traditional insect/mosquito repellent plants were Woira*(1) (Olea europaea) 44%, Tinjut* (Ostostegia integrifolia) 39%, Neem* (Azadirachta indica) 14.1%, Wogert* (Silene macroserene) 1.4%, and Kebercho* (Echinops sp.) 1.1%. Indigenous traditional insect/mosquito repellent plants have been used by local hamlet since ancient times for various medicinal purposes. Besides, they are not toxic like existing modern synthetic chemical repellents. Therefore, the traditional use of repellent plants should be encouraged and promoted among the local community.

  15. Mode of action of mosquito repellents

    USDA-ARS?s Scientific Manuscript database

    The mode of action of mosquito repellents remains a controversial topic. However, electrophysiological studies and molecular approaches have provided a better understanding of how repellents exert their effects. Here, we briefly discuss various notions of repellent action and present the current sta...

  16. Reception of odors and repellents in mosquitoes

    PubMed Central

    Ray, Anandasankar

    2015-01-01

    Mosquitoes use their sense of smell to find hosts, nectar, and oviposition sites, and to avoid repellents. A small number of mosquito species are adapted to feed on humans and have a major impact on public health by transmitting malaria, dengue, filariasis, etc. The application of odorants for behavioral control has not been fully realized yet due to complexity of the mosquito olfactory system. Recent progress in molecular and computational tools has enabled rigorous investigations of the mosquito olfactory system function and has started to reveal how specific receptors contribute to attractive and aversive behaviors. Here we discuss recent advances in linking odors to receptors and in exploiting this knowledge in finding attractants and repellents for mosquitoes. PMID:26202080

  17. Evaluation of extracts and oils of mosquito (Diptera: Culicidae) repellent plants from Sweden and Guinea-Bissau.

    PubMed

    Jaenson, Thomas G T; Pålsson, Katinka; Borg-Karlson, Anna-Karin

    2006-01-01

    In laboratory tests, ethyl acetate extracts of Hyptis suaveolens Poit. from Guinea-Bissau and Rhododendon tomentosum (Stokes) H. Harmaja (formerly Ledum palustre L.) and Myrica gale L. significantly reduced probing activity of Aedes aegypti (L.). In the field in southern Sweden, extracts of leaves of R. tomentosum, M. gale, and Achillea millefolium L. significantly reduced biting by Aedes mosquitoes. Volatile compounds from M. gale, R. tomentosum, A. millefolium, and H. suaveolens were collected by solid phase microextraction (SPME). Alternatively, compounds in the plants were subjected to extraction by organic solvents of different polarities or by steam distillation and collection by SPME. Compounds collected were identified by gas chromatography-mass spectrometry. Leaves of H. suaveolens contained mainly beta-caryophyllene, bergamotene, and terpinolene. The volatile fraction of an ethyl acetate extract of H. suaveolens was collected by SPME and included beta-caryophyllene, (-) -sabinene, beta-pinene, limonene, alpha-pinene, and bergamotene. The main volatiles detected were alpha-pinene, alpha-phellandrene, myrcene, and limonene from M. gale leaves or inflorescences; pcymene, sabinene, and terpinyl acetate from leaves of R. tomentosum; and (-)-germacrene D, beta-pinene, sabinene, and alpha-pinene from A. millefolium leaves or inflorescences. The selected plant species contained numerous volatiles known to have insecticidal, acaricidal, "pesticidal," and/ or insect repellent properties.

  18. Mosquito repellency of novel Trifluoromethylphenyl amides

    USDA-ARS?s Scientific Manuscript database

    Human diseases caused by mosquito-transmitted pathogens include malaria, dengue and yellow fever and are responsible for several million human deaths every year, according to the World Health Organization (WHO). Our current research projects focus on the development of new insecticides and repellent...

  19. Mosquito larvicidal activity of botanical-based mosquito repellents.

    PubMed

    Zhu, Junwei; Zeng, Xiaopeng; O'Neal, Megan; Schultz, Gretchen; Tucker, Brad; Coats, Joel; Bartholomay, Lyric; Xue, Rui-De

    2008-03-01

    The larvicidal activity of 4 plant essential oils--innamon oil, lemon eucalyptus oil, sandalwood oil, and turmeric oil--previously reported as insect repellents was evaluated in the laboratory against 4th instars of Aedes albopictus, Ae. aegypti, and Culex pipiens. Sandalwood oil appeared to be the most effective of the larvicides, killing larvae of all 3 mosquito species in relatively short times. The values of LT50 and LT90 at the application dosage (0.2 mg/ml) were 1.06 +/- 0.11 and 3.24 +/- 0.14 h for Ae. aegypti, 1.82 +/- 0.06 and 3.33 +/- 0.48 h for Ae. albopictus, and 1.55 +/- 0.07 and 3.91 +/- 0.44 h for Cx. pipiens, respectively. Chemical compositions of these essential oils were also studied, and the lavicidal activity of their major ingredient compounds was compared with that of each of the essential oils. The acute toxicity of the 4 essential oils to fathead minnows was also evaluated. The safe use of these natural plant essential oils in future applications of mosquito control was discussed.

  20. Repellent action of neem cream against mosquitoes.

    PubMed

    Dua, V K; Nagpal, B N; Sharma, V P

    1995-06-01

    Neem cream was used as mosquito repellent to provide protection against Aedes albopictus, Ae. aegypti, Culex quinquefasciatus, Anopheles culicifacies and An. subpictus mosquitoes. The application of neem cream on exposed body parts @2.0 gm/person showed 78 (range 65-95), 89 (range 66-100) and 94.4 (range 66-100) per cent protection against Aedes, Culex and Anopheles mosquitoes respectively. Significant difference was observed between neem cream treated and untreated group of population for Aedes mosquitoes (p < 0.001). Application of neem cream was found to be a safe and suitable alternative to insecticide impregnated coils for personal protection against mosquitoes and one application was 68% effective for four hours.

  1. New and improved mosquito repellents based on structural similarity

    USDA-ARS?s Scientific Manuscript database

    N,N-diethyl-3-methylbenzamide (DEET) is the most effective and best studied mosquito repellent currently on the market in the U.S.; however, this repellent is not a highly efficacious, repellent of long duration that prevents bites from all medically important mosquito species, especially those that...

  2. Novel Carboxamides as Potential Mosquito Repellents

    DTIC Science & Technology

    2010-09-01

    effective dosage to prevent Aedes aegypti (L.) (Diptera: Culicidae) bites . One compound, (E)-N-cyclohexyl-N-ethyl-2-hexenamide, was superior to N,N...versus 0.047 mol/cm2). KEY WORDS repellents, carboxamides, quantitative structure-activity relationship, CPT, Aedes aegypti N,N-diethyl-3-methylbenzamide...these were synthe- sized. The model was validated by subsequent bioas- says with female Aedes aegypti (L.) (Diptera: Culici- dae) mosquitoes, wherein

  3. Repellent Plants Provide Affordable Natural Screening to Prevent Mosquito House Entry in Tropical Rural Settings—Results from a Pilot Efficacy Study

    PubMed Central

    Mng'ong'o, Frank C.; Sambali, Joseph J.; Sabas, Eustachkius; Rubanga, Justine; Magoma, Jaka; Ntamatungiro, Alex J.; Turner, Elizabeth L.; Nyogea, Daniel; Ensink, Jeroen H. J.; Moore, Sarah J.

    2011-01-01

    Sustained malaria control is underway using a combination of vector control, prompt diagnosis and treatment of malaria cases. Progress is excellent, but for long-term control, low-cost, sustainable tools that supplement existing control programs are needed. Conventional vector control tools such as indoor residual spraying and house screening are highly effective, but difficult to deliver in rural areas. Therefore, an additional means of reducing mosquito house entry was evaluated: the screening of mosquito house entry points by planting the tall and densely foliated repellent plant Lantana camara L. around houses. A pilot efficacy study was performed in Kagera Region, Tanzania in an area of high seasonal malaria transmission, where consenting families within the study village planted L. camara (Lantana) around their homes and were responsible for maintaining the plants. Questionnaire data on house design, socioeconomic status, malaria prevention knowledge, attitude and practices was collected from 231 houses with Lantana planted around them 90 houses without repellent plants. Mosquitoes were collected using CDC Light Traps between September 2008 and July 2009. Data were analysed with generalised negative binomial regression, controlling for the effect of sampling period. Indoor catches of mosquitoes in houses with Lantana were compared using the Incidence Rate Ratio (IRR) relative to houses without plants in an adjusted analysis. There were 56% fewer Anopheles gambiae s.s. (IRR 0.44, 95% CI 0.28–0.68, p<0.0001); 83% fewer Anopheles funestus s.s. (IRR 0.17, 95% CI 0.09–0.32, p<0.0001), and 50% fewer mosquitoes of any kind (IRR 0.50, 95% CI 0.38–0.67, p<0.0001) in houses with Lantana relative to controls. House screening using Lantana reduced indoor densities of malaria vectors and nuisance mosquitoes with broad community acceptance. Providing sufficient plants for one home costs US $1.50 including maintenance and labour costs, (30 cents per person). L. camara

  4. Repellent plants provide affordable natural screening to prevent mosquito house entry in tropical rural settings--results from a pilot efficacy study.

    PubMed

    Mng'ong'o, Frank C; Sambali, Joseph J; Sabas, Eustachkius; Rubanga, Justine; Magoma, Jaka; Ntamatungiro, Alex J; Turner, Elizabeth L; Nyogea, Daniel; Ensink, Jeroen H J; Moore, Sarah J

    2011-01-01

    Sustained malaria control is underway using a combination of vector control, prompt diagnosis and treatment of malaria cases. Progress is excellent, but for long-term control, low-cost, sustainable tools that supplement existing control programs are needed. Conventional vector control tools such as indoor residual spraying and house screening are highly effective, but difficult to deliver in rural areas. Therefore, an additional means of reducing mosquito house entry was evaluated: the screening of mosquito house entry points by planting the tall and densely foliated repellent plant Lantana camara L. around houses. A pilot efficacy study was performed in Kagera Region, Tanzania in an area of high seasonal malaria transmission, where consenting families within the study village planted L. camara (Lantana) around their homes and were responsible for maintaining the plants. Questionnaire data on house design, socioeconomic status, malaria prevention knowledge, attitude and practices was collected from 231 houses with Lantana planted around them 90 houses without repellent plants. Mosquitoes were collected using CDC Light Traps between September 2008 and July 2009. Data were analysed with generalised negative binomial regression, controlling for the effect of sampling period. Indoor catches of mosquitoes in houses with Lantana were compared using the Incidence Rate Ratio (IRR) relative to houses without plants in an adjusted analysis. There were 56% fewer Anopheles gambiae s.s. (IRR 0.44, 95% CI 0.28-0.68, p<0.0001); 83% fewer Anopheles funestus s.s. (IRR 0.17, 95% CI 0.09-0.32, p<0.0001), and 50% fewer mosquitoes of any kind (IRR 0.50, 95% CI 0.38-0.67, p<0.0001) in houses with Lantana relative to controls. House screening using Lantana reduced indoor densities of malaria vectors and nuisance mosquitoes with broad community acceptance. Providing sufficient plants for one home costs US $1.50 including maintenance and labour costs, (30 cents per person). L. camara mode

  5. Mini Review: Mode of Action of Mosquito Repellents

    DTIC Science & Technology

    2013-01-01

    Mini review: Mode of action of mosquito repellents Joseph C. Dickens ⇑, Jonathan D. Bohbot United States Department of Agriculture, Agricultural...Modulation a b s t r a c t The mode of action of mosquito repellents remains a controversial topic. However, electrophysiological studies and molecular...annoyance that can disrupt outdoor activities. The use of repellents decreases contacts between mosquitoes and their hosts, and may even lower the rate of

  6. LARVICIDAL POTENTIAL AND MOSQUITO REPELLENT ACTIVITY OF CASSIA MIMOSOIDES EXTRACTS.

    PubMed

    Alayo, M A; Femi-Oyewo, M N; Bakre, L G; Fashina, A O

    2015-07-01

    This study aims to investigate larvicidal activities of extracts of Cassia mimosoides leaves and pods as a potential agent in vector control of malaria and to evaluate repellent effect against Anopheles gambiae mosquito of the extract formulated in an aqueous cream base. Petroleum spirit, ethanol, water and dichloromethane extracts were tested against third and fourth instar Anopheles gambiae larvae. The petroleum extract was formulated in an aqueous cream base and repellency determined using N-N-diethyl-m-toluamide (DEET) as control. Phytochemical analysis showed the presence of saponins, tannins, anthraquinones, steroids, and flavonoids but absence of cardiac glycosides and alkaloids in powdered C. mimosoides. A dose related response was observed in the mortality rate of the extracts, with 2 mg/ml petroleum ether and dichloromethane extracts achieving 100 % mortality. Larvicidal activity of extracts based on LC50 values was petroleum ether > dichloromethane > ethanol > water. The formulated petroleum ether extract cream had a characteristic odor, hard and smooth texture, skin feeling of smoothness, ease of application by rubbing, easy removal using soap and water, non-irritating effect on skin and an acceptable pH value. The cream containing 2%-6% (w/w) extract and control achieved 100% repellency against mosquitoes after an exposure time of 5 minutes. There was a linear relationship between percent concentration of plant extract in the cream samples and repellent activity. These results suggest that crude extracts of C. mimosoides can be developed as eco-friendly larvicide and mosquito repellent and encourage further effort to investigate the bioactive compounds in the extracts.

  7. Insecticidal and repellent activity of Clausena dentata (Rutaceae) plant extracts against Aedes aegypti and Culex quinquefasciatus mosquitoes (Diptera: Culicidae).

    PubMed

    Ramkumar, Govindaraju; Karthi, Sengodan; Muthusamy, Ranganathan; Natarajan, Devarajan; Shivakumar, Muthugounder Subramanian

    2015-03-01

    Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol agents. The present study is to evaluate adulticidal activity of Clausena dentata plant extract against Aedes aegypti and Culex quinquefasciatus mosquitoes. The adult mortality was observed after 24 h of exposure. The highest mortality was found in acetone extracts against Ae. aegypti and Cx. quinquefasciatus with the LC50 and LC90 4.1783 mg/ml (3.8201-7.1026), 9.3884 mg/ml (7. 8258-13.1820) and 4.2451 mg/ml (3.8547-8.0254), 12.3214 mg/ml (10.9287-16.2220), respectively. Smoke toxicity was observed at 10-min interval for 40 min, and the mortality data were recorded. Result shows that Ae. aegypti and Cx. quinquefasciatus are 85 ± 2 and 89 ± 1.5, respectively. A mortality of 100 % was recorded in the commercial mosquito control. These results suggest that the leaf extracts of C. dentata have a potential to be used as an ideal eco-friendly approach for the control of mosquitoes.

  8. Multiple activities of insect repellents on odorant receptors in mosquitoes

    USDA-ARS?s Scientific Manuscript database

    Several lines of evidence suggest that insect repellent molecules reduce mosquito-host contacts by interacting with odorants and odorant receptors (ORs) ultimately affecting olfactory-driven behaviors. We describe the molecular effects of ten insect repellents and a pyrethroid insecticide with known...

  9. Evaluation of Hexane Extract of Tuber of Root of Cyperus rotundus Linn (Cyperaceae) for Repellency against Mosquito Vectors

    PubMed Central

    Singh, S. P.; Raghavendra, K.; Dash, A. P.

    2009-01-01

    Hexane extract of tuber of plant Cyperus rotundus (Cyperaceae) was screened under laboratory conditions for repellent activity against mosquito vector Anopheles culicifacies Giles species A (Diptera: Culicidae), Anopheles stephensi Liston (Diptera: Culicidae), and Culex quinquefasciatus Say (Diptera: Culicidae). The Cyperus rotundus tuber extract was used to determine their effect on mosquito vector, and comparison with the DEET (NN Diethyl 1-3 methyl Benzamide, formerly known as diethyl 1-m-toluamide). The tuber extracts showed more effective at all the dose. Result obtained from the laboratory experiment showed that the tuber extracts are more effective for repellency of allthe mosquito vector even at low dose. Clear dose response relationships were established with the highest dose of 10% tuber extract evoking 100% repellency. Percent protection obtained against An. culicifacies Giles species A 100% repellency in 4 hours, 6 hours, An. stephensi 100% repellency in 6 hours and Cx. quinquefasciatus was 100% repellency in 6 hours at the 10% concentration. Against DEET- 2.5% An. culicifacies A 100% repellency in 1 hour, 2 hours, 6 hours, An. stephensi have shown 100% repellency in 6 hours, and Culex quinquefasciatus have shown 100% repellency in 1 hour, 2 hours, 6 hours. The consolidated data of the repellency observed in different species is given and it is evident that the over all repellency rates varied between 80 and 100% for different repellents concentrations (2.5%, 5%, and 10%). The extract can be applied as an effective personal protective measure against mosquito bites. PMID:20798887

  10. [Study on essential oils of medicinal plants in insect repellent].

    PubMed

    Zhao, Hong-Zheng; Luo, Jiao-Yang; Liu, Qiu-Tao; Lv, Ze-Liang; Yang, Shi-Hai; Yang, Mei-Hua

    2016-01-01

    Mosquitoes are seriously harmful to human health for transmitting some mortal diseases. Among the methods of mosquito control, synthetical insecticides are the most popular. However, as a result of longterm use of these insecticides, high resistant mosquitos and heavy environmental pollution appear. Thus, eco-friendly prevention measures are taken into the agenda. Essential oils extracted from medicinal plants have repellent and smoked killing effects on mosquitoes. With abundant medical plants resources and low toxicity, they have the potential of being developed as a new type of mosquito and insect repellent agent. The recent application advances of essential oils of medicinal plants in insect repellent and its application limitations are overviewed. This review will provide references for the future development and in-depth study of essential oils. Copyright© by the Chinese Pharmaceutical Association.

  11. Insect Repellents: Modulators of mosquito odorant receptor activity

    USDA-ARS?s Scientific Manuscript database

    Mosquitoes vector numerous pathogens that cause diseases including malaria, yellow fever, dengue fever and chikungunya. DEET, IR3535, Picaridin and 2-undecanone are insect repellents that are used to prevent interactions between humans and a broad array of disease vectors including mosquitoes. While...

  12. Estimating a mosquito repellent's potential to reduce malaria in communities.

    PubMed

    Kiszewski, A E; Darling, S T

    2010-12-01

    Probability models for assessing a mosquito repellent's potential to reduce malaria transmission are not readily available to public health researchers. To provide a means for estimating the epidemiological efficacy of mosquito repellents in communities, we developed a simple mathematical model. A static probability model is presented to simulate malaria infection in a community during a single transmission season. The model includes five parameters- sporozoite rate, human infection rate, biting pressure, repellent efficacy, and product-acceptance rate. The model assumes that a certain percentage of the population uses a personal mosquito repellent over the course of a seven-month transmission season and that this repellent maintains a constant rate of protective efficacy against the bites of malaria vectors. This model measures the probability of evading infection in circumstances where vector biting pressure, repellent efficacy, and product acceptance may vary. [corrected] Absolute protection using mosquito repellents alone requires high rates of repellent efficacy and product acceptance. [corrected] Using performance data from a highly effective repellent, the model estimates an 88.9% reduction of infections over a seven- month transmission season. A corresponding reduction in the incidence of super-infection in community members not completely evading infection can also be presumed. Thus, the model shows that mass distribution of a repellent with >98% efficacy and >98% product acceptance would suppress new malaria infections to levels lower than those achieved with insecticide treated nets (ITNs). A combination of both interventions could create synergies that result in reductions of disease burden significantly greater than with the use of ITNs alone.

  13. Odorant-binding protein-based identification of natural spatial repellents for the African malaria mosquito Anopheles gambiae.

    PubMed

    Kröber, Thomas; Koussis, Konstantinos; Bourquin, Martine; Tsitoura, Panagiota; Konstantopoulou, Maria; Awolola, Taiwo Sam; Dani, Francesca R; Qiao, Huili; Pelosi, Paolo; Iatrou, Kostas; Guerin, Patrick M

    2018-05-01

    There is increasing interest in the development of effective mosquito repellents of natural origin to reduce transmission of diseases such as malaria and yellow fever. To achieve this we have employed an in vitro competition assay involving odorant-binding proteins (OBPs) of the malaria mosquito, Anopheles gambiae, with a predominantly female expression bias to identify plant essential oils (EOs) containing bioactive compounds that target mosquito olfactory function. EOs and their fractions capable of binding to such OBPs displayed repellence against female mosquitoes in a laboratory repellent assay. Repellent EOs were subjected to gas chromatographic analysis linked to antennogram (EAG) recordings from female A. gambiae to identify the biologically active constituents. Among these compounds cumin alcohol, carvacrol, ethyl cinnamate and butyl cinnamate proved as effective as DEET at an equivalent dose in the repellent assay, and combinations of carvacrol with either butyl cinnamate or cumin alcohol proved to be significantly more effective than DEET in the assay. When tested as spatial repellents in experimental shelters housing sleeping humans in northern Nigeria a binary mixture of carvacrol plus cumin alcohol caused mosquitoes to leave shelters in significantly higher numbers to those induced by DEET in female Anopheles spp. and in numbers equivalent to that of DEET in Culex spp. mosquitoes. These findings indicate an approach for the identification of biologically active molecules of natural origin serving as repellents for mosquitoes. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. A promising azeotrope-like mosquito repellent blend.

    PubMed

    Izadi, Homa; Focke, Walter W; Asaadi, Erfan; Maharaj, Rajendra; Pretorius, Jannie; Loots, Mattheüs Theodor

    2017-08-31

    Topical repellents play a key role in reducing the outdoor transmission of mosquito-borne diseases by reducing human-vector contact. Excellent repellents are available, but there is always room for improvement. This article reports on a particularly effective binary repellent blend of ethyl butylacetylaminopropionate and nonanoic acid. A composition containing 25 mol% of the acid exhibits negative pseudo-azeotrope behaviour at 50 °C, meaning that the liquid vapour pressure is lower than that of the parent compounds and evaporation occurs without a change in the liquid composition. In tests performed using the South African Medical Research Council's cup-on-arm procedure, this mixture provided better protection for a longer time than the "gold standard of mosquito repellents", namely N,N-diethyl-m-toluamide, commonly known as DEET.

  15. Evaluation of a Noncontact, Alternative Mosquito Repellent Assay System.

    PubMed

    Tisgratog, Rungarun; Kongmee, Monthathip; Sanguanpong, Unchalee; Prabaripai, Atchariya; Bangs, Michael J; Chareonviriyaphap, Theeraphap

    2016-09-01

    A novel noncontact repellency assay system (NCRAS) was designed and evaluated as a possible alternative method for testing compounds that repel or inhibit mosquitoes from blood feeding. Deet and Aedes aegypti were used in a controlled laboratory setting. Using 2 study designs, a highly significant difference were seen between deet-treated and untreated skin placed behind the protective screens, indicating that deet was detected and was acting as a deterrence to mosquito landing and probing behavior. However, a 2nd study showed significant differences between protected (behind a metal screen barrier) and unprotected (exposed) deet-treated forearms, indicating the screen mesh might restrict the detection of deet and thus influences landing/biting response. These findings indicate the prototype NCRAS shows good promise but requires further evaluation and possible modification in design and testing protocol to achieve more desirable operational attributes in comparison with direct skin-contact repellency mosquito assays.

  16. Does Zika virus infection affect mosquito response to repellents?

    PubMed Central

    Leal, Walter S.; Barbosa, Rosângela M. R.; Zeng, Fangfang; Faierstein, Gabriel B.; Tan, Kaiming; Paiva, Marcelo H. S.; Guedes, Duschinka R. D.; Crespo, Mônica M.; Ayres, Constância F. J.

    2017-01-01

    The World Health Organization (WHO) recommends that people travelling to or living in areas with Zika virus (ZIKV) outbreaks or epidemics adopt prophylactic measures to reduce or eliminate mosquito bites, including the use of insect repellents. It is, however, unknown whether repellents are effective against ZIKV-infected mosquitoes, in part because of the ethical concerns related to exposing a human subject’s arm to infected mosquitoes in the standard arm-in-cage assay. We used a previously developed, human subject-free behavioural assay, which mimics a human subject to evaluate the top two recommended insect repellents. Our measurements showed that DEET provided significantly higher protection than picaridin provided against noninfected, host-seeking females of the southern house mosquito, Culex quinquefasciatus, and the yellow fever mosquito, Aedes aegypti. When tested at lower doses, we observed a significant reduction in DEET-elicited protection against ZIKV-infected yellow fever mosquitoes from old and recent laboratory colonies. The reduction in protection is more likely associated with aging than the virus infection and could be compensated by applying a 5x higher dose of DEET. A substantial protection against ZIKV-infected and old noninfected mosquitoes was achieved with 5% DEET, which corresponds approximately to a 30% dose in the conventional arm-in-cage assays. PMID:28205633

  17. Lantana montevidensis Essential Oil: Chemical Composition and Mosquito Repellent Activity against Aedes aegypti

    USDA-ARS?s Scientific Manuscript database

    The essential oil (EO) of Lantana montevidensis (Spreng.) Briq. (L. sellowiana Link & Otto) was investigated for its chemical composition and mosquito repellent activity. The essential oil obtained by hydrodistillation of aerial plant parts was analyzed by GC-FID and GC-MS. The major constituents we...

  18. Repellency of Lantana camara (Verbenaceae) flowers against Aedes mosquitoes.

    PubMed

    Dua, V K; Gupta, N C; Pandey, A C; Sharma, V P

    1996-09-01

    The repellent effect of Lantana camara flowers was evaluated against Aedes mosquitoes. Lantana flower extract in coconut oil provided 94.5% protection from Aedes albopictus and Ae. aegypti. The mean protection time was 1.9 h. One application of Lantana flower can provide more than 50% protection up to 4 h against the possible bites of Aedes mosquitoes. No adverse effects of the human volunteers were observed through 3 months after the application.

  19. Repellent and mosquitocidal effects of leaf extracts of Clausena anisata against the Aedes aegypti mosquito (Diptera: Culicidae).

    PubMed

    Mukandiwa, Lillian; Eloff, Jacobus Nicolaas; Naidoo, Vinny

    2016-06-01

    Mosquitoes are rapidly developing resistance to insecticides that millions of people relied on to protect themselves from the diseases they carry, thereby creating a need to develop new insecticides. Clausena anisata is used traditionally as an insect repellent by various communities in Africa and Asia. For this study, the repellency and adulticidal activities of leaf extracts and compounds isolated from this plant species were evaluated against the yellow fever mosquito, Aedes aegypti. In the topical application assays, using total bites as an indicator, repellency was dose dependent, with the acetone crude extract (15 %) having 93 % repellence and the hexane fraction (7.5 %) 67 % repellence after 3 h. Fractionation resulted in a loss of total repellence. As mosquito-net treating agents, the acetone and hexane extracts of C. anisata, both at 15 %, had average repellences of 46.89 ± 2.95 and 50.13 ± 2.02 %, respectively, 3 h after exposure. The C. anisata acetone extract and its hexane fraction caused mosquito knockdown and eventually death when nebulised into the testing chamber, with an EC50 of 78.9 mg/ml (7.89 %) and 71.6 mg/ml (7.16 %) in the first 15 min after spraying. C. anisata leaf extracts have potential to be included in protection products against mosquitoes due to the repellent and cidal compounds contained therein.

  20. Traditional use of mosquito-repellent plants in western Kenya and their evaluation in semi-field experimental huts against Anopheles gambiae: ethnobotanical studies and application by thermal expulsion and direct burning.

    PubMed

    Seyoum, A; Pålsson, K; Kung'a, S; Kabiru, E W; Lwande, W; Killeen, G F; Hassanali, A; Knols, B G J

    2002-01-01

    Ethnobotanical survey in 2 communities in western Kenya revealed that the most commonly known repellent plants were Ocimum americanum L. (64.1%), Lantana camara L. (17.9%), Tagetes minuta L. (11.3%) and Azadirachta indica A. Juss (8.7%) on Rusinga Island, and Hyptis suaveolens Poit. (49.2%), L. camara (30.9%) and O. basilicum L. (30.4%) in Rambira. Direct burning of plants is the most common method of application for O. americanum (68.8%), L. camara (100%) and O. basilicum (58.8%). Placing branches or whole plants inside houses is most common for H. suaveolens (33.3 and 57.8% for the respective locations), A. indica (66.7 and 100%), and T. minuta (54.8 and 56.0%). The repellency of plants suggested by the ethnobotanical survey and other empirical information was evaluated against the malaria vector Anopheles gambiae s.s. Giles in experimental huts within a screenwalled greenhouse. Thermal expulsion and direct burning were tested as alternative application methods for the selected plants O. americanum, O. kilimandscharicum Guerke, O. suave Willd., L. camara, A. indica, H. suaveolens, Lippia uckambensis Spreng and Corymbia citriodora Hook. When thermally expelled, only H. suaveolens failed to repel mosquitoes, whereas the leaves of C. citriodora (74.5%, P < 0.0001), leaves and seeds of O. suave (53.1%, P < 0.0001) and O. kilimandscharicum (52.0%, P < 0.0001) were the most effective. Leaves of C. citriodora also exhibited the highest repellency (51.3%, P < 0.0001) by direct burning, followed by leaves of L. uckambensis (33.4%, P = 0.0004) and leaves and seeds of O. suave (28.0%, P = 0.0255). The combination of O. kilimandscharicum with L. uckambensis repelled 54.8% of mosquitoes (P < 0.0001) by thermal expulsion. No combination of plants increased repellency by either method. The semi-field system described appears a promising alternative to full-field trials for screening large numbers of candidate repellents without risk of malaria exposure.

  1. Field evaluation of New Mountain Sandalwood Mosquito Sticks and New Mountain Sandalwood Botanical Repellent against mosquitoes in North Queensland, Australia.

    PubMed

    Ritchie, Scott A; Williams, Craig R; Montgomery, Brian L

    2006-03-01

    The mosquito repellent efficacy of New Mountain Sandalwood Mosquito Sticks (containing 0.5% w/w essential oils) and New Mountain Sandalwood Botanical Repellent (containing soybean and geranium oils) was assessed. Tests were conducted in the field with 4 volunteers in a wooded area near Cairns, North Queensland, Australia. Predominant biting species were Verrallina funerea and Ve. lineata. A pair of burning Mosquito Sticks immediately upwind of the subject (acting as an area repellent) provided a 73.1% mean reduction in mosquito landing and probing over the 3-h test period. The Botanical Repellent and a DEET-based control were both 100% effective in preventing mosquito probing for 3 h. These data are consistent with other studies of area repellents in that such products provide significant protection from mosquito bites, albeit inferior to the protection provided by topically applied repellents.

  2. Aqueous 2% geraniol as a mosquito repellent failed against Aedes aegypti on ponies.

    PubMed

    Reeves, Will K; Miller, Myrna M

    2010-09-01

    Organic insect repellents are of interest to many agricultural producers and animal owners. Geraniol, a plant-derived alcohol, is naturally produced by a wide range of plants and is a US Environmental Protection Agency minimum risk pesticide. Previous studies have shown various concentrations of geraniol repel or kill mosquitoes; however, geraniol might cause allergic contact dermatitis in humans or animals. We tested a commercially available 2% aqueous solution of geraniol on ponies as a mosquito repellent. Five trials were conducted on ponies treated with a 60-ml aerosol mist (30 ml per side) of 2% geraniol or as untreated controls. Animals were observed 3 h postapplication to check for skin irritation. Aedes aegypti, in feeding tubes, were held on the ponies for 7 min. The average percent of biting on control animals was 56%, with a range of 16-90%, and the average for the treatments was 13%, with a range of 0-86%. Based on statistical models, there was no significant difference (P = 0.081) in the percent bites between treated and untreated animals after 3 h. Based on our data, 2% geraniol was not an adequate mosquito repellent for horses. We did not observe any skin irritation on the animals treated with 2% geraniol.

  3. Current and Future Repellent Technologies: The Potential of Spatial Repellents and Their Place in Mosquito-Borne Disease Control.

    PubMed

    Norris, Edmund J; Coats, Joel R

    2017-01-29

    Every year, approximately 700,000 people die from complications associated with etiologic disease agents transmitted by mosquitoes. While insecticide-based vector control strategies are important for the management of mosquito-borne diseases, insecticide-resistance and other logistical hurdles may lower the efficacy of this approach, especially in developing countries. Repellent technologies represent another fundamental aspect of preventing mosquito-borne disease transmission. Among these technologies, spatial repellents are promising alternatives to the currently utilized contact repellents and may significantly aid in the prevention of mosquito-borne disease if properly incorporated into integrated pest management approaches. As their deployment would not rely on prohibitively expensive or impractical novel accessory technologies and resources, they have potential utility in developing countries where the burden of mosquito-borne disease is most prevalent. This review aims to describe the history of various repellent technologies, highlight the potential of repellent technologies in preventing the spread of mosquito-borne disease, and discuss currently known mechanisms that confer resistance to current contact and spatial repellents, which may lead to the failures of these repellents. In the subsequent section, current and future research projects aimed at exploring long-lasting non-pyrethroid spatial repellent molecules along with new paradigms and rationale for their development will be discussed.

  4. Current and Future Repellent Technologies: The Potential of Spatial Repellents and Their Place in Mosquito-Borne Disease Control

    PubMed Central

    Norris, Edmund J.; Coats, Joel R.

    2017-01-01

    Every year, approximately 700,000 people die from complications associated with etiologic disease agents transmitted by mosquitoes. While insecticide-based vector control strategies are important for the management of mosquito-borne diseases, insecticide-resistance and other logistical hurdles may lower the efficacy of this approach, especially in developing countries. Repellent technologies represent another fundamental aspect of preventing mosquito-borne disease transmission. Among these technologies, spatial repellents are promising alternatives to the currently utilized contact repellents and may significantly aid in the prevention of mosquito-borne disease if properly incorporated into integrated pest management approaches. As their deployment would not rely on prohibitively expensive or impractical novel accessory technologies and resources, they have potential utility in developing countries where the burden of mosquito-borne disease is most prevalent. This review aims to describe the history of various repellent technologies, highlight the potential of repellent technologies in preventing the spread of mosquito-borne disease, and discuss currently known mechanisms that confer resistance to current contact and spatial repellents, which may lead to the failures of these repellents. In the subsequent section, current and future research projects aimed at exploring long-lasting non-pyrethroid spatial repellent molecules along with new paradigms and rationale for their development will be discussed. PMID:28146066

  5. Relative efficacy of various oils in repelling mosquitoes.

    PubMed

    Ansari, M A; Razdan, R K

    1995-09-01

    Field studies were carried out to determine the relative efficacy of repellant action of vegetable, essential and chemical base oils against vector mosquitoes. Results revealed that essential oils viz. Cymbopogan martinii martinii var. Sofia (palmarosa), Cymbopogan citratus (lemon grass) and Cymbopogan nardus (citronella) oils are as effective as chemical base oil namely mylol. These oils provide almost complete protection against Anopheles culicifacies and other anopheline species. Per cent protection against Culex quinquefasciatus ranged between 95-96%. Camphor (C. camphora) oil also showed repellent action and provided 97.6% protection against An. culicifacies and 80.7% against Cx. quinquefasciatus. Vegetable oils namely mustard (B. compestris) and coconut (C. nucisera) showed repellent action, however the efficacy of these oils was not much pronounced against Cx. quinquefasciatus. Results of statistical analysis revealed significant difference between vegetable and essential oils (p < 0.01) against tested species of mosquitoes. Essential oils were found marginally superior in repellancy than camphor and mylol (p < 0.01) against An. culicifacies and Cx. quinquefasciatus.

  6. Repellent effect of microencapsulated essential oil in lotion formulation against mosquito bites.

    PubMed

    Misni, Norashiqin; Nor, Zurainee Mohamed; Ahmad, Rohani

    2017-01-01

    repellent effect of the essential oils, suggesting that the ME formulation of essential oils have potential to be commercialized as an alternative plant-based repellent in the market against the mosquitoes.

  7. Field Evaluation of Four Spatial Repellent Devices Against Arkansas Rice-Land Mosquitoes

    DTIC Science & Technology

    2014-03-01

    FIELD EVALUATION OF FOUR SPATIAL REPELLENT DEVICES AGAINST ARKANSAS RICE-LAND MOSQUITOES DAVID A. DAME,1 MAX V. MEISCH,2 CAROLYN N. LEWIS,2 DANIEL L... mosquitoes to locate a host. There are many commercially available spatial repellent products currently on the market. These products include...a large rice growing area where late-spring and summer agricultural irriga- tion generates dense mosquito populations. Spatial repellent devices

  8. REPELLENT EFFECT OF OCIMUM BASILICUM AND GLYCYRRHIZA GLABRA EXTRACTS AGAINST THE MOSQUITO VECTOR, CULEX PIPIENS (DIPTERA: CULICIDAE).

    PubMed

    Hassan, Mostafa I; Hammad, Kotb M; Saeed, Saeed M

    2015-08-01

    Essential or volatile oils of plants have been variously reported to have many medicinal applications. Methanol, acetone and petroleum ether extracts of Ocimum basilicum and Glycyrrhiza glabra were screened for their repellency effect against Culex pipiens mosquito. The repellent action of the present plants extracts were varied depending on the solvent used and dose of extract. Methanol extract of O. basilicum exhibited the lowest repellent activity as it recorded 77.4% at 6.7mg/cm2. The petroleum ether and acetone extract of 0. basilicum showed repellency of 98.1 & 84.6% respectively, at dose of 6.7mg/cm2, while methanolic extract of G. glabra recorded 73.8 & 50.3% at dose of 6.7 &1.7mg/cm2 respectively, the petroleum ether and acetone extract of G. glabra showed repellency of 76.3 & 81.6%, respectively at dose of 6.7mg/cm2, compared with the commercial formulation, N.N. diethyl toulamide (DEET) which exhibited 100% repellent action at dose of 1.8mg/cm2, respectively. The results may contribute to design an alternative way to control mosquitoes currently based on applications of synthetic insecticides. These extracts could be developed commercially as an effective personal protection meaure against mosquito bites and thus to control diseases caused by mosquito-borne pathogens.

  9. Constituents of the Essential Oil of Suregada zanzibariensis Leaves are Repellent to the Mosquito, Anopheles gambiae s.s.

    PubMed Central

    Innocent, Ester; Joseph, Cosam C.; Gikonyo, Nicholas K.; Nkunya, Mayunga H.H.; Hassanali, Ahmed

    2010-01-01

    In traditional African communities, repellent volatiles from certain plants generated by direct burning or by thermal expulsion have played an important role in protecting households against vectors of malaria and other diseases. Previous research on volatile constituents of plants has shown that some are good sources of potent mosquito repellents. In this bioprospecting initiative, the essential oil of leaves of the tree, Suregada zanzibariensis Verdc. (Angiospermae: Euphobiaceae) was tested against the mosquito, Anopheles gambiae s.s. Giles (Diptera: Culicidae) and found to be repellent. Gas chromatography (GC), GC-linked mass spectrometry (GC-MS) and, where possible, GC-co-injections with authentic compounds, led to the identification of about 34 compounds in the essential oil. About 56% of the constituents were terpenoid ketones, mostly methyl ketones. Phenylacetaldehyde (14.4%), artemisia ketone (10.1%), (1S)-(-)-verbenone (12.1%) and geranyl acetone (9.4%) were the main constituents. Apart from phenylacetaldehyde, repellent activities of the other main constituents were higher than that of the essential oil. The blends of the main constituents in proportions found in the essential oil were more repellent to An. gambiae s.s. than was the parent oil (p < 0.05), and the presence of artemisia ketone in the blend caused a significant increase in the repellency of the resulting blend. These results suggested that blends of some terpenoid ketones can serve as effective An. gambiae s.s. mosquito repellents. PMID:20569134

  10. Constituents of the essential oil of Suregada zanzibariensis leaves are repellent to the mosquito, Anopheles gambiae s.s.

    PubMed

    Innocent, Ester; Joseph, Cosam C; Gikonyo, Nicholas K; Nkunya, Mayunga H H; Hassanali, Ahmed

    2010-01-01

    In traditional African communities, repellent volatiles from certain plants generated by direct burning or by thermal expulsion have played an important role in protecting households against vectors of malaria and other diseases. Previous research on volatile constituents of plants has shown that some are good sources of potent mosquito repellents. In this bioprospecting initiative, the essential oil of leaves of the tree, Suregada zanzibariensis Verdc. (Angiospermae: Euphobiaceae) was tested against the mosquito, Anopheles gambiae s.s. Giles (Diptera: Culicidae) and found to be repellent. Gas chromatography (GC), GC-linked mass spectrometry (GC-MS) and, where possible, GC-co-injections with authentic compounds, led to the identification of about 34 compounds in the essential oil. About 56% of the constituents were terpenoid ketones, mostly methyl ketones. Phenylacetaldehyde (14.4%), artemisia ketone (10.1%), (1S)-(-)-verbenone (12.1%) and geranyl acetone (9.4%) were the main constituents. Apart from phenylacetaldehyde, repellent activities of the other main constituents were higher than that of the essential oil. The blends of the main constituents in proportions found in the essential oil were more repellent to An. gambiae s.s. than was the parent oil (p < 0.05), and the presence of artemisia ketone in the blend caused a significant increase in the repellency of the resulting blend. These results suggested that blends of some terpenoid ketones can serve as effective An. gambiae s.s. mosquito repellents.

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

    PubMed

    Coro, F; Suárez, S

    1998-01-01

    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.

  12. Plant-based insect repellents: a review of their efficacy, development and testing

    PubMed Central

    2011-01-01

    Plant-based repellents have been used for generations in traditional practice as a personal protection measure against host-seeking mosquitoes. Knowledge on traditional repellent plants obtained through ethnobotanical studies is a valuable resource for the development of new natural products. Recently, commercial repellent products containing plant-based ingredients have gained increasing popularity among consumers, as these are commonly perceived as “safe” in comparison to long-established synthetic repellents although this is sometimes a misconception. To date insufficient studies have followed standard WHO Pesticide Evaluation Scheme guidelines for repellent testing. There is a need for further standardized studies in order to better evaluate repellent compounds and develop new products that offer high repellency as well as good consumer safety. This paper presents a summary of recent information on testing, efficacy and safety of plant-based repellents as well as promising new developments in the field. PMID:21411012

  13. Microencapsulated citronella oil for mosquito repellent finishing of cotton textiles.

    PubMed

    Specos, M M Miró; García, J J; Tornesello, J; Marino, P; Vecchia, M Della; Tesoriero, M V Defain; Hermida, L G

    2010-10-01

    Microcapsules containing citronella essential oil were prepared by complex coacervation and applied to cotton textiles in order to study the repellent efficacy of the obtained fabrics. Citronella released from treated textiles was indirectly monitored by the extractable content of its main components. Repellent activity was assessed by exposure of a human hand and arm covered with the treated textiles to Aedes aegypti mosquitoes. Fabrics treated with microencapsulated citronella presented a higher and longer lasting protection from insects compared to fabrics sprayed with an ethanol solution of the essential oil, assuring a repellent effect higher than 90% for three weeks. Complex coacervation is a simple, low cost, scalable and reproducible method of obtaining encapsulated essential oils for textile application. Repellent textiles were achieved by padding cotton fabrics with microcapsules slurries using a conventional pad-dry method. This methodology requires no additional investment for textile finishing industries, which is a desirable factor in developing countries. Copyright © 2010 Royal Society of Tropical Medicine and Hygiene.

  14. Ethnobotanical knowledge on botanical repellents employed in the African region against mosquito vectors - A review.

    PubMed

    Pavela, Roman; Benelli, Giovanni

    2016-08-01

    Mosquitoes (Diptera: Culicidae) represent a huge threat for millions of humans and animals worldwide, since they act as vectors for important parasites and pathogens, including malaria, filariasis and important arboviruses, such as dengue, West Nile and Zika virus. No vaccines or other specific treatments are available against the arboviruses transmitted by mosquitoes, and avoidance of mosquito bites remains the best strategy. African regions are usually hit most whose inhabitants are poor, and the use of repellent plants is the only efficient protection against vectors they have. Ethnobotanical knowledge of such plants and their use is usually passed on orally from one generation to another. However, it is also important to preserve this information in a written form, as well. Ethnobotanical research projects carried out in the regions of today's Ethiopia, South Africa, Nigeria, Kenya, and Tanzania indicate that the native inhabitants of the African study regions traditionally use 64 plant species, belonging to 30 families. Aromatic plants (i.e., Citrus spp., Eucalyptus spp., Lantana camara, Ocimum spp. and Lippia javanica) the most commonly used in all the study regions. Native people know three major methods of using repellent plants: (i) production of repellent smoke from burning plants, (ii) hanging plants inside the house or sprinkling leaves on the floor, (iii) the use of plant oils, juices from crushed fresh parts of the plants, or various prepared extracts applied on uncovered body parts. Overall, this review covers studies conducted only in a limited part of the African continent, highlighting the importance to undertake further research efforts to preserve the unique knowledge and traditions of the native tribes. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Insect Repellents: Modulators of Mosquito Odorant Receptor Activity

    DTIC Science & Technology

    2010-08-01

    Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Plant Sciences Institute, Agricultural Research Service, United States Department...origin. 2-U is a naturally occurring compound produced by the glandular trichomes of wild tomato plants as part of a plant defense mechanism against...antennal OSNs responding to carboxylic acids and monoterpenes [23]. In our study, we investigate the action of 4 insect repellents on the activities of

  16. Natural insect repellents: activitity against mosquitoes and cockroaches

    Treesearch

    Gretchen Schultz; Chris Peterson; Joel Coats

    2006-01-01

    Recent research has focused on the repellent properties of extracts from the catnip plant (Nepeta cataria) and the Osage orange (Maclura pornifera) fruit. This chapter includes results on German cockroach (Blattella germanica), and house fly (Musca domestics) contact irritancy to catnip...

  17. Repellency effect of forty-one essential oils against Aedes, Anopheles, and Culex mosquitoes.

    PubMed

    Amer, Abdelkrim; Mehlhorn, Heinz

    2006-09-01

    Since ancient times, plant products were used in various aspects. However, their use against pests decreased when chemical products became developed. Recently, concerns increased with respect to public health and environmental security requiring detection of natural products that may be used against insect pests. In this study, 41 plant extracts and 11 oil mixtures were evaluated against the yellow fever mosquito, Aedes aegypti (Linnaeus), the malaria vector, Anopheles stephensi (Liston), and the filariasis and encephalitis vector, Culex quinquefasciatus (Say) (Diptera: Culicidae) using the skin of human volunteers to find out the protection time and repellency. The five most effective oils were those of Litsea (Litsea cubeba), Cajeput (Melaleuca leucadendron), Niaouli (Melaleuca quinquenervia), Violet (Viola odorata), and Catnip (Nepeta cataria), which induced a protection time of 8 h at the maximum and a 100% repellency against all three species. This effect needs, however, a peculiar formulation to fix them on the human skin.

  18. A new in vitro bioassay system for discovery and quantitative evaluation of mosquito repellents

    USDA-ARS?s Scientific Manuscript database

    Mosquitoes are vectors of many pathogens that cause human diseases. Although prevention and control of immature stages is the best method to control mosquitoes, repellents play a significant role in reducing the risk of these diseases by preventing mosquito bites. The In vitro K & D bioassay system ...

  19. A Novel in vitro Bioassay to Explore the Repellent Effects of Compounds Against Mosquito Aedes aegypti (Diptera: Culicidae).

    PubMed

    Rehman, Junaid U; Tabanca, Nurhayat; Khan, Ikhlas A

    2016-01-01

    Mosquitoes are vectors for many pathogens resulting in many deaths of humans. Repellents play an important role in reducing mosquito bites and the spread of mosquito-borne diseases. Currently, Klun & Debboun (K & D) and human-arm-based bioassay systems are used to identify repellent properties of compounds, extracts, and essential oils. Risks involved with human-arm-based systems are allergic reactions and limited replicates. We are reporting an in vitro bioassay method “NCNPR repellent bioassay (NCNPR-RB)” that can closely simulate the results of the cloth patch bioassay system used to determine repellency against mosquitoes. The NCNPRRB method uses heat to attract mosquito and edible collagen sheets as an alternate to human skin. Multiple plant compounds with documented repellency were tested. DEET (N,N-diethyl-3-methylbenzamide) was used as a positive control. Treatments were prepared in EtOH and applied in dosages ranging from 0.011–1.5mg/cm2 to a 20-cm2 collagen sheet. The number of mosquitoes commencing to bite per probe was recorded visually for 1 min. The minimum effective dosage (mg/cm2) of compounds: DEET (0.021), carvacrol (0.011), thymol (0.013), undecanoic acid (0.023), thymol methyl ether (0.269), and 2-nonanone (>0.375 mg/cm2) determined in NCNPRRB were similar to those reported in literature using a cloth patch bioassay system. The NCNPR-RB can be used to screen compounds with reasonable reproducibility of the data at a faster rate than the cloth patch bioassay, which involves the use of human subjects.

  20. Essential oil based polymeric patch development and evaluating its repellent activity against mosquitoes.

    PubMed

    Chattopadhyay, Pronobesh; Dhiman, Sunil; Borah, Somi; Rabha, Bipul; Chaurasia, Aashwin Kumar; Veer, Vijay

    2015-07-01

    Essential oil based insect repellents are environment friendly and provide dependable personal protection against the bites of mosquitoes and other blood-sucking insects. In the present study, optimized mixture of three essential oils was embedded into the ethylcellulose (EC) and polyvinylpyrrolidone (PVP K-30) polymers to develop essential oils based patch type mosquito repellent formulation. The developed formulation was characterized for various physico-chemical properties, oil release efficiency and essential oil-polymer interaction. Repellent activity of the formulation was evaluated against Ae. (S) albopictus mosquitoes and compared with commercially available synthetic insecticide based mosquito repellent cream Odomos(®) in the laboratory. The developed patches were 100% flat and there was no interaction between oil components and the excipients. Patches were smooth, homogenous and provided excellent mosquito repellent activity comparable to Odomos(®) under laboratory condition. Morphological and physico-chemical characterization indicated that the formulation was stable and suitable with the polymeric combination. The patch formulation did not show any inhalation toxicity in experimental Wistar rat. The repellent patches developed and evaluated currently, may provide a suitable, eco-friendly, acceptable and safe alternative to the existing synthetic repellent formulations for achieving protection against mosquitoes. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. [Evaluation of effectiveness of several repellents against mosquito bites available at the Polish market].

    PubMed

    Mikulak, Ewa; Gliniewicz, Aleksandra; Królasik, Agnieszka; Sawicka, Bozena; Rabczenko, Daniel

    2012-01-01

    BACKGROUND. Mosquitoes are blood-sucking insects, nuisance to humans and animals. Their bites cause itching and allergic reactions. These insects are also vectors of several viruses, bacteria and parasites. Protection against mosquitoes is therefore justified and desirable. This can give repellents and products for protection small outdoor areas such as terraces, home gardens. OBJECTIVE. The aim of this study was to evaluate the effectiveness of eight selected products with different formulations used against mosquitoes including: 5 preparations for use on the body or clothing (repellents A, B, C, D, E and 3 products for use in small outdoor spaces (I, J, K). [corrected] Repellents were tested in laboratory trials, when volunteers were exposed to Aedes aegypti females breeding in the laboratory. Products I, J, K were tested in field trials; volunteers were exposed to female mosquitoes at various ages from the environment (Aedes sp, Culex sp). The results showed that all tested repellents were efficient during 4 hrs. After this time their effectiveness decreased--fast in the case of repellent B (10% DEET), not very fast, but significant--in the case of repellent C (15% DEET). Three products for small area protection gave (each of them) 3-hour protection against mosquito bites. Product K (21,97% allethrin) was 100% effective (no bites at all). Both kinds of product can give effective protection against mosquito bites. Their use is most effective, cheaper and more safe for the environment method of protection against mosquitoes than chemical spraying of large areas.

  2. Celery-based topical repellents as a potential natural alternative for personal protection against mosquitoes.

    PubMed

    Tuetun, B; Choochote, W; Pongpaibul, Y; Junkum, A; Kanjanapothi, D; Chaithong, U; Jitpakdi, A; Riyong, D; Pitasawat, B

    2008-12-01

    Celery-based products were investigated for chemical composition, skin irritation, and mosquito repellency in comparison to commercial repellents and the standard chemical, N,N-diethyl-3-methylbenzamide (DEET), with a goal to develop a natural alternative to synthetic repellents for protection against mosquitoes. Chemical identification by gas chromatography coupled with mass spectrometry discovered that the major constituents of Apium graveolens hexane extract (AHE) were 3-n-butyl-tetrahydrophthalide (92.48%), followed by 5.10% beta-selinene and 0.68% gamma-selinene. Evaluation of skin irritation in 27 human volunteers revealed no irritant potential from 25% ethanolic AHE solution. Laboratory investigated repellent against female Aedes aegypti mosquitoes demonstrated that G10 formula, the best AHE-developed product, provided remarkable repellency with a median protection time of 4.5 h (4.5-5 h), which was greater than that of ethanolic DEET solution (25% DEET, 3.5 h) and comparable to that of the best commercial repellent, Insect Block 28 (28.5% DEET, 4.5 h). According to significantly promising results, including highly effective repellency and no potential skin irritation or other side effects, the G10 formula is a worthwhile product that has the promise of being developed for commercialized registration. This developed AHE product could be an acceptable and affordable alternative to conventional synthetic chemicals in preventing mosquito bites, and in turn, helping to interrupt mosquito-borne disease transmission.

  3. MODELING, SYNTHESIS AND BIOASSAY OF ACYLPIPERIDINES AND CARBOXAMIDES AS IMPROVED MOSQUITO REPELLENTS

    USDA-ARS?s Scientific Manuscript database

    Novel mosquito repellents are being designed through collaborative research between the United States Department of Agriculture (USDA)-Agricultural Research Service and the University of Florida, Department of Chemistry. The approach involves state-of-the-art modeling, organic synthesis, and repell...

  4. Spatial repellents on strips of camouflage netting reduce mosquito collections in a field environment

    USDA-ARS?s Scientific Manuscript database

    Barrier treatments can be effective in reducing host seeking mosquito vectors and provide an additional layer of passive defense, reducing disease risk. Devices designed to release spatial repellents or direct application of spatial repellents to artificial surfaces can serve as efficient barriers r...

  5. Traditional use of indigenous mosquito-repellents to protect humans against mosquitoes and other insect bites in a rural community of Cameroon.

    PubMed

    Ntonifor, N N; Ngufor, C A; Kimbi, H K; Oben, B O

    2006-10-01

    To document and test the efficacy of indigenous traditional personal protection methods against mosquito bites and general nuisance. A prospective study based on a survey and field evaluation of selected plant-based personal protection methods against mosquito bites. Bolifamba, a rural setting of the Mount Cameroon region. A structured questionnaire was administered to 179 respondents and two anti-mosquito measures were tested under field conditions. Identified traditional anti-mosquito methods used by indigenes of Bolifamba. Two plants tested under field conditions were found to be effective. Of the 179 respondents, 88 (49.16%) used traditional anti-mosquito methods; 57 (64.77%) used plant-based methods while 31 (35.2%) used various petroleum oils. The rest of the respondents, 91 (50.8%) used conventional personal protection methods. Reasons for using traditional methods were because they were available, affordable and lack of known more effective alternatives. The demerits of these methods were: labourious to implement, stain dresses, produce a lot of smoke/ repulsive odours when used; those of conventional methods were lack of adequate information about them, high cost and non-availability. When the two most frequently used plants, Saccharum officinarium and Ocimum basilicum were evaluated under field conditions, each gave a better protection than the control. Most plants used against mosquitoes in the area are known potent mosquito repellents but others identified in the study warrant further research. The two tested under field conditions were effective though less than the commonly used commercial diethyltoluamide.

  6. Larvicidal and repellent properties of Adansonia digitata against medically important human malarial vector mosquito Anopheles stephensi (Diptera: Culicidae).

    PubMed

    Krishnappa, K; Elumalai, K; Dhanasekaran, S; Gokulakrishnan, J

    2012-06-01

    Development of plant-based alternative compounds for mosquito control has gained importance now-a-days, in view of increasing resistance in mosquito vectors to existing insecticides. The larvicidal and repellent activities of benzene, chloroform, hexane and methanol leaf extracts of Indian medicinal plant, Adansonia digitata were investigated against malarial vector, Anopheles stephensi. In all, 25 III instar larvae of An. stephensi were exposed to various concentrations (30-180 mg/l) in the laboratory by using the standard protocol described by WHO (2005). The larvae were exposed for 24 h and mortalities were subjected to log-probit analysis. Repellent activity of crude leaf extract at the dosages of 2, 4 and 6 mg/cm2 was evaluated in a net cage (45 × 30 × 45 cm) containing 100 blood starved female mosquitoes of An. stephensi using the protocol of WHO (1996). Preliminary phytochemical analysis of A. digitata showed the presence of triterpenoids and saponins. The LC50 and LC90 values of hexane, benzene, chloroform, and methanol extracts of A. digitata against An. stephensi larvae in 24 h were 111.32, 97.13, 88.55, 78.18 and 178.63, 176.19, 168.14, 155.42 mg/l, respectively. The repellent activity of methanol extract was found to be most effective and at higher concentration of 6 mg/cm2 benzene, chloroform hexane and methanol extracts provided 100% protection up to 150, 180, 120 and 210 min against An. stephensi, respectively. The preliminary study indicated that A. digitata showed larvicidal and repellent activities against An. stephensi and could be used for controlling mosquitoes. Further studies are indicated to purify the active compounds from these plants for developing larvicide and repellents.

  7. Insecticidal and repellent activity of Hiptage benghalensis L. Kruz (Malpighiaceae) against mosquito vectors.

    PubMed

    Lalrotluanga; Ngente, Lalchawimawii; Nachimuthu, Senthil Kumar; Guruswami, Gurusubramanian

    2012-09-01

    Plant-based insecticides for vector control are urgently needed for Anopheles barbirostris, Culex quinquefasciatus, and Aedes albopictus which are the primary vectors of malaria, lymphatic filariasis, and dengue, respectively, in India and other South East Asian countries. In the present study, larvicidal, adulticidal, and repellent activities of acetone root bark extract of Hiptage benghalensis were tested against the larvae and adults of the three mosquito vectors. The acetone root bark extracts of H. benghalensis was more effective as larvicides with low LC(50) (11.15-16.78 ppm) and LT50 (1.25-4.84 h at 200 and 400 ppm) values. Results of log probit analysis (at 95 % confidence level) and regression analysis of crude acetone root bark extract of H. benghalensis revealed that lethal concentration (LC(50)) values gradually decreased with the exposure periods; lethal time (LT(50)) decreased with the concentration, and the mortality is positively correlated with the concentration. The order of susceptibility of the three mosquito species was as follows: A. albopictus > A. barbirostris > C. quinquefascitus. Biochemical changes were also evidenced in third instar larvae of three mosquito species following a sublethal exposure for 24 h. The level of sugar, glycogen, lipids, and proteins was significantly (P < 0.05) reduced in larvae treated with H. benghalensis. The acetone root bark extracts of H. benghalensis is less toxic to adults and repelled laboratory-reared female A. barbirostris, A. albopictus, and C. quinquefascitus with the short median protection times of 57.66-135, 72.41-134.16, and 47.66-93 min, respectively. The present investigation proves it as a potent larvicide against A. albopictus, A. barbirostris, and C. quinquefascitus, which can be recommended to control these mosquito species on its breeding site. However, further investigations are needed to confirm the lethal effects of H. benghalensis in field conditions and its impact on the nontarget

  8. Gustatory receptor neuron responds to chemically diverse insect repellents in the common malaria mosquito Anopheles quadrimaculatus

    USDA-ARS?s Scientific Manuscript database

    Female mosquitoes feed on blood from animal hosts to obtain nutritional resources used for egg production. These contacts facilitate the spread of harmful human diseases. Chemical repellents are used to disrupt mosquito host seeking and blood feeding behaviors; however, little is known about the g...

  9. Repellent Activity of TRIG (N-N Diethyl Benzamide) against Man-Biting Mosquitoes.

    PubMed

    Msangi, Shandala; Kweka, Eliningaya; Mahande, Aneth

    2018-01-01

    A study was conducted to assess efficacy of a new repellent brand TRIG (15% N-N Diethyl Benzamide) when compared to DEET (20% N-N Methyl Toluamide). The repellents were tested in laboratory and field. In the laboratory, the repellence was tested on human volunteers, by exposing their repellent-treated arms on starved mosquitoes in cages for 3 minutes at hourly intervals, while counting the landing and probing attempts. Anopheles gambiae and Aedes aegypti mosquitoes were used. Field evaluation was conducted by Human Landing Catch technique. During the night, the repellents were applied on arms and legs and mosquitoes landing on these areas were collected. In laboratory tests, TRIG provided complete protection (100%) against Anopheles gambiae when applied at 1.25 g, while DEET provided this at 0.75 g. When tested on Aedes aegypti, TRIG provided complete protection when applied at 1 g, compared to 0.5 g for DEET. In the field, when applied at a recommended dose, both TRIG and DEET achieved above 90% protection against both An. arabiensis and Culex quinquefasciatus and a Complete Protection Time of about 6 hrs against both species of mosquitoes. The performances of the two products were found to be comparable and TRIG was recommended for use as repellent against mosquito bites.

  10. Mosquito repellents: An insight into the chronological perspectives and novel discoveries.

    PubMed

    Islam, Johirul; Zaman, Kamaruz; Duarah, Sanjukta; Raju, Pakalapati Srinivas; Chattopadhyay, Pronobesh

    2017-03-01

    Mosquito being the major medically important arthropod vector; requires utmost attention to reduce the sufferings and economic consequences of those living in the endemic regions. This is only possible by minimising the human-mosquito contact by an absolute preventing measure. However, unfortunately, such absolute measures are yet to be developed despite enormous efforts and huge investments worldwide. In the absence of vaccines for number of mosquito-borne diseases, repellents could be an attractive option for both military personal and civilians to minimise the risk of contacting different mosquito-borne diseases. However, to achieve this golden goal, the detailed knowledge of a particular repellent is must, including its mode of repellency and other relevant informations. Here, in the present article, an effort has been made to convey the best and latest information on repellents in order to enhance the knowledge of scientific community. The review offers an overview on mosquito repellents, the novel discoveries, and areas in need of attention such as novel repellent formulations and their future prospective. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Preliminary study on mosquito repellent and mosquitocidal activities of Ocimum gratissimum (L.) grown in eastern Nigeria.

    PubMed

    Oparaocha, Evangeline T; Iwu, Iraneus; Ahanakuc, J E

    2010-03-01

    The study examined the mosquito-repellent and mosquitocidal activities of the volatile oil of Ocimum gratissimum at three different locations (World Bank Estate, Ihitte and Umuekunne) in Imo State, eastern Nigeria, with the purpose of sourcing for mosquito repellent that is cheap, abundant, environment and user-friendly. Four different lotions; 20% (v/v) and 30% (v/v) concentrations each of the extracted volatile oil in two natural oil bases (olive and palm kernel) were made and six volunteered human baits were used to evaluate the mosquito repellent and mosquitocidal activities of the stock materials at the three different centres from September to November 2008. Topical application of each of the four different lotions significantly (p <0.05) reduced the biting rate of mosquitoes in all the three locations tested. The 30% (v/v) concentration in olive oil base exhibiting highest average percentage repellencies of 97.2, 95.7 and 96.3% at World Bank Estate, Ihitte and Umuekunne centres respectively while the 20% (v/v) concentration in palm kernel oil base had the least repellency of 36.3, 41.6 and 36.3%, respectively. The other two formulations had values ranging from 67.8 to 80% in the three locations. The 30% (v/v) concentration in both olive and palm kernel oil bases afforded all night protection against mosquito bites in all the centres, and demonstrated fast knockdown and paralyzing effect on few mosquitoes at the urban centre (World Bank Estate). The study confirms that O. gratissimum grown in eastern Nigeria has mosquito-repellent and mosquitocidal potentials and the formulations could be used to reduce human-mosquito contacts and hence mosquito-borne diseases and irritations caused by their bites.

  12. Mosquito larvicidal, ovicidal, and repellent properties of botanical extracts against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae).

    PubMed

    Govindarajan, M; Mathivanan, T; Elumalai, K; Krishnappa, K; Anandan, A

    2011-08-01

    Mosquito-borne diseases have an economic impact, including loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates; however, no part of the world is free from vector-borne diseases. In mosquito control programs, botanical origin may have the potential to be used successfully as eggs, larvae, and adult. The larvicidal, ovicidal, and repellent activities of crude benzene and ethyl acetate extracts of leaf of Ervatamia coronaria and Caesalpinia pulcherrima were assayed for their toxicity against three important vector mosquitoes, viz., Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in benzene extract of E. coronaria against the larvae of Anopheles Stephensi, Aedes aegypti, and Culex quinquefasciatus with the LC(50) and LC(90) values were 79.08, 89.59, and 96.15 ppm and 150.47, 166.04, and 174.10 ppm, respectively. Mean percent hatchability of the ovicidal activity was observed 48 h posttreatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. The leaf extract of E. coronaria was found to be most effective than Caesalpinia pulcherrima against eggs/egg rafts of three vector mosquitoes. For E. coronaria, the benzene extract exerted 300, 250, and 200 ppm against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, respectively. The results of the repellent activity of benzene and ethyl acetate extract of E. coronaria and Caesalpinia pulcherrima plants at three different concentrations of 1.0, 2.5, and 5.0 mg/cm(2) were applied on skin of fore arm in man and exposed against adult female mosquitoes. In this observation, these two plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the

  13. Synergistic mosquito-repellent activity of Curcuma longa, Pogostemon heyneanus and Zanthoxylum limonella essential oils.

    PubMed

    Das, N G; Dhiman, Sunil; Talukdar, P K; Rabha, Bipul; Goswami, Diganta; Veer, Vijay

    2015-01-01

    Mosquito repellents play an important role in preventing man-mosquito contact. In the present study, we evaluated the synergistic mosquito-repellent activity of Curcuma longa, Pogostemon heyneanus and Zanthoxylum limonella essential oils. The mosquito repellent efficacies of three essential oils were evaluated separately and in combination under laboratory and field conditions. N,N-Diethylphenylacetamide (DEPA) and dimethylphthalate (DMP) were used for comparison of the protection time of the mixture of essential oils. At an optimum concentration of 20%, the essential oils of C. longa, Z. limonella and P. heyneanus provided complete protection times (CPTs) of 96.2, 91.4 and 123.4 min, respectively, against Aedes albopictus mosquitoes in the laboratory. The 1:1:2 mixture of the essential oils provided 329.4 and 391.0 min of CPT in the laboratory and field trials, respectively. The percent increases in CPTs for the essential oil mixture were 30 for DMP and 55 for N,N-diethylphenylacetamide (DEPA). The synergistic repellent activity of the essential oils used in the present study might be useful for developing safer alternatives to synthetic repellents for personal protection against mosquitoes. Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  14. The Mosquito Repellent Citronellal Directly Potentiates Drosophila TRPA1, Facilitating Feeding Suppression.

    PubMed

    Du, Eun Jo; Ahn, Tae Jung; Choi, Min Sung; Kwon, Ilmin; Kim, Hyung-Wook; Kwon, Jae Young; Kang, KyeongJin

    2015-10-01

    Citronellal, a well-known plant-derived mosquito repellent, was previously reported to repel Drosophila melanogaster via olfactory pathways involving but not directly activating Transient Receptor Potential Ankyrin 1 (TRPA1). Here, we show that citronellal is a direct agonist for Drosophila and human TRPA1s (dTRPA1 and hTRPA1) as well as Anopheles gambiae TRPA1 (agTRPA1). Citronellal-induced activity is isoform-dependent for Drosophila and Anopheles gambiae TRPA1s. The recently identified dTRPA1(A) and ag-TRPA1(A) isoforms showed citronellal-provoked currents with EC50s of 1.0 B1 0.2 and 0.1 B1 0.03 mM, respectively, in Xenopus oocytes, while the sensitivities of TRPA1(B)s were much inferior to those of TRPA1(A)s. Citronellal dramatically enhanced the feeding-inhibitory effect of the TRPA1 agonist N-methylmaleimide (NMM) in Drosophila at an NMM concentration that barely repels flies. Thus, citronellal can promote feeding deterrence of fruit flies through direct action on gustatory dTRPA1, revealing the first isoform-specific function for TRPA1(A).

  15. Using Repellent Products to Protect against Mosquito-Borne Illnesses

    MedlinePlus

    ... Illnesses More Information CDC-Avoid Mosquito Bites CDC-Dengue CDC-Zika Virus CDC-Mosquito bite prevention for ... how to protect against the mosquitoes that transmit dengue, Zika, and other viral diseases ( Aedes albopictus and ...

  16. Efficacy of Thai herbal essential oils as green repellent against mosquito vectors.

    PubMed

    Soonwera, Mayura; Phasomkusolsil, Siriporn

    2015-02-01

    Repellency activity of Thai essential oils derived from ylang ylang (Cananga odorata (Lamk.) Hook.f. & Thomson: Annonaceae) and lemongrass (Cymbopogon citratus (DC.) Stapf: Poaceae) were tested against two mosquito vectors, Aedes aegypti (L.) and Culex quinquefasciatus (Say). There were compared with two chemical repellents (DEET 20% w/w; Sketolene Shield(®) and IR3535, ethyl butylacetylaminopropionate 12.5% w/w; Johnson's Baby Clear Lotion Anti-Mosquito(®)). Each herbal repellent was applied in three diluents; coconut oil, soybean oil and olive oil at 0.33 μl/cm(2) on the forearm of volunteers. All herbal repellent exhibited higher repellent activity than IR3535 12.5% w/w, but lower repellent activity than DEET 20% w/w. The C. odorata oil in coconut oil exhibited excellent activity with 98.9% protection from bites of A. aegypti for 88.7±10.4 min. In addition, C. citratus in olive oil showed excellent activity with 98.8% protection from bites of C. quinquefasciatus for 170.0±9.0 min. While, DEET 20% w/w gave protection for 155.0±7.1-182.0±12.2 min and 98.5% protection from bites of two mosquito species. However, all herbal repellent provided lower repellency activity (97.4-98.9% protection for 10.5-88.7 min) against A. aegypti than C. quinquefasciatus (98.3-99.2% protection for 60-170 min). Our data exhibited that C. odorata oil and C. citratus oil are suitable to be used as green repellents for mosquito control, which are safe for humans, domestic animals and environmental friendly. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Field evaluation of repellent formulations containing deet and picaridin against mosquitoes in Northern Territory, Australia.

    PubMed

    Frances, S P; Waterson, D G E; Beebe, N W; Cooper, R D

    2004-05-01

    Field efficacy of repellent formulations containing picaridin (1-methyl-propyl 2-(2-hydroxyethyl)-1-piperidinecarboxylate) or deet (N,N,-diethyl-3-methylbenzamide) against mosquitoes in Northern Territory, Australia, was evaluated. The following repellent treatments were evaluated: 19.2% picaridin (Autan Repel Army 20), a solution of 20% deet in ethanol, and 35% deet in a gel (Australian Defense Force [ADF]). The predominant mosquito species were Culex annulirostris Skuse (57.8%), Anopheles merankensis Venhuis (15.4%), and Anopheles bancroftii Giles (13.2%). The protection provided by repellents against Anopheles spp. was relatively poor, with 19.2% picaridin and ADF deet providing >95% protection for only 1 h, whereas 20% deet provided <95% protection at 1 h after repellent application. In contrast, the repellents provided good protection against Cx. annulirostris, with 19.2% picaridin providing >95% protection for 5 h and both deet formulations providing >95% protection for 7 h when collections ceased. This study provides additional field data showing tolerance of Anopheles spp. for repellents. The response of field populations of Cx. annulirostris, an important vector of arboviruses in Australia, to repellents containing deet and picaridin is reported for the first time.

  18. Protection against mosquito vectors Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus using a novel insect repellent, ethyl anthranilate.

    PubMed

    Islam, Johirul; Zaman, Kamaruz; Tyagi, Varun; Duarah, Sanjukta; Dhiman, Sunil; Chattopadhyay, Pronobesh

    2017-10-01

    Growing concern on the application of synthetic mosquito repellents in the recent years has instigated the identification and development of better alternatives to control different mosquito-borne diseases. In view of above, present investigation evaluates the repellent activity of ethyl anthranilate (EA), a non-toxic, FDA approved volatile food additive against three known mosquito vectors namely, Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus under laboratory conditions following standard protocols. Three concentration levels (2%, 5% and 10% w/v) of EA were tested against all the three selected mosquito species employing K & D module and arm-in-cage method to determine the effective dose (ED 50 ) and complete protection time (CPT), respectively. The repellent activity of EA was further investigated by modified arm-in-cage method to determine the protection over extended spatial ranges against all mosquito species. All behavioural situations were compared with the well-documented repellent N,N-diethylphenyl acetamide (DEPA) as a positive control. The findings demonstrated that EA exhibited significant repellent activity against all the three mosquitoes species. The ED 50 values of EA, against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus were found to be 0.96%, 5.4% and 3.6% w/v, respectively. At the concentration of 10% w/v, it provided CPTs of 60, 60 and 30min, respectively, against Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus mosquitoes. Again in spatial repellency evaluation, EA was found to be extremely effective in repelling all the three tested species of mosquitoes. Ethyl anthranilate provided comparable results to standard repellent DEPA during the study. Results have concluded that the currently evaluated chemical, EA has potential repellent activity against some well established mosquito vectors. The study emphasizes that repellent activity of EA could be exploited for developing effective, eco

  19. Insect repellents and sunscreen: implications for personal protection strategies against mosquito-borne disease.

    PubMed

    Webb, Cameron E; Russell, Richard C

    2009-10-01

    To determine the protection times provided by insect repellent and sunscreen in combined formulations against biting mosquitoes. To determine if concurrent use of repellent and sunscreen influenced protection times. Insect repellent containing comparable concentrations of N, N-diethyl-3-methylbenzamide (DEET) with and without sunscreen were tested on human skin to determine the mean protection time (MPT) against Aedes aegypti (L.) in the laboratory. Further trials were undertaken to determine the effect on MPT of sunscreen reapplication over repellent every two hours. There was no significant difference in the MPT provided by 80% DEET with (MPT+/-SE=770+/-54.8 minutes) and without (MPT+/-SE=830+/-20.2 minutes) sunscreen or 7.14% DEET with (MPT+/-SE =240+/-15.5 minutes) and 6.98% DEET without (MPT+/-SE =230+/-18.4 minutes) sunscreen. Reapplication of sunscreen resulted in a significantly lower MPT of a 17.0% DEET formulation when sunscreen was reapplied concurrently (MPT+/-SE=330+/-25.2 minutes), compared with DEET alone (MPT+/-SE =400+/-12.7 minutes). When combined in a single formulation with sunscreen, the MPT provided by both high and low concentrations of DEET is not reduced. However, if sunscreen is reapplied over insect repellent, protection times can be reduced significantly. In areas of endemic mosquito-borne disease, the reapplication of a low concentration repellent and sunscreen formulation may provide the most effective protection from biting mosquitoes while minimising the risk of overexposure to DEET.

  20. New repellent effective against African malaria mosquito Anopheles gambiae: implications for vector control.

    PubMed

    Hodson, C N; Yu, Y; Plettner, E; Roitberg, B D

    2016-12-01

    Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) is a vector for Plasmodium, the causative agent of malaria. Current control strategies to reduce the impact of malaria focus on reducing the frequency of mosquito attacks on humans, thereby decreasing Plasmodium transmission. A need for new repellents effective against Anopheles mosquitoes has arisen because of changes in vector behaviour as a result of control strategies and concern over the health impacts of current repellents. The response of A. gambiae to potential repellents was investigated through an electroantennogram screen and the most promising of these candidates (1-allyloxy-4-propoxybenzene, 3c{3,6}) chosen for behavioural testing. An assay to evaluate the blood-host seeking behaviour of A. gambiae towards a simulated host protected with this repellent was then performed. The compound 3c{3,6} was shown to be an effective repellent, causing mosquitoes to reduce their contact with a simulated blood-host and probe less at the host odour. Thus, 3c{3,6} may be an effective repellent for the control of A. gambiae. © 2016 The Royal Entomological Society.

  1. Application of mosquito repellent coils and associated self-reported health issues in Ghana.

    PubMed

    Hogarh, Jonathan N; Antwi-Agyei, Philip; Obiri-Danso, Kwasi

    2016-02-04

    The use of mosquito coils has gained widespread patronage in malaria-endemic countries, even though it is not a recommended preventive measure for avoiding mosquitoes. Mosquito coils contain insecticides, which are expected to vaporize slowly once the coil is lit, to provide protection against the mosquito. The mosquito coil base material contains a variety of compounds capable of burning slowly to gradually release the insecticide. The mosquito coil smoke, however, is potentially a source of indoor air pollution with implications for acute respiratory infections (ARI) and other illnesses. The present study investigated the application of mosquito coils and associated self-reported health issues in Ghana. A cross-sectional study was undertaken in which questionnaires were randomly administered to 480 households across four districts in Ghana. Respondents who exclusively applied mosquito coils were grouped as test cohort, while those who did not apply any mosquito repellency method constituted a control cohort. The test group that applied mosquito coils reported malaria incidence rate of 86.3 %. The control group that did not apply any mosquito repellency method reported an incidence rate of malaria at 72.4 %. Chi square analysis suggested that the observed difference was statistically significant (x (2) = 4.25; p = 0.04). The number of respondents who reported symptoms of cough from mosquito coil application (52.6 % incidence rate) was marginally greater than their counterparts who did not apply coils (46.1 % incidence rate). It was also found that respondents with shortage of breath, which was used as a proxy for ARI, were more likely to have applied mosquito coil. The application of mosquito coils did not necessarily reduce the incidence of malaria in the study communities. It however presented a potential respiratory risk factor, which should be further investigated by critically examining exposure to particulate matter emissions from burning coils.

  2. Discovery of novel mosquito repellents from structure-activity studies

    USDA-ARS?s Scientific Manuscript database

    For the AGRO division: Recent Developments in Invertebrate Repellents. The USDA historical archives of repellents and toxicants consists of over 30,000 chemical structures tested over the past 60 years. We have undertaken a collaborative research project to initially target six subsets of these com...

  3. Pupicidal and repellent activities of Pogostemon cablin essential oil chemical compounds against medically important human vector mosquitoes

    PubMed Central

    Gokulakrishnan, J; Kuppusamy, Elumalai; Shanmugam, Dhanasekaran; Appavu, Anandan; Kaliyamoorthi, Krishnappa

    2013-01-01

    Objective To determine the repellent and pupicidal activities of Pogostemon cablin (P. cablin) chemical compositions were assayed for their toxicity against selected important vector mosquitoes, viz., Aedes aegypti (Ae. aegypti), Anopheles stephensi (An. stephensi) and Culex quinquefasciatus (Cx. quinquefasciatus) (Diptera: Culicidae). Methods The plants dry aerial parts were subjected to hydrodistillation using a modified Clevenger-type apparatus. The composition of the essential oil was analyzed by Gas Chromatography (GC) and GC mass spectrophotometry. Evaluation was carried out in a net cage (45 cm×30 cm×45 cm) containing 100 blood starved female mosquitoes and were assayed in the laboratory condition by using the protocol of WHO 2010. The repellent activity of P. cablin chemical compositions at concentration of 2mg/cm2were applied on skin of fore arm in man and exposed against adult female mosquitoes. The pupicidal activity was determined against selected important vector mosquitoes to concentration of 100 mg/L and mortality of each pupa was recorded after 24 h of exposure to the compounds. Results Chemical constituents of 15 compounds were identified in the oil of P.cablin compounds representing to 98.96%. The major components in essential oil were â-patchoulene, á-guaiene, ã-patchoulene, á-bulnesene and patchouli alcohol. The repellent activity of patchouli alcohol compound was found to be most effective for repellent activity and 2 mg/cm2 concentration provided 100% protection up to 280 min against Ae. aegypti, An. stephensi and Cx. quinquefasciatus, respectively. Similarly, pupae exposed to 100 mg/L concentrations of P. cablin chemical compositions. Among five compounds tested patchouli alcoholwas found to be most effective for pupicidal activity provided 28.44, 26.28 and 25.36 against Ae.aegypti, An.stephensi and Cx. quinquefasciatus, respectively. The percent adult emergence was inversely proportional to the concentration of compounds and directly

  4. Adulticidal and repellent properties of indigenous plant extracts against Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae).

    PubMed

    Govindarajan, Marimuthu; Sivakumar, Rajamohan

    2012-05-01

    Several diseases are associated to the mosquito-human interaction. Mosquitoes are the carriers of severe and well-known illnesses such as malaria, arboviral encephalitis, dengue fever, chikunguniya fever, West Nile virus, and yellow fever. These diseases produce significant morbidity and mortality in humans and livestock around the world. The adulticidal and repellent activities of crude hexane, ethyl acetate, benzene, chloroform, and methanol extracts of leaf of Eclipta alba and Andrographis paniculata were assayed for their toxicity against two important vector mosquitoes, viz., Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae). The adult mortality was observed after 24 h of exposure. All extracts showed moderate adulticide effects; however, the highest adult mortality was found in methanol extract of A. paniculata against the adults of C. quinquefasciatus and A. aegypti with the LC(50) and LC(90) values were 149.81, 172.37 ppm and 288.12, 321.01 ppm, respectively. The results of the repellent activity of hexane, ethyl acetate, benzene, chloroform, and methanol extract of E. alba and A. paniculata plants at three different concentrations of 1.0, 2.5, and 5.0 mg/cm(2) were applied on skin of forearm in man and exposed against adult female mosquitoes. In this observation, these two plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity is dependent on the strength of the plant extracts. These results suggest that the leaf solvent plant extracts have the potential to be used as an ideal ecofriendly approach for the control of mosquitoes. This is the first report on the mosquito adulticidal and repellent activities of the reported E. alba and A. paniculata plants.

  5. Studies on repellent activity of seed oils alone and in combination on mosquito, Aedes aegypti.

    PubMed

    Mukesh, Y; Savitri, P; Kaushik, R; Singh, N P

    2014-09-01

    The study was undertaken to investigate the relative repellency of Pongamia pinnata and Azadirachta indica seed oils on vector mosquito, Aedes aegypti under laboratory conditions. The repellents were formulated into 3 groups: seed oils, their mixture and combination of seed oils with three carrier oils viz. olive, mustard and coconut oil. Different formulations of each oil were tested at the concentrations of 1% and 5% on human baits. Efficiency was assessed, based on the total protection time; biting rate and percent protection provided by each formulation. Results showed that 5% formulation of the Pongamia pinnata and Azadirachta indica seed oils, mixed in 1:1 ratio exhibited highest percentage repellency of 85%, protection time of 300 min and bite rate of 6%. 5% concentration of A. indica and P. pinnata seed oil in mustard oil base offered 86.36% and 85% protection respectively with total protection time of 230 and 240 min respectively. The study confirms that Azadirachta indica and Pongamia pinnata have mosquito-repellent potential. When mixed in different ratios or with some carrier oil their efficacy increases 2-fold in some cases. These formulations are very promising for topical use (> 5 hrs complete protection) and are comparable to the protection provided by advanced Odomos mosquito repellent cream available commercially and thus are recommended for field trial.

  6. Laboratory evaluation techniques to investigate the spatial potential of repellents for push & pull mosquito control systems

    USDA-ARS?s Scientific Manuscript database

    A protocol has been developed for the indoor evaluation of candidate spatial repellents intended for use in push and pull systems. Single treatments (catnip oil, 1-methylpiperazine and homopiperazine) and a mixture of catnip oil and homopiperazine were tested with yellow-fever mosquitoes (Aedes aegy...

  7. Efficacy of Some Wearable Devices Compared with Spray-On Insect Repellents for the Yellow Fever Mosquito, Aedes aegypti (L.) (Diptera: Culicidae)

    PubMed Central

    Chung, Hae-Na; Gonzales, Kristina K.; Vulcan, Julia; Li, Yiyi; Ahumada, Jorge A.; Romero, Hector M.; De La Torre, Mario; Shu, Fangjun; Hansen, Immo A.

    2017-01-01

    The current Zika health crisis in the Americas has created an intense interest in mosquito control methods and products. Mosquito vectors of Zika are of the genus Aedes, mainly the yellow fever mosquito, Aedes aegypti. L. The use of repellents to alter mosquito host seeking behavior is an effective method for the prevention of mosquito-borne diseases. A large number of different spray-on repellents and wearable repellent devices are commercially available. The efficacies of many repellents are unknown. This study focuses on the efficacy of eleven different repellents in reducing the number of Ae. aegypti female mosquitoes attracted to human bait. We performed attraction-inhibition assays using a taxis cage in a wind tunnel setting. One person was placed upwind of the taxis cage and the mosquito movement towards or away from the person was recorded. The person was treated with various spray-on repellents or equipped with different mosquito repellent devices. We found that the spray-on repellents containing N,N-Diethyl-meta-toluamide and p-menthane-3,8-diol had the highest efficacy in repelling mosquitoes compared to repellents with other ingredients. From the five wearable devices that we tested, only the one that releases Metofluthrin significantly reduced the numbers of attracted mosquitoes. The citronella candle had no effect. We conclude that many of the products that we tested that were marketed as repellents do not reduce mosquito attraction to humans. PMID:28423421

  8. Aqueous 2% Geraniol as a mosquito repellent failed against Aedes Aegypti on ponies

    USDA-ARS?s Scientific Manuscript database

    Organic insect repellents are of interest to many agricultural producers and animal owners. Geraniol, a plant-derived alcohol is naturally produced by a wide range of plants and is an EPA “minimum risk pesticide”. Previous studies have shown various concentrations of geraniol to repel or kill mosqui...

  9. Pyrethroid insecticides maintain repellent effect on knock-down resistant populations of Aedes aegypti mosquitoes.

    PubMed

    Bowman, Natalie M; Akialis, Kristin; Cave, Grayson; Barrera, Roberto; Apperson, Charles S; Meshnick, Steven R

    2018-01-01

    Pyrethroid-treated clothing is commonly worn for protection against mosquitoes; pyrethroids are both insecticides and repellents. Pyrethroid resistance has become increasingly common in Aedes aegypti, the vector of dengue, Zika, and other arboviruses, but it is not clear whether resistance is associated with reductions in repellency. In order to determine whether long-lasting permethrin impregnated (LLPI) clothing is protective, we used Aedes aegypti from New Orleans, LA (pyrethroid-sensitive) and San Juan, PR (resistant) to measure both lethality and repellency. PCR and Sanger sequencing were used to confirm resistance status by detecting mutations in the kdr gene at positions 1016 and 1534. Arm-in-cage trials of 100 Aedes aegypti females from both populations were performed for 10 minutes to bare arm or an arm clothed in untreated military camouflage or military camouflage impregnated with deltamethrin, permethrin, or etofenprox. Trials were repeated 4-5 times on different days. Number of landings, number of blood meals, and immediate and 24-hour mortality were recorded. Mortality was extremely low in all trials. Compared to untreated cloth, mosquitoes demonstrated a trend towards a 2%-63% reduction in landings and a statistically significant 78-100% reduction in blood feeding on pyrethroid-treated cloth for most insecticides. Effects were observed in both pyrethroid-sensitive and pyrethroid-resistant mosquito populations. Our data show that kdr mutations are associated with pyrethroid resistance but are likely not the only contributors. Pyrethroids appear to maintain repellent effect against resistant mosquitoes. This finding suggests that even in places where pyrethroid resistance is widespread, permethrin still has a role for use as a repellent on clothing to protect against mosquito bites.

  10. Field evaluation of four spatial repellent devices against Arkansas rice-land mosquitoes.

    PubMed

    Dame, David A; Meisch, Max V; Lewis, Carolyn N; Kline, Daniel L; Clark, Gary G

    2014-03-01

    Four commercially available spatial repellent devices were tested in a rice-land habitat near Stuttgart, AR, after semi-field level assessments had been made at the Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, US Department of Agriculture in Gainesville, FL. OFF! Clip-On(metofluthrin), Mosquito Cognito (linalool), No-Pest Strip (dichlorvos), and ThermaCELL (d-cisltrans allethrin) were selected for this study from >20 candidate products. The units based on metofluthrin, linalool, or d-cisltrans allethrin significantly reduced captures of 1 or more of the mosquito species at surrogate human sites (unlit Centers for Disease Control and Prevention traps with CO2 and octenol). Among the mosquito species analyzed statistically (Anopheles quadrimaculatus, Culex erraticus, and Psorophora columbiae), there were significantly different responses (up to 84% reduction) to individual products, suggesting that combinations of certain spatial repellents might provide significantly greater protection.

  11. Assessment of Angelica sinensis (Oliv.) Diels as a repellent for personal protection against mosquitoes under laboratory and field conditions in northern Thailand.

    PubMed

    Champakaew, Danita; Junkum, Anuluck; Chaithong, Udom; Jitpakdi, Atchariya; Riyong, Doungrat; Wannasan, Anchalee; Intirach, Jitrawadee; Muangmoon, Roongtawan; Chansang, Arpaporn; Tuetun, Benjawan; Pitasawat, Benjawan

    2016-06-29

    Angelica sinensis (Oliv.) hexane extract (AHE) has been reported as a proven and impressive repellent against laboratory-reared female Aedes aegypti mosquitoes. With the aim of promoting products of plant origin as a viable alternative to conventional synthetic substances, this study was designed to transform AHE-based repellents for exploitable commercial production by enhancing their efficacy and assessing their physical and biological stability as well as repellency against mosquitoes under laboratory and field conditions. The chemical profile of AHE was analyzed by qualitative gas chromatography-mass spectrometry (GC-MS) technique. AHE was supplemented with vanillin, as a fixative, and then investigated for repellency and comparison to the standard synthetic repellent, DEET, under both laboratory and field conditions. Determination of physical and biological stability as a repellent was carried out after keeping AHE samples under varying temperatures and for different storage times. GC-MS analysis revealed that AHE contained at least 21 phytochemical compounds, constituting 95.74 % of the total content, with the major constituent of 3-N-butylphthalide (66.67 %). Ethanolic formulations of AHE and DEET showed improvement of repellency in a dose-dependent manner when vanillin was added in laboratory assessment. While 5-25 % AHE alone provided median complete-protection times of 2.0-6.5 h against Ae. aegypti, these times were increased to 4.0-8.5 h with a combination of AHE and 5 % vanillin (AHEv). Protection times against Ae. aegypti were extended from 2.25 to 7.25 h to 4.25-8.25 h when 5-25 % DEET was combined with 5 % vanillin (DEETv). In determining stability, all stored AHE samples exhibited similar characteristics such as liquid phases with aromatic odor comparable to those of fresh preparations. Furthermore, repellent activity of stored AHE samples lasted for at least six months, with varied efficacy (4.5-10.0 h) against Ae. aegypti. Field trials

  12. Mosquito larvicidal, pupicidal, adulticidal, and repellent activity of Artemisia nilagirica (Family: Compositae) against Anopheles stephensi and Aedes aegypti.

    PubMed

    Panneerselvam, Chellasamy; Murugan, Kadarkarai; Kovendan, Kalimuthu; Mahesh Kumar, Palanisamy

    2012-12-01

    Mosquito-borne diseases have an economic impact, including loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates; however, no part of the world is free from vector-borne diseases. The aim of the present study, to evaluate the larvicidal, pupicidal, repellent, and adulticidal activities of methanol crude extract of Artemisia nilagirica were assayed for their toxicity against two important vector mosquitoes, viz., Anopheles stephensi and Aedes aegypti (Diptera: Culicidae). The fresh leaves of A. nilagirica were washed thoroughly in tap water and shade dried at room temperature (28 ± 2 °C) for 5-8 days. The air-dried materials were powdered separately using commercial electrical blender. From the plants, 500 g powdered was macerated with 1.5 L organic solvents of methanol sequentially for a period of 72 h each and filtered. The larval and pupal mortality was observed after 24 h of exposure; no mortality was observed in the control group. The first- to fourth-instar larvae and pupae of A. stephensi had values of LC(50) = 272.50, 311.40, 361.51, 442.51, and 477.23 ppm, and the LC(90) = 590.07, 688.81, 789.34, 901.59, and 959.30 ppm; the A. aegypti had values of LC(50) = 300.84, 338.79, 394.69, 470.74, and 542.11 ppm, and the LC(90) = 646.67, 726.07, 805.49, 892.01, and 991.29 ppm, respectively. The results of the repellent activity of plant extract of A. nilagirica plants at five different concentrations of 50, 150, 250, 350, and 450 ppm were applied on skin of fore arm in man and exposed against adult female mosquitoes. In this observation, the plant crude extract gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity is dependent on the strength of the plant extracts. The adult mortality was found in methanol extract of A. nilagirica, with the LC(50) and LC(90) values of 205.78 and 459.51 ppm for A. stephensi, and 242.52 and 523.73 ppm for A. aegypti

  13. Mediation of deet repellency in mosquitoes (Diptera: Culicidae) by species, age, and parity.

    PubMed

    Barnard, D R

    1998-05-01

    Laboratory bioassays assessed differences in the protection time provided by the repellent deet (N,N-diethyl-3-methylbenzamide) against 5-d-old nulliparous and 10-, 15-, and 20-d-old nulliparous and parous female Aedes aegypti (L.), Anopheles albimanus (Weidemann), and Anopheles quadrimaculatus Say sensu lato. Mean protection time was shortest against An. albimanus (1.6 h) and An. quadrimaculatus (1.5 h) and longest against Ae. aegypti (6.5 h), but was not significantly influenced by mosquito age or parity. Mean percentage of biting at repellent failure time was highest in An. albimanus (14.2%), followed by An. quadrimaculatus (7.0%) and Ae. aegypti (2.9%), was higher in parous females (10.8%) than in nulliparous females (5.9%), and was highest overall (35%) in 20-d-old parous An. albimanus. Interaction between mosquito species and parity and between parity and age factors, respectively, resulted from a significant decrease in percentage of biting by parous An. quadrimaculatus compared with other females, and a significant increase in biting by 20-d-old parous females compared with other females. The main finding of this study is that repellent protection time is unaffected by parity; this is important because parous mosquitoes are the primary target of personal-protection measures in disease-endemic areas. When repellent failure did occur, there was a higher risk of bite by old, parous An. albimanus than for any other species, age, or parity grouping of females.

  14. Protection capacity of mosquito repellent ink from citronella (Cymbopogon nardus L.) and clove leaf oils (Syzygium aromaticum) againts Aedes aegypti

    NASA Astrophysics Data System (ADS)

    Harismah, Kun; Vitasari, Denny; Mirzaei, Mahmoud; Fuadi, Ahmad Muhammad; Aryanto, Yanur Hendra

    2017-06-01

    The study of combination citronella and clove oils in mosquito repellent newspaper ink has been done. The background of this study was there prevalences of diseases such as malaria, zikka, and dengue fever that are carried by mosquitoes which hunt in the morning, at time while people usually read newspaper. Tests were undertaken in 3 (three) repetitions to determine the effectiveness of ink (as a control) and two types of mosquito repellent inks that consisted of ink and citronella-clove leaf oil with ratio of 4:1 and 1:1 of substances that were presumed to have insect repellent qualities. The results of this study indicated that the mixture of newspaper ink and citronella-clove oil with ratio of 1:4 and 1:1 offer limited protection against mosquitoes bite in the range of 1-5 hours. The efficacy of the citronella-clove leaf oi mixture as mosquito repellent was between 75.85 to 91.10%. Hece, a blend of citronella and clove leaf oil could be added to printing ink and could be commercial potential as a short-period mosquito repellent. However, it is important in disseminating public health messages to emphasize the greater effectiveness of citronella and clove oils-based repellents ink in areas with risks of mosquito-borne disease.

  15. Comparative Evaluation of a Silicone Membrane as an Alternative to Skin for Testing Mosquito Repellents.

    PubMed

    Agramonte, Natasha M; Gezan, Salvador A; Bernier, Ulrich R

    2017-05-01

    Repellents prevent mosquito bites and help reduce mosquito-borne disease, a global public health issue. Laboratory-based repellent bioassays predict the ability of compounds to deter mosquito feeding, but the variety of repellent bioassays and statistical analysis methods makes it difficult to compare results across methodologies. The most realistic data are collected when repellents are applied on the skin; however, this method exposes volunteers to chemicals and mosquito bites. Silicone membranes were investigated as an alternative to human skin in assays of repellent efficacy. Results from module system bioassays conducted in vitro with a silicone membrane were compared with in vivo bioassays conducted with N,N-diethyl-3-methylbenzamide (referred to as DEET), 1-piperidinecarboxylic acid 2-(2-hydroxyethyl)-1-methylpropylester (referred to as Picaridin), ethyl 3-[acetyl(butyl)amino]propanoate (referred to as IR3535), and para-menthane-3,8-diol (referred to as PMD) applied directly on the skin of the leg. No significant difference in mosquito feeding was found when comparing skin and volunteer-worn membrane controls using blood; however, feeding was significantly lower in unworn membrane controls using either 10% sucrose or blood, indicating that worn membranes are a possible surrogate for untreated human skin. Pooled data from six volunteers were used to generate dose-response curves of blood-feeding activity. Results from skin-applied repellents were modeled to determine if membranes could provide a predictive correlate for skin. Goodness-of-fit comparisons indicated that the nonlinear dose-response curves for the skin and membrane differed significantly for DEET and Picaridin, but did not differ significantly for IR3535 and PMD. With knowledge of the dose-response relationships and further modifications to this system, the membrane-based tests could be used for standardized repellent testing with infected vectors. Published by Oxford University Press on behalf

  16. Bioassay-guided investigation of two monarda essential oils as repellents of yellow fever mosquito Aedes aegypti

    USDA-ARS?s Scientific Manuscript database

    As part of an ongoing research program to identify active mosquito repellents, Monarda bradburiana Beck and M. fistulosa L. essential oils showed potent repellents with minimum effective dosages (MED) of 0.055 ± 0.036 and 0.078 ± 0.027 mg/cm2, respectively, compared to reference standard N,N-diethyl...

  17. A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies.

    PubMed

    Ogoma, Sheila B; Moore, Sarah J; Maia, Marta F

    2012-12-07

    Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propose scientific consensus on terminologies and methodologies used for evaluation of product formats that could contain spatial chemical actives, including indoor residual spraying (IRS), long lasting insecticide treated nets (LLINs) and insecticide treated materials (ITMs). PubMed, (National Centre for Biotechnology Information (NCBI), U.S. National Library of Medicine, NIH), MEDLINE, LILAC, Cochrane library, IBECS and Armed Forces Pest Management Board Literature Retrieval System search engines were used to identify studies of pyrethroid based coils and emanators with key-words "Mosquito coils" "Mosquito emanators" and "Spatial repellents". It was concluded that there is need to improve statistical reporting of studies, and reach consensus in the methodologies and terminologies used through standardized testing guidelines. Despite differing evaluation methodologies, data showed that coils and emanators induce mortality, deterrence, repellency as well as reduce the ability of mosquitoes to feed on humans. Available data on efficacy outdoors, dose-response relationships and effective distance of coils and emanators is inadequate for developing a target product profile (TPP), which will be required for such chemicals before optimized implementation can occur for maximum benefits in disease control.

  18. Chemosensory responses to the repellent nepeta essential oil and its major component nepetalactone by the yellow fever mosquito, aedes aegypti, a vector of zika virus

    USDA-ARS?s Scientific Manuscript database

    Nepeta essential oil (Neo) (catnip) and its major component, nepetalactone, have long been known to repel insects including mosquitoes. However, the neural mechanisms through which these repellents are detected by mosquitoes, including the yellow fever mosquito Aedes aegypti, an important vector of...

  19. On the analysis of effectiveness in mass application of mosquito repellent for dengue disease prevention

    NASA Astrophysics Data System (ADS)

    Aldila, D.; Soewono, E.; Nuraini, N.

    2012-05-01

    Dengue disease has been known as one of dangerous vector-borne diseases and become serious threat in many tropical countries. With no vaccine and antiviral available until nowadays, and frequent appearance of extraordinary dengue outbreaks, many governments are forced to declare national problem for dengue. At this moment, the only method available to prevent dengue disease transmission is to combat the disease-carrying mosquitoes as well as to reduce the contact between human and mosquitoes. The fast growing dengue transmission in many countries in recent years indicates that the mosquito control programs are far from successful. The use of mosquito repellent is one possible instrument which could be used as an effective mass treatment to prevent the dengue outbreak during endemic period. Here in this paper a Susceptible-Infectious-Recovered (S-I-R) dengue transmission model with repellent mass treatment is being applied to portions of children and adult compartments. Analysis of the basic reproductive ratio (Ro) of the model is done. It is shown, with reasonable choices of portions of treated children and adults, in combination with reduction of mosquito population, the basic reproductive ratio can be significantly reduced and occurrence of endemic can be avoided. Numerical simulations are shown for various treatment scenarios.

  20. Phoenix dactylifera L. spathe essential oil: chemical composition and repellent activity against the yellow fever mosquito.

    PubMed

    Demirci, Betül; Tsikolia, Maia; Bernier, Ulrich R; Agramonte, Natasha M; Alqasoumi, Saleh I; Al-Yahya, Mohammed A; Al-Rehaily, Adnan J; Yusufoglu, Hasan S; Demirci, Fatih; Başer, K Hüsnü Can; Khan, Ikhlas A; Tabanca, Nurhayat

    2013-12-01

    Date palm, Phoenix dactylifera L. (Arecaceae), grows commonly in the Arabian Peninsula and is traditionally used to treat various diseases. The aim of the present study was to identify chemical composition of the essential oil and to investigate the repellent activity. The essential oil of P. dactylifera was obtained by hydrodistillation from the spathe, a specialized leaf structure that surrounds the pollinating organs of the palm. The oil was subsequently analyzed by GC-FID and GC-MS. The oil showed promising repellent activity against yellow fever mosquito - Aedes aegypti. Sixteen components were characterized, constituting 99% of the oil. The main components were 3,4-dimethoxytoluene (73.5%), 2,4-dimethoxytoluene (9.5%), β-caryophyllene (5.5%), p-cresyl methyl ether (3.8%), and caryophyllene oxide (2.4%). The minimum effective dosage (MED) for repellency for the P. dactylifera oil was 0.051mg/cm(2), which had moderately lower potency compared to reference standard N,N-diethyl-3-methylbenzamide, DEET (0.018mg/cm(2)) in the "cloth patch assay". The five major compounds were individually assayed for repellency to determine to what extent each is responsible for repellency from the oil. 3,4-Dimethoxytoluene and 2,4-dimethoxytoluene showed the best repellent activity with the same MED value of 0.063mg/cm(2), respectively. The results indicate that these two constituents which comprise a large proportion of the P. dactylifera oil (83%) are likely responsible for the observed repellent activity. In this aspect, the P. dactylifera spathe oil is a sustainable, promising new source of natural repellents. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Synthesis and Bioassay of Improved Mosquito Repellents Predicted From Chemical Structure

    DTIC Science & Technology

    2008-05-27

    blood meal to develop their eggs. Repellents play a vital role in interrupting this mosquito/human interaction by serving as a means of personal ...provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB...ABSTRACT Same as Report (SAR) 18. NUMBER OF PAGES 6 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE

  2. Mosquito adulticidal and repellent activities of botanical extracts against malarial vector, Anopheles stephensi Liston (Diptera: Culicidae).

    PubMed

    Govindarajan, Marimuthu; Sivakumar, Rajamohan

    2011-12-01

    To determine the adulticidal and repellent activities of different solvent leaf extracts of Eclipta alba (E. alba) and Andrographis paniculata (A. paniculata) against malarial vector, Anopheles stephensi (An. stephensi). Adulticidal efficacy of the crude leaf extracts of E. alba and A. paniculata with five different solvents like benzene, hexane, ethyl acetate, methanol and chloroform was tested against the five to six day old adult female mosquitoes of An. stephensi. The adult mortality was observed after 24 h under the laboratory conditions. The repellent efficacy was determined against An. stephensi mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm(2) under laboratory conditions. Among the tested solvents the maximum efficacy was observed in the methanol extract. The LC(50) and LC(90) values of E. alba and A. paniculata against adults of An. stephensi were 150.36, 130.19 ppm and 285.22, 244.16 ppm, respectively. No mortality was observed in controls. The chi-square values were significant at P<0.05 level. Methanol extract of E. alba and A. paniculata was produce maximum repellency against An. stephensi. From the results it can be concluded the crude extract of E. alba and A. paniculata was an excellent potential for controlling An. stephensi mosquitoes. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  3. Ultrafine particle emissions from essential-oil-based mosquito repellent products.

    PubMed

    Liu, J; Fung, D; Jiang, J; Zhu, Y

    2014-06-01

    Ultrafine particle (UFP) emissions from three essential-oil-based mosquito repellent products (lemon eucalyptus (LE), natural insects (NI), and bite shield (BS)) were tested in a 386 l chamber at a high air exchange rate of 24/h with filtered laboratory air. Total particle number concentration and size distribution were monitored by a condensation particle counter and a scanning mobility particle sizer, respectively. UFPs were emitted from all three products under indoor relevant ozone concentrations (~ 17 ppb). LE showed a nucleation burst followed by a relatively stable and continuous emission while the other two products (NI and BS) showed episodic emissions. The estimated maximum particle emission rate varied from 5.4 × 10(9) to 1.2 × 10(12) particles/min and was directly related to the dose of mosquito repellent used. These rates are comparable to those due to other indoor activities such as cooking and printing. The emission duration for LE lasted for 8-78 min depending on the dose applied while the emission duration for NI and BS lasted for 2-3 h. Certain essential-oil-based mosquito repellents can produce high concentrations of UFPs when applied, even at low ozone levels. Household and personal care products that contain essential oil may need to be tested at indoor relevant ozone levels to determine their potential to increase personal UFP exposures. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Gustatory receptor neuron responds to DEET and other insect repellents in the yellow-fever mosquito, Aedes aegypti

    NASA Astrophysics Data System (ADS)

    Sanford, Jillian L.; Shields, Vonnie D. C.; Dickens, Joseph C.

    2013-03-01

    Three gustatory receptor neurons were characterized for contact chemoreceptive sensilla on the labella of female yellow-fever mosquitoes, Aedes aegypti. The neuron with the smallest amplitude spike responded to the feeding deterrent, quinine, as well as N, N-diethyl-3-methylbenzamide and other insect repellents. Two other neurons with differing spikes responded to salt (NaCl) and sucrose. This is the first report of a gustatory receptor neuron specific for insect repellents in mosquitoes and may provide a tool for screening chemicals to discover novel or improved feeding deterrents and repellents for use in the management of arthropod disease vectors.

  5. Efficacy of Advanced Odomos repellent cream (N, N-diethyl-benzamide) against mosquito vectors.

    PubMed

    Mittal, P K; Sreehari, U; Razdan, R K; Dash, A P; Ansari, M A

    2011-04-01

    Repellents are commonly used personal protection measures to avoid mosquito bites. In the present study, Advanced Odomos cream (12% N, N-diethyl-benzamide) was tested for its efficacy against mosquitoes in comparison to DEET (N,N-diethyl-3-methyl benzamide). Bioassays were conducted to assess the repellency of Advanced Odomos and DEET creams against Anopheles stephensi and Aedes aegypti. Their efficacy was tested on human volunteers applied with different concentrations of test creams ranging from 1 to 12 mg/cm 2 and by exposing them to mosquitoes at hourly intervals. Field evaluation was also carried out to test the duration of protection of the test creams against Anopheles and Aedes mosquitoes during whole night and day time collections, respectively on human volunteers. Mosquito collections were done using torch light and aspirator. Complete (100%) protection was achieved at 10 mg/cm 2 cream formulation of Advanced Odomos (1.2 mg a.i/cm 2 ) dose against An. stephensi and 12 mg/cm 2 (1.44 mg a.i./cm 2 ) against Ae. aegypti on human baits. There was no statistically significant differences in per cent protection against mosquito bites between Advanced Odomos and DEET cream (P>0.05) in respective doses. Complete protection up to 11 h was observed against Anopheles mosquitoes during whole night collections and up to 6 h against Ae. aegypti in day time collections. No adverse reactions such as itching, irritation, vomiting, nausea, etc. were reported by the volunteers. Advanced Odomos cream applied at 10 mg/cm 2 concentration provided 100% protection from Anopheles mosquitoes up to 11 h whereas about 6 h protection was recorded against Ae. aegypti. The laboratory and field trials indicate that for longer protection against Anopheles mosquitoes 10 mg/cm 2 will be appropriate and in case of Ae. aegypti more than 10 mg/cm 2 application is required for complete protection. In conclusion, the Advanced Odomos cream was comparable to the known repellent cream DEET for

  6. Characterization and mosquito repellent activity of citronella oil nanoemulsion.

    PubMed

    Sakulku, Usawadee; Nuchuchua, Onanong; Uawongyart, Napaporn; Puttipipatkhachorn, Satit; Soottitantawat, Apinan; Ruktanonchai, Uracha

    2009-05-08

    Encapsulated citronella oil nanoemulsion prepared by high pressure homogenization at varying amounts of surfactant and glycerol, was studied in terms of the droplet size, stability, release characteristics and in vivo mosquito protection. Transparent nanoemulsion can be obtained at optimal concentration of 2.5% surfactant and 100% glycerol. Physical appearance and the stability of the emulsion were greatly improved through an addition of glycerol, owing to its co-solvent and highly viscous property. The increasing emulsion droplet increased the oil retention. The release behavior could be attributed to the effect of droplet size and concentrations of surfactant and glycerol. By fitting to Higuchi's equation, an increase in glycerol and surfactant concentrations resulted in slow release of the oil. The release rate related well to the protection time where a decrease in release rate can prolong mosquito protection time.

  7. orco mutant mosquitoes lose strong preference for humans and are not repelled by volatile DEET.

    PubMed

    DeGennaro, Matthew; McBride, Carolyn S; Seeholzer, Laura; Nakagawa, Takao; Dennis, Emily J; Goldman, Chloe; Jasinskiene, Nijole; James, Anthony A; Vosshall, Leslie B

    2013-06-27

    Female mosquitoes of some species are generalists and will blood-feed on a variety of vertebrate hosts, whereas others display marked host preference. Anopheles gambiae and Aedes aegypti have evolved a strong preference for humans, making them dangerously efficient vectors of malaria and Dengue haemorrhagic fever. Specific host odours probably drive this strong preference because other attractive cues, including body heat and exhaled carbon dioxide (CO2), are common to all warm-blooded hosts. Insects sense odours via several chemosensory receptor families, including the odorant receptors (ORs), membrane proteins that form heteromeric odour-gated ion channels comprising a variable ligand-selective subunit and an obligate co-receptor called Orco (ref. 6). Here we use zinc-finger nucleases to generate targeted mutations in the orco gene of A. aegypti to examine the contribution of Orco and the odorant receptor pathway to mosquito host selection and sensitivity to the insect repellent DEET (N,N-diethyl-meta-toluamide). orco mutant olfactory sensory neurons have greatly reduced spontaneous activity and lack odour-evoked responses. Behaviourally, orco mutant mosquitoes have severely reduced attraction to honey, an odour cue related to floral nectar, and do not respond to human scent in the absence of CO2. However, in the presence of CO2, female orco mutant mosquitoes retain strong attraction to both human and animal hosts, but no longer strongly prefer humans. orco mutant females are attracted to human hosts even in the presence of DEET, but are repelled upon contact, indicating that olfactory- and contact-mediated effects of DEET are mechanistically distinct. We conclude that the odorant receptor pathway is crucial for an anthropophilic vector mosquito to discriminate human from non-human hosts and to be effectively repelled by volatile DEET.

  8. Fresh, dried or smoked? repellent properties of volatiles emitted from ethnomedicinal plant leaves against malaria and yellow fever vectors in Ethiopia

    PubMed Central

    2011-01-01

    Background In the search for plant-based mosquito repellents, volatile emanations were investigated from five plant species, Corymbia citriodora, Ocimum suave, Ocimum lamiifolium, Olea europaea and Ostostegia integrifolia, traditionally used in Ethiopia as protection against mosquitoes. Methods The behaviour of two mosquitoes, the malaria vector Anopheles arabiensis and the arbovirus vector Aedes aegypti, was assessed towards volatiles collected from the headspace of fresh and dried leaves, and the smoke from burning the dried leaves in a two-choice landing bioassay and in the background of human odour. Results Volatile extracts from the smoke of burning dried leaves were found to be more repellent than those from fresh leaves, which in turn were more repellent to mosquitoes than volatiles from dried leaves. Of all smoke and fresh volatile extracts, those from Co. citriodora (52-76%) and Oc. suave (58-68%) were found to be the most repellent, Os. integrifolia (29-56%) to be intermediate while Ol. europaea (23-40%) and Os. integrifolia (19-37%) were the least repellent. One volatile present in each of the fresh leaf extracts of Co. citriodora, Oc. suave and Os. integrifolia was ß-ocimene. The levels of ß-ocimene reflected the mosquito repellent activity of these three fresh leaf extracts. Female host-seeking mosquitoes responded dose-dependently to ß-ocimene, both physiologically and behaviourally, with a maximal behavioural repulsion at 14% ß-ocimene. ß-ocimene (14%) repels mosquitoes in our 6-minute landing assays comparable to the synthetic insect repellent N,N-diethyl-m-toluamide (10% DEET). Conclusions Volatiles in the smoke of burning as well as fresh leaves of Co. citriodora and Oc. suave have significant repellent properties against host seeking An. arabiensis and Ae. aegypti mosquitoes. ß-ocimene, present in the fresh leaf headspace of Co. citriodora, Oc. suave and Os. integrifolia, is a significantly effective volatile mosquito repellent in the

  9. Fresh, dried or smoked? Repellent properties of volatiles emitted from ethnomedicinal plant leaves against malaria and yellow fever vectors in Ethiopia.

    PubMed

    Dube, Fitsum Fikru; Tadesse, Kassahun; Birgersson, Göran; Seyoum, Emiru; Tekie, Habte; Ignell, Rickard; Hill, Sharon R

    2011-12-19

    In the search for plant-based mosquito repellents, volatile emanations were investigated from five plant species, Corymbia citriodora, Ocimum suave, Ocimum lamiifolium, Olea europaea and Ostostegia integrifolia, traditionally used in Ethiopia as protection against mosquitoes. The behaviour of two mosquitoes, the malaria vector Anopheles arabiensis and the arbovirus vector Aedes aegypti, was assessed towards volatiles collected from the headspace of fresh and dried leaves, and the smoke from burning the dried leaves in a two-choice landing bioassay and in the background of human odour. Volatile extracts from the smoke of burning dried leaves were found to be more repellent than those from fresh leaves, which in turn were more repellent to mosquitoes than volatiles from dried leaves. Of all smoke and fresh volatile extracts, those from Co. citriodora (52-76%) and Oc. suave (58-68%) were found to be the most repellent, Os. integrifolia (29-56%) to be intermediate while Ol. europaea (23-40%) and Os. integrifolia (19-37%) were the least repellent. One volatile present in each of the fresh leaf extracts of Co. citriodora, Oc. suave and Os. integrifolia was ß-ocimene. The levels of ß-ocimene reflected the mosquito repellent activity of these three fresh leaf extracts. Female host-seeking mosquitoes responded dose-dependently to ß-ocimene, both physiologically and behaviourally, with a maximal behavioural repulsion at 14% ß-ocimene. ß-ocimene (14%) repels mosquitoes in our 6-minute landing assays comparable to the synthetic insect repellent N,N-diethyl-m-toluamide (10% DEET). Volatiles in the smoke of burning as well as fresh leaves of Co. citriodora and Oc. suave have significant repellent properties against host seeking An. arabiensis and Ae. aegypti mosquitoes. ß-ocimene, present in the fresh leaf headspace of Co. citriodora, Oc. suave and Os. integrifolia, is a significantly effective volatile mosquito repellent in the laboratory. In addition to its repellent

  10. Ethnobotanical survey of medicinal plants used as insects repellents in six malaria endemic localities of Cameroon.

    PubMed

    Youmsi, Roger Ducos Fokouo; Fokou, Patrick Valère Tsouh; Menkem, Elisabeth Zeuko'o; Bakarnga-Via, Issakou; Keumoe, Rodrigue; Nana, Victor; Boyom, Fabrice Fekam

    2017-06-08

    The combined efforts to combat outdoor/indoor transmission of malaria parasites are hampered by the emerging vector resistance in a wide variety of malaria-endemic settings of Africa and the rest of the world, stressing the need for alternative control measures. This study aimed at documenting insect's repellent plant species used by indigenous populations of 6 localities of East, South, West and Centre regions of Cameroon. Information was gathered through face-to-face interviews guided by a semi-structured questionnaire on the knowledge of medicinal plants with insect repellent properties. A total of 182 informants aged from 25 to 75 years were recruited by convenience from May to June 2015. The informants had general knowledge about insects' repellent plants (78.6%). A total of 16 plant species were recorded as insects' repellents with 50% being trees. The most cited plants were Canarium schweinfurthii (Burseraceae) (in four localities, 58/182), Elaeis guineensis (Arecaceae) (in three localities, 38/182), Chromolaena odorata (Compositae) (16/182) and Citrus limon (Rutaceae) (11/182) in two localities each. Among the repellent plant species recorded, 50% were reported to be burnt to produce in-house smokes, 31.2% were mashed and applied on the body, and 18.8% were hung in the houses. The leaf was the most commonly used plant part (52.9%), followed by the bark (17.6%). This study has shown that rural populations of the 6 targeted localities possess indigenous knowledge on repellent plants that are otherwise cost-effective and better choice for repelling insects including malaria-transmitting mosquitoes. Meanwhile, such practices should be validated experimentally and promoted as sustainable malaria transmission control tools in the remotely located communities.

  11. Potential mode of action of a novel plumbagin as a mosquito repellent against the malarial vector Anopheles stephensi, (Culicidae: Diptera).

    PubMed

    Pradeepa, Venkatraman; Senthil-Nathan, Sengottayan; Sathish-Narayanan, Subbiah; Selin-Rani, Selvaraj; Vasantha-Srinivasan, Prabhakaran; Thanigaivel, Annamalai; Ponsankar, Athirstam; Edwin, Edward-Sam; Sakthi-Bagavathy, Muthiah; Kalaivani, Kandaswamy; Murugan, Kadarkarai; Duraipandiyan, Veeramuthu; Al-Dhabi, Naif Abdullah

    2016-11-01

    Plumbagin was isolated and characterized from the roots of Plumbago zeylanica using chromatography: TLC, Column chromatogram, HPLC, FTIR and 1 H NMR. The isolated pure compounds were assayed for potency as inhibitors of: acetylcholine esterase (AchE), glutathione S-transferases (GST), superoxide dismutase (SOD), cytochrome P450 and α, β-esterase, and for repellency with Anopheles stephensi at four different concentrations (25, 50, 75 and 100ppm). The enzyme assay against the pure compound reveals that the level of esterase and SOD was decreased significantly in contrast the level of GST and cytochrome P450 was increased significantly. Our results suggests that novel Plumbagin has significantly alters the level of enzyme comparable to the control. Evaluations resulted in Plumbagin producing maximum repellency scores against An. stephensi mosquitoes in dose dependent manner with highest repellence was observed in the 100ppm. Histological examination showed that the midgut, hindgut and muscles are the most affected tissues. These tissues affected with major changes including separation and collapse of epithelial layer and cellular vacuolization. The results support the utility of plant compound Plumbagin for vector control as an alternative to synthetic insecticides, however, more vigorous field trials are needed to determine viability under natural conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Enhanced repellency of binary mixtures of Zanthoxylum armatum seed oil, vanillin, and their aerosols to mosquitoes under laboratory and field conditions.

    PubMed

    Kwon, Hyung Wook; Kim, Soon-Il; Chang, Kyu-Sik; Clark, J Marshall; Ahn, Young-Joon

    2011-01-01

    The repellency of Zanthoxylum armatum seed oil (ZA-SO), alone or in combination with vanillin (VA), its six major constituents, and another four major previously known Zanthoxylum piperitum fruit oil constituents, as well as aerosol products containing 5 or 10% ZA-SO and 5% VA, was evaluated against female Aedes aegypti in laboratory and field studies. Results were then compared with those of N,N-diethyl-3-methylbenzamide (DEET) as a standard. Hand in cage laboratory tests showed that 0.2, 0.1, and 0.05 mg/cm2 ZA-SO resulted in > 92% protection through 30-min postexposure and was not significantly different than 0.05 mg/cm2 DEET. Skin treated with linalool and limonene (from Z. armatum) provided > 80% repellency to female Ae. aegypti at 10-min exposure, whereas cuminaldehyde, citronellal, geranyl acetate, and cuminyl alcohol (from Zanthoxylum piperitum) provided > 90% protection during this same time period. Only cuminaldehyde and citronellal provided complete protection comparable to DEET at 10-min postexposure. After that time, repellency of all plant constituents to mosquitoes was considerably decreased (< approximately 65%). An increase in repellency and duration of effectiveness was produced by a binary 1:4 mixture of ZA-SO and VA (0.05:0.2 mg/cm2) that was significantly more effective than 0.05 mg/cm2 DEET through 90 min. In field tests, an aerosol formulation containing 5 or 10% ZA-SO plus 5% VA gave 100% repellency at 60-min postexposure. Although these formulations were equal to the level of protection afforded by 10% DEET, repellency to the binary ZA-SO aerosol formulations at 90 min was significantly less effective than DEET. However, mixtures formulated from ZA-SO and VA merit further study as potential repellents for protection of humans and domestic animals from biting and nuisance caused by mosquitoes.

  13. Efficacy of Some Wearable Devices Compared with Spray-On Insect Repellents for the Yellow Fever Mosquito, Aedes aegypti (L.) (Diptera: Culicidae).

    PubMed

    Rodriguez, Stacy D; Chung, Hae-Na; Gonzales, Kristina K; Vulcan, Julia; Li, Yiyi; Ahumada, Jorge A; Romero, Hector M; De La Torre, Mario; Shu, Fangjun; Hansen, Immo A

    2017-01-01

    The current Zika health crisis in the Americas has created an intense interest in mosquito control methods and products. Mosquito vectors of Zika are of the genus Aedes, mainly the yellow fever mosquito, Aedes aegypti. L. The use of repellents to alter mosquito host seeking behavior is an effective method for the prevention of mosquito-borne diseases. A large number of different spray-on repellents and wearable repellent devices are commercially available. The efficacies of many repellents are unknown. This study focuses on the efficacy of eleven different repellents in reducing the number of Ae. aegypti female mosquitoes attracted to human bait. We performed attraction-inhibition assays using a taxis cage in a wind tunnel setting. One person was placed upwind of the taxis cage and the mosquito movement towards or away from the person was recorded. The person was treated with various spray-on repellents or equipped with different mosquito repellent devices. We found that the spray-on repellents containing N,N-Diethyl-meta-toluamide and p-menthane-3,8-diol had the highest efficacy in repelling mosquitoes compared to repellents with other ingredients. From the five wearable devices that we tested, only the one that releases Metofluthrin significantly reduced the numbers of attracted mosquitoes. The citronella candle had no effect. We conclude that many of the products that we tested that were marketed as repellents do not reduce mosquito attraction to humans. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  14. Mosquito repellents for the traveller: does picaridin provide longer protection than DEET?

    PubMed

    Goodyer, Larry; Schofield, Steven

    2018-05-01

    This review examines the published laboratory and field tests where the repellents DEET and picaridin have been compared for their efficacy as repellents against mosquitoes. The review is limited to an assessment of whether the duration of protection afforded by picaridin is similar to or better than DEET. Identification and analysis of laboratory and field-based trials published in peer-reviewed journals that compared DEET to picaridin efficacy. Only eight field studies and three laboratory studies met the review criteria for inclusion and most were considered to be of high risk of bias and of lower quality when judged against evidence-based principles. Overall, the studies showed little potential difference between DEET and picaridin applied at the same dosage, with some evidence pointing to a superior persistence for picaridin. Applied dosage is one important variable in determining the persistence of a repellent experienced by users but the maximum concentration in current picaridin formulation is <30%w/v. Therefore, where only 30% DEET or lower concentrations are available, then on current evidence, it is reasonable to offer DEET or picaridin as a first choice. Where >50% DEET products are available then the protection time advantage associated with these formulations reasonably can be invoked to consider them as first choice repellents.

  15. Characterizing pollutant emissions from mosquito repellents incenses and implications in risk assessment of human health.

    PubMed

    Wang, Lina; Zheng, Xinran; Stevanovic, Svetlana; Xiang, Zhiyuan; Liu, Jing; Shi, Huiwen; Liu, Jing; Yu, Mingzhou; Zhu, Chun

    2018-01-01

    Mosquito-repellent incense is one of the most popular products used for dispelling mosquitos during summer in China. It releases large amounts of particulate and gaseous pollutants which constitute a potential hazard to human health. We conducted chamber experiment to characterize major pollutants from three types of mosquito-repellent incenses, further assessed the size-fractionated deposition in human respiratory system, and evaluated the indoor removing efficiency by fresh air. Results showed that the released pollutant concentrations were greater than permissible levels in regulations in GB3095-2012, as well as suggested by the World Health Organization (WHO). Formaldehyde accounted for 10-20% of the total amount of pollutants. Fine particles dominated in the total particulate concentrations. Geometric standard deviation (GSD) of particle number size distributions was in the range of 1.45-1.93. Count median diameter (CMD) ranged from 100 to 500 nm. Emission rates, burning rates and emission factors of both particulate and gaseous pollutants were compared and discussed. The deposition fractions in pulmonary airway from the disc solid types reached up to 52.7% of the total deposition, and the largest deposition appeared on juvenile group. Computational Fluid Dynamics (CFD) modellings indicated air-conditioner on and windows closed was the worst case. The highest concentration was 180-200 times over the standard limit. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Mosquito density, biting rate and cage size effects on repellent tests.

    PubMed

    Barnard, D R; Posey, K H; Smith, D; Schreck, C E

    1998-01-01

    Mosquito biting rates and the mean duration of protection (in hours) from bites (MDPB) of Aedes aegypti and Anopheles quadrimaculatus, using the repellent 'deet' (N,N-diethyl-3-methylbenzamide) on a 50 cm2 area of healthy human skin, were observed in small (27 l), medium (approximately 65 l) and large (125 l) cages containing low, medium or high densities of mosquitoes: respectively, 640, 128 or 49 cm3 of cage volume per female. At the initial treatment rate of approximately 0.4 microliter/cm2 (1 ml of 25% deet in ethanol on 650 cm2 of skin), the MDPB for deet against Ae. aegypti ranged from 4.5 to 6.5 h and was significantly less (5.0 +/- 0.8 h) in large cages compared with medium (6.2 +/- 0.9 h) and small (6.2 +/- 0.8 h) cages, regardless of the density. Against An. quadrimaculatus the MDPB for deet 0.4 microliter/cm2 was 1.5-8.0 h, less in small (3.7 +/- 2.3 h) and large (2.2 +/- 1.1 h) cages at medium (3.7 +/- 2.3 h) and high (2.5 +/- 1.7 h) mosquito densities, and was longest in medium cages (6.2 +/- 2.6 h) at low mosquito densities (5.8 +/- 2.8 h). With equinoxial photoperiodicity (light on 06.00-18.00 hours) the biting rate was influenced by the time of observation (08.00, 12.00, 16.00 hours) for Ae. aegypti but not for An. quadrimaculatus. For both species, the biting rate was inversely proportional to mosquito density and the MDPB. The shortest MDPBs were obtained in large cages with high densities of mosquitoes and longest protection times occurred in medium sized cages with low mosquito densities.

  17. Repellency of essential oils extracted from Thai native plants against Aedes aegypti (Linn.) and Culex quinquefasciatus (Say).

    PubMed

    Phukerd, Ubol; Soonwera, Mayura

    2014-09-01

    Repellent activity of essential oils derived from 10 Thai native plants, belonging to three families were evaluated against female Aedes aegypti and Culex quinquefasciatus and to compare them with a commercial chemical repellents (DEET; N,N-diethyl-3-methylbenzamide 20% w/w; Sketolene Shield). Each test repellent was applied at 1, 5, and 10% concentrations for testing by arm in cage method. The results showed significant differences in repellency among the repellents by mosquito species. The protection time of the essential oils against Ae. aegypti ranged from 3 to 30 min. According to the Culex mosquito, it showed the protection time ranged from 3 to 260 min. 10 % Boesenbergia rotunda essential oil provided the best efficiency, in which protection time was 4.3 h as equal as DEET. The essential oils which exhibited protection time more than 2 h were those of 10% Zingiber zerumbet, Litsea petiolata, Curcuma zedoaria, and Zingiber cassumunar essential oils (3.1, 2.8, 2.6, and 2.3 h, respectively). The biting percentage ranged from 0.9 to 18.0% and 0.8 to 3.6% against Ae. aegypti and Cx. quinquefasciatus, respectively. The results revealed that the potential of essential oil extracted from B. rotunda, Z. zerumbet, L. petiolata, C. zedoaria, and Z. cassumunar had attributes of good repellent and deterred biting. We recommend the five essential oils for further study to develop as commercial repellents.

  18. Field evaluation of the Off! Clip-on Mosquito Repellent (metofluthrin) against Aedes albopictus and Aedes taeniorhynchus (Diptera: Culicidae) in northeastern Florida.

    PubMed

    Xue, Rui-De; Qualls, Whitney A; Smith, Michael L; Gaines, Marcia K; Weaver, James H; Debboun, Mustapha

    2012-05-01

    Repellent efficacy of the Off! Clip-on Mosquito Repellent device (S. C. Johnson and Son, Inc., Racine, WI) containing Metofluthrin was evaluated on six human volunteers against the container-breeding mosquito Aedes albopictus (Skuse) and the salt marsh mosquito Aedes taeniorhynchus (Wiedemann) at two field locations in northeastern Florida. The device repelled mosquitoes by releasing a vaporized form of the pyrethroid insecticide metofluthrin ([AI] 31.2%) and provided 70% protection from Ae. albopictus bites for > 3 h. For the second field trial, a repellent device that was used in the first trial was tested after being open for >1 wk. This device provided 79% protection from Ae. taeniorhynchus bites for 3 h. Our field results showed that the repellent device was 70 and 79% effective at repelling Ae. albopictus and Ae. taeniorhynchus from human test subjects in both field locations in northeastern Florida.

  19. Micro/nanoencapsulation of essential oils and fragrances: Focus on perfumed, antimicrobial, mosquito-repellent and medical textiles.

    PubMed

    Ghayempour, Soraya; Montazer, Majid

    2016-09-01

    Herbal products have been widely used due to good antimicrobial, fragrance and medical properties. Essential oils and fragrances can be applied on the textile substrates as micro/nanocapsules to prolong lifetime by controlling the release rate. The present review tries to give a general overview on the application of micro/nanoencapsulated essential oils on the textile substrates to achieve aromatherapy textiles. These are divided into four diverse categories as the following: antimicrobial, perfumed, mosquito-repellent and medical textiles. The reports in this field revealed that the encapsulation technique plays an important role in the finishing of plant extracts on the textile substrates. It is also anticipated that aromatherapy textiles have to be developed in the new fields such as multifunctional textiles having wound-healing, antimicrobial and fragrant properties.

  20. Bitter-sensitive gustatory receptor neuron responds to chemically diverse insect repellents in the common malaria mosquito Anopheles quadrimaculatus.

    PubMed

    Sparks, Jackson T; Dickens, Joseph C

    2016-06-01

    Female mosquitoes feed on blood from animal hosts to obtain nutritional resources used for egg production. These contacts facilitate the spread of harmful human diseases. Chemical repellents are used to disrupt mosquito host-seeking and blood-feeding behaviors; however, little is known about the gustatory sensitivity of mosquitoes to known repellents. Here, we recorded electrical responses from gustatory receptor neurons (GRNs) housed within the labellar sensilla of female Anopheles quadrimaculatus to N,N-diethyl-3-methylbenzamide (DEET), picaridin, IR3535, 2-undecanone, p-menthane-3,8-diol, geraniol, trans-2-hexen-1-ol, quinine, and quinidine. A bitter-sensitive GRN responded to all tested repellents and quinine, a known feeding deterrent. Responses of the bitter-sensitive neuron to quinine and an isomer, quinidine, did not differ. Delayed bursts of electrical activity were observed in response to continuous stimulation with synthetic repellents at high concentrations. Electrophysiological recordings from bitter-sensitive GRNs associated with mosquito gustatory sensilla represent a convenient model to evaluate candidate repellents.

  1. Bitter-sensitive gustatory receptor neuron responds to chemically diverse insect repellents in the common malaria mosquito Anopheles quadrimaculatus

    NASA Astrophysics Data System (ADS)

    Sparks, Jackson T.; Dickens, Joseph C.

    2016-06-01

    Female mosquitoes feed on blood from animal hosts to obtain nutritional resources used for egg production. These contacts facilitate the spread of harmful human diseases. Chemical repellents are used to disrupt mosquito host-seeking and blood-feeding behaviors; however, little is known about the gustatory sensitivity of mosquitoes to known repellents. Here, we recorded electrical responses from gustatory receptor neurons (GRNs) housed within the labellar sensilla of female Anopheles quadrimaculatus to N,N-diethyl-3-methylbenzamide (DEET), picaridin, IR3535, 2-undecanone, p-menthane-3,8-diol, geraniol, trans-2-hexen-1-ol, quinine, and quinidine. A bitter-sensitive GRN responded to all tested repellents and quinine, a known feeding deterrent. Responses of the bitter-sensitive neuron to quinine and an isomer, quinidine, did not differ. Delayed bursts of electrical activity were observed in response to continuous stimulation with synthetic repellents at high concentrations. Electrophysiological recordings from bitter-sensitive GRNs associated with mosquito gustatory sensilla represent a convenient model to evaluate candidate repellents.

  2. Field evaluation of commercial repellents against the floodwater mosquito Psorophora columbiae (Diptera: Culicidae) in St. Johns County, Florida.

    PubMed

    Qualls, Whitney A; Xue, Rui-De; Holt, J Adam; Smith, Mike L; Moeller, Jeanne J

    2011-11-01

    Three plant-based repellents-REPEL LEMON Eucalyptus Insect Repellent Lotion (active ingredient [AI] 30% oil of eucalyptus), Bite Blocker Xtreme Sportsman Organic Insect Repellent ([AI] 3% soybean oil, 6% geranium oil, and 8% castor oil), and Bite Blocker BioUD Insect Repellent ([AI] 7.75% 2-undecanone)--were evaluated against OFF! ([AI] 15% N,N-diethyl-m-toluamide or N,N-diethyl-3-methyl-benzamide, also called DEET) at a field site in Elkton, FL, to determine the mean protection time provided against Psorophora columbiae (Dyar & Knab). These products provided different protection times against biting Ps. columbiae. REPEL provided the longest protection time (330 min) followed by Bite Blocker Xtreme Sportsman (163 min), Bite Blocker BioUD (140 min), and OFF! (130 min). This study provides the first information about plant-based insect repellent protection times against Ps. columbiae.

  3. Creams Formulated with Ocimum gratissimum L. and Lantana camara L. Crude Extracts and Fractions as Mosquito Repellents Against Aedes aegypti L. (Diptera: Culicidae)

    PubMed Central

    Keziah, Ezeike Amarachi; Nukenine, Elias Nchiwan; Danga, Simon Pierre Yinyang; Younoussa, Lame; Esimone, Charles Okechukwu

    2015-01-01

    Mosquitoes are the most deadly vectors of parasites that cause diseases such as malaria, yellow fever, and filariasis. In view of the recent increased interest in developing plant origin insecticides as an alternative to chemical insecticides, the objective of this study was to determine the repellent activity of creams formulated with methanol crude extract (MCE), hexane fraction (HF), and ethyl acetate fractions (EAFs) of Ocimum gratissimum and Lantana camara leaves in single and combined actions against female Aedes aegypti. Evaluation was carried out in the net cages (30 by 30 by 30 cm) containing 60 blood-starved female mosquitoes each and were assayed in the laboratory condition following World Health Organization 2009 protocol. All formulations (single and mixture) were applied at 2, 4, 6, and 8 mg/cm2 in the exposed area of human hands. Only acetone + white soft paraffin served as negative control and odomos (12% DEET) as positive control. All the formulations presented good protection against mosquito bites without any allergic reaction by the human volunteers. The repellent activity was dependent on the strength of the extracts and fractions. Among the tested formulations, the maximum protection time was observed in MCE (120 min) and EAF (150 min) of O. gratissimum; MCE:MCE (150 min) and HF:HF (120 min) mixtures of both plants. In addition, MCE:MCE and HF:HF mixtures from both plants showed possible synergistic effect. From the results, the combination of O. gratissimum and L. camara to formulate natural mosquito repellent using small amount of extracts can be encouraging to be an alternative to conventional DEET. PMID:25881633

  4. Creams formulated with Ocimum gratissimum L. and Lantana camara L. crude extracts and fractions as mosquito repellents against Aedes aegypti L. (Diptera: Culicidae).

    PubMed

    Keziah, Ezeike Amarachi; Nukenine, Elias Nchiwan; Danga, Simon Pierre Yinyang; Younoussa, Lame; Esimone, Charles Okechukwu

    2015-01-01

    Mosquitoes are the most deadly vectors of parasites that cause diseases such as malaria, yellow fever, and filariasis. In view of the recent increased interest in developing plant origin insecticides as an alternative to chemical insecticides, the objective of this study was to determine the repellent activity of creams formulated with methanol crude extract (MCE), hexane fraction (HF), and ethyl acetate fractions (EAFs) of Ocimum gratissimum and Lantana camara leaves in single and combined actions against female Aedes aegypti. Evaluation was carried out in the net cages (30 by 30 by 30 cm) containing 60 blood-starved female mosquitoes each and were assayed in the laboratory condition following World Health Organization 2009 protocol. All formulations (single and mixture) were applied at 2, 4, 6, and 8 mg/cm(2) in the exposed area of human hands. Only acetone + white soft paraffin served as negative control and odomos (12% DEET) as positive control. All the formulations presented good protection against mosquito bites without any allergic reaction by the human volunteers. The repellent activity was dependent on the strength of the extracts and fractions. Among the tested formulations, the maximum protection time was observed in MCE (120 min) and EAF (150 min) of O. gratissimum; MCE:MCE (150 min) and HF:HF (120 min) mixtures of both plants. In addition, MCE:MCE and HF:HF mixtures from both plants showed possible synergistic effect. From the results, the combination of O. gratissimum and L. camara to formulate natural mosquito repellent using small amount of extracts can be encouraging to be an alternative to conventional DEET. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

  5. Identification of the mosquito biting deterrent constituents from the Indian folk remedy plant Jatropha curcas

    USDA-ARS?s Scientific Manuscript database

    An investigation of the Indian folk remedy plant, Jatropha curcas, was performed to specifically identify the constituents responsible for the mosquito biting deterrent activity of the oil as a whole. Jatropha curcas seed oil is burned in oil lamps in India and part of Africa to repel biting insect...

  6. A novel approach for development and characterization of effective mosquito repellent cream formulation containing citronella oil.

    PubMed

    Yadav, Narayan Prasad; Rai, Vineet Kumar; Mishra, Nidhi; Sinha, Priyam; Bawankule, Dnyaneshwar Umrao; Pal, Anirban; Tripathi, Arun Kumar; Chanotiya, Chandan Singh

    2014-01-01

    Citronella essential oil (CEO) has been reported as an excellent mosquito repellent; however, mild irritancy and rapid volatility limit its topical application. It was aimed to develop a nonirritant, stable, and consistent cream of CEO with improved residence time on skin using an industrial approach. Phase inversion temperature technique was employed to prepare the cream. It was optimized and characterized based on sensorial evaluation, emulsification, and consistency in terms of softness, greasiness, stickiness, and pH. The optimum batch (B5) was evaluated for viscosity (90249.67±139.95 cP), texture profile with respect to firmness (38.67±0.88 g), spreadability (70.33±0.88 mJ), and extrudability (639.67±8.09±0.1 mJ) using texture analyzer along with two most popular marketed products selected as reference standard. Subsequently, B5 was found to be stable for more than 90 days and showed enhanced duration of mosquito repellency as compared to CEO. HS-GC ensured the intactness of CEO in B5. Investigated primary irritation index (PII 0.45) positioned B5 into the category of irritation barely perceptible. The pronounced texture profile and stability of B5 with extended residence time and less PII revealed its potential application in industry and offered a promising alternative to the marketed products of synthetic origin.

  7. Potential mosquito repellent compounds of Ocimum species against 3N7H and 3Q8I of Anopheles gambiae.

    PubMed

    Gaddaguti, Venugopal; Venkateswara Rao, Talluri; Prasada Rao, Allu

    2016-06-01

    Mosquitoes are exceptionally efficient in detecting their hosts for blood meal using odorant binding proteins, viz. 3N7H and 3Q8I and spread several dreadful diseases. DEET is a synthetic mosquito repellent widely used all over world for protection against mosquito bite. Reports reveal that, synthetic mosquito repellents may pose health problems in considerably large population. In view of the above fact, we made an attempt to discover efficient and novel natural mosquito repellent compounds with least impact on human health. Methanolic leaf extracts of Ocimum basilicum Linn. var. pilosum (willd.)-Benth and Ocimum tenuiflorum var. CIM-AYU were subjected to GC-MS analysis and obtained 35 phytochemical constituents. Repellent potentiality of the Ocimum compounds was assessed against 3Q8I and 3N7H of Anopheles gambiae. PDB structures of mosquito odorant binding proteins were downloaded, processed and docking studies were performed along with reference ligand DEET using Schrodinger MAESTRO 9.2 software. Molecular docking results reveal that phenol, 2-methoxy-3-(2-propenyl)-, licopersin, gamma sitosterol and benzene, 1,2-dimethoxy-4-(2-propenyl)- from O. tenuiflorum var. CIM-AYU are strongly bound with 3N7H. Whereas, 4h-1-benzopyran-4-one, 5-hydroxy-6,7-dimethoxy-2-(4-methoxyphenyl)-, catechol and monoacetin from O. basilicum Linn. var. pilosum (willd.)-Benth. show high binding affinity with odorant binding protein 3Q8I. All natural compounds tested in the present study display better docking scores than DEET. The results further substantiate that the 12 out of 35 compounds of the two Ocimum species found to be ideal candidates for design and development of potential mosquito repellents. ADME properties of the tested compounds further confirm that bioactive compounds of Ocimum species were found to be in acceptable range. Synchronized application of at least two different natural compounds (with best docking scores) which target 3N7H and 3Q8I (Odorant Binding Proteins

  8. Field investigation on the repellent activity of some aromatic plants by traditional means against Anopheles arabiensis and An. pharoensis (Diptera: Culicidae) around Koka, central Ethiopia.

    PubMed

    Dugassa, Sisay; Medhin, Girmay; Balkew, Meshesha; Seyoum, Aklilu; Gebre-Michael, Teshome

    2009-10-01

    A study was undertaken to evaluate the impact of traditional application methods of mosquito repellent plants in the reduction of the human-vector contact of malaria vectors in central Ethiopia. The plants (Corymbia citriodora, Eucalyptus camaldulensis, Ocimum suave and Ocimum basilicum) were tested by thermal expulsion and direct burning on traditional stoves in the field against two important malaria vectors in Ethiopia (Anopheles arabiensis and An. pharoensis). A Latin-square design was applied for randomly assigning the treatment plants and control to experimental houses over different nights. The percentage repellency of each candidate plant by both application methods was estimated from the catches of mosquitoes in the treatment and control houses. On direct burning of the plants, O. basilicum showed the highest percentage repellency (73.11%, P<0.001) and E. camaldulensis the least repellency (65.29%, P<0.001) against An. arabiensis. By the same method of application, C. citriodora on the other hand gave the highest repellency (72.87%, P<0.001) while E. camaldulensis was still the least repellent plant (66.60%, P<0.001) against An. pharoensis. On thermal expulsion, C. citriodora exhibited the highest repellency (78.69%, P<0.001) while E. camaldulensis was the lowest repellent plant (71.91%, P<0.001) against An. arabiensis. Against An. pharoensis, C. citriodora gave the highest repellency (72.9%, P<0.001) while E. camaldulensis still gave the least repellency (72.2%, P<0.001) on the same method of application. All the tested plants by both methods of application gave partial but significant protection (>65%) against the house-entry and biting of two important malaria vectors in Ethiopia, and thus have a potential to be used at least as supplements to other control methods. However, feasibility and actual impact on disease transmission need to be known on these and other potentially useful plants.

  9. Gustatory receptor neuron responds to DEET and other insect repellents in the yellow fever mosquito, aedes aegypti

    USDA-ARS?s Scientific Manuscript database

    Three gustatory receptor neurons were characterized for contact chemoreceptive sensilla on the labella of female yellow fever mosquitoes, Aedes aegypti. The neuron with the smallest amplitude spike responded to the feeding deterrent, quinine, as well as DEET and other insect repellents. Two other ...

  10. Effect of combining mosquito repellent and insecticide treated net on malaria prevalence in Southern Ethiopia: a cluster-randomised trial.

    PubMed

    Deressa, Wakgari; Yihdego, Yemane Y; Kebede, Zelalem; Batisso, Esey; Tekalegne, Agonafer; Dagne, Getachew A

    2014-03-28

    A mosquito repellent has the potential to prevent malaria infection, but there has been few studies demonstrating the effectiveness of combining this strategy with the highly effective long-lasting insecticidal nets (LLINs). This study aimed to determine the effect of combining community-based mosquito repellent with LLINs in the reduction of malaria. A community-based clustered-randomised trial was conducted in 16 rural villages with 1,235 households in southern Ethiopia between September and December of 2008. The villages were randomly assigned to intervention (mosquito repellent and LLINs, eight villages) and control (LLINs alone, eight villages) groups. Households in the intervention villages received mosquito repellent (i.e., Buzz-Off petroleum jelly, essential oil blend) applied every evening. The baseline survey was followed by two follow-up surveys, at one month interval. The primary outcome was detection of Plasmodium falciparum, Plasmodium vivax, or both parasites, through microscopic examination of blood slides. Analysis was by intention to treat. Baseline imbalances and clustering at individual, household and village levels were adjusted using a generalized linear mixed model. 3,078 individuals in intervention and 3,004 in control group were enrolled into the study. Compared with the control arm, the combined use of mosquito repellent and LLINs significantly reduced malaria infection of all types over time [adjusted Odds Ratio (aOR) = 0.66; 95% CI = 0.45-0.97]. Similarly, a substantial reduction in P. falciparum malaria infection during the follow-up surveys was observed in the intervention group (aOR = 0.53, 95% CI = 0.31-0.89). The protective efficacy of using mosquito repellent and LLINs against malaria infection of both P. falciparum/P. vivax and P. falciparum was 34% and 47%, respectively. Daily application of mosquito repellent during the evening followed by the use of LLINs during bedtime at community level has significantly

  11. Anopheline and culicine mosquitoes are not repelled by surfaces treated with the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana.

    PubMed

    Mnyone, Ladslaus L; Koenraadt, Constantianus Jm; Lyimo, Issa N; Mpingwa, Monica W; Takken, Willem; Russell, Tanya L

    2010-08-27

    Entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana, are promising bio-pesticides for application against adult malaria mosquito vectors. An understanding of the behavioural responses of mosquitoes towards these fungi is necessary to guide development of fungi beyond the 'proof of concept' stage and to design suitable intervention tools. Here we tested whether oil-formulations of the two fungi could be detected and avoided by adult Anopheles gambiae s.s., Anopheles arabiensis and Culex quinquefasciatus. The bioassays used a glass chamber divided into three compartments (each 250 × 250 × 250 mm): release, middle and stimulus compartments. Netting with or without fungus was fitted in front of the stimulus compartment. Mosquitoes were released and the proportion that entered the stimulus compartment was determined and compared between treatments. Treatments were untreated netting (control 1), netting with mineral oil (control 2) and fungal conidia formulated in mineral oil evaluated at three different dosages (2 × 1010, 4 × 1010 and 8 × 1010 conidia m-2). Neither fungal strain was repellent as the mean proportion of mosquitoes collected in the stimulus compartment did not differ between experiments with surfaces treated with and without fungus regardless of the fungal isolate and mosquito species tested. Our results indicate that mineral-oil formulations of M. anisopliae and B. bassiana were not repellent against the mosquito species tested. Therefore, both fungi are suitable candidates for the further development of tools that aim to control host-seeking or resting mosquitoes using entomopathogenic fungi.

  12. Anopheline and culicine mosquitoes are not repelled by surfaces treated with the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana

    PubMed Central

    2010-01-01

    Background Entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana, are promising bio-pesticides for application against adult malaria mosquito vectors. An understanding of the behavioural responses of mosquitoes towards these fungi is necessary to guide development of fungi beyond the 'proof of concept' stage and to design suitable intervention tools. Methods Here we tested whether oil-formulations of the two fungi could be detected and avoided by adult Anopheles gambiae s.s., Anopheles arabiensis and Culex quinquefasciatus. The bioassays used a glass chamber divided into three compartments (each 250 × 250 × 250 mm): release, middle and stimulus compartments. Netting with or without fungus was fitted in front of the stimulus compartment. Mosquitoes were released and the proportion that entered the stimulus compartment was determined and compared between treatments. Treatments were untreated netting (control 1), netting with mineral oil (control 2) and fungal conidia formulated in mineral oil evaluated at three different dosages (2 × 1010, 4 × 1010 and 8 × 1010 conidia m-2). Results Neither fungal strain was repellent as the mean proportion of mosquitoes collected in the stimulus compartment did not differ between experiments with surfaces treated with and without fungus regardless of the fungal isolate and mosquito species tested. Conclusion Our results indicate that mineral-oil formulations of M. anisopliae and B. bassiana were not repellent against the mosquito species tested. Therefore, both fungi are suitable candidates for the further development of tools that aim to control host-seeking or resting mosquitoes using entomopathogenic fungi. PMID:20799937

  13. Larvicidal and repellent potential of Zingiber nimmonii (J. Graham) Dalzell (Zingiberaceae) essential oil: an eco-friendly tool against malaria, dengue, and lymphatic filariasis mosquito vectors?

    PubMed

    Govindarajan, Marimuthu; Rajeswary, Mohan; Arivoli, Subramanian; Tennyson, Samuel; Benelli, Giovanni

    2016-05-01

    Mosquitoes (Diptera: Culicidae) are important vectors of terms of public health relevance, especially in tropical and sub-tropical regions. The continuous and indiscriminate use of conventional pesticides for the control of mosquito vectors has resulted in the development of resistance and negative impacts on non-target organisms and the environment. Therefore, there is a need for development of effective mosquito control tools. In this study, the larvicidal and repellent activity of Zingiber nimmonii rhizome essential oil (EO) was evaluated against the malaria vector Anopheles stephensi, the dengue vector Aedes aegypti, and the lymphatic filariasis vector Culex quinquefasciatus. The chemical composition of the EO was analyzed by gas chromatography-mass spectroscopy (GC-MS). GC-MS revealed that the Z. nimmonii EO contained at least 33 compounds. Major constituents were myrcene, β-caryophyllene, α-humulene, and α-cadinol. In acute toxicity assays, the EO showed significant toxicity against early third-stage larvae of An. stephensi, Ae. aegypti, and Cx. quinquefasciatus, with LC50 values of 41.19, 44.46, and 48.26 μg/ml, respectively. Repellency bioassays at 1.0, 2.0, and 5.0 mg/cm(2) of Z. nimmonii EO gave 100 % protection up to 120, 150, and 180 min. against An. stephensi, followed by Ae. aegypti (90, 120, and 150 min) and Cx. quinquefasciatus (60, 90, and 120 min). Furthermore, the EO was safer towards two non-target aquatic organisms, Diplonychus indicus and Gambusia affinis, with LC50 values of 3241.53 and 9250.12 μg/ml, respectively. Overall, this research adds basic knowledge to develop newer and safer natural larvicides and repellent from Zingiberaceae plants against malaria, dengue, and filariasis mosquito vectors.

  14. A Novel Approach for Development and Characterization of Effective Mosquito Repellent Cream Formulation Containing Citronella Oil

    PubMed Central

    Yadav, Narayan Prasad; Rai, Vineet Kumar; Mishra, Nidhi; Sinha, Priyam; Bawankule, Dnyaneshwar Umrao; Pal, Anirban; Tripathi, Arun Kumar; Chanotiya, Chandan Singh

    2014-01-01

    Citronella essential oil (CEO) has been reported as an excellent mosquito repellent; however, mild irritancy and rapid volatility limit its topical application. It was aimed to develop a nonirritant, stable, and consistent cream of CEO with improved residence time on skin using an industrial approach. Phase inversion temperature technique was employed to prepare the cream. It was optimized and characterized based on sensorial evaluation, emulsification, and consistency in terms of softness, greasiness, stickiness, and pH. The optimum batch (B5) was evaluated for viscosity (90249.67 ± 139.95 cP), texture profile with respect to firmness (38.67 ± 0.88 g), spreadability (70.33 ± 0.88 mJ), and extrudability (639.67 ± 8.09 ± 0.1 mJ) using texture analyzer along with two most popular marketed products selected as reference standard. Subsequently, B5 was found to be stable for more than 90 days and showed enhanced duration of mosquito repellency as compared to CEO. HS-GC ensured the intactness of CEO in B5. Investigated primary irritation index (PII 0.45) positioned B5 into the category of irritation barely perceptible. The pronounced texture profile and stability of B5 with extended residence time and less PII revealed its potential application in industry and offered a promising alternative to the marketed products of synthetic origin. PMID:25379509

  15. Relative efficacy of repellent-treated wristbands against three major mosquito (Diptera: Culicidae) vectors of disease, under laboratory conditions.

    PubMed

    Karunamoorthi, Kaliyaperumal; Sabesan, Shanmugavelu

    2009-12-01

    A laboratory study was carried out to evaluate the relative efficacy of N-N-diethyl-m-toluamide (DEET)- and N,N-diethyl phenylacetamide (DEPA)-treated wristbands against three major vector mosquitoes viz., Anopheles stephensi Liston, Culex quinquefasciatus Say and Aedes aegypti (L.), at two different concentrations viz., 1.5 and 2.0 mg/cm(2). Overall, both DEET and DEPA have shown various degrees of repellency impact against all three vector mosquitoes. DEET offered the highest 317.0 min mean complete protection against An. stephensi and DEPA provided 275.6 min complete protection to Cx. quinquefasciatus at 2.0 mg/cm(2). However, DEPA-treated wristbands did not show any significant differences in terms of reduction of human landing rate and mean complete protection time against An. stephensi and Ae. aegypti between 1.5 and 2.0 mg/cm(2). DEET demonstrated relatively higher repellency impact to vector mosquitoes than DEPA. However, χ(2) analysis revealed that there was no statistically significant difference found in repellent efficiency between DEET and DEPA (P = 0.924). The present study result suggests that repellent-treated wristbands could serve as a means of potential personal protection expedient to avoid insect's annoyance and reduce vector-borne disease transmission. They are extremely valuable whenever and wherever other kinds of personal protection measures are unfeasible.

  16. Larvicidal and repellent activity of Hyptis suaveolens (Lamiaceae) essential oil against the mosquito Aedes albopictus Skuse (Diptera: Culicidae).

    PubMed

    Conti, Barbara; Benelli, Giovanni; Flamini, Guido; Cioni, Pier Luigi; Profeti, Raffaele; Ceccarini, Lucia; Macchia, Mario; Canale, Angelo

    2012-05-01

    Lamiaceae have traditionally been used in developing countries for their insecticidal and repellent properties against several insect species. In our research, the essential oil (EO) extracted from fresh leaves of Hyptis suaveolens (Lamiaceae), and its main constituents were evaluated for larvicidal and repellent activity against the Asian tiger mosquito, Aedes albopictus Skuse (Diptera: Culicidae), currently the most invasive mosquito worldwide. H. suaveolens EO had insecticidal activity against A. albopictus larvae and mortality was dosage dependent. At the highest dosages of 450 and 400 ppm, there were no significant differences on larval mortality, as mortality ranged between 98.33% and 93.33%, respectively. At dosages ranging from 250 to 350 ppm, mortality rates were lower and not significantly different from each other. Terpinolene was found to be the most effective pure compound. Efficacy protection from H. suaveolens EO, at dosages ranging from 0.03748 to 0.7496 μg cm(-2) of skin, was evaluated during 150 min of observation. Results indicated that this EO had a significant repellent activity (RD(50) = 0.00035 μg cm(-2); RD(90) = 0.00048 μg cm(-2)), with differences in repellency rates, as a function of both concentration and observation time. Protection time ranged from 16 to 135 min. These results clearly evidenced that the larvicidal and repellent activity of H. suaveolens EO could be used for the development of new and safer products against A. albopictus.

  17. Mosquito Control

    MedlinePlus

    ... Labs and Research Centers Contact Us Share Mosquito Control About Mosquitoes General Information Life Cycle Information from ... Repellent that is Right for You DEET Mosquito Control Methods Success in mosquito control: an integrated approach ...

  18. Insecticidal and Repellent Activity of Several Plant-Derived Essential Oils Against Aedes aegypti.

    PubMed

    Castillo, Ruth M; Stashenko, Elena; Duque, Jonny E

    2017-03-01

    We examined the pupicidal, adulticidal, repellent, and oviposition-deterrent activities of essential oils (EOs) from Lippia alba, L. origanoides, Eucalyptus citriodora, Cymbopogon citratus, Cymbopogon flexuosus, Citrus sinensis , Cananga odorata , Swinglea glutinosa, and Tagetes lucida plants against Aedes aegypti under laboratory conditions. Pupicidal and adulticidal activities were assessed at exploratory concentrations of 250, 310, and 390 parts per million (ppm); and 30, 300, and 1,000 ppm, respectively. The greatest pupicidal activity was exhibited at 390 ppm with a 24-h exposure by L. origanoides, and 390 ppm with a 48-h exposure by Citrus sinensis . Lippia origanoides killed all adult mosquitoes at 300 ppm after 120 min of exposure. Only L. origanoides and E. citriodora EOs, applied at 1,000 ppm to human skin, produced the greatest repellency (100%) to host-seeking Ae. aegypti after 2 min of exposure; the repellency decreased between 12% and 10% after 15 min. Complete oviposition deterrence by gravid Ae. aegypti was observed for E. citriodora EOs at 200 ppm with an oviposition activity index of -1.00. These results confirm that the EOs assessed in this study have insecticidal, repellent, and oviposition-deterrent activities against the dengue vector, Ae. aegypti.

  19. Pyrethroids in indoor air during application of various mosquito repellents: Occurrence, dissipation and potential exposure risk.

    PubMed

    Li, Huizhen; Lydy, Michael J; You, Jing

    2016-02-01

    Commercial mosquito repellents (MRs) are generally applied as mosquito coils, electric vaporizers (liquid and solid) or aerosol spray, with pyrethroids often being the active ingredients. Four types of MRs were applied individually in a 13-m(2) bedroom to study the occurrence, dissipation and risk of pyrethroids in indoor environments. Total air concentrations (in gas and particle phases) of allethrin, cypermethrin, dimefluthrin and tetramethrin during MR applications were three to six orders of magnitude higher than indoor levels before the applications, and allethrin emitted from a vaporizing mat reached the highest concentration measured during the current study (18,600 ± 4980 ng m(-3)). The fate of airborne pyrethroids was different when the four MRs were applied. Particle-associated allethrin accounted for 95% of its total concentration from the aerosol spray, and was significantly higher than the vaporizing mat (67%), suggesting that the released phase of MRs and size distribution of pyrethroid-carrying particles played important roles in the gas-particle partitioning process. In addition, air exchange through open windows more effectively reduced the levels of indoor pyrethroids than ventilation using an air conditioner. The inhalation risk quotients (RQ) for allethrin derived from application of the vaporizing mat ranged from 1.04 ± 0.40 to 1.98 ± 0.75 for different age-subgroups of the population, suggesting potential exposure risk. Special attention should be given concerning indoor exposure of pyrethroids to these vulnerable groups. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. In vitro characterization and mosquito (Aedes aegypti) repellent activity of essential-oils-loaded nanoemulsions.

    PubMed

    Nuchuchua, Onanong; Sakulku, Usawadee; Uawongyart, Napaporn; Puttipipatkhachorn, Satit; Soottitantawat, Apinan; Ruktanonchai, Uracha

    2009-01-01

    The nanoemulsions composed of citronella oil, hairy basil oil, and vetiver oil with mean droplet sizes ranging from 150 to 220 nm were prepared and investigated both in vitro and in vivo. Larger emulsion droplets (195-220 nm) shifted toward a smaller size (150-160 nm) after high-pressure homogenization and resulted in higher release rate. We proposed that thin films obtained from the nanoemulsions with smaller droplet size would have higher integrity, thus increasing the vaporization of essential oils and subsequently prolonging the mosquito repellant activity. The release rates were fitted with Avrami's equations and n values were in the same range of 0.6 to 1.0, implying that the release of encapsulated limonene was controlled by the diffusion mechanism from the emulsion droplet. By using high-pressure homogenization together with optimum concentrations of 5% (w/w) hairy basil oil, 5% (w/w) vetiver oil (5%), and 10% (w/w) citronella oil could improve physical stability and prolong mosquito protection time to 4.7 h due to the combination of these three essential oils as well as small droplet size of nanoemulsion.

  1. Bioassay-guided investigation of two Monarda essential oils as repellents of yellow fever mosquito Aedes aegypti.

    PubMed

    Tabanca, Nurhayat; Bernier, Ulrich R; Ali, Abbas; Wang, Mei; Demirci, Betul; Blythe, Eugene K; Khan, Shabana I; Baser, K Husnu Can; Khan, Ikhlas A

    2013-09-11

    As part of an ongoing research program to identify active mosquito repellents, Monarda bradburiana Beck and Monarda fistulosa L. essential oils showed good repellent activity with minimum effective dosages (MED) of 0.055 ± 0.036 and 0.078 ± 0.027 mg/cm(2), respectively, compared to reference standard N,N-diethyl-3-methylbenzamide (DEET) (0.039 ± 0.014 mg/cm(2)). Systematic bioassay-guided fractionation of essential oils of both Monarda species was performed to identify the active repellent compounds, and isolated pure compounds were individually tested for repellency. Of the isolated compounds, carvacrol, thymol, eugenol, and carvacrol methyl ether were found to be the repellent compounds with MEDs in the range of 0.013-0.063 mg/cm(2). Active repellent compounds were also tested for larvicidal activity against 1-day-old Aedes aegypti larvae. Thymol was the best larvicide among the tested individual compounds (LD50 of 13.9 ppm). None of the individual compounds showed cytotoxicity against mammalian cells; however, the essential oils were toxic to all cell lines.

  2. Encapsulation of Citronellal from Citronella Oil using β-Cyclodextrin and Its Application as Mosquito (Aedes aegypti) Repellent

    NASA Astrophysics Data System (ADS)

    Pujiastuti, A.; Cahyono, E.; Sumarni, W.

    2017-04-01

    Mosquito (Aedes aegypti) is a threat to human health due to its capability to spread dengue fever. Citronellal in citronella oil is one ofnatural active compound that has repellent activity. Essential oil is a sensitive material whichiseasy to degrade. Encapsulation is coating technology use to avoid essential oil from degradation problems. β-Cyclodextrin is frequently used as acoating material in encapsulation. The aims of this study wereto prepare the citronellal encapsulation and to evaluate its control-released and repellency. In this study, encapsulated citronellal was prepared using 83.65% citronellal and encapsulation were prepared with the theemulsion-based method and dried using freeze-dryer. The best-controlled release was performed in citronellal encapsulate with a weight ratio of 1:1 (citronellal : β-Cyclodextrin). The morphology of encapsulated citronellal was analyzed using SEM. SEM result showed it has three dimensions random shape and agglomerate in some part with thebrighter spot. Citronellal encapsulate showed the highest repellent effect at 84,67% for 5 minutes in mosquito repellency test although it has lower result compared with citronellal inliquid form.

  3. Adulticidal, repellent, and ovicidal properties of indigenous plant extracts against the malarial vector, Anopheles stephensi (Diptera: Culicidae).

    PubMed

    Panneerselvam, Chellasamy; Murugan, Kadarkarai

    2013-02-01

    Mosquito-borne diseases with an economic impact create loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates. Mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. Extracts from plants may be alternative sources of mosquito control agents because they constitute a rich source of bioactive compounds that are biodegradable into nontoxic products and potentially suitable for use to control mosquitoes. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, this study was undertaken to assess the adulticidal, repellent, and ovicidal potential of the crude hexane, ethyl acetate, benzene, aqueous, and methanol solvent extracts from the medicinal plants Andrographis paniculata, Cassia occidentalis, and Euphorbia hirta against the medically important mosquito vector, Anopheles stephensi (Diptera: Culicidae).The adult mortality was observed after 24 h of exposure. All extracts showed moderate adulticide effects; however, the highest adult mortality was found in methanol extract of A. paniculata followed by C. occidentalis and E. hirta against the adults of A. stephensi with LC(50) and LC(90) values of 210.30, 225.91, and 263.91 ppm and 527.31, 586.36, and 621.91 ppm, respectively. The results of the repellent activity of hexane, ethyl acetate, benzene, aqueous, and methanol extract of A. paniculata, C. occidentalis, and E. hirta plants at three different concentrations of 1.0, 3.0, and 6.0 mg/cm(2) were applied on skin of forearm in man and exposed against adult female mosquitoes. In this observation, these three plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity is dependent on the strength of the plant extracts

  4. Plant extracts as potential mosquito larvicides

    PubMed Central

    Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

    2012-01-01

    Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain and adverse effects on environmental quality and non target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are non-toxic, easily available at affordable prices, biodegradable and show broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on phytochemical sources and mosquitocidal activity, their mechanism of action on target population, variation of their larvicidal activity according to mosquito species, instar specificity, polarity of solvents used during extraction, nature of active ingredient and promising advances made in biological control of mosquitoes by plant derived secondary metabolites have been reviewed. PMID:22771587

  5. Plant extracts as potential mosquito larvicides.

    PubMed

    Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

    2012-05-01

    Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain and adverse effects on environmental quality and non target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are non-toxic, easily available at affordable prices, biodegradable and show broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on phytochemical sources and mosquitocidal activity, their mechanism of action on target population, variation of their larvicidal activity according to mosquito species, instar specificity, polarity of solvents used during extraction, nature of active ingredient and promising advances made in biological control of mosquitoes by plant derived secondary metabolites have been reviewed.

  6. The use of mosquito repellents at three sites in India with declining malaria transmission: surveys in the community and clinic.

    PubMed

    van Eijk, Anna Maria; Ramanathapuram, Lalitha; Sutton, Patrick L; Peddy, Nandini; Choubey, Sandhya; Mohanty, Stuti; Asokan, Aswin; Ravishankaran, Sangamithra; Priya, G Sri Lakshmi; Johnson, Justin Amala; Velayutham, Sangeetha; Kanagaraj, Deena; Patel, Ankita; Desai, Nisha; Tandel, Nikunj; Sullivan, Steven A; Wassmer, Samuel C; Singh, Ranveer; Pradhan, K; Carlton, Jane M; Srivasatava, H C; Eapen, Alex; Sharma, S K

    2016-07-27

    Repellents such as coils, vaporizers, mats and creams can be used to reduce the risk of malaria and other infectious diseases. Although evidence for their effectiveness is limited, they are advertised as providing an additional approach to mosquito control in combination with other strategies, e.g. insecticide-treated nets. We examined the use of repellents in India in an urban setting in Chennai (mainly Plasmodium vivax malaria), a peri-urban setting in Nadiad (both P. vivax and P. falciparum malaria), and a more rural setting in Raurkela (mainly P. falciparum malaria). The use of repellents was examined at the household level during a census, and at the individual level in cross-sectional surveys and among patients visiting a clinic with fever or other symptoms. Factors associated with their use were examined in a multivariate analysis, and the association between malaria and the use of repellents was assessed among survey- and clinic participants. Characteristics of participants differed by region, with more people of higher education present in Chennai. Use of repellents varied between 56-77 % at the household level and between 32-78 % at the individual level. Vaporizers were the main repellents used in Chennai, whereas coils were more common in Nadiad and Raurkela. In Chennai and Nadiad, vaporizers were more likely to be used in households with young male children. Vaporizer use was associated with higher socio-economic status (SES) in households in Chennai and Nadiad, whereas use of coils was greater in the lower SES strata. In Raurkela, there was a higher use of coils among the higher SES strata. Education was associated with the use of a repellent among survey participants in Chennai and clinic study participants in Chennai and Nadiad. Repellent use was associated with less malaria in the clinic study in Chennai and Raurkela, but not in the surveys, with the exception of the use of coils in Nadiad. Repellents are widely used in India. Their use is

  7. Insect repellent plants traditional usage practices in the Ethiopian malaria epidemic-prone setting: an ethnobotanical survey.

    PubMed

    Karunamoorthi, Kaliyaperumal; Hailu, Teklu

    2014-02-12

    The usage of insect repellent plants (IRPs) is one of the centuries-old practices in Africa. In Ethiopia, malaria remains a leading cause of morbidity and mortality, subsequently the majority of people have a tendency to apply various plants as repellents to reduce or interrupt the biting activity of insects. Accordingly, this survey was undertaken to document and evaluate knowledge and usage practices of the local inhabitants on IRPs in the malaria epidemic-prone setting of Ethiopia. Ethnobotanical survey was conducted between January and May 2013. Selected 309 household members were interviewed by administering pre-tested questionnaire on knowledge and usage practices of repellent plants, in Bechobore Kebele, Jimma Zone, Ethiopia. Overall, 70.2% (217/309) and 91.8% (199/217) of the respondents have had ample awareness and usage practices of repellent plants, respectively. Informants cited about twenty-two plant species as repellents and also indicated that these plants are useful(85.5%), accessible(86.8%), and affordable(83.9%) too. Residents mainly applying dried leaves [93.9% (187/199)] by means of burning/smouldering [98.9% (197/199)] with the traditional charcoal stove to repel insects, primarily mosquitoes. About 52.8% (105/199) of the informants using approximately 15g of dried plant-materials every day. A Chi-square analysis shows statistically a significant link between the knowledge on repellent plants and gender as well as average monthly income although not with the age of the respondents. Nevertheless, the repellent plant usage custom was not significantly associated with gender, monthly income, and age of the informants. Though most of the people have had an adequate awareness still a sizable faction of society suffers with deprivation of IRPs knowledge and usage practices. Therefore, this study calls for more surveys to conserve the existing indigenous knowledge and cultural practices. It could lay the first stone to develop the next generation cost

  8. Insect repellent plants traditional usage practices in the Ethiopian malaria epidemic-prone setting: an ethnobotanical survey

    PubMed Central

    2014-01-01

    Background The usage of insect repellent plants (IRPs) is one of the centuries-old practices in Africa. In Ethiopia, malaria remains a leading cause of morbidity and mortality, subsequently the majority of people have a tendency to apply various plants as repellents to reduce or interrupt the biting activity of insects. Accordingly, this survey was undertaken to document and evaluate knowledge and usage practices of the local inhabitants on IRPs in the malaria epidemic-prone setting of Ethiopia. Methods Ethnobotanical survey was conducted between January and May 2013. Selected 309 household members were interviewed by administering pre-tested questionnaire on knowledge and usage practices of repellent plants, in Bechobore Kebele, Jimma Zone, Ethiopia. Results Overall, 70.2% (217/309) and 91.8% (199/217) of the respondents have had ample awareness and usage practices of repellent plants, respectively. Informants cited about twenty-two plant species as repellents and also indicated that these plants are useful(85.5%), accessible(86.8%), and affordable(83.9%) too. Residents mainly applying dried leaves [93.9% (187/199)] by means of burning/smouldering [98.9% (197/199)] with the traditional charcoal stove to repel insects, primarily mosquitoes. About 52.8% (105/199) of the informants using aproximately15g of dried plant-materials every day. A Chi-square analysis shows statistically a significant link between the knowledge on repellent plants and gender as well as average monthly income although not with the age of the respondents. Nevertheless, the repellent plant usage custom was not significantly associated with gender, monthly income, and age of the informants. Conclusion Though most of the people have had an adequate awareness still a sizable faction of society suffers with deprivation of IRPs knowledge and usage practices. Therefore, this study calls for more surveys to conserve the existing indigenous knowledge and cultural practices. It could lay the first stone

  9. Microencapsulation of citronella oil for mosquito-repellent application: formulation and in vitro permeation studies.

    PubMed

    Solomon, B; Sahle, F F; Gebre-Mariam, T; Asres, K; Neubert, R H H

    2012-01-01

    Citronella oil (CO) has been reported to possess a mosquito-repellent action. However, its application in topical preparations is limited due to its rapid volatility. The objective of this study was therefore to reduce the rate of evaporation of the oil via microencapsulation. Microcapsules (MCs) were prepared using gelatin simple coacervation method and sodium sulfate (20%) as a coacervating agent. The MCs were hardened with a cross-linking agent, formaldehyde (37%). The effects of three variables, stirring rate, oil loading and the amount of cross-linking agent, on encapsulation efficiency (EE, %) were studied. Response surface methodology was employed to optimize the EE (%), and a polynomial regression model equation was generated. The effect of the amount of cross-linker was insignificant on EE (%). The response surface plot constructed for the polynomial equation provided an optimum area. The MCs under the optimized conditions provided EE of 60%. The optimized MCs were observed to have a sustained in vitro release profile (70% of the content was released at the 10th hour of the study) with minimum initial burst effect. Topical formulations of the microencapsulated oil and non-microencapsulated oil were prepared with different bases, white petrolatum, wool wax alcohol, hydrophilic ointment (USP) and PEG ointment (USP). In vitro membrane permeation of CO from the ointments was evaluated in Franz diffusion cells using cellulose acetate membrane at 32 °C, with the receptor compartment containing a water-ethanol solution (50:50). The receptor phase samples were analyzed with GC/MS, using citronellal as a reference standard. The results showed that microencapsulation decreased membrane permeation of the CO by at least 50%. The amount of CO permeated was dependent on the type of ointment base used; PEG base exhibited the highest degree of release. Therefore, microencapsulation reduces membrane permeation of CO while maintaining a constant supply of the oil

  10. Field evaluation of G10, a celery (Apium graveolens)-based topical repellent, against mosquitoes (Diptera: Culicidae) in Chiang Mai province, northern Thailand.

    PubMed

    Tuetun, B; Choochote, W; Pongpaibul, Y; Junkum, A; Kanjanapothi, D; Chaithong, U; Jitpakdi, A; Riyong, D; Wannasan, A; Pitasawat, B

    2009-02-01

    The potential of G10, a celery (Apium graveolens)-based topical product, as a repellent against natural mosquito populations was evaluated in comparison to commercial (Insect Block 28) and standard (25% DEET) repellents in Chiang Mai province, northern Thailand. These repellent products afforded encouragingly excellent personal protection against a broad range of mosquito species belonging to various genera, including Aedes, Anopheles, Armigeres, Culex, and Mansonia. No mosquito bite was observed on the volunteers treated with G10 and Insect Block 28 throughout the field study, whereas two species, i.e., six A. barbirostris and two A. subalbatus, came to bite or land on 25% DEET-treated volunteers. Thus, it can be concluded that while G10 and Insect Block 28 exhibited similarly powerful repellent activities with complete (100%) protection, 25% DEET was effective in minimizing bites with 99.68% protection. G10 formula was also studied for physical properties and biological stability after being kept under two conditions; a heating and cooling cycle, and varying temperature and time storage. Most samples of stored G10 not only demonstrated a similarity in appearance and physical properties, but also provided comparable repellency to that of the fresh preparation. These findings encourage commercial development of G10 formula as an alternative to conventional synthetic repellents.

  11. Repellent activity of catmint, Nepeta cataria, and iridoid nepetalactone isomers against Afro-tropical mosquitoes, ixodid ticks and red poultry mites.

    PubMed

    Birkett, Michael A; Hassanali, Ahmed; Hoglund, Solveig; Pettersson, Jan; Pickett, John A

    2011-01-01

    The repellent activity of the essential oil of the catmint plant, Nepeta cataria (Lamiaceae), and the main iridoid compounds (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone, was assessed against (i) major Afro-tropical pathogen vector mosquitoes, i.e. the malaria mosquito, Anopheles gambiae s.s. and the Southern house mosquito, Culex quinquefasciatus, using a World Health Organisation (WHO)-approved topical application bioassay (ii) the brown ear tick, Rhipicephalus appendiculatus, using a climbing repellency assay, and (iii) the red poultry mite, Dermanyssus gallinae, using field trapping experiments. Gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS) analysis of two N. cataria chemotypes (A and B) used in the repellency assays showed that (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone were present in different proportions, with one of the oils (from chemotype A) being dominated by the (4aS,7S,7aR) isomer (91.95% by GC), and the other oil (from chemotype B) containing the two (4aS,7S,7aR) and (4aS,7S,7aS) isomers in 16.98% and 69.83% (by GC), respectively. The sesquiterpene hydrocarbon (E)-(1R,9S)-caryophyllene was identified as the only other major component in the oils (8.05% and 13.19% by GC, respectively). Using the topical application bioassay, the oils showed high repellent activity (chemotype A RD(50)=0.081 mg cm(-2) and chemotype B RD(50)=0.091 mg cm(-2)) for An. gambiae comparable with the synthetic repellent DEET (RD(50)=0.12 mg cm(-2)), whilst for Cx. quinquefasciatus, lower repellent activity was recorded (chemotype A RD(50)=0.34 mg cm(-2) and chemotype B RD(50)=0.074 mg cm(-2)). Further repellency testing against An. gambiae using the purified (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone isomers revealed overall lower repellent activity, compared to the chemotype A and B oils. Testing of binary mixtures of the (4aS,7S,7aR) and (4aS,7S,7aS) isomers across a range of ratios, but all at the same overall dose (0.1 mg), revealed not only a

  12. The essential oil of Zingiber officinalis Linn (Zingiberaceae) as a mosquito larvicidal and repellent agent against the filarial vector Culex quinquefasciatus Say (Diptera: Culicidae).

    PubMed

    Pushpanathan, Thambusamy; Jebanesan, Arulsamy; Govindarajan, Marimuthu

    2008-05-01

    Essential oils extracted by steam distillation from Zingiber officinalis was evaluated for larvicidal and repellent activity against the filarial mosquito Culex quinquefasciatus. The larval mortality was observed after 24 h treated for late third instar. The LC50 value was 50.78 ppm. Skin repellent test at 1.0, 2.0, 3.0, and 4.0 mg/cm2 concentration of Z. officinalis gave 100% protection up to 15, 30, 60, and 120 min. These results clearly reveal that the essential oil of Z. officinalis served as a potential larvicidal and repellent agent against filarial vector C. quinquefasciatus.

  13. Experimental hut evaluation of linalool spatial repellent agar gel against Anopheles gambiae sensu stricto mosquitoes in a semi-field system in Bagamoyo, Tanzania.

    PubMed

    Tambwe, Mgeni Mohamed; Mbeyela, Edgar Mtaki; Massinda, Brian Migamyo; Moore, Sarah Jane; Maia, Marta Ferreira

    2014-12-05

    Malaria vector control is in need of new tools to face its current challenges such as the spread of pyrethroid-resistance and the increase of outdoor feeding mosquitoes. New strategies such as spatial repellents need to be evaluated as supplemental tools to existing control measures such as insecticide treated bed nets and indoor residual spraying. Linalool is a naturally occurring terpene alcohol commonly found in flowers and spices with reportedly repellent properties. Four experimental huts fitted with exit traps and enclosed inside a large screened semi-field system were used for the evaluation. The tested spatial repellent product consisted of an agar gel emanator containing 73% linalool. Two rounds of experiments using a Latin square design were conducted to evaluate the efficacy of the linalool emanators compared to no treatment (negative control) and a transfluthrin coil (positive) against lab-reared disease free Anopheles gambiae s.s.. The emanators were hung inside experimental huts where two volunteers were sleeping unprotected. The outcome measures were repellency, % feeding inhibition, %mortality and post 24 h % mortality. Unlike the mosquito coil, the linalool emanators did not show any feeding inhibition, repellency or induced mortality compared to the negative control. On the other hand mosquitoes kept for 24 h post exposure were 3 times more likely to die after being exposed to two 73% linalool emanators than the negative control. Our results indicate that linalool agar gel emanators are not adequate as a spatial repellent against Anopheles gambiae s.s.. However adding linalool to known repellent formulations could be advantageous, not only because of its pleasant scent but also because of the delayed mortality effect it has on mosquitoes.

  14. Plant Secondary Metabolites as Rodent Repellents: a Systematic Review.

    PubMed

    Hansen, Sabine C; Stolter, Caroline; Imholt, Christian; Jacob, Jens

    2016-09-01

    The vast number of plant secondary metabolites (PSMs) produced by higher plants has generated many efforts to exploit their potential for pest control. We performed a systematic literature search to retrieve relevant publications, and we evaluated these according to PSM groups to derive information about the potential for developing plant-derived rodent repellents. We screened a total of 54 publications where different compounds or plants were tested regarding rodent behavior/metabolism. In the search for widely applicable products, we recommend multi-species systematic screening of PSMs, especially from the essential oil and terpenoid group, as laboratory experiments have uniformly shown the strongest effects across species. Other groups of compounds might be more suitable for the management of species-specific or sex-specific issues, as the effects of some compounds on particular rodent target species or sex might not be present in non-target species or in both sexes. Although plant metabolites have potential as a tool for ecologically-based rodent management, this review demonstrates inconsistent success across laboratory, enclosure, and field studies, which ultimately has lead to a small number of currently registered PSM-based rodent repellents.

  15. Repellency of synthetic and plant-derived preparations for Culicoides imicola.

    PubMed

    Braverman, Y; Chizov-Ginzburg, A

    1997-10-01

    The study was conducted to find a safer and longer lasting repellent for C.imicola than di-ethyl toluamide (DEET), to validate whether the current recommendations in Israel for application of repellents during an outbreak of disease caused by pathogens borne by Culicoides imicola are justified, and to test plant-derived preparations as potential replacements for the synthetic repellents. Seven repellents were compared by a method using treated netting across the entrance of a suction light trap. Those inferior to DEET were: oregano and Herbipet which showed a slight non-significant repellency for 2 h, Tri-Tec 14TM which showed significant (P < 0.05) repellency with respect to controls for 2 h and Stomoxin which showed significant (P < 0.05) repellency for 1 h. As the active ingredient of Stomoxin is permethrin, this indicates that recommendations to spray animals with this insecticide to prevent the spread of C.imicola-borne pathogens will not be useful. The repellents superior to DEET were: the plant-derived material Ag 1000 that repelled significantly (P < 0.05) with respect to controls for up to 4 h following a similar pattern to but somewhat more strongly than DEET, and pyrethroid-T which exerted significant (P < 0.05) repellency for 9 h. Pyrethroid-T proved to be the best repellent tested, and if sprayed nightly it might provide protection from C.imicola-borne pathogens.

  16. [Evaluation of the use of repellent against mosquito bite by military personnel in the Amazon Basin].

    PubMed

    Ribas, Jonas; Carreño, Ana Maria

    2010-01-01

    In Brazil, diseases caused by insect bites are frequent. Therefore, it is extremely important that prophylatic measures are adequately carried out, especially in endemic areas such as the Amazon which receives a great number of visitors, for both business and tourism purposes.. To evaluate the use of insect repellents available in the market by military personnel who often go in missions in the middle of the jungle, in the Amazon region. Fifty - one militaries in the Amazon region were selected and they answered a questionnaire in June/2008. 63,7% of the militaries used products that contained Deet in the maximum concentration of only 15% that has minimum repellent action; 36% reported to combine these products with sun protective products which increased the risk of intoxication; 36,4% used a natural repellent during their missions; two of the militaries participants used vitamin B and considered their repellent action ineffective. The repellents that contain Deet and which were used by the group present concentrations that are lower than the concentrations considered safe for using in the jungle. It was frequent the combination of Deet with sun protective products ,which is a potentially toxic association. Natural repellents that have "andiroba" and" copaíba" as components presented a higher perception of protection from the participants.

  17. Essential oils of Cupressus funebris, Juniperus communis, and J. chinensis (Cupressaceae) as repellents against ticks (Acari: Ixodidae) and mosquitoes (Diptera: Culicidae) and as toxicants against mosquitoes.

    PubMed

    Carroll, John F; Tabanca, Nurhayat; Kramer, Matthew; Elejalde, Natasha M; Wedge, David E; Bernier, Ulrich R; Coy, Monique; Becnel, James J; Demirci, Betul; Başer, Kemal Husnu Can; Zhang, Jian; Zhang, Sui

    2011-12-01

    Juniperus communis leaf oil, J. chinensis wood oil, and Cupressus funebris wood oil (Cupressaceae) from China were analyzed by gas chromatography and gas chromatography-mass spectrometry. We identified 104 compounds, representing 66.8-95.5% of the oils. The major components were: α-pinene (27.0%), α-terpinene (14.0%), and linalool (10.9%) for J. communis; cuparene (11.3%) and δ-cadinene (7.8%) for J. chinensis; and α-cedrene (16.9%), cedrol (7.6%), and β-cedrene (5.7%) for C. funebris. The essential oils of C. funebris, J. chinensis, and J. communis were evaluated for repellency against adult yellow fever mosquitoes, Aedes aegypti (L.), host-seeking nymphs of the lone star tick, Amblyomma americanum (L.), and the blacklegged tick, Ixodes scapularis Say, and for toxicity against Ae. aegypti larvae and adults, all in laboratory bioassays. All the oils were repellent to both species of ticks. The EC(95) values of C. funebris, J. communis, and J. chinensis against A. americanum were 0.426, 0.508, and 0.917 mg oil/cm(2) filter paper, respectively, compared to 0.683 mg deet/cm(2) filter paper. All I. scapularis nymphs were repelled by 0.103 mg oil/cm(2) filter paper of C. funebris oil. At 4 h after application, 0.827 mg oil/cm(2) filter paper, C. funebris and J. chinensis oils repelled ≥80% of A. americanum nymphs. The oils of C. funebris and J. chinensis did not prevent female Ae. aegypti from biting at the highest dosage tested (1.500 mg/cm(2) ). However, the oil of J. communis had a Minimum Effective Dosage (estimate of ED(99) ) for repellency of 0.029 ± 0.018 mg/cm(2) ; this oil was nearly as potent as deet. The oil of J. chinensis showed a mild ability to kill Ae. aegypti larvae, at 80 and 100% at 125 and 250 ppm, respectively. © 2011 The Society for Vector Ecology.

  18. Bioassay-Guided Investigation of Two Monarda Essential Oils as Repellents of Yellow Fever Mosquito Aedes aegypti

    DTIC Science & Technology

    2013-08-06

    been major sources for the discovery of novel natural insecticides and repellents.9 On the basis of our preliminary screening results from medicinal and...fistulosa (wild bergamot) has been used medicinally by Native American groups for treating wounds, heart problems, colds and flu, stomach pain, nose...receptor interactions. The ornamental and traditional medicinal plants M. bradburiana and M. fistulosa can contribute to native plant gardens

  19. A novel test cage with an air ventilation system as an alternative to conventional cages for the efficacy testing of mosquito repellents.

    PubMed

    Obermayr, U; Rose, A; Geier, M

    2010-11-01

    We have developed a novel test cage and improved method for the evaluation of mosquito repellents. The method is compatible with the United States Environmental Protection Agency, 2000 draft OPPTS 810.3700 Product Performance Test Guidelines for Testing of Insect Repellents. The Biogents cages (BG-cages) require fewer test mosquitoes than conventional cages and are more comfortable for the human volunteers. The novel cage allows a section of treated forearm from a volunteer to be exposed to mosquito probing through a window. This design minimizes residual contamination of cage surfaces with repellent. In addition, an air ventilation system supplies conditioned air to the cages after each single test, to flush out and prevent any accumulation of test substances. During biting activity tests, the untreated skin surface does not receive bites because of a screen placed 150 mm above the skin. Compared with the OPPTS 810.3700 method, the BG-cage is smaller (27 liters, compared with 56 liters) and contains 30 rather than hundreds of blood-hungry female mosquitoes. We compared the performance of a proprietary repellent formulation containing 20% KBR3023 with four volunteers on Aedes aegypti (L.) (Diptera: Culicidae) in BG- and conventional cages. Repellent protection time was shorter in tests conducted with conventional cages. The average 95% protection time was 4.5 +/- 0.4 h in conventional cages and 7.5 +/- 0.6 h in the novel BG-cages. The protection times measured in BG-cages were more similar to the protection times determined with these repellents in field tests.

  20. Evaluation of the laboratory mouse model for screening topical mosquito repellents.

    PubMed

    Rutledge, L C; Gupta, R K; Wirtz, R A; Buescher, M D

    1994-12-01

    Eight commercial repellents were tested against Aedes aegypti 0 and 4 h after application in serial dilution to volunteers and laboratory mice. Results were analyzed by multiple regression of percentage of biting (probit scale) on dose (logarithmic scale) and time. Empirical correction terms for conversion of values obtained in tests on mice to values expected in tests on human volunteers were calculated from data obtained on 4 repellents and evaluated with data obtained on 4 others. Corrected values from tests on mice did not differ significantly from values obtained in tests on volunteers. Test materials used in the study were dimethyl phthalate, butopyronoxyl, butoxy polypropylene glycol, MGK Repellent 11, deet, ethyl hexanediol, Citronyl, and dibutyl phthalate.

  1. Repellent and insecticidal efficacy of a new combination of fipronil and permethrin against three mosquito species (Aedes albopictus, Aedes aegypti and Culex pipiens) on dogs.

    PubMed

    Fankhauser, Becky; Dumont, Pascal; Hunter, James S; McCall, John W; Kaufmann, Christian; Mathis, Alexander; Young, David R; Carroll, Scott P; McCall, Scott; Chester, S Theodore; Soll, Mark D

    2015-01-30

    Three laboratory studies were conducted to assess the repellent and insecticidal efficacy of a combination of fipronil and permethrin (Frontline Tri- Act/Frontect) against three mosquito species (Aedes albopictus, Aedes aegypti and Culex pipiens) on dogs. In each study, 16 healthy adult dogs were allocated to two groups. Eight dogs were treated with the new topical spot-on combination of fipronil and permethrin on Day 0 and the other eight dogs served as untreated controls. Each dog was exposed to mosquitoes on Days 1, 7, 14, 21 and 28 (and also on Day 35 in the A. aegypti study). After a 1-h exposure period, all mosquitoes were counted and categorized as live or dead and fed or non-fed. Live mosquitoes were kept in an insectary and observed for mortality counts 4, 24 and 48 h post-exposure (PE) for Aedes spp. and 24 and 48 h PE for C. pipiens. Repellency and insecticidal efficacies were defined as the percent reduction in the number of fed and live mosquitoes, respectively, in the treated group as compared to the untreated control group. Repellency against A. albopictus was ≥93.4% through Day 21 and 86.9% on Day 28. It was ≥91.0% through Day 35 against A. aegypti and ≥90.4% through Day 28 against C. pipiens. Insecticidal efficacy against A. albopictus was ≥97.1% at 24 h PE from Day 7 to Day 28. It was ≥98.0% for the first 3 weeks and still 75.7% on Day 35 against A. aegypti at 24 h PE. For C. pipiens, insecticidal efficacy ranged from 93.8% (Day 7) to 30.9% (Day 28) at 48 h PE. A single topical administration of the combination of fipronil and permethrin provides repellency against mosquitoes on dogs for at least 4 weeks. The product may therefore significantly reduce the potential for the transmission of vector-borne pathogens through the inhibition of mosquito feeding, as well as the discomfort associated with mosquito bites. Moreover, mosquito mortality was induced by contact with the treated dogs, which could aid in the control of mosquitoes, and

  2. Acute toxicity and repellent activity of the Origanum scabrum Boiss. & Heldr. (Lamiaceae) essential oil against four mosquito vectors of public health importance and its biosafety on non-target aquatic organisms.

    PubMed

    Govindarajan, Marimuthu; Kadaikunnan, Shine; Alharbi, Naiyf S; Benelli, Giovanni

    2016-11-01

    The recent outbreaks of dengue, chikungunya, and Zika virus highlighted the pivotal importance of mosquito vector control in tropical and subtropical areas worldwide. However, mosquito control is facing hot challenges, mainly due to the rapid development of pesticide resistance in Culicidae and the limited success of biocontrol programs on Aedes mosquitoes. In this framework, screening botanicals for their mosquitocidal potential may offer effective and eco-friendly tools in the fight against mosquitoes. In the present study, the essential oil (EO) obtained from the medicinal plant Origanum scabrum was analyzed by GC-MS and evaluated for its mosquitocidal and repellent activities towards Anopheles stephensi, Aedes aegypti, Culex quinquefasciatus, and Culex tritaeniorhynchus. GC-MS analysis showed a total of 28 compounds, representing 97.1 % of the EO. The major constituents were carvacrol (48.2 %) and thymol (16.6 %). The EO was toxic effect to the A. stephensi, A. aegypti, C. quinquefasciatus, and C. tritaeniorhynchus larvae, with LC 50 of 61.65, 67.13, 72.45, and 78.87 μg/ml, respectively. Complete ovicidal activity was observed at 160, 200, 240, and 280 μg/ml, respectively. Against adult mosquitoes, LD 50 were 122.38, 134.39, 144.53, and 158.87 μg/ml, respectively. In repellency assays, the EOs tested at 1.0, 2.5, and 5.0 mg/cm 2 concentration of O. scabrum gave 100 % protection from mosquito bites up to 210, 180, 150, and 120 min, respectively. From an eco-toxicological point of view, the EO was tested on three non-target mosquito predators, Gambusia affinis, Diplonychus indicus, and Anisops bouvieri, with LC 50 ranging from 4162 to 12,425 μg/ml. Overall, the EO from O. scabrum may be considered as a low-cost and eco-friendly source of phytochemicals to develop novel repellents against Culicidae.

  3. Toxicity comparison of eight repellents against four species of female mosquitoes (Diptera: Culicidae)

    USDA-ARS?s Scientific Manuscript database

    The relative toxicities of eight repellents (DMP, Rutgers 612, DEET, IR3535, Picardin, PMD, AI3-35765, and AI3-37220) were evaluated by topical application against females of Aedes aegypti (L.) Culex quinquefasciatus Say, Anopheles quadrimaculatus Say, and Anopheles albimanus Weidemann. Based on 24h...

  4. Phoenix dactylifera L. spathe essential oil: Chemical composition and repellent activity against the yellow fever mosquito

    USDA-ARS?s Scientific Manuscript database

    Date palm, Phoenix dactylifera L. (Arecaceae), grows commonly in the Arabian Peninsula and is traditionally used to treat various diseases. The aim of the present study was to identify chemical composition of the essential oil and to investigate the repellent activity. The essential oil of P. dacty...

  5. Advice to travelers on topical insect repellent use against dengue mosquitoes in Far North Queensland, Australia.

    PubMed

    Webb, Cameron E; Russell, Richard C

    2011-01-01

    Dengue outbreaks occur annually in Far North Queensland, Australia. Advice on topical insect repellents provided by health authorities rarely addresses the wide range of formulations and active ingredients currently registered for use in Australia. Recommendations on the use of registered products require review. © 2011 International Society of Travel Medicine.

  6. Field evaluation of four spatial repellent devices against Arkansas rice-land mosquitoes

    USDA-ARS?s Scientific Manuscript database

    Four commercially available spatial repellent devices were tested in a rice land habitat near Stuttgart, Arkansas after semi-field level assessments had been made at the Center for Medical, Agricultural, and Veterinary Entomology, ARS, USDA in Gainesville, FL. OFF! Clip-On® (a.i. metofluthrin, S.C....

  7. Discovery of mosquito attractants and attraction-inhibitors invited talk on attractants and repellents

    USDA-ARS?s Scientific Manuscript database

    The United States Department of Agriculture (USDA) has developed repellents and insecticides for the U.S. military since 1942. A small component of this research program has aimed at the discovery of attractants that can be used to produce potent lures for haematophagous arthropods, with a primary f...

  8. Repellency Effect of Essential Oils of some Native Plants and Synthetic Repellents against Human Flea, Pulex irritans (Siphonaptera: Pulicidae)

    PubMed Central

    Ghavami, Mohammad Bagher; Poorrastgoo, Fahimeh; Taghiloo, Behrooz; Mohammadi, Jamshid

    2017-01-01

    Background: Fleas are important vectors of human and animal disease, and control measures for protection against their bites and flea-borne diseases are necessary. Methods: The essential oils (EOs) of four native medicinal plants, Ziziphora tenuiore, Myrtus communis, Achillea wilhelmsii and Mentha piperita were isolated by hydrodistillation technique and analyzed by GC-MC. The repellent activity of EOs and synthetic compounds, DEET and permethrin, were assayed on human subjects against field collected fleas. The effective doses of 50% and 90% of EOs and synthetic compounds were estimated by probit analysis of dose and response regression line. Results: Analysis of EOs revealed about 19 major components. All oils were found to be more repellent (ED50 range= 208–955μg cm−2) than DEET and permethrin (ED50 range= 27–182 × 103μg cm−2). Thyme and myrtle oils showed high repellent activities and among the total detected terpenes, thymol (36.26%) and α-pinene (32.5%) were the major components of those oils respectively. Conclusion: Low repellent potency of DEET and permethrin against fleas might be related to flea olfactory system and further molecular and electrophysiological studies are required to conceive new ideas for the discovery and development of the next generation of repellents. Based on high repellent activity of thyme and myrtle essential oils against Pulex irritans further studies should be staged to develop their appropriate effective formulations. Likewise, field trials should be carried out to evaluate the operational feasibility and dermal toxicity over a long period. PMID:29026857

  9. Repellency of Plant Extracts against the Legume Flower Thrips Megalurothrips sjostedti (Thysanoptera: Thripidae)

    PubMed Central

    Abtew, Andnet; Subramanian, Sevgan; Cheseto, Xavier; Kreiter, Serge; Tropea Garzia, Giovanna; Martin, Thibaud

    2015-01-01

    Megalurothrips sjostedti Trybom is an important pest of cowpea (Vigna unguiculata L.) in Africa. To propose an alternative to chemical control, the repellency of 24 plant extracts was evaluated against adult female thrips of M. sjostedti in the laboratory. Plant extracts in ethanol were separately applied on a filter paper disk in a still air visual cue olfactometer. The results showed highly significant differences in repellency among extract type, concentration and their interactions. We classified the level of repellency into four categories as strong, good, moderate and weak or non- repellent based on hierarchical ascendant classification. We identified Piper nigrum, Cinnamomum zeylanicum, Cinnamomum cassia as strong repellents. Five extracts were classified as good, eight as moderate and the remaining eight extracts were weak or non-repellent. Repellency of the extracts increased with the concentration suggesting that the behavioral response of M. sjostedti was dose-dependent. Mono- and sesquiterpene hydrocarbon compounds from seven highly repellent extracts were identified by gas chromatography-mass spectrometry (GC/MS). The use of repellent extracts could be useful in developing integrated pest management strategies for thrips on legume crops. In this regard, the specific modes of action of the identified compounds need to be investigated to incorporate them into the existing crop protection strategies. PMID:26463406

  10. Field evaluation and user acceptability of repellent formulations containing DEET against mosquitoes in Australia.

    PubMed

    Frances, Stephen P

    2013-09-01

    Field efficacy trials comparing 2 formulations of deet against mosquitoes in Redcliffe, Queensland, Australia were conducted in February 2009. A formulation containing 35% deet in a gel (Australian Defence Force deet) provided > 95% protection for 3 h, while a formulation containing 40% deet in ethanol (Bushman) in a spray applicator provided > 95% for 6 h. A user acceptability study showed that 82% of soldiers using the Bushman formulation during contingency operations for 14-28 days in Timor-Leste would recommend this formulation to others and believed that the formulation provided protection against mosquitoes.

  11. In vitro comparison of three common essential oils mosquito repellents as inhibitors of the Ross River virus

    PubMed Central

    Ralambondrainy, Miora; Belarbi, Essia; Viranaicken, Wildriss; Baranauskienė, Renata; Venskutonis, Petras Rimantas; Desprès, Philippe; El Kalamouni, Chaker; Sélambarom, Jimmy

    2018-01-01

    Background The essential oils of Cymbopogon citratus (CC), Pelargonium graveolens (PG) and Vetiveria zizanioides (VZ) are commonly used topically to prevent mosquito bites and thus the risk of infection by their vectored pathogens such as arboviruses. However, since mosquito bites are not fully prevented, the effect of these products on the level of viral infection remains unknown. Objectives To evaluate in vitro the essentials oils from Reunion Island against one archetypal arbovirus, the Ross River virus (RRV), and investigate the viral cycle step that was impaired by these oils. Methods The essential oils were extracted by hydrodistillation and analyzed by a combination of GC-FID and GC×GC-TOF MS techniques. In vitro studies were performed on HEK293T cells to determine their cytotoxicity, their cytoprotective and virucidal capacities on RRV-T48 strain, and the level of their inhibitory effect on the viral replication and residual infectivity prior, during or following viral adsorption using the reporter virus RRV-renLuc. Results Each essential oil was characterized by an accurate quantification of their terpenoid content. PG yielded the least-toxic extract (CC50 > 1000 μg.mL-1). For the RRV-T48 strain, the monoterpene-rich CC and PG essential oils reduced the cytopathic effect but did not display virucidal activity. The time-of-addition assay using the gene reporter RRV-renLuc showed that the CC and PG essential oils significantly reduced viral replication and infectivity when applied prior, during and early after viral adsorption. Overall, no significant effect was observed for the low monoterpene-containing VZ essential oil. Conclusion The inhibitory profiles of the three essential oils suggest the high value of the monoterpene-rich essential oils from CC and PG against RRV infection. Combined with their repellent activity, the antiviral activity of the essential oils of CC and PG may provide a new option to control arboviral infection. PMID:29771946

  12. Evaluating plant and plant oil repellency against the sweetpotato whitefly

    USDA-ARS?s Scientific Manuscript database

    The sweetpotato whitefly, Bemisia tabaci is a major insect pest of vegetables world-wide. We evaluated the effect of commercial plant oils – garlic oil, hot pepper wax, and mustard oil against B. tabaci. Cucumber plants served as the control. Additional treatments included no plants or oil (clear ai...

  13. Repellent Activity of Apiaceae Plant Essential Oils and their Constituents Against Adult German Cockroaches.

    PubMed

    Lee, Hyo-Rim; Kim, Gil-Hah; Choi, Won-Sil; Park, Il-Kwon

    2017-04-01

    We evaluated the repellent activity of 12 Apiaceae plant essential oils and their components against male and female adult German cockroaches, Blattella germanica L., to find new natural repellents. Of all the plant essential oils tested, ajowan (Trachyspermum ammi Sprague) and dill (Anethum graveolens L.) essential oils showed the most potent repellent activity against male and female adult German cockroaches. Repellent activities of chemicals already identified in active oils were also investigated. Of the compounds identified, carvacrol, thymol, and R-(-)-carvone showed >80% repellent activity against male and female adult German cockroaches at 2.5 µg/cm2. S-(+)-Carvone, (+)-dihydrocarvone, and terpinen-4-ol showed >70% repellent activity against male and female adult German cockroaches at 10 µg/cm2. Our results indicated that Apiaceae plant essential oils and their constituents have good potential as natural repellents against adult German cockroaches. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. [Repellent activity of plant essential oils against bites of Lutzomyia migonei (Diptera: Psychodidae)].

    PubMed

    Nieves, Elsa; Fernández Méndez, Janett; Lias, José; Rondón, Maritza; Briceño, Benito

    2010-12-01

    Natural repellents from plant extracts have demonstrated good efficacy against bites of some insect species. The present study evaluated the repellent effect of essential oils extracted from 8 plants species against bites of Lutzomyia migonei, the Leishmania vector. The essential oils were extracted by steam destillation in Clevenger chamber, from the following plants: Hyptis suaveolens, Pimenta racemosa, Piper marginatum, Monticalia imbricatifolia, Pseudognaphalium caeruleocanum, Espeletia shultzii, Plecthranthus amboinicus and Cinnamomun zeylanicum. Repellency tests were performed under laboratory conditions by the human hand method in cage assays, using female colonies of L. migonei. The more effective oils were tested at variable concentrations on different volunteers. The protection percentage and time were calculated. The results showed what oils of P. caeruleocanum and C. zeylanicum were the most effective. Although P. amboinicus oil also had repellent effect showed an irritant effect. The oils P. marginatum, H. suaveolens and P. racemosa showed no repellent effect, while the rest of oil extracts showed significant repellency in variable degrees. P. caeruleocanum and C. zeylanicum oils provided the 95% protection against bites of L. migonei for 3 h. The P. caeruleocanum oil showed the greatest protection time, with a mean over 4h and 3h at concentrations of 50% and 10% respectively. The results suggest that the P. caeruleocanum oil could represent a potential natural repellent against Leishmania vectors.

  15. Insect repellent activity of medicinal plant oils against Aedes aegypti (Linn.), Anopheles minimus (Theobald) and Culex quinquefasciatus Say based on protection time and biting rate.

    PubMed

    Phasomkusolsil, Siriporn; Soonwera, Mayura

    2010-07-01

    This study investigated insect bite protection and length of the protection with 30 repellents which were divided into 3 categories: plant oil, essential oil and essential oil with ethyl alcohol, tested against three mosquito species, Aedes aegypti, Anopheles minimus and Culex quinquefasciatus, under laboratory conditions. The plant oil group was comprised of Phlai (Zingiber cassumunar) and Sweet basil (Ocimum basilicum). Both substances were effective as repellents and feeding deterrents against An. minimus (205 minutes protection time and a biting rate of 0.9%), Cx. quinquefasciatus (165 minutes protection time and 0.9% biting rate) and Ae. aegypti (90 minutes protection time and 0.8% biting rate). Essential oil from citronella grass (Cymbopogon nardus) exhibited protection against biting from all 3 mosquito species: for An. minimus, Cx. quinquefasciatus and Ae. aegypti, the results were 130 minutes and 0.9%, 140 minutes and 0.8%, and 115 minutes and 0.8%, respectively. The period of protection time against Ae. aegypti for all repellent candidates tested was lower than the Thai Industrial Standards Institute (TISI) determined time of greater than 2 hours.

  16. Repellents Inhibit P450 Enzymes in Stegomyia (Aedes) aegypti

    PubMed Central

    Jaramillo Ramirez, Gloria Isabel; Logan, James G.; Loza-Reyes, Elisa; Stashenko, Elena; Moores, Graham D.

    2012-01-01

    The primary defence against mosquitoes and other disease vectors is often the application of a repellent. Despite their common use, the mechanism(s) underlying the activity of repellents is not fully understood, with even the mode of action of DEET having been reported to be via different mechanisms; e.g. interference with olfactory receptor neurones or actively detected by olfactory receptor neurones on the antennae or maxillary palps. In this study, we discuss a novel mechanism for repellence, one of P450 inhibition. Thirteen essential oil extracts from Colombian plants were assayed for potency as P450 inhibitors, using a kinetic fluorometric assay, and for repellency using a modified World Health Organisation Pesticide Evaluations Scheme (WHOPES) arm-in cage assay with Stegomyia (Aedes) aegypti mosquitoes. Bootstrap analysis on the inhibition analysis revealed a significant correlation between P450-inhibition and repellent activity of the oils. PMID:23152795

  17. Longitudinal evaluation of Ocimum and other plants effects on the feeding behavioral response of mosquitoes (Diptera: Culicidae) in the field in Tanzania

    PubMed Central

    Kweka, Eliningaya J; Mosha, Franklin W; Lowassa, Asanterabi; Mahande, Aneth M; Mahande, Michael J; Massenga, Charles P; Tenu, Filemoni; Lyatuu, Ester E; Mboya, Michael A; Temu, Emmanuel A

    2008-01-01

    Background The use of repellent materials from plants against nuisance insects is common with great potential to compliment existing malaria control programmes and this requires evaluation in the field. Ocimum plant species, Ocimum suave (Willd) and O. kilimandscharicum (Guerke) materials and their essential oils extracted by steam distillation were evaluated in the field and experimental huts for repellence, exophily and feeding inhibition effects against three mosquito species, Anopheles arabiensis (Patton), An. gambiae ss (Giles) and Culex quinquefasciatus (Say). The protective effect of essential oils from Ocimum plants were compared with N, N-diethly-3- methylbenzamide (DEET), a standard synthetic repellent. Also, the protective effect of fumigation by burning of repellent plants; Ocimum suave, Ocimum kilimandscharicum, Azadirachta indica, Eucalyptus globules and Lantana camara were tested in experimental huts and selected local houses. Results In the field, protection by Ocimum plants from mosquito bites was high and there was small variation among different mosquito species. Protection efficiency was 93.4%, 91.98% and 89.75% for An. arabiensis while for Cx. quinquefaciatus it was 91.30%, 88.65% and 90.50% for DEET, Ocimum suave and O. kilimandscharicum respectively. In the experimental hut, deterrence induced by burning of Ocimum and other plants ranged from 73.1.0% to 81.9% for An. arabiensis and 56.5% to 67.8% for Cx. quinquefaciatus, while feeding inhibition was 61.1% to 100% for An. arabiensis and 50% to 100% for Cx. quinquefaciatus. Evaluations under field conditions confirmed high protective efficacy, enhanced feeding inhibition and house entry inhibition (Deterrence). Conclusion This study shows the potential of Ocimum suave and Ocimum kilimandscharicum crude extracts and whole plants of Ocimum suave, Ocimum kilimandscharicum, Azadirachta indica, Eucalyptus globules and Lantana camara for use in protecting against human biting while the burning of

  18. Behavioral Response of Aedes aegypti Mosquito towards Essential Oils Using Olfactometer

    PubMed Central

    Uniyal, Ashish; Tikar, Sachin N; Mendki, Murlidhar J; Singh, Ram; Shukla, Shakti V; Agrawal, Om P; Veer, Vijay; Sukumaran, Devanathan

    2016-01-01

    Background: Aedes aegypti mosquito is responsible for transmitting human diseases like dengue and chikungunya. Personal or space protection with insect repellents is a practical approach to reducing human mosquito contact, thereby minimizing disease transmission. Essential oils are natural volatile substances from plants used as protective measure against blood-sucking mosquitoes. Methods: Twenty-three essential oils were evaluated for their repellent effect against Ae. aegypti female mosquito in laboratory conditions using Y-tube olfactometer. Results: The essential oils exhibited varying degree of repellency. Litsea oil showed 50.31%, 60.2 %, and 77.26% effective mean repellency at 1 ppm, 10 ppm and 100 ppm respectively, while DEET exhibited 59.63%, 68.63%, 85.48% and DEPA showed 57.97%, 65.43%, and 80.62% repellency at respective above concentrations. Statistical analysis revealed that among the tested essential oils, litsea oil had effective repellency in comparison with DEET and DEPA against Ae. aegypti mosquito at all concentration. Essential oils, DEET and DEPA showed significant repellence against Ae. aegypti (P< 0.05) at all 3 concentration tested. Conclusion: Litsea oil exhibited effective percentage repellency similar to DEET and DEPA. The essential oils are natural plant products that may be useful for developing safer and newer herbal based effective mosquito repellents. PMID:27308295

  19. Repellent and Anti-quorum Sensing Activity of Six Aromatic Plants Occurring in Colombia.

    PubMed

    Cervantes-Ceballos, Leonor; Caballero-Gallardo, Karina; Olivero-Verbel, Jesus

    2015-10-01

    Essential oils (EOs) are widely used as biopesticides and to control bacterial infections. This study describes the ability of six EOs isolated from plants cultivated in Colombia to perform as repellents against Ulomoides dermestoides and as quorum sensing (QS) inhibitors. EOs from Aloysia triphylla, Cymbopogon nardus, Lippia origanoides, Hyptis suaveolens, Swinglea glutinosa and Eucalyptus globulus were repellents classified as Class IV, IV, IV, III, II, and II, respectively, whereas the commercial repellent IR3535 only reached Class II after 2 h exposure. All EOs presented small, but significant inhibitory properties against the QS system in Escherichia coli (pJBA132) at 25 μg/mL after 4 h exposure. These data suggest evaluated EOs from Colombia are sustainable, promising new sources of natural repellents and could be important as anti-quorum sensing molecules.

  20. Shifting the paradigm in Dirofilaria immitis prevention: blocking transmission from mosquitoes to dogs using repellents/insecticides and macrocyclic lactone prevention as part of a multimodal approach.

    PubMed

    McCall, John W; Varloud, Marie; Hodgkins, Elizabeth; Mansour, Abdelmoneim; DiCosty, Utami; McCall, Scott; Carmichael, James; Carson, Ben; Carter, Justin

    2017-11-09

    This study assessed the influence of a topical ectoparasiticide (dinotefuran-permethrin-pyriproxyfen, DPP, Vectra® 3D, Ceva Animal Health) combined with a macrocyclic lactone (milbemycin oxime, MBO, Interceptor®, Virbac) on transmission of heartworm L3 from mosquitoes to dogs and subsequent development of worms in treated dogs exposed to infected mosquitoes. Thirty-two beagle dogs were allocated to four groups of eight: Group 1, untreated controls; Group 2, treated topically with DPP on Day 0; Group 3, treated orally with MBO on Day 51; and Group 4, treated with DPP on Day 0 and MBO on Day 51. Dogs were exposed under sedation for 1 h to Dirofilaria immitis (JYD-34)-infected Aedes aegypti on Days 21 and 28. At the end of each exposure, mosquitoes were classified as live, moribund, or dead and engorged or non-engorged. Live or moribund mosquitoes were incubated for daily survival assessment for 3 days. Mosquitoes were dissected before and after exposure to estimate the number of L3 transmitted to each dog. Dogs were necropsied 148 to 149 days postinfection. A total of 418 mosquitoes fed on the 16 dogs in Groups 1 and 3, while only 6 fed on the 16 DPP-treated dogs in Groups 2 and 4. Mosquito anti-feeding (repellency) effect in Groups 2 and 4 was 98.1 and 99.1%, respectively. The estimated numbers of L3 transmitted to controls, DPP-treated, MBO-treated and DPP + MBO-treated dogs were 76, 2, 78, and 1, respectively. No heartworms were detected in any of the DPP + MBO-treated dogs (100% efficacy), while 8 out of 8 were infected in the control group (range, 21-66 worms per dog), 8 out of 8 were infected in the MBO-treated group (58% efficacy), and 3 out of 8 were infected in the DPP-treated group (96% efficacy). DPP repelled and killed most mosquitoes that were capable of transmitting heartworm L3 to dogs. The "Double Defense" protocol of DPP + MBO had better efficacy for protecting dogs against heartworm transmission and infection than MBO alone. This added

  1. Repellency Awareness Graphic

    EPA Pesticide Factsheets

    Companies can apply to use the voluntary new graphic on product labels of skin-applied insect repellents. This graphic is intended to help consumers easily identify the protection time for mosquitoes and ticks and select appropriately.

  2. Mosquito and tick repellency of two Anthemis essential oils from Saudi Arabia

    USDA-ARS?s Scientific Manuscript database

    The essential oils (EO) of Anthemis melampodina (Am) and Anthemis scrobicularis (As) (Asteraceae) were extracted from the aerial parts of the plant by hydrodistillation, and their chemical compositions were subsequently analyzed using GC-FID and GC-MS. Fifty-six components representing 85.5% of the ...

  3. Water repellency, plants, agriculture abandonment and fire in citrus plantations. The Canyoles river watershed study site

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Jordán, Antonio; Doerr, Stefan Helmut

    2017-04-01

    Soil water repellency (SWR) is a key soil property that determine the soil and water losses, soil fertility and plant development. Although until the 90's the soil water repellency was seeing as an uncommon soil characteristic, now is considered a key soil property to understand the soil hydrology (Alanís et al., 2016; Hewelke et al., 2016; Keesstra et al., 2016; Jiménez-Morillo et al., 2016). The inspiring research of Leonard DeBano and Stefan H Doerr changed the fate of the science (DeBano, 2000; Doerr et al. 2000). Soil water repellency was associated to forest fire affected land due to the pioneer contribution of professor DeBano in the 70's and Professor Doerr in the 90's. The research during the last two decades demonstrate that fire affects the reallocation of the hydrophobic substances and can reduce or increase the severity of the soil water repellence at different soil depths and horizons. The SWR is usually measured by sampling to show the influence of key soil properties (texture, structure, plant cover, litter, season…) on the degree of soil water repellency. The sampling is applied usually with a few drops when the Water Drop Penetration Time method is applied, and this inform of the time of penetration, but few researches focussed in the spatial distribution of the water repellency, which is a key factor of the runoff generation, the water infiltration and the water redistribution such as demonstrate the wetting fronts. Our approach research the spatial distribution of the water repellency by means of an intense sampling of soil surface water repellency. One thousand drops were distributed in a square meter (100 lines separated 1 cm and 100 drops per each line of 100 cm, with a total od 1000 drops in 1m2) on 10 sampling points on 4 land managements: ploughing and herbicide agriculture fields treatment), abandoned 10 years, and burnt. The research was carried out in citrus plantations of the Canyoles river watershed. The results show that the

  4. Plant-based strategies for mosquito control

    USDA-ARS?s Scientific Manuscript database

    Mosquitoes transmit some of the most devastating emerging infectious diseases of humans, domestic animals, and wildlife. Although vector control by use of chemical insecticides has played an important role in prevention and management of these diseases, their sustained use remains questionable due t...

  5. Isolation and Identification of Mosquito (Aedes aegypti) Biting-Deterrent Compounds from the Native American Ethnobotanical Remedy Plant Hierochloë odorata (Sweetgrass).

    PubMed

    Cantrell, Charles L; Jones, A Maxwell P; Ali, Abbas

    2016-11-09

    Hierochloë odorata (L.) P. Beauv. (Poaceae), commonly known as sweetgrass, has documented use as an insect repellent by the Flatheads of Montana and Blackfoot of Alberta. Both the Flatheads of Montana and Blackfoot of Alberta would use braided plant material in a sachet in clothing or burn them from one end as incense, air/clothing freshener, and insect repellent. This study evaluated the insect-repellent properties of this plant using an in vitro mosquito Aedes aegypti feeding bioassay-directed approach to identify the compound(s) responsible for the observed activities. Evaluation of crude extracts produced from H. odorata revealed that the hydrodistillate had the highest level of mosquito biting deterrence. Fractionation of this extract, followed by re-evaluation for mosquito biting deterrence, produced many active fractions, which were evaluated by spectroscopic techniques and determined to contain phytol, coumarin, and 2-methoxy-4-vinylphenol. Phytol and coumarin were both determined to be responsible for the Ae. aegypti biting deterrency. Scientific evidence reported here validates its traditional use as a biting-insect deterrent.

  6. Repellent response of female agromyzid flies to leafminer-infested bean plants

    USDA-ARS?s Scientific Manuscript database

    Liriomyza sativae Blanchard, L. trifolii (Burgess) and L. huidobrensis (Blanchard) are three invasive leafminer species (Diptera: Agromyzidae) in China that have caused significant economic damage on vegetables and ornamental plants. In the current study, the repellent responses of female adults to ...

  7. Reduction of mosquito biting-pressure: spatial repellents or mosquito traps? A field comparison of seven commercially available products in Israel

    USDA-ARS?s Scientific Manuscript database

    The personal protection capability of seven commercially available mosquito control devices (MCD) is compared under field conditions in Israel. Trials were performed in a high biting-pressure area inhabited by large populations of mosquito and biting midge species and using human volunteers for lan...

  8. Essential oils of aromatic Egyptian plants repel nymphs of the tick Ixodes ricinus (Acari: Ixodidae).

    PubMed

    El-Seedi, Hesham R; Azeem, Muhammad; Khalil, Nasr S; Sakr, Hanem H; Khalifa, Shaden A M; Awang, Khalijah; Saeed, Aamer; Farag, Mohamed A; AlAjmi, Mohamed F; Pålsson, Katinka; Borg-Karlson, Anna-Karin

    2017-09-01

    Due to the role of Ixodes ricinus (L.) (Acari: Ixodidae) in the transmission of many serious pathogens, personal protection against bites of this tick is essential. In the present study the essential oils from 11 aromatic Egyptian plants were isolated and their repellent activity against I. ricinus nymphs was evaluated Three oils (i.e. Conyza dioscoridis L., Artemisia herba-alba Asso and Calendula officinalis L.) elicited high repellent activity in vitro of 94, 84.2 and 82%, respectively. The most active essential oil (C. dioscoridis) was applied in the field at a concentration of 6.5 µg/cm 2 and elicited a significant repellent activity against I. ricinus nymphs by 61.1%. The most repellent plants C. dioscoridis, C. officinalis and A. herba-alba yielded essential oils by 0.17, 0.11 and 0.14%, respectively. These oils were further investigated using gas chromatography-mass spectrometry analysis. α-Cadinol (10.7%) and hexadecanoic acid (10.5%) were the major components of C. dioscoridis whereas in C. officinalis, α-cadinol (21.2%) and carvone (18.2%) were major components. Artemisia herba-alba contained piperitone (26.5%), ethyl cinnamate (9.5%), camphor (7.7%) and hexadecanoic acid (6.9%). Essential oils of these three plants have a potential to be used for personal protection against tick bites.

  9. Assuring access to topical mosquito repellents within an intensive distribution scheme: a case study in a remote province of Cambodia.

    PubMed

    Heng, Somony; Durnez, Lies; Gryseels, Charlotte; Van Roey, Karel; Mean, Vanna; Uk, Sambunny; Siv, Sovannaroth; Grietens, Koen Peeters; Sochantha, Tho; Coosemans, Marc; Sluydts, Vincent

    2015-11-24

    The public health value of a vector control tool depends on its epidemiological efficacy, but also on its ease of implementation. This study describes an intensive distribution scheme of a topical repellent implemented in 2012 and 2013 for the purpose of a cluster-randomized trial using the existing public health system. The trial aimed to assess the effectiveness of repellents in addition to long-lasting insecticidal nets (LLIN) and occurred in a province of Cambodia. Determinants for accessibility and consumption of this tool were explored. 135 individuals were appointed to be repellent distributors in 57 villages. A 2-weekly bottle exchange programme was organized. Distributors recorded information regarding the amount of bottles exchanged, repellent leftover, and reasons for not complying in household data sheets. Distributor-household contact rates and average 2-weekly consumption of repellent were calculated. Household and distributors characteristics were obtained using questionnaires, surveying 50 households per cluster and all distributors. Regression models were used to explore associations between contact and consumption rates and determinants such as socio-economic status. Operational costs for repellent and net distribution were obtained from the MalaResT project and the provincial health department. A fourfold increase in distributor-household contact rates was observed in 2013 compared to 2012 (median2012 = 20 %, median2013 = 88.9 %). Consumption rate tripled over the 2-year study period (median2012 = 20 %, median2013 = 57.89 %). Contact rates were found to associate with district, commune and knowing the distributor, while consumption was associated with district and household head occupation. The annual operational cost per capita for repellent distribution was 31 times more expensive than LLIN distribution (USD 4.33 versus USD 0.14). After the existing public health system was reinforced with programmatic and logistic support, an intense 2-weekly

  10. Darwin’s finches treat their feathers with a natural repellent

    PubMed Central

    Cimadom, Arno; Causton, Charlotte; Cha, Dong H.; Damiens, David; Fessl, Birgit; Hood-Nowotny, Rebecca; Lincango, Piedad; Mieles, Alejandro E.; Nemeth, Erwin; Semler, Elizabeth M.; Teale, Stephen A.; Tebbich, Sabine

    2016-01-01

    Darwin’s finches are highly innovative. Recently we recorded for the first time a behavioural innovation in Darwin’s finches outside the foraging context: individuals of four species rubbed leaves of the endemic tree Psidium galapageium on their feathers. We hypothesised that this behaviour serves to repel ectoparasites and tested the repellency of P. galapageium leaf extracts against parasites that negatively affect the fitness of Darwin’s finches, namely mosquitoes and the invasive hematophagous fly Philornis downsi. Mosquitoes transmit pathogens which have recently been introduced by humans and the larvae of the fly suck blood from nestlings and incubating females. Our experimental evidence demonstrates that P. galapageium leaf extracts repel both mosquitoes and adult P. downsi and also inhibit the growth of P. downsi larvae. It is therefore possible that finches use this plant to repel ectopoarasites. PMID:27721475

  11. The efficacy of repellents against Aedes, Anopheles, Culex and Ixodes spp. - a literature review.

    PubMed

    Lupi, Eleonora; Hatz, Christoph; Schlagenhauf, Patricia

    2013-01-01

    Travellers are confronted with a variety of vector-borne threats. Is one type of repellent effective against all biting vectors? The aim of this review is to examine the literature, up to December 31st, 2012, regarding repellent efficacy. We searched PubMed for relevant papers. Repellents of interest were DEET, Icaridin as well as other piperidine-derived products (SS220), Insect Repellent (IR) 3535 (ethyl-butylacetyl-amino-propionat, EBAAP) and plant-derived products, including Citriodora (para-menthane-3,8-diol). As vectors, we considered the mosquito species Anopheles, Aedes and Culex as well as the tick species Ixodes. We selected only studies evaluating the protective efficacy of repellents on human skin. We reviewed a total of 102 publications. Repellents were evaluated regarding complete protection time or as percentage efficacy [%] in a time interval. We found no standardized study for tick bite prevention. Regarding Aedes, DEET at concentration of 20% or more, showed the best efficacy providing up to 10 h protection. Citriodora repellency against this mosquito genus was lower compared to the other products. Also between subspecies a difference could be observed: Ae. aegypti proved more difficult to repel than Ae. Albopictus. Fewer studies have been conducted on mosquito species Anopheles and Culex. The repellency profile against Anopheles species was similar for the four principal repellents of interest, providing on average 4-10 h of protection. Culex mosquitoes are easier to repel and all four repellents provided good protection. Few studies have been conducted on the tick species Ixodes. According to our results, the longest protection against Ixodes scapularis was provided by repellents containing IR3535, while DEET and commercial products containing Icaridin or PMD showed a better response than IR3535 against Ixodes ricinus. Many plant-based repellents provide only short duration protection. Adding vanillin 5% to plant-based repellents and to DEET

  12. Larvicidal and repellent activity of medicinal plant extracts from Eastern Ghats of South India against malaria and filariasis vectors.

    PubMed

    Kamaraj, Chinnaperumal; Rahuman, Abdul Abdul; Bagavan, Asokan; Elango, Gandhi; Zahir, Abdul Abduz; Santhoshkumar, Thirunavukkarasu

    2011-09-01

    To evaluate the larvicidal and repellent activities of ethyl acetate and methanol extracts of Acacia concinna (A. concinna), Cassia siamea (C. siamea), Coriandrum sativum (C. sativum),Cuminum cyminum (C. cyminum), Lantana camara (L. camara), Nelumbo nucifera (N. nucifera) Phyllanthus amarus (P. amarus), Piper nigrum (P. nigrum) and Trachyspermum ammi (T. ammi) against Anopheles stephensi (An. stephensi) and Culex quinquefasciatus (Cx. quinquefasciatus). The larvicidal activity of medicinal plant extracts were tested against early fourth-instar larvae of malaria and filariasis vectors. The mortality was observed 24 h and 48 h after treatment, data were subjected to probit analysis to determine the lethal concentrations (LC(50) and LC(90)) to kill 50 and 90 per cent of the treated larvae of the tested species. The repellent efficacy was determined against two mosquito species at five concentrations (31.25, 62.50, 125.00, 250.00, and 500.00 ppm) under the laboratory conditions. All plant extracts showed moderate effects after 24 h and 48 h of exposure; however, the highest activity was observed after 24 h in the leaf methanol extract of N. nucifera, seed ethyl acetate and methanol extract of P. nigrum against the larvae of An. stephensi (LC(50) = 34.76, 24.54 and 30.20 ppm) and against Cx. quinquefasciatus (LC(50) = 37.49, 43.94 and 57.39 ppm), respectively. The toxic effect of leaf methanol extract of C. siamea, seed methanol extract of C. cyminum, leaf ethyl acetate extract of N. nucifera, leaf ethyl acetate and methanol extract of P. amarus and seed methanol extract of T. ammi were showed 100% mortality against An. stephensi and Cx. quinquefasciatus after 48 h exposer. The maximum repellent activity was observed at 500 ppm in methanol extracts of N. nucifera, ethyl acetate and methanol extract of P. nigrum and methanol extract of T. ammi and the mean complete protection time ranged from 30 to 150 min with the different extracts tested. These results suggest that

  13. Repellent effect of Salvia dorisiana, S. longifolia, and S. sclarea (Lamiaceae) essential oils against the mosquito Aedes albopictus Skuse (Diptera: Culicidae).

    PubMed

    Conti, Barbara; Benelli, Giovanni; Leonardi, Michele; Afifi, Fatma U; Cervelli, Claudio; Profeti, Raffaele; Pistelli, Luisa; Canale, Angelo

    2012-07-01

    Aedes albopictus (Diptera: Culicidae) has been one of the fastest spreading insects over the past 20 years. Its medical importance is due to the aggressive daytime human-biting behavior and the ability to vector many viruses, including dengue, LaCrosse, Eastern Equine encephalitis and West Nile viruses. In this research, the essential oils (EOs) extracted from fresh air dried leaves of Salvia dorisiana, S. longifolia, and S. sclarea (Lamiaceae) were evaluated for their repellent activity against A. albopictus by using the human-bait technique. The EOs chemical composition was also investigated, and EOs were divided in three different profiles on the basis of their chemical composition: EO with large amount of monoterpenes from S. sclarea, EO rich in oxygenated sesquiterpenes from S. dorisiana, and S. longifolia EO characterized by similar percentages of monoterpenes and sesquiterpenes. The efficacy protection from S. dorisiana, S. longifolia, and S. sclarea EOs, at dosages ranging from 0.004 to 0.4 μL cm(-2) of skin, was evaluated during 120 min of observation. Results indicated that S. dorisiana, S. longifolia, and S. sclarea EOs had a significant repellent activity (RD(50) =0.00035, 0.00049, and 0.00101 μL cm(-2), respectively), with differences in repellency rates, as a function of oil, dosage, and observation time. S. dorisiana was the most effective oil: at the two higher dosages, it gave almost complete protection (with a protective efficacy of 90.99% and 95.62%, respectively) for 90 min. The best protection time was achieved with S. dorisiana essential oil. It ranged from 9.2 to 92.4 min. Protection times of S. longifolia and S. sclarea oils ranged from 3.2 to 60 min, and from 3.6 to 64.2 min, respectively. Our findings clearly reveal that these EOs have a good repellent activity against A. albopictus, therefore they can be proposed to improve the efficacy of repellent formulations against the Asian tiger mosquito.

  14. The insect repellent DEET (N,N-diethyl-3-methylbenzamide) increases the synthesis of glutathione S-transferase in cultured mosquito cells.

    PubMed

    Hellestad, Vanessa J; Witthuhn, Bruce A; Fallon, Ann M

    2011-04-01

    DEET (N,N-diethyl-3-methylbenzamide) is the active ingredient used in many commonly used insect repellents, but its mode of action remains poorly understood. Efforts to identify properties that could lead to the development of more effective active ingredients have distinguished among DEET's repellent, deterrent, and insecticidal activities. We used an Aedes albopictus mosquito cell line to evaluate DEET's toxicological properties in the absence of sensory input mediated by the olfactory system. When cells were treated with DEET and labeled with [(35)S]methionine/cysteine, a single 25-kDa protein was induced, relative to other proteins, on SDS-polyacrylamide gels. The 25-kDa band from DEET-treated cells was enriched in peptides corresponding to glutathione S-transferase D10 and/or theta in the Aedes aegypti genome. Consistent with the increased expression of the labeled protein, DEET-treated cells had increased glutathione S-transferase activity, and the radiolabeled band bound to Sepharose 4B containing reduced glutathione. By analyzing partial tryptic digests, we established that DEET induces the homolog of A. aegypti glutathione S-transferase, class theta, corresponding to protein XP_001658009.1 in the NCBI database. This specific effect of DEET at the subcellular level suggests that DEET induces physiological responses that extend beyond recognition by the peripheral olfactory system.

  15. Larvicidal, ovicidal and repellent activities of Cymbopogan citratus Stapf (Graminae) essential oil against the filarial mosquito Culex quinquefasciatus (Say) (Diptera : Culicidae).

    PubMed

    Pushpanathan, T; Jebanesan, A; Govindarajan, M

    2006-12-01

    Essential oils extracted by steam distillation from Cymbopogan citratus were evaluated for larvicidal, ovicidal and repellent activities against the filarial mosquito Culex quinquefasciatus. The larval mortality was observed after 24 hours treatment. The LC(50) values calculated for the 2nd, 3rd and 4th larval instar were 144.54 +/- 2.3, 165.70 +/- 1.2 and 184.18 +/- 0.8 ppm respectively. Hundred percent ovicidal activity was observed at 300 ppm. Skin repellent test at 1.0, 2.5 and 5.0 mg/cm(2) concentration of C. citratus gave 100% protection up to 3.00, 4.00 and 5.00 hours respectively. The total percentage of protection of this essential oil was 49.64% at 1.0 mg/cm(2), 62.19% at 2.5 mg/cm(2) and 74.03% at 5.0 mg/cm(2) for 12 hours.

  16. Synergy between repellents and organophosphates on bed nets: efficacy and behavioural response of natural free-flying An. gambiae mosquitoes.

    PubMed

    Pennetier, Cédric; Costantini, Carlo; Corbel, Vincent; Licciardi, Séverine; Dabiré, Roch K; Lapied, Bruno; Chandre, Fabrice; Hougard, Jean-Marc

    2009-11-19

    Chemicals are used on bed nets in order to prevent infected bites and to kill aggressive malaria vectors. Because pyrethroid resistance has become widespread in the main malaria vectors, research for alternative active ingredients becomes urgent. Mixing a repellent and a non-pyrethroid insecticide seemed to be a promising tool as mixtures in the laboratory showed the same features as pyrethroids. We present here the results of two trials run against free-flying Anopheles gambiae populations comparing the effects of two insect repellents (either DEET or KBR 3023, also known as icaridin) and an organophosphate insecticide at low-doses (pirimiphos-methyl, PM) used alone and in combination on bed nets. We showed that mixtures of PM and the repellents induced higher exophily, blood feeding inhibition and mortality among wild susceptible and resistant malaria vectors than compounds used alone. Nevertheless the synergistic interactions are only involved in the high mortality induced by the two mixtures. These field trials argue in favour of the strategy of mixing repellent and organophosphate on bed nets to better control resistant malaria vectors.

  17. Repellency of the Origanum onites L. Essential Oil and Constituents to the Lone Star Tick and Yellow Fever Mosquito

    USDA-ARS?s Scientific Manuscript database

    The oregano, Origanum onites L., essential oil (EO) was tested in laboratory behavioral bioassays for repellent activity against Amblyomma americanum (L.) and Aedes aegypti (L.). The O. onites EO was characterized using GC-FID and GC-MS. Carvacrol (75.70 %), linalool (9.0 %), p-cymene (4.33 %) and t...

  18. Synergy between Repellents and Organophosphates on Bed Nets: Efficacy and Behavioural Response of Natural Free-Flying An. gambiae Mosquitoes

    PubMed Central

    Pennetier, Cédric; Costantini, Carlo; Corbel, Vincent; Licciardi, Séverine; Dabiré, Roch K.; Lapied, Bruno; Chandre, Fabrice; Hougard, Jean-Marc

    2009-01-01

    Background Chemicals are used on bed nets in order to prevent infected bites and to kill aggressive malaria vectors. Because pyrethroid resistance has become widespread in the main malaria vectors, research for alternative active ingredients becomes urgent. Mixing a repellent and a non-pyrethroid insecticide seemed to be a promising tool as mixtures in the laboratory showed the same features as pyrethroids. Methodology/Principal Findings We present here the results of two trials run against free-flying Anopheles gambiae populations comparing the effects of two insect repellents (either DEET or KBR 3023, also known as icaridin) and an organophosphate insecticide at low-doses (pirimiphos-methyl, PM) used alone and in combination on bed nets. We showed that mixtures of PM and the repellents induced higher exophily, blood feeding inhibition and mortality among wild susceptible and resistant malaria vectors than compounds used alone. Nevertheless the synergistic interactions are only involved in the high mortality induced by the two mixtures. Conclusion These field trials argue in favour of the strategy of mixing repellent and organophosphate on bed nets to better control resistant malaria vectors. PMID:19936249

  19. Plant based insect repellent and insecticide treated bed nets to protect against malaria in areas of early evening biting vectors: double blind randomised placebo controlled clinical trial in the Bolivian Amazon.

    PubMed

    Hill, N; Lenglet, A; Arnéz, A M; Carneiro, I

    2007-11-17

    To determine the effectiveness in reducing malaria of combining an insect repellent with insecticide treated bed nets compared with the nets alone in an area where vector mosquitoes feed in the early evening. A double blind, placebo controlled cluster-randomised clinical study. Rural villages and peri-urban districts in the Bolivian Amazon. 4008 individuals in 860 households. All individuals slept under treated nets; one group also used a plant based insect repellent each evening, a second group used placebo. Episodes of Plasmodium falciparum or P vivax malaria confirmed by rapid diagnostic test or blood slide, respectively. We analysed 15,174 person months at risk and found a highly significant 80% reduction in episodes of P vivax in the group that used treated nets and repellent (incidence rate ratio 0.20, 95% confidence interval 0.11 to 0.38, P<0.001). Numbers of P falciparum cases during the study were small and, after adjustment for age, an 82% protective effect was observed, although this was not significant (0.18, 0.02 to 1.40, P=0.10). Reported episodes of fever with any cause were reduced by 58% in the group that used repellent (0.42, 0.31 to 0.56, P<0.001). Insect repellents can provide protection against malaria. In areas where vectors feed in the early evening, effectiveness of treated nets can be significantly increased by using repellent between dusk and bedtime. This has important implications in malaria vector control programmes outside Africa and shows that the combined use of treated nets and insect repellents, as advocated for most tourists travelling to high risk areas, is fully justified. NCT 00144716.

  20. Mosquito Bite Prevention For Travelers

    MedlinePlus

    ... is an insecticide that kills mosquitoes and other insects. - Do not wash bed nets or expose them ... for extra protection. Use only an EPA-registered insect repellent Š Consider bringing insect repellent with you. Š Always ...

  1. Insect Repellents: Reducing Insect Bites

    MedlinePlus

    ... Labs and Research Centers Contact Us Share Repellents: Protection against Mosquitoes, Ticks and Other Arthropods About Insect ... Snapshot No FEAR Act Data Privacy Privacy and Security Notice Connect. Data.gov Inspector General Jobs Newsroom ...

  2. Comparison of the effect of two excipients (karite nut butter and vaseline) on the efficacy of Cocos nucifera, Elaeis guineensis and Carapa procera oil-based repellents formulations against mosquitoes biting in Ivory Coast.

    PubMed

    Konan, Y L; Sylla, M S; Doannio, J M; Traoré, S

    2003-06-01

    Repellents in the form of dermal pomades are recommended as a protection against awakening and bedtime mosquito bites. If synthesis repellents are available, they are nevertheless not common and the prices remain out of reach for the communities concerned. The people therefore have to resort more and more to traditional concoctions, some of which have been shown to be effective. After demonstrating that oil-based formulations (lotions, creams, pomades) of Cocos nucifera (coconut), Elaeis guineensis (oil palm) and Carapa procera (gobi) were effective against mosquitoes, it became necessary to study the impact of the two excipients used in their manufacture, on the effectiveness of the repellents. Experiments were carried with Anopheles gambiae and Aedes aegypti under lobaratory conditions and any other mosquitoes collected under field conditions in Ivory Coast. The laboratory results indicate that the average protection times obtained with formulations with karite nut butter as excipient (54.8 +/- 37.0 mn and 74.6 +/- 26.4 mn respectively on An. gambiae and Ae. aegypti) are higher than those recorded with vaseline as excipient (respectively 42.7 +/- 30.0 mn and 60.8 +/- 33.9 mn). On the other hand, under field conditions, the biting rate percentage reduction obtained with the products with karite nut butter and vaseline excipient were similar (respectively 29.8% and 35.9% for all mosquitoes collected and 45.7% and 47.4% against An. gambiae). Nevertheless, the use of karite nut butter on repellent products should be encouraged because its sale price is very lower (10 time less) than the vaseline's.

  3. Plant essential oils and potassium metabisulfite as repellents for Drosophila suzukii (Diptera: Drosophilidae)

    PubMed Central

    Renkema, Justin M.; Wright, Derek; Buitenhuis, Rose; Hallett, Rebecca H.

    2016-01-01

    Spotted wing drosophila, Drosophila suzukii, is a globally invasive pest of soft-skinned fruit. Females oviposit into ripening fruit and larvae cause direct destruction of tissues. As many plant essential oils are permitted food additives, they may provide a safe means of protecting fruit from D. suzukii infestation in both conventional and organic production systems. Twelve oils and potassium metabisulfite (KMS) were screened in the laboratory as repellents for D. suzukii flies. Most essential oils deterred D. suzukii flies from cotton wicks containing attractive raspberry juice. Peppermint oil was particularly effective, preventing almost all flies from contacting treated wicks and remaining 100% repellent for 6 d post-application. Thyme oil was unique because it caused high male mortality and reduced the number of responding flies compared to other oils. KMS was not found to be repellent to D. suzukii, but may have fumigant properties, particularly at high concentrations. Peppermint oil appears to be the best candidate for field testing to determine the effectiveness and feasibility of using essential oils as part of a push-pull management strategy against D. suzukii. This is the first time that essential oils have been evaluated and proven effective in preventing fruit-infesting flies from contacting attractive stimuli. PMID:26893197

  4. LD50 and repellent effects of essential oils from Argentinian wild plant species on Varroa destructor.

    PubMed

    Ruffinengo, Sergio; Eguaras, Martin; Floris, Ignazio; Faverin, Claudia; Bailac, Pedro; Ponzi, Marta

    2005-06-01

    The repellent and acaricidal effects of some essential oils from the most typical wild plant species of northern Patagonia, Argentina, on Varroa destructor Anderson & Trueman were evaluated using a complete exposure test. Honey bees, Apis mellifera L., and mites (five specimens of each per dish) were introduced in petri dishes having different oil concentrations (from 0.1 to 25 micro per cage). Survival of bees and mites was registered after 24, 48, and 72 h. An attraction/repellence test was performed using a wax tube impregnated with essential oil and another tube containing wax only. The lowest LD50 values for mites were registered for Acantholippia seriphioides (A. Gray) Mold. (1.27 microl per cage) and Schinus molle L. (2.65 microl per cage) after 24 h, and for Wedelia glauca (Ortega) O. Hoffm. ex Hicken (0.59 microl per cage) and A. seriphioides (1.09 microl per cage) after 72 h of treatment. The oil with the highest selectivity ratio (A. mellifera LD50/V. destructor LD50) was the one extracted from S. molle (>16). Oils of Lippia junelliana (Mold.) Troncoso, Minthostachys mollis (HBK) Grieseb., and Lippia turbinata Grieseb. mixed with wax had repellent properties. None of the oils tested had attractive effects on Varroa mites.

  5. An Evidence-Based Review on Medicinal Plants Used as Insecticide and Insect Repellent in Traditional Iranian Medicine.

    PubMed

    Cheraghi Niroumand, Mina; Farzaei, Mohammad Hosein; Karimpour Razkenari, Elahe; Amin, Gholamreza; Khanavi, Mahnaz; Akbarzadeh, Tahmineh; Shams-Ardekani, Mohammad Reza

    2016-02-01

    Insects can be the cause of major ecological problems; they can transmit microbes and parasites that affect humans, and damage food crops, trees, and homes. The total economic cost of insect-related damage and disease is immeasurable. In traditional Iranian medicine (TIM), several medicinal plants have been identified as insecticides or insect repellents, but many of them are still unknown. Therefore, the aim of this study was to review the insecticidal or insect repellent activity of certain medicinal plants described in TIM. Information about medicinal plants proposed as insecticides and insect repellents in the TIM was collected from the TIM literature, and searched in modern medical databases to find studies that confirmed their efficacy. Modern investigations have supported the claims of the insecticidal activity of several plants, including Allium sativum, Artemisia absinthium, Citrullus colocynthis, Laurus nobilis, Mentha pulegium, Myrtus communis, Nerium oleander, Ocimum basilicum, and Origanum majorana. However, in the cases of plants like Iris florentina and Malva sylvestris, there is not enough evidence in modern medicine to prove their effectiveness with regard to their insecticidal and insect repellent activities. This study confirmed the Iranian traditional medicine claims of the insecticidal and insect repellent activity of certain plants. Further pharmacological and clinical studies are recommended to evaluate the overall efficacy and possible mechanisms underlying these herbs.

  6. An Evidence-Based Review on Medicinal Plants Used as Insecticide and Insect Repellent in Traditional Iranian Medicine

    PubMed Central

    Cheraghi Niroumand, Mina; Farzaei, Mohammad Hosein; Karimpour Razkenari, Elahe; Amin, Gholamreza; Khanavi, Mahnaz; Akbarzadeh, Tahmineh; Shams-Ardekani, Mohammad Reza

    2016-01-01

    Context Insects can be the cause of major ecological problems; they can transmit microbes and parasites that affect humans, and damage food crops, trees, and homes. The total economic cost of insect-related damage and disease is immeasurable. In traditional Iranian medicine (TIM), several medicinal plants have been identified as insecticides or insect repellents, but many of them are still unknown. Therefore, the aim of this study was to review the insecticidal or insect repellent activity of certain medicinal plants described in TIM. Evidence Acquisition Information about medicinal plants proposed as insecticides and insect repellents in the TIM was collected from the TIM literature, and searched in modern medical databases to find studies that confirmed their efficacy. Results Modern investigations have supported the claims of the insecticidal activity of several plants, including Allium sativum, Artemisia absinthium, Citrullus colocynthis, Laurus nobilis, Mentha pulegium, Myrtus communis, Nerium oleander, Ocimum basilicum, and Origanum majorana. However, in the cases of plants like Iris florentina and Malva sylvestris, there is not enough evidence in modern medicine to prove their effectiveness with regard to their insecticidal and insect repellent activities. Conclusions This study confirmed the Iranian traditional medicine claims of the insecticidal and insect repellent activity of certain plants. Further pharmacological and clinical studies are recommended to evaluate the overall efficacy and possible mechanisms underlying these herbs. PMID:27186389

  7. Duration of repellency of various synthetic and plant-derived preparations for Culicoides imicola, the vector of African horse sickness virus.

    PubMed

    Braverman, Y; Chizov-Ginzburg, A

    1998-01-01

    Objectives of the study were threefold: to find a safer and longer lasting repellent of the biting midge Culicoides imicola than di-ethyl toluamide (DEET), to examine whether the current recommendations in Israel for application of repellents during an outbreak of C. imicola-borne pathogens are justified; and to examine whether plant-derived preparations that have no known detrimental side effects are potential replacements of synthetic repellents. Of the seven repellents tested, those inferior to DEET were: oregano and Herbipet which showed a slight non-significant repellency for 2 h and 1 h respectively and Stomoxin which showed significant (P < 0.05) repellency for only 1 h. As the active ingredient of Stomoxin is permethrin, this suggests that recommendations to spray animals with this insecticide to prevent the spread of C. imicola-borne pathogens are not useful. Tri-Tec14 showed significant (P < 0.05) repellency with respect to controls for 2 h only, but performed similarly to, or slightly better than DEET. The repellents clearly superior to DEET were: the plant-derived material Ag1000 that repelled significantly (P < 0.05) with respect to controls for up to 4 h following a similar pattern to but somewhat more strongly than DEET, and pyrethroid-T which exerted significant (P < 0.05) repellency for 9 h. Pyrethroid-T proved to be the best repellent tested and if sprayed nightly it might provide protection from C. imicola-borne pathogens.

  8. The Influence of Plant Litter on Soil Water Repellency: Insight from 13C NMR Spectroscopy.

    PubMed

    Cesarano, Gaspare; Incerti, Guido; Bonanomi, Giuliano

    2016-01-01

    Soil water repellency (SWR, i.e. reduced affinity for water owing to the presence of organic hydrophobic coatings on soil particles) has relevant hydrological implications because low rates of infiltration enhance water runoff, and untargeted diffusion of fertilizers and pesticides. Previous studies investigated the occurrence of SWR in ecosystems with different vegetation cover but did not clarify its relationships with litter biochemical quality. Here, we investigated the capability of different plant litter types to induce SWR by using fresh and decomposed leaf materials from 12 species, to amend a model sandy soil over a year-long microcosm experiment. Water repellency, measured by the Molarity of an Ethanol Droplet (MED) test, was tested for the effects of litter species and age, and compared with litter quality assessed by 13C-CPMAS NMR in solid state and elemental chemical parameters. All litter types were highly water repellent, with MED values of 18% or higher. In contrast, when litter was incorporated into the soil, only undecomposed materials induced SWR, but with a large variability of onset and peak dynamics among litter types. Surprisingly, SWR induced by litter addition was unrelated to the aliphatic fraction of litter. In contrast, lignin-poor but labile C-rich litter, as defined by O-alkyl C and N-alkyl and methoxyl C of 13C-CPMAS NMR spectral regions, respectively, induced a stronger SWR. This study suggests that biochemical quality of plant litter is a major controlling factor of SWR and, by defining litter quality with 13C-CPMAS NMR, our results provide a significant novel contribution towards a full understanding of the relationships between plant litter biochemistry and SWR.

  9. Ethnobotanical survey of plants used as repellents against housefly, Musca domestica L. (Diptera: Muscidae) in Budondo Subcounty, Jinja District, Uganda.

    PubMed

    Baana, Kalori; Angwech, Harriet; Malinga, Geoffrey Maxwell

    2018-05-10

    The housefly, Musca domestica L., is a major public health and domestic pest that spoils food and causes irritation and is a vector of many infectious disease pathogens of medical and veterinary importance. Currently, its control relies largely on chemical pesticides. However, the adverse health and environmental effects of pesticides, risk of development of insect resistance, and bioaccumulation through the food chain emphasize the need to search for environmentally friendly alternatives. This study aimed at documenting traditional knowledge about plants used as repellents against the houseflies by the people of Budondo Subcounty, Uganda. An ethnobotanical survey was conducted between November 2016 and June 2017. A total of 372 household members were interviewed on knowledge and use of traditional insect repellents, through face-to-face interviews guided by semi-structured questionnaires administered in nine villages in Budondo Subcounty. Overall, only 24.5% of the respondents had ample knowledge about insect repellent plants. A chi-square analysis shows a significant association between respondents' knowledge of insect repellent plants and age, educational status, occupation, religion, and marital status although not with gender. Overall, eight plants from seven families and eight genera were mentioned as repellents. The growth forms encountered were tree, shrub, and herb. Plants that were commonly mentioned by respondents were Cupressus sempervirens L. (16.9%), followed by Lantana camara L.(16.1%), Eucalyptus globulus Labill. (11.0%), Carica papaya L. (8.6%), Cymbopogon citratus (de Candolle) Stapf (4.3%), Mentha × piperita L. (2.4%), Azadirachta indica A. Juss (2.2%), and Ocimum kilimandscharicum Gürke (0.8%) in descending order. Leaves were the most commonly used plant part (76.9%), followed by the stem/bark (19.8%), flowers (2.2%), and root (1.1%). Burning of the plant materials in order to generate smoke was the most popular method of application. This

  10. Knowledge and self-reported practice of the local inhabitants on traditional insect repellent plants in Western Hararghe zone, Ethiopia.

    PubMed

    Karunamoorthi, Kaliyaperumal; Husen, Ebrahim

    2012-05-07

    This paper reveals the trend of knowledge and self-reported practice of traditional insect repellent plants (TIRPs) and could serve as a baseline data to identify/formulate novel plant-based insect repellents in the near future. Insect repellent plants usage is a long-standing and age old tradition. Thus, the major objective of this survey was to assess the knowledge and self-reported practice of the local inhabitants on TIRPs in Western Hararghe zone, Ethiopia. The ethnobotanical survey was conducted between January and March 2011 via administering pre-tested questionnaire by involving the selected 150 household members in the study area. The survey results clearly reveal that nearly 92.1% [90.1% (99/110) of female and 97.5% (39/40) of male] of the respondents have had adequate awareness on TIRPs. Leaves were the most widely applied plant parts and burning/smoldering the plant materials in order to generate smoke was the most common practice. Chi-square statistical analysis shows that there was no significant difference observed in the knowledge of the repellent plants between the gender (P-value=0.134), average monthly income (P-value=0.529) and educational status (P-value=0.107) but there was a significant association with the age (P-value=0.012) of respondents. However, repellent plants usage custom is significantly associated with gender (P-value=0.021) and educational status (P-value=0.003) of the respondents but, there was such no significant relationship between the age (P-value=0.312) average monthly income (P-value=0.111) and repellent plants usage custom. Conducting more ethnobotanical survey on TIRPs is extremely important in order to generate and maintain the data-base. Besides, identifying the bio-active molecules, which are responsible for the repellent activity and eventually conducting laboratory and field based studies to evaluate their efficacy and safety are extremely imperative to formulate new classes of plant-based insect repellents

  11. Laboratory evaluation of aromatic essential oils from thirteen plant species as candidate repellents against Leptotrombidium chiggers (Acari: Trombiculidae), the vector of scrub typhus.

    PubMed

    Eamsobhana, Praphathip; Yoolek, Adisak; Kongkaew, Wittaya; Lerdthusnee, Kriangkrai; Khlaimanee, Nittaya; Parsartvit, Anchana; Malainual, Nat; Yong, Hoi-Sen

    2009-03-01

    Scrub typhus, a rickettsial disease transmitted by several species of Leptotrombidium chiggers (larvae), is endemic in many areas of Asia. The disease is best prevented by the use of personal protective measures, including repellents. In this study commercially produced aromatic, essential oils of 13 plant species and ethanol (control) were tested in the laboratory for repellency against host-seeking chiggers of Leptotrombidium imphalum Vercammen-Grandjean and Langston (Acari: Trombiculidae). A rapid, simple and economic in vitro test method was used by exposing the chigger for up to 5 min. Repellency was based on relative percentages of chiggers attracted to test and control substances. Four of the 13 essential oils showed promise as effective repellent against L. imphalum chiggers. Syzygium aromaticum (clove) oil exhibited 100% repellency at 5% concentration (dilution with absolute ethanol), whereas Melaleuca alternifolia (tea tree) oil exhibited 100% repellency at 40% concentration. Undiluted oils of Zingiber cassamunar (plai) and Eucalyptus globules (blue gum) exhibited 100% repellency. Of the remaining nine essential oils, only 100% Pelargonium graveolens (geranium) exhibited >50% repellency (viz. 57%). Styrax torkinensis (benzoin) oil did not exhibit any repellency. These findings show that several aromatic, essential oils of plants may be useful as chigger repellent for the prevention of scrub typhus. Syzygium aromaticum oil may be safer and more economical to prevent chigger attacks than commercially available synthetic chemicals, such as DEET that may have harmful side effects.

  12. Laboratory evaluation of traditionally used plant-based insect repellent against the malaria vector Anopheles arabiensis Patton (Diptera: Culicidae).

    PubMed

    Karunamoorthi, Kaliyaperumal; Ilango, Kandan; Murugan, Kadarkarai

    2010-04-01

    A laboratory study was carried out to evaluate the repellent efficacy of a methanol-leaf extract of Ethiopian traditionally used insect repellent plant viz., Lomi sar [vernacular name (local native language, Amharic); Cymbopogon citratus (DC) Stapf. (Poaceae)] against Anopheles arabiensis at four different concentrations viz., 1.0, 1.5, 2.0, and 2.5 mg/cm(2). The percentage protection in relation to the dose method was performed. C. citratus extract has shown various degrees of repellency impact against A. arabiensis. It provided the maximum total percentage protection of 78.83% at 2.5 mg/cm(2) and followed 68.06% at 2.0 mg/cm(2) for 12 h. All four tested concentrations of C. citratus extract offered significant protection and Student's t test results shows statistically significant (p value = 0.001) [1.0 mg/cm(2) (t = 22.89; df = 4); 1.5 mg/cm(2) (t = 24.03; df = 4); 2.0 mg/cm(2) (t = 36.92; df = 4); 2.5 mg/cm(2) (t = 22.31; df = 4)] difference between treated and control groups. The result suggests that it could serve as a potent insect repellent against vectors of disease. Globally, C. citratus is renowned for its therapeutic values. Above and beyond, due to its user- as well as environmental-friendly nature, it should be promoted among the marginalized populations in order to reduce man-vector contact. In addition, this appropriate strategy affords the opportunity to minimize chemical repellent usage and the risks associated with adverse side effects. At the end of the day, traditionally used plant-based insect repellents could be viable safer alternative sources for chemical insect repellents.

  13. Repellence of plant essential oils to Dermanyssus gallinae and toxicity to the non-target invertebrate Tenebrio molitor.

    PubMed

    George, D R; Sparagano, O A E; Port, G; Okello, E; Shiel, R S; Guy, J H

    2009-05-26

    With changes in legislation and consumer demand, alternatives to synthetic acaricides to manage the poultry red mite Dermanyssus gallinae (De Geer) in laying hen flocks are increasingly needed. These mites may cause losses in egg production, anaemia and even death of hens. It may be possible to use plant-derived products as D. gallinae repellents, especially if such products have a minimal impact on non-target organisms. An experiment was conducted with D. gallinae to assess the repellence of a range of plant essential oils, previously found to be of varying toxicity (relatively highly toxic to non-toxic) to this pest. Experiments were also undertaken to assess the toxicity of these products to mealworm beetles (Tenebrio molitor L.), a non-target invertebrate typical of poultry production systems. Results showed that all seven essential oils tested (manuka, thyme, palmarosa, caraway, spearmint, black pepper and juniper leaf) were repellent to D. gallinae at 0.14mg oil/cm(3) (initial concentration) during the first 2 days of study. Thyme essential oil appeared to be the most effective, where repellence lasted until the end of the study period (13 days). At the same concentration toxicity to T. molitor differed, with essential oils of palmarosa and manuka being no more toxic to adult beetles than the control. There was neither a significant association between the rank toxicity and repellence of oils to D. gallinae, nor the toxicity of oils to D. gallinae (as previously determined) and T. molitor.

  14. Chemical composition and repellency of essential oils from four medicinal plants against Ixodes ricinus nymphs (Acari: Ixodidae).

    PubMed

    El-Seedi, Hesham R; Khalil, Nasr S; Azeem, Muhammad; Taher, Eman A; Göransson, Ulf; Pålsson, Katinka; Borg-Karlson, Anna-Karin

    2012-09-01

    In our search for effective tick repellents from plant origin, we investigated the effect of essential oils of four medicinal and culinary plants belonging to the family Lamiaceae on nymphs of the tick Ixodes ricinus (L.). The essential oils of the dry leaves of Rosmarinus officinalis (Rosemary) (L.), Mentha spicata (Spearmint) (L.), Origanum majorana (Majoram) (L.), and Ocimum basilicum (Basil) (L.) were isolated by steam distillation and 15 microg/cm2 concentration of oils was tested against ticks in a laboratory bioassay. The oils of R. officinalis, M. spicata, and O. majorana showed strong repellency against the ticks 100, 93.2, and 84.3%, respectively, whereas O. basilicum only showed 64.5% repellency. When tested in the field, the oils of R. officinalis and M. spicata showed 68.3 and 59.4% repellency at a concentration of 6.5 microg/cm2 on the test cloths. The oils were analyzed by gas chromatography mass spectrometry and the major compounds from the most repellent oils were 1,8-cineole, camphor, linalool, 4-terpineol, borneol, and carvone.

  15. Synthesis of (-)-callicarpenal a natural arthropod-repellent terpenoid

    USDA-ARS?s Scientific Manuscript database

    Callicarpenal, a natural terpenoid extracted from American beautyberry (Callicarpa americana), has shown significant repellent activity against mosquitoes, ticks and imported fire ants. Here we report an efficient synthetic approach to this natural product. We also present results of the mosquito ...

  16. Plant Insecticide L-Canavanine Repels Drosophila via the Insect Orphan GPCR DmX

    PubMed Central

    Framery, Bérénice; Bockaert, Joël; Parmentier, Marie-Laure; Grau, Yves

    2009-01-01

    For all animals, the taste sense is crucial to detect and avoid ingesting toxic molecules. Many toxins are synthesized by plants as a defense mechanism against insect predation. One example of such a natural toxic molecule is l-canavanine, a nonprotein amino acid found in the seeds of many legumes. Whether and how insects are informed that some plants contain l-canavanine remains to be elucidated. In insects, the taste sense relies on gustatory receptors forming the gustatory receptor (Gr) family. Gr proteins display highly divergent sequences, suggesting that they could cover the entire range of tastants. However, one cannot exclude the possibility of evolutionarily independent taste receptors. Here, we show that l-canavanine is not only toxic, but is also a repellent for Drosophila. Using a pharmacogenetic approach, we find that flies sense food containing this poison by the DmX receptor. DmXR is an insect orphan G-protein–coupled receptor that has partially diverged in its ligand binding pocket from the metabotropic glutamate receptor family. Blockade of DmXR function with an antagonist lowers the repulsive effect of l-canavanine. In addition, disruption of the DmXR encoding gene, called mangetout (mtt), suppresses the l-canavanine repellent effect. To avoid the ingestion of l-canavanine, DmXR expression is required in bitter-sensitive gustatory receptor neurons, where it triggers the premature retraction of the proboscis, thus leading to the end of food searching. These findings show that the DmX receptor, which does not belong to the Gr family, fulfills a gustatory function necessary to avoid eating a natural toxin. PMID:19564899

  17. Larvicidal and repellent activity of essential oils from wild and cultivated Ruta chalepensis L. (Rutaceae) against Aedes albopictus Skuse (Diptera: Culicidae), an arbovirus vector.

    PubMed

    Conti, Barbara; Leonardi, Michele; Pistelli, Luisa; Profeti, Raffaele; Ouerghemmi, Ines; Benelli, Giovanni

    2013-03-01

    Rutaceae are widely recognized for their toxic and repellent activity exerted against mosquitoes. In our research, the essential oils extracted from fresh leaves of wild and cultivated plants of Ruta chalepensis L. (Rutaceae) were evaluated for larvicidal and repellent activity against the Asian tiger mosquito, Aedes albopictus Skuse (Diptera: Culicidae), currently the most invasive mosquito worldwide. In this research, gas chromatography and gas chromatography-mass spectrometry analyses of the essential oils from wild and cultivated plants showed only quantitative differences, in particular relatively to the amounts of ketone derivatives, while the qualitative profile evidenced a similar chemical composition. Both essential oils from wild and cultivated R. chalepensis plants were able to exert a very good toxic activity against A. albopictus larvae (wild plants, LC(50) = 35.66 ppm; cultivated plants, LC(50) = 33.18 ppm), and mortality was dosage dependent. These data are the first evidence of the toxicity of R. chalepensis against mosquitoes. Furthermore, the R. chalepensis essential oil from wild plants was an effective repellent against A. albopictus, also at lower dosages: RD(50) was 0.000215 μL/cm(2) of skin, while RD(90) was 0.007613 μL/cm(2). Our results clearly evidenced that the larvicidal and repellent activity of R. chalepensis essential oil could be used for the development of new and safer products against the Asian tiger mosquito.

  18. Biting Deterrence, Repellency, and Larvicidal Activity of Ruta chalepensis (Sapindales: Rutaceae) Essential Oil and Its Major Individual Constituents Against Mosquitoes

    DTIC Science & Technology

    2013-01-01

    application rates whereas only the essential oil showed activity similar to DEET against An. quadrimaculatus. 2-undecanone was the most active compound in in...Chikungunya. When sig- niÞcant levels of transmission occur, epidemics can result in high rates of humanmorbidity andmortality. The primary method to...Gunaydin and Savci 2005, GonzalezÐTrujano et al. 2006). The plant also has analgesic, antipyretic, anti-inßammatory, antifungal, emmenagogue, insect

  19. A Primary Screening and Applying of Plant Volatiles as Repellents to Control Whitefly Bemisia tabaci (Gennadius) on Tomato

    PubMed Central

    Du, Wenxiao; Han, Xiaoqing; Wang, Yubo; Qin, Yuchuan

    2016-01-01

    With the goal of finding a new way to reduce population densities of Bemisia tabaci biotype Q in greenhouses, seven repellent volatile chemicals and their combinations were screened. The mixture of DLCO (D-limonene, citral and olive oil (63:7:30)) had a better cost performance(SC50 = 22.59 mg/ml)to repel whiteflies from settling than the other mixtures or single chemicals. In the greenhouse, in both the choice test and the no-choice tests, the number of adult whiteflies that settled on 1% DLCO-treated tomato plants was significantly lower than those settling on the control plants for the different exposure periods (P < 0.01). In the choice test, the egg amount on the treated tomato plants was significantly lower (P < 0.01) than that on the control plants, but there was no significant difference (P > 0.05) between the number of eggs on treated and control plants in the no-choice test. Compared with the controls, 1% DLCO did not cause significantly statistic mortality rates (P > 0.05) out of different living stages of B. tabaci. The tests for evaluating the repellent efficacy, showed that a slow-releasing bottle containing the mixture had a period of efficacy of 29 days, and the application of this mixture plus a yellow board used as a push-pull strategy in the greenhouse was also effective. PMID:26907368

  20. A Primary Screening and Applying of Plant Volatiles as Repellents to Control Whitefly Bemisia tabaci (Gennadius) on Tomato

    NASA Astrophysics Data System (ADS)

    Du, Wenxiao; Han, Xiaoqing; Wang, Yubo; Qin, Yuchuan

    2016-02-01

    With the goal of finding a new way to reduce population densities of Bemisia tabaci biotype Q in greenhouses, seven repellent volatile chemicals and their combinations were screened. The mixture of DLCO (D-limonene, citral and olive oil (63:7:30)) had a better cost performance(SC50 = 22.59 mg/ml)to repel whiteflies from settling than the other mixtures or single chemicals. In the greenhouse, in both the choice test and the no-choice tests, the number of adult whiteflies that settled on 1% DLCO-treated tomato plants was significantly lower than those settling on the control plants for the different exposure periods (P < 0.01). In the choice test, the egg amount on the treated tomato plants was significantly lower (P < 0.01) than that on the control plants, but there was no significant difference (P > 0.05) between the number of eggs on treated and control plants in the no-choice test. Compared with the controls, 1% DLCO did not cause significantly statistic mortality rates (P > 0.05) out of different living stages of B. tabaci. The tests for evaluating the repellent efficacy, showed that a slow-releasing bottle containing the mixture had a period of efficacy of 29 days, and the application of this mixture plus a yellow board used as a push-pull strategy in the greenhouse was also effective.

  1. Investigating the repellency of trifluoromethylphenyl amides analogues against Aedes aegypti

    USDA-ARS?s Scientific Manuscript database

    The purpose of this study is to develop new repellents and evaluate their efficacy for personal protection against mosquitoes. The minimum effective dosage (MED) was determined to estimate the lowest passing concentration of a repellent that prevents >99% of mosquito bites through a treated cloth. D...

  2. Diaphorina citri Induces Huanglongbing-Infected Citrus Plant Volatiles to Repel and Reduce the Performance of Propylaea japonica.

    PubMed

    Lin, Yongwen; Lin, Sheng; Akutse, Komivi S; Hussain, Mubasher; Wang, Liande

    2016-01-01

    Transmission of plant pathogens through insect vectors is a complex biological process involving interactions between the host plants, insects, and pathogens. Simultaneous impact of the insect damage and pathogenic bacteria in infected host plants induce volatiles that modify not only the behavior of its insect vector but also of their natural enemies, such as parasitoid wasps. Therefore, it is essential to understand how insects such as the predator ladybird beetle responds to volatiles emitted from a host plant and how the disease transmission alters the interactions between predators, vector, pathogens, and plants. In this study, we investigated the response of Propylaea japonica to volatiles from citrus plants damaged by Diaphorina citri and Candidatus Liberibacter asiaticus through olfactometer bioassays. Synthetic chemical blends were also used to determine the active compounds in the plant volatile. The results showed that volatiles emitted by healthy plants attracted more P. japonica than other treatments, due to the presence of high quantities of D-limonene and beta-ocimene, and the lack of methyl salicylate. When using synthetic chemicals in the olfactory tests, we found that D-limonene attracted P. japonica while methyl salicylate repelled the predator. However, beta-ocimene attracted the insects at lower concentrations but repelled them at higher concentrations. These results indicate that P. japonica could not efficiently search for its host by using volatile cues emitted from psyllids- and Las bacteria-infected citrus plants.

  3. Plant-Derived Tick Repellents Activate the Honey Bee Ectoparasitic Mite TRPA1.

    PubMed

    Peng, Guangda; Kashio, Makiko; Morimoto, Tomomi; Li, Tianbang; Zhu, Jingting; Tominaga, Makoto; Kadowaki, Tatsuhiko

    2015-07-14

    We have identified and characterized the TRPA1 channel of Varroa destructor (VdTRPA1), a major ectoparasitic mite of honey bee. One of the two VdTRPA1 isoforms, VdTRPA1L, was activated by a variety of plant-derived compounds, including electrophilic compounds, suggesting that chemical activation profiles are mostly shared between arthropod TRPA1 channels. Nevertheless, carvacrol and α-terpineol activated VdTRPA1L but not a honey bee noxious-stimuli-sensitive TRPA, AmHsTRPA, and Drosophila melanogaster TRPA1. Activation of VdTRPA1L in D. melanogaster taste neurons by the above compounds was sufficient to modify the gustatory behaviors. Carvacrol and α-terpineol repelled V. destructor in a laboratory assay, and α-terpineol repressed V. destructor entry for reproduction into the brood cells in hives. Understanding the functions of parasite TRP channels not only gives clues about the evolving molecular and cellular mechanisms of parasitism but also helps in the development of control methods. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Neuromolecular basis of repellent action

    USDA-ARS?s Scientific Manuscript database

    Physical contact is not required for insect repellents to affect mosquito behavior; DEET not only interferes with the detection of host and oviposition sites suggesting the involvement of the olfactory pathway, but it also deters feeding, perhaps indicating involvement of the gustatory sense. Howev...

  5. An innovative mosquito trap for testing attractants

    USDA-ARS?s Scientific Manuscript database

    We describe a simple trap modification for testing or using attractants to collect flying mosquitoes. The trap also can test the effectiveness of spatial repellents. The proposed design may facilitate standardized testing of mosquito attractants and repellents. The trap uses a standard Centers f...

  6. Host plant forensics and olfactory-based detection in Afro-tropical mosquito disease vectors

    PubMed Central

    Nyasembe, Vincent O.; Tchouassi, David P.; Pirk, Christian W. W.; Sole, Catherine L.

    2018-01-01

    The global spread of vector-borne diseases remains a worrying public health threat, raising the need for development of new combat strategies for vector control. Knowledge of vector ecology can be exploited in this regard, including plant feeding; a critical resource that mosquitoes of both sexes rely on for survival and other metabolic processes. However, the identity of plant species mosquitoes feed on in nature remains largely unknown. By testing the hypothesis about selectivity in plant feeding, we employed a DNA-based approach targeting trnH-psbA and matK genes and identified host plants of field-collected Afro-tropical mosquito vectors of dengue, Rift Valley fever and malaria being among the most important mosquito-borne diseases in East Africa. These included three plant species for Aedes aegypti (dengue), two for both Aedes mcintoshi and Aedes ochraceus (Rift Valley fever) and five for Anopheles gambiae (malaria). Since plant feeding is mediated by olfactory cues, we further sought to identify specific odor signatures that may modulate host plant location. Using coupled gas chromatography (GC)-electroantennographic detection, GC/mass spectrometry and electroantennogram analyses, we identified a total of 21 antennally-active components variably detected by Ae. aegypti, Ae. mcintoshi and An. gambiae from their respective host plants. Whereas Ae. aegypti predominantly detected benzenoids, Ae. mcintoshi detected mainly aldehydes while An. gambiae detected sesquiterpenes and alkenes. Interestingly, the monoterpenes β-myrcene and (E)-β-ocimene were consistently detected by all the mosquito species and present in all the identified host plants, suggesting that they may serve as signature cues in plant location. This study highlights the utility of molecular approaches in identifying specific vector-plant associations, which can be exploited in maximizing control strategies such as such as attractive toxic sugar bait and odor-bait technology. PMID:29462150

  7. Host plant forensics and olfactory-based detection in Afro-tropical mosquito disease vectors.

    PubMed

    Nyasembe, Vincent O; Tchouassi, David P; Pirk, Christian W W; Sole, Catherine L; Torto, Baldwyn

    2018-02-01

    The global spread of vector-borne diseases remains a worrying public health threat, raising the need for development of new combat strategies for vector control. Knowledge of vector ecology can be exploited in this regard, including plant feeding; a critical resource that mosquitoes of both sexes rely on for survival and other metabolic processes. However, the identity of plant species mosquitoes feed on in nature remains largely unknown. By testing the hypothesis about selectivity in plant feeding, we employed a DNA-based approach targeting trnH-psbA and matK genes and identified host plants of field-collected Afro-tropical mosquito vectors of dengue, Rift Valley fever and malaria being among the most important mosquito-borne diseases in East Africa. These included three plant species for Aedes aegypti (dengue), two for both Aedes mcintoshi and Aedes ochraceus (Rift Valley fever) and five for Anopheles gambiae (malaria). Since plant feeding is mediated by olfactory cues, we further sought to identify specific odor signatures that may modulate host plant location. Using coupled gas chromatography (GC)-electroantennographic detection, GC/mass spectrometry and electroantennogram analyses, we identified a total of 21 antennally-active components variably detected by Ae. aegypti, Ae. mcintoshi and An. gambiae from their respective host plants. Whereas Ae. aegypti predominantly detected benzenoids, Ae. mcintoshi detected mainly aldehydes while An. gambiae detected sesquiterpenes and alkenes. Interestingly, the monoterpenes β-myrcene and (E)-β-ocimene were consistently detected by all the mosquito species and present in all the identified host plants, suggesting that they may serve as signature cues in plant location. This study highlights the utility of molecular approaches in identifying specific vector-plant associations, which can be exploited in maximizing control strategies such as such as attractive toxic sugar bait and odor-bait technology.

  8. Efficacy of topical mosquito repellent (picaridin) plus long-lasting insecticidal nets versus long-lasting insecticidal nets alone for control of malaria: a cluster randomised controlled trial.

    PubMed

    Sluydts, Vincent; Durnez, Lies; Heng, Somony; Gryseels, Charlotte; Canier, Lydie; Kim, Saorin; Van Roey, Karel; Kerkhof, Karen; Khim, Nimol; Mao, Sokny; Uk, Sambunny; Sovannaroth, Siv; Grietens, Koen Peeters; Sochantha, Tho; Menard, Didier; Coosemans, Marc

    2016-10-01

    Although effective topical repellents provide personal protection against malaria, whether mass use of topical repellents in addition to long-lasting insecticidal nets can contribute to a further decline of malaria is not known, particularly in areas where outdoor transmission occurs. We aimed to assess the epidemiological efficacy of a highly effective topical repellent in addition to long-lasting insecticidal nets in reducing malaria prevalence in this setting. A cluster randomised controlled trial was done in the 117 most endemic villages in Ratanakiri province, Cambodia, to assess the efficacy of topical repellents in addition to long-lasting insecticidal nets in controlling malaria in a low-endemic setting. We did a pre-trial assessment of village accessibility and excluded four villages because of their inaccessibility during the rainy season. Another 25 villages were grouped because of their proximity to each other, resulting in 98 study clusters (comprising either a single village or multiple neighbouring villages). Clusters were randomly assigned (1:1) to either a control (long-lasting insecticidal nets) or intervention (long-lasting insecticidal nets plus topical repellent) study group after a restricted randomisation. All clusters received one long-lasting insecticidal net per individual, whereas those in the intervention group also received safe and effective topical repellents (picaridin KBR3023, SC Johnson, Racine, WI, USA), along with instruction and promotion of its daily use. Cross-sectional surveys of 65 randomly selected individuals per cluster were done at the beginning and end of the malaria transmission season in 2012 and 2013. The primary outcome was Plasmodium species-specific prevalence in participants obtained by real-time PCR, assessed in the intention-to-treat population. Complete safety analysis data will be published seperately; any ad-hoc adverse events are reported here. This trial is registered with ClinicalTrials.gov, number NCT

  9. Post-fire interactions between soil water repellency, soil fertility and plant growth in soil collected from a burned piñon-juniper woodland

    USGS Publications Warehouse

    Fernelius, Kaitlynn J.; Madsen, Matthew D.; Hopkins, Bryan G.; Bansal, Sheel; Anderson, Val J.; Eggett, Dennis L.; Roundy, Bruce A.

    2017-01-01

    Woody plant encroachment can increase nutrient resources in the plant-mound zone. After a fire, this zone is often found to be water repellent. This study aimed to understand the effects of post-fire water repellency on soil water and inorganic nitrogen and their effects on plant growth of the introduced annual Bromus tectorum and native bunchgrass Pseudoroegneria spicata. Plots centered on burned Juniperus osteosperma trees were either left untreated or treated with surfactant to ameliorate water repellency. After two years, we excavated soil from the untreated and treated plots and placed it in zerotension lysimeter pots. In the greenhouse, half of the pots received an additional surfactant treatment. Pots were seeded separately with B. tectorum or P. spicata. Untreated soils had high runoff, decreased soilwater content, and elevated NO3eN in comparison to surfactant treated soils. The two plant species typically responded similar to the treatments. Above-ground biomass and microbial activity (estimated through soil CO2 gas emissions) was 16.8-fold and 9.5-fold higher in the surfactant-treated soils than repellent soils, respectably. This study demonstrates that water repellency can influence site recovery by decreasing soil water content, promoting inorganic N retention, and impairing plant growth and microbial activity.

  10. Alteration of plant species assemblages can decrease the transmission potential of malaria mosquitoes.

    PubMed

    Ebrahimi, Babak; Jackson, Bryan T; Guseman, Julie L; Przybylowicz, Colin M; Stone, Christopher M; Foster, Woodbridge A

    2018-03-01

    Knowledge of the link between a vector population's pathogen-transmission potential and its biotic environment can generate more realistic forecasts of disease risk due to environmental change. It also can promote more effective vector control by both conventional and novel means.This study assessed the effect of particular plant species assemblages differing in nectar production on components of the vectorial capacity of the mosquito Anopheles gambiae s.s. , an important vector of African malaria.We followed cohorts of mosquitoes for three weeks in greenhouse mesocosms holding nectar-poor and nectar-rich plant species by tracking daily mortalities and estimating daily biting rates and fecundities. At death, a mosquito's insemination status and wing length were determined. These life history traits allowed incorporation of larval dynamics into a vectorial capacity estimate. This new study provided both novel assemblages of putative host plants and a human blood host within a nocturnal period of maximum biting.Survivorship was significantly greater in nectar-rich environments than nectar-poor ones, resulting in greater total fecundity. Daily biting rate and fecundity per female between treatments was not detected. These results translated to greater estimated vectorial capacities in the nectar-rich environment in all four replicates of the experiment (means: 1,089.5 ± 125.2 vs. 518.3 ± 60.6). When mosquito density was made a function of survival and fecundity, rather than held constant, the difference between plant treatments was more pronounced, but so was the variance, so differences were not statistically significant. In the nectar-poor environment, females' survival suffered severely when a blood host was not provided. A sugar-accessibility experiment confirmed that Parthenium hysterophorus is a nectar-poor plant for these mosquitoes. Synthesis and applications. This study, assessing the effect of particular plant species assemblages on the vectorial capacity

  11. Plant-Mediated Effects on Mosquito Capacity to Transmit Human Malaria

    PubMed Central

    Hien, Domonbabele F. d. S.; Roche, Benjamin; Diabaté, Abdoulaye; Yerbanga, Rakiswende S.; Cohuet, Anna; Yameogo, Bienvenue K.; Gouagna, Louis-Clément; Hopkins, Richard J.; Ouedraogo, Georges A.; Simard, Frédéric; Ignell, Rickard; Lefevre, Thierry

    2016-01-01

    The ecological context in which mosquitoes and malaria parasites interact has received little attention, compared to the genetic and molecular aspects of malaria transmission. Plant nectar and fruits are important for the nutritional ecology of malaria vectors, but how the natural diversity of plant-derived sugar sources affects mosquito competence for malaria parasites is unclear. To test this, we infected Anopheles coluzzi, an important African malaria vector, with sympatric field isolates of Plasmodium falciparum, using direct membrane feeding assays. Through a series of experiments, we then examined the effects of sugar meals from Thevetia neriifolia and Barleria lupilina cuttings that included flowers, and fruit from Lannea microcarpa and Mangifera indica on parasite and mosquito traits that are key for determining the intensity of malaria transmission. We found that the source of plant sugar meal differentially affected infection prevalence and intensity, the development duration of the parasites, as well as the survival and fecundity of the vector. These effects are likely the result of complex interactions between toxic secondary metabolites and the nutritional quality of the plant sugar source, as well as of host resource availability and parasite growth. Using an epidemiological model, we show that plant sugar source can be a significant driver of malaria transmission dynamics, with some plant species exhibiting either transmission-reducing or -enhancing activities. PMID:27490374

  12. Nepetalactones from essential oil of Nepeta cataria represent a stable fly feeding and oviposition repellent.

    PubMed

    Zhu, J J; Berkebile, D R; Dunlap, C A; Zhang, A; Boxler, D; Tangtrakulwanich, K; Behle, R W; Baxendale, F; Brewer, G

    2012-06-01

    The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is one of the most serious pests to livestock. It feeds mainly on cattle and causes significant economic losses in the cattle industry. Standard stable fly control involving insecticides and sanitation is usually costly and often has limited effectiveness. As we continue to evaluate and develop safer fly control strategies, the present study reports on the effectiveness of catnip (Nepeta cataria L.) oil and its constituent compounds, nepetalactones, as stable fly repellents. The essential oil of catnip reduced the feeding of stable flies by >96% in an in vitro bioassay system, compared with other sesquiterpene-rich plant oils (e.g. amyris and sandalwood). Catnip oil demonstrated strong repellency against stable flies relative to other chemicals for repelling biting insects, including isolongifolenone, 2-methylpiperidinyl-3-cyclohexen-1-carboxamide and (1S,2'S)-2-methylpiperidinyl-3-cyclohexen-1-carboxamide. The repellency against stable flies of the most commonly used mosquito repellent, DEET, was relatively low. In field trials, two formulations of catnip oil provided >95% protection and were effective for up to 6 h when tested on cattle. Catnip oil also acted as a strong oviposition repellent and reduced gravid stable fly oviposition by 98%. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

  13. Effect of Variable Solvents on Particle Size of Geranium Oil-Loaded Solid Lipid Nanoparticle (Ge-SLN) For Mosquito Repellent Applications

    NASA Astrophysics Data System (ADS)

    Asnawi, Syalwati; Aziz, Azila A.; Aziz, Ramlan A.

    2009-06-01

    A new delivery system for insect repellent is proposed by the incorporation of geranium oil into solid lipid nanoparticle (SLN). A variety of solvents which act as co-surfactants, were introduced to increase the particle size of GE-SLN. Ethanol, which has a high boiling point and a long chain alcohol produced larger particle than dichloromethane. The structure of SLN was not stable when methanol and acetone were used as co-solvents. Concentration of solvents can also influence the size of SLN. In vitro release experiments showed that SLN was able to reduce the rapid evaporation of geranium oil.

  14. Insect Repellents: Protect Your Child from Insect Bites

    MedlinePlus

    ... Print Share Choosing an Insect Repellent for Your Child Page Content Mosquitoes, biting flies, and tick bites ... container with you. Other Ways to Protect Your Child from Insect Bites While you can’t prevent ...

  15. Repellent effectiveness of seven plant essential oils, sunflower oil and natural insecticides against horn flies on pastured dairy cows and heifers.

    PubMed

    Lachance, S; Grange, G

    2014-06-01

    Plant essential oils (basil, geranium, balsam fir, lavender, lemongrass, peppermint, pine and tea tree), mixed with either sunflower oil or ethyl alcohol, were applied at 5% concentrations to the sides of Holstein cattle. Pastured cattle treated with essential oils diluted in sunflower oil had less flies than the untreated control for a 24-h period. However, the essential oil treatments were not significantly different than the carrier oil alone. Barn-held heifers treated with essential oils and sunflower oil alone had significantly less flies than the untreated control for up to 8 h after treatment. Basil, geranium, lavender, lemongrass and peppermint repelled more flies than sunflower oil alone for a period ranging from 1.5 to 4 h after treatments applied to heifers. All essential oils repelled > 75% of the flies on the treated area for 6 and 8 h on pastured cows and indoor heifers, respectively. Geranium, lemongrass and peppermint stayed effective for a longer duration. Essential oils mixed with ethyl alcohol demonstrated less repellence than when mixed with the carrier oil. Safer's soap, natural pyrethrins without piperonyl butoxide and ethyl alcohol alone were not efficient at repelling flies. Essential oils could be formulated for use as fly repellents in livestock production. © 2013 The Royal Entomological Society.

  16. Efficacy and Safety of Catnip (Nepeta cataria) as a Novel Filth Fly Repellent

    USDA-ARS?s Scientific Manuscript database

    The essential oil of catnip (Nepeta cataria) has recently been reported as an alternative mosquito repellent on mosquitoes both topically and spatially. The present study reports that catnip oil resulted in an average repellency of 96% in feeding against stable fly (Stomoxys calcitrans) and 79% to t...

  17. Spatial repellency screening in a high-throughput apparatus with Aedes aegypti and Anopheles gambiae

    USDA-ARS?s Scientific Manuscript database

    Spatial repellents are essential for personal protection against mosquitoes, such as Aedes aegypti and Anopheles gambiae, to reduce annoyance biting and transmission of mosquito-borne diseases. The number of safe and effective repellents, including DEET, picaridin, and IR3535, is limited and contin...

  18. [Prevention with repellent in children].

    PubMed

    Sorge, F

    2009-10-01

    Use of topical insect repellent is an important component in prophylaxis of arthropod bite vector borne diseases. Topical insect repellent are used in a three part management regimen, along with impregnated clothing and mosquito netting. Parental training for efficacious and secure use of repellents for their children is essential part of a successful strategy to combat Lyme borreliosis, dengue fever, Chikungunya, West Nile virus infection and malaria, amongst children, according to local epidemiological risks. Rational repellent prescription for a child must take into account age, active substance concentration, topical substance tolerance, nature and surface of the skin to protect, number of daily applications, and the length of use in a benefit-risk ratio assessment perspective. The 4 currently repellents recommended by Whopes (Who) for their long lasting efficacy and patient tolerance are: 1) Citriodiol (PMD), 2) DEET, 3) Icaridine (KB3023), and 4) IR3535. In field trials the minimum required concentration of each four of these agents to be effective for 3 hours against most arthropods is 20% (in cream, roll-on or spray vehicle). Described side effects of these agents are mild, being limited to local irritative dermatitis and allergy. The risk of severe side effects has been related to DEET misused and neurotoxicity. The international recommendations concerning utilization of topical repellent amongst children for prophylaxis of arthropod borne diseases is concerning short term usage (several weeks). But the use of repellent is sub chronic or chronic amongst the majority of children living in subtropical regions where these vector borne diseases are endemic. And toxicity of topical repellent when used sub-chronically and chronically is not well studied in pediatric age groups. Taking into account these considerations, the current recommendations of the French Group of Tropical Paediatrics are to teach the parents of children who live in arthropod vector disease

  19. Evaluation of plant-mediated synthesized silver nanoparticles against vector mosquitoes.

    PubMed

    Veerakumar, Kaliyan; Govindarajan, Marimuthu; Hoti, S L

    2014-12-01

    Diseases transmitted by blood-feeding mosquitoes, such as dengue fever, dengue hemorrhagic fever, Japanese encephalitis, malaria, and filariasis, are increasing in prevalence, particularly in tropical and subtropical zones. To control mosquitoes and mosquito-borne diseases, which have worldwide health and economic impacts, synthetic insecticide-based interventions are still necessary, particularly in situations of epidemic outbreak and sudden increases of adult mosquitoes. Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and eco-friendly reducing and capping agents. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, in the present study, the adulticidal activity of silver nanoparticles (AgNPs) synthesized using Heliotropium indicum plant leaf extract against adults of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined. Adult mosquitoes were exposed to varying concentrations of aqueous extract of H. indicum and synthesized AgNPs for 24 h. AgNPs were rapidly synthesized using the leaf extract of H. indicum, and the formation of nanoparticles was observed within 6 h. The results recorded from UV-vis spectrum, Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy support the biosynthesis and characterization of AgNPs. The maximum efficacy was observed in synthesized AgNPs against the adult of A. stephensi (lethal dose (LD)₅₀ = 26.712 μg/mL; LD₉₀ = 49.061 μg/mL), A. aegypti (LD₅₀ = 29.626 μg/mL; LD₉₀ = 54.269 μg/mL), and C. quinquefasciatus (LD₅₀ = 32.077 μg/mL; LD₉₀ = 58.426 μg/mL), respectively. No mortality was observed in the control. These results suggest that the leaf aqueous extracts of H.indicum and green synthesis of AgNPs have the potential to be used as an ideal eco-friendly approach for the control of

  20. Origin of pitcher plant mosquitoes in Aedes (Stegomyia): a molecular phylogenetic analysis using mitochondrial and nuclear gene sequences.

    PubMed

    Sota, Teiji; Mogi, Motoyoshi

    2006-09-01

    Two mosquito species of the subgenus Stegomyia (genus Aedes) (Diptera: Culicidae) on the islands of Palau and Yap (Aedes dybasi Bohart and Aedes maehleri Bohart) are adapted to aquatic habitats occupied by Nepenthes pitcher plants. To reveal the origin of these pitcher plant mosquitoes, we attempted a molecular phylogenetic analysis with 11 Stegomyia species by using sequence data from mitochondrial cytochrome oxidase subunit I and 16SrRNA genes as well as the nuclear 28SrRNA gene. Ae. dybasi, a pitcher plant specialist, was sister to Aedes palauensis Bohart within the scutellaris group from the same islands. Ae. maehleri, an opportunistic pitcher plant mosquito, was in a distinct lineage related to the scutellaris group. The adaptation to pitcher plants could have occurred independently in these two species, and recent differentiation of the pitcher plant mosquito Ae. dybasi from the nonpitcher plant mosquito Ae. palauensis was suggested by a relatively small sequence divergence between these species. We also discuss the implications of this analysis for the phylogeny of some other Stegomyia species.

  1. Repellency of 29 Synthetic and Natural Commercial Topical Insect Repellents Against Aedes aegypti (Diptera: Culicidae) in Central Mexico.

    PubMed

    Kuri-Morales, Pablo A; Correa-Morales, Fabián; González-Acosta, Cassandra; Sánchez-Tejeda, Gustavo; Moreno-Garcia, Miguel; Dávalos-Becerril, Eduardo; Juárez-Franco, Marissa F; Benitez-Alva, José Ismael; González-Roldán, Jesús F

    2017-09-01

    In Mexico, the use of repellents to prevent insects from landing and biting is a common practice. However, variation in the efficiency of natural and synthetic repellents has been observed. In this study, we evaluated the repellency and protection time of 16 synthetic and 13 natural-based commercial products against Aedes aegypti (L.) from an endemic dengue area (Jojutla, Morelos) in Central Mexico. The "arm exposure" cage test was used to assess the efficacy of the repellents. Tests were conducted by three adult volunteers. Results showed that DEET (N, N-Diethyl-3-methylbenzamide) repellents provided the highest protection and duration times against Ae. aegypti. However, low repellency and short-time protection was observed (when compared with the manufacturers' protection times). Natural-based products did not repel (either landing or biting) mosquitoes for >30 min. These results show that most of the repellent products did not provide satisfactory levels of personal protection against mosquito bites. Frequent reapplication of repellents (synthetic and natural-based) may compensate for their short duration of action. Repellent efficacy data must be integrated into the decision-making process for an optimal response to the local (or specific region) situation. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Mode of action of insect repellents

    USDA-ARS?s Scientific Manuscript database

    The mode of action of DEET and other insect repellents has been a topic of interest since the discovery of DEET in the mid twentieth century. Nearly 60 years have passed since DEET applied topically to the skin was shown to be effective in preventing mosquito bites. With the discovery and characte...

  3. Personal Insect Repellents and Minimum Risk Pesticides

    EPA Pesticide Factsheets

    An exempt pesticide product may not bear claims to control rodent, insect or microbial pests in a way that links the pests with specific disease. We are considering a proposal to remove personal mosquito and tick repellents from the minimum risk exemption.

  4. Synanthropy of mosquitoes and sand flies near the Aimorés hydroelectric power plant, Brazil.

    PubMed

    Barata, R A; Ursine, R L; Nunes, F P; Morais, D H; Araújo, H S

    2012-12-01

    The environmental changes resulting from the construction of hydroelectric dams may affect the fauna of insect vectors and consequently the epidemiology of the diseases they transmit. This work examined the mosquito and sand fly fauna in the area of the Aimorés hydroelectric power plant, analyzing the seasonal distribution and the degree of species synanthropy in different ecotopes. Between November, 2008 and September, 2009, entomological captures were performed with the help of HP light traps in the rural, urban, and forest areas of Aimorés, Ituêta, Resplendor, and Baixo Guandu counties. The fauna proved to be quite diversified. Twenty-two species of mosquitoes and 11 species of sand flies were found. Culex quinquefasciatus was predominant among mosquitoes (76.7%), while Lutzomyia intermedia prevailed among sand flies (34.5%). Some of the captured species have medical interest. Supported by the high degree of synanthropy, those species reinforce the need for epidemiological surveillance. © 2012 The Society for Vector Ecology.

  5. Larvicidal and repellent properties of some essential oils against Culex tritaeniorhynchus Giles and Anopheles subpictus Grassi (Diptera: Culicidae).

    PubMed

    Govindarajan, Marimuthu

    2011-02-01

    To investigate the larvicidal and repellent properties of essential oils from various parts of four plant species Cymbopogan citrates, Cinnamomum zeylanicum, Rosmarinus officinalis and Zingiber officinale against Culex tritaeniorhynchus (Cx. tritaeniorhynchus) and Anopheles subpictus (An. subpictus). Essential oils were obtained by hydro-distillation method. The mosquitoes were reared in the vector control laboratory and twenty five late third instar larvae of Cx. tritaeniorhynchus and An. subpictus were exposed to based on the wide range and narrow range test, essential oil tested at various concentrations ranging from 25 to 250 ppm. The larval mortality was observed after 24 h under the laboratory conditions. The repellent efficacy was determined against two mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm(2) under laboratory conditions. Results showed all the four plant essential oil produced significant larval mortality against two mosquito species. However, the highest larvicidal activity was observed in the essential oil from Zingiber officinale against Cx. tritaeniorhynchus and An. subpictus with the LC(50) and LC(90) values as 98.83, 57.98 ppm and 186.55, 104.23 ppm, respectively. All the four essential oil shows significant repellency against Cx. tritaeniorhynchus than An. subpictus. Among four essential oil tested the highest repellency was observed in Zingiber officinale, a higher concentration of 5.0 mg/cm(2) provided 100% protection up to 150 and 180 min against Cx. tritaeniorhynchus and An. subpictus, respectively. In this work, it can be concluded that four essential oils which were distilled from Cymbopogan citrates, Cinnamomum zeylanicum, Rosmarinus officinalis and Zingiber officinale showed promising larvicidal and repellent agent against Cx. tritaeniorhynchus and An. subpictus. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  6. Repellents and acaricides as personal protection measures in the prevention of tick-borne diseases.

    PubMed

    Cisak, Ewa; Wójcik-Fatla, Angelina; Zając, Violetta; Dutkiewicz, Jacek

    2012-01-01

    A number of preventive measures for the protection of humans against tick-borne diseases were evaluated. Measures involving the avoidance of tick bites with the use of protective clothing and insect repellents are the simplest and most effective. Repellents are applied directly to the skin or clothing and other fabrics, such as bednets, tents and anti-mosquito screens. Currently, DEET (N,N-diethyl-m-toluamide) is considered the most efficient arthropod repellent reference substance. The registered and recommended active repellent ingredients for skin and/or cloths application, among others, are: DEET, 1-methyl-propyl-2- (hydroxyethyl)-1-piperidinecarboxylate (picaridin), p-menthane-3,8-diol (PMD), ethyl butylactyloaminopropionate ( IR3535), 1S,2S-2-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220), racemic 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (AI3-37220) and synthethic pyrethroid - 3-phenoxybenzyl-cis-trans-3(2,2 dichlorovinyl)-2,2-dimethylcyclopropancarboxylate (permethrin) - an acaricide with repellent properties. To achieve the protection from tick bites by avoiding attachment and/or engorgement by the arthropod, acaricides with repellent properties, such as synthetic pyrethroid-permethrin are used. This pyrethroid is an acaricide of choice used for clothing impregnation, which is effective for personal protection against all three parasitic stages of western black-legged ticks. Products based on natural compounds, e.g. eugenol from Ocimum basilicum, 2-undecanone originally derived from wild tomato, geraniol - a natural product extracted from plants, and many others, represent an interesting alternative to common synthetic repellents and/or acaricides.

  7. Field evaluation of picaridin repellents reveals differences in repellent sensitivity between Southeast Asian vectors of malaria and arboviruses.

    PubMed

    Van Roey, Karel; Sokny, Mao; Denis, Leen; Van den Broeck, Nick; Heng, Somony; Siv, Sovannaroth; Sluydts, Vincent; Sochantha, Tho; Coosemans, Marc; Durnez, Lies

    2014-12-01

    Scaling up of insecticide treated nets has contributed to a substantial malaria decline. However, some malaria vectors, and most arbovirus vectors, bite outdoors and in the early evening. Therefore, topically applied insect repellents may provide crucial additional protection against mosquito-borne pathogens. Among topical repellents, DEET is the most commonly used, followed by others such as picaridin. The protective efficacy of two formulated picaridin repellents against mosquito bites, including arbovirus and malaria vectors, was evaluated in a field study in Cambodia. Over a period of two years, human landing collections were performed on repellent treated persons, with rotation to account for the effect of collection place, time and individual collector. Based on a total of 4996 mosquitoes collected on negative control persons, the overall five hour protection rate was 97.4% [95%CI: 97.1-97.8%], not decreasing over time. Picaridin 20% performed equally well as DEET 20% and better than picaridin 10%. Repellents performed better against Mansonia and Culex spp. as compared to aedines and anophelines. A lower performance was observed against Aedes albopictus as compared to Aedes aegypti, and against Anopheles barbirostris as compared to several vector species. Parity rates were higher in vectors collected on repellent treated person as compared to control persons. As such, field evaluation shows that repellents can provide additional personal protection against early and outdoor biting malaria and arbovirus vectors, with excellent protection up to five hours after application. The heterogeneity in repellent sensitivity between mosquito genera and vector species could however impact the efficacy of repellents in public health programs. Considering its excellent performance and potential to protect against early and outdoor biting vectors, as well as its higher acceptability as compared to DEET, picaridin is an appropriate product to evaluate the epidemiological

  8. Field Evaluation of Picaridin Repellents Reveals Differences in Repellent Sensitivity between Southeast Asian Vectors of Malaria and Arboviruses

    PubMed Central

    Denis, Leen; Van den Broeck, Nick; Heng, Somony; Siv, Sovannaroth; Sluydts, Vincent; Sochantha, Tho; Coosemans, Marc; Durnez, Lies

    2014-01-01

    Scaling up of insecticide treated nets has contributed to a substantial malaria decline. However, some malaria vectors, and most arbovirus vectors, bite outdoors and in the early evening. Therefore, topically applied insect repellents may provide crucial additional protection against mosquito-borne pathogens. Among topical repellents, DEET is the most commonly used, followed by others such as picaridin. The protective efficacy of two formulated picaridin repellents against mosquito bites, including arbovirus and malaria vectors, was evaluated in a field study in Cambodia. Over a period of two years, human landing collections were performed on repellent treated persons, with rotation to account for the effect of collection place, time and individual collector. Based on a total of 4996 mosquitoes collected on negative control persons, the overall five hour protection rate was 97.4% [95%CI: 97.1–97.8%], not decreasing over time. Picaridin 20% performed equally well as DEET 20% and better than picaridin 10%. Repellents performed better against Mansonia and Culex spp. as compared to aedines and anophelines. A lower performance was observed against Aedes albopictus as compared to Aedes aegypti, and against Anopheles barbirostris as compared to several vector species. Parity rates were higher in vectors collected on repellent treated person as compared to control persons. As such, field evaluation shows that repellents can provide additional personal protection against early and outdoor biting malaria and arbovirus vectors, with excellent protection up to five hours after application. The heterogeneity in repellent sensitivity between mosquito genera and vector species could however impact the efficacy of repellents in public health programs. Considering its excellent performance and potential to protect against early and outdoor biting vectors, as well as its higher acceptability as compared to DEET, picaridin is an appropriate product to evaluate the epidemiological

  9. Metalized polyethylene mulch to repel Asian citrus psyllid, slow spread of huanglongbing and improve growth of new citrus plantings.

    PubMed

    Croxton, Scott D; Stansly, Philip A

    2014-02-01

    Greening or huanglongbing (HLB) is a debilitating disease of citrus caused by Candidatus Liberibactor asiaticus and transmitted by the Asian citrus psyllid (ACP), Diaphorina citri. HLB now occurs worldwide in all major citrus growing regions except the Mediterranean and Australia. Management relies principally on insecticidal control of the ACP vector, but is insufficient, even for young trees which are most susceptible to the disease. We tested the ability of metalized polyethylene mulch to repel adult ACP as well as effects on incidence of HLB and early tree growth. Metalized mulch significantly reduced ACP populations and HLB incidence compared to whiteface mulch or bare ground. In addition, metalized mulch, together with the associated drip irrigation and fertigation system, increased soil moisture, reduced weed pressure, and increased tree growth rate. Metalized mulch slows spread of ACP and therefore HLB pressure on young citrus trees. Metalized mulch can thereby augment current control measures for young trees based primarily on systemic insecticides. Additional costs could be compensated for by increased tree growth rate which would shorten time to crop profitability. These advantages make a compelling case for large-scale trials using metalized mulch in young citrus plantings threatened by HLB. © 2013 Society of Chemical Industry.

  10. The formulation of the essential oil of Piper aduncum Linnaeus (Piperales: Piperaceae) increases its efficacy as an insect repellent.

    PubMed

    Mamood, S N H; Hidayatulfathi, O; Budin, S B; Ahmad Rohi, G; Zulfakar, M H

    2017-02-01

    The essential oil (EO) of Piper aduncum Linnaeus, known as 'sireh lada' to locals Malaysian, has the potential to be used as an alternative to synthetic insect repellents such as N,N-diethyl-meta-toluamide. However, the EO's efficacy as a repellent decreases after application due to the high volatility of its active ingredients. A number of studies have showed that optimizing the formulation of plant-based EOs can improve their efficacy as repellents. The present study sought to evaluate the effectiveness of 10% P. aduncum EO in ethanol and in three different semisolid formulations: ointment, cream and gel. These formulations were tested on Aedes aegypti under laboratory conditions. Each formulation was applied to the subject's hands, which were then inserted into a cage containing 25 nulliparous A. aegypti. The number of mosquitoes landing on or biting each subject's hand was recorded, and the repellency percentage, landing/biting percentage and protection time for each of the formulations were compared. There were no statistically significant differences between the semisolid EO formulations with regards to the repellency percentage and the landing/biting percentage at 4 h post-application. All three semisolid EO formulations were able to repel >65% of the A. aegypti at 4 h post-application. The EO ointment formulation provided a protection time (182.5 ± 16.01 min) that was statistically significantly longer than that associated with the EO gel formulation (97.5 ± 14.93 min). Meanwhile, the EO cream formulation provided a protection time of 162.5 ± 6.29 min. As the EO cream and ointment formulations displayed better repellent properties than the EO gel formulation, they appear to be the most promising P. aduncum EO formulations to be developed and commercialized as alternatives to synthetic repellents.

  11. Laboratory and semi-field evaluations of two (Transfluthrin) spatial repellent devices against Aedes aegypti (L.) (Diptera: Culicidae)

    USDA-ARS?s Scientific Manuscript database

    Two transfluthrin-based spatial repellent products (Raid Dual Action Insect Repellent and Home Freshener and Raid Shield (currently not commercially available), SC Johnson, Racine WI) were evaluated for spatial repellent effects against female Aedes aegypti (L.) mosquitoes underlaboratory (wind tunn...

  12. Insecticidal properties of essential plant oils against the mosquito Culex pipiens molestus (Diptera: Culicidae).

    PubMed

    Traboulsi, Abdallah F; Taoubi, K; el-Haj, Samih; Bessiere, J M; Rammal, Salma

    2002-05-01

    The insecticidal activities of essential oil extracts from leaves and flowers of aromatic plants against fourth-instar larvae of the mosquito Culex pipiens molestus Forskal were determined. Extracts of Myrtus communis L were found to be the most toxic, followed by those of Origanum syriacum L, Mentha microcorphylla Koch, Pistacia lentiscus L and Lavandula stoechas L with LC50 values of 16, 36, 39, 70 and 89 mg litre-1, respectively. Over 20 major components were identified in extracts from each plant species. Eight pure components (1,8-cineole, menthone, linalool, terpineol, carvacrol, thymol, (1S)-(-)-alpha-pinene and (1R)-(+)-alpha-pinene) were tested against the larvae. Thymol, carvacrol, (1R)-(+)-alpha-pinene and (1S)-(-)-alpha-pinene were the most toxic (LC50 = 36-49 mg litre-1), while menthone, 1,8-cineole, linalool and terpineol (LC50 = 156-194 mg litre-1) were less toxic.

  13. Larvicidal activity of few select indigenous plants of North East India against disease vector mosquitoes (Diptera: Culicidae).

    PubMed

    Dohutia, C; Bhattacharyya, D R; Sharma, S K; Mohapatra, P K; Bhattacharjee, K; Gogoi, K; Gogoi, P; Mahanta, J; Prakash, A

    2015-03-01

    Mosquitoes are the vectors of several life threatening diseases like dengue, malaria, Japanese encephalitis and lymphatic filariasis, which are widely present in the north-eastern states of India. Investigations on five local plants of north-east India, selected on the basis of their use by indigenous communities as fish poison, were carried out to study their mosquito larvicidal potential against Anopheles stephensi (malaria vector), Stegomyia aegypti (dengue vector) and Culex quinquefasciatus (lymphatic filariasis vector) mosquitoes. Crude Petroleum ether extracts of the roots of three plants viz. Derris elliptica, Linostoma decandrum and Croton tiglium were found to have remarkable larvicidal activity; D. elliptica extract was the most effective and with LC50 value of 0.307 μg/ml its activity was superior to propoxur, the standard synthetic larvicide. Half-life of larvicidal activity of D. elliptica and L. decandrum extracts ranged from 2-4 days.

  14. Applicability of citronella oil (Cymbopogon winteratus) for the prevention of mosquito-borne diseases in the rural area of Tikapur, far-western Nepal.

    PubMed

    Sajo, Ma Easter Joy; Song, Soon-Bong; Bajgai, Johny; Kim, Young-Je; Kim, Pan-Suk; Ahn, Dong-Won; Khanal, Narendra; Lee, Kyu-Jae

    2015-01-01

    Mosquito-borne diseases are a serious global problem, particularly in tropical and sub-tropical countries such as Nepal. Citronella oil is a natural mosquito repellent as well as a local fragrance in Nepal, which is accessible at very low cost because citronella plants are widely cultivated in rural areas of the Terai belt in Nepal. This study was conducted using a real-life randomized controlled pilot trial to confirm the effectiveness and applicability of locally-produced citronella oil as a mosquito repellent for the prevention of mosquito-borne diseases in Nepal. A repellency activity test was performed with 100% citronella oil (Cymbopogon winteratus) from April to May 2013 in the Tikapur Municipality of the Kailali district, Nepal. The test was divided into two trials: an indoor exposure (IE) test (N=101) and an outdoor exposure (OE) test (N=140) from 5.00 pm to 7.00 pm. Each trial contained an experimental citronella oil-applied group and a non-applied (control) group. The outcome measures were the protective effect of citronella oil against mosquitoes, the number of mosquito bites, the repellency percentage, the smell satisfaction and the irritation level. Experimental group had a significant protective effect against mosquito bites in IE (96.5%, n=57) and OE (95.7%, n=70) tests compared to the control group in IE (29.5%, n=44) and OE (28.6%, n=70) tests (experimental vs control groups, p<0.001). The repellency percentage for the OE test was 96.7%. In the smell satisfaction test (n=127), most of the participants responded with high satisfaction: 'good' (67.7%), 'very good' (16.5%), 'bad' (13.4%) and 'very bad' (2.4%). IE and OE tests showed similar satisfaction levels in each category. In the irritation level test (n=127), 87.4% and 12.6% responded with no irritation and slight irritation, respectively. There were no reports of moderate or severe irritation. The topical application of citronella oil can be employed as an easily-available, affordable and

  15. Repellency and Larvicidal Activity of Essential oils from Xylopia laevigata, Xylopia frutescens, Lippia pedunculosa, and Their Individual Compounds against Aedes aegypti Linnaeus.

    PubMed

    Nascimento, A M D; Maia, T D S; Soares, T E S; Menezes, L R A; Scher, R; Costa, E V; Cavalcanti, S C H; La Corte, R

    2017-04-01

    In order to find new alternatives for vector control and personal protection, we evaluated the larvicidal and repellent activity of essentials oils from plants found in the Northeast of Brazil against Aedes aegypti Linnaeus mosquitoes. The plants tested include Xylopia laevigata, Xylopia frutescens, and Lippia pedunculosa and their major compounds, piperitenone oxide, and (R)-limonene. The essential oil of L. pedunculosa and its major volatile compounds were shown to be toxic for Ae. aegypti larvae with a LC 50 lower than 60 ppm. The essential oil of plants from the Xylopia genus, on the other hand, showed no activity against Ae. aegypti, proving to be toxic to mosquito larvae only when concentrations were higher than 1000 ppm. All plants tested provided some degree of protection against mosquitoes landing, but only the essential oil of L. pedunculosa and the volatile compound piperitenone oxide suppressed 100% of mosquitoes landing on human skin, in concentrations lower than 1%. Among the plants studied, the essential oil of L. pedunculosa and its volatiles compounds have shown the potential for the development of safe alternative for mosquito larvae control and protection against Ae. aegypti mosquito bites.

  16. Evaluation of larvicidal activity of medicinal plant extracts against three mosquito vectors.

    PubMed

    Bagavan, A; Rahuman, A Abdul

    2011-01-01

    To evaluate the mosquito larvicidal activity of plant extracts. The hexane, chloroform, ethyl acetate, acetone, and methanol leaf, flower and seed extracts of Abrus precatorius (A. precatorius), Croton bonplandianum (C. bonplandianum), Cynodon dactylon (C. dactylon), Musa paradisiaca (M. paradisiaca) and Syzygium aromaticum (S. aromaticum) were tested against fourth instar larvae of Anopheles vagus (An. vagus), Armigeres subalbatus (Ar. subalbatus) and Culex vishnui (Cx. vishnui). The highest larval mortality was found in seed ethyl acetate extracts of A. precatorius and leaf extracts of C. bonplandianum, flower chloroform and methanol extracts of M. paradisiaca, and flower bud hexane extract of S. aromaticum against An. vagus with LC(50) values of 19.31, 39.96, 35.18, 79.90 and 85.90 μg/mL; leaf ethyl acetate and methanol extracts of C. dactylon, flower methanol extract of M. paradisiaca, flower bud methanol extract of S. aromaticum against Ar. subalbatus with LC(50) values of 21.67, 32.62, 48.90 and 78.28 μg/mL, and seed methanol of A. precatorius, flower methanol extract of M. paradisiaca, flower bud hexane extract of S. aromaticum against Cx. vishnui with LC(50) values of 136.84, 103.36 and 149.56 μg/mL, respectively. These results suggest that the effective plant crude extracts have the potential to be used as an ideal ecofriendly approach for the control of disease vectors. This study provides the first report on the larvicidal activity of crude solvent extracts of different mosquitoes. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  17. Callicarpenal and Intermedeol: Two Natural Arthropod Feeding Deterrent and Repellent Compounds Identified from the Southern Folk Remedy Plant, Callicarpa americana

    USDA-ARS?s Scientific Manuscript database

    In previous studies on the American beautyberry (Callicarpa americana), it was demonstrated that callicarpenal and intermedeol were responsible for the arthropod repellent and feeding deterrent activity of this folk remedy. Both compounds showed significant bite-deterring activity against Aedes aeg...

  18. Repellent activity of essential oils: a review.

    PubMed

    Nerio, Luz Stella; Olivero-Verbel, Jesus; Stashenko, Elena

    2010-01-01

    Currently, the use of synthetic chemicals to control insects and arthropods raises several concerns related to environment and human health. An alternative is to use natural products that possess good efficacy and are environmentally friendly. Among those chemicals, essential oils from plants belonging to several species have been extensively tested to assess their repellent properties as a valuable natural resource. The essential oils whose repellent activities have been demonstrated, as well as the importance of the synergistic effects among their components are the main focus of this review. Essential oils are volatile mixtures of hydrocarbons with a diversity of functional groups, and their repellent activity has been linked to the presence of monoterpenes and sesquiterpenes. However, in some cases, these chemicals can work synergistically, improving their effectiveness. In addition, the use of other natural products in the mixture, such as vanillin, could increase the protection time, potentiating the repellent effect of some essential oils. Among the plant families with promising essential oils used as repellents, Cymbopogon spp., Ocimum spp. and Eucalyptus spp. are the most cited. Individual compounds present in these mixtures with high repellent activity include alpha-pinene, limonene, citronellol, citronellal, camphor and thymol. Finally, although from an economical point of view synthetic chemicals are still more frequently used as repellents than essential oils, these natural products have the potential to provide efficient, and safer repellents for humans and the environment.

  19. Water repellents and water-repellent preservatives for wood

    Treesearch

    R. Sam Williams; William C. Feist

    1999-01-01

    Water repellents and water-repellent preservatives increase the durability of wood by enabling the wood to repel liquid water. This report focuses on water-repellent finishes for wood exposed outdoors above ground. The report includes a discussion of the effects of outdoor exposure on wood, the characteristics of water repellent and water-repellent preservative...

  20. Risk of Disease from Mosquito and Tick Bites

    EPA Pesticide Factsheets

    Insect repellents help reduce the risk of mosquito and tick bites, which can transmit diseases including West Nile Virus, malaria, encephalitis, yellow fever, dengue fever, chikungunya virus, Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis.

  1. The influence of fire history, plant species and post-fire management on soil water repellency in a Mediterranean catchment: the Mount Carmel range, Israel

    NASA Astrophysics Data System (ADS)

    Keesstra, Saskia; Wittenberg, Lea; Maroulis, Jerry; Malkinson, Dan; Cerdà, Artemi; Pereira, Paulo

    2016-04-01

    Fire is a key factor impacting soil hydrology in many Mediterranean catchments. Soil water repellency (SWR) can stimulate land degradation processes by reducing the affinity of soil and water thereby triggering a reduction in soil fertility and increasing soil and water losses (. The effects of two consequent fires (1989 and 2005) on SWR were assessed in the Carmel Mountains, Israel. Fire history, plant recovery and post-fire management were investigated as determining factors in a time dependent system. SWR was highest in the >50 years unburnt plots, where soil under Pinus halepensis is most hydrophobic. In the most disturbed soils (twice burnt), many sites have a low to absent SWR even if the soil is very dry. The dynamics and fluctuations in SWR differ in magnitude under different plant species. The areas treated with CC (chipping of charred trees) showed a much higher SWR than areas left untreated. From these insights, a conceptual model of the reaction of SWR on multiple fires was developed. KEYWORDS: Soil water repellency, WDPT, Wildfires, Vegetation recovery, post-fire management, Mediterranean.

  2. The effects of plant essential oils on escape response and mortality rate of Aedes aegypti and Anopheles minimus.

    PubMed

    Sathantriphop, Sunaiyana; Achee, Nicole L; Sanguanpong, Unchalee; Chareonviriyaphap, Theeraphap

    2015-12-01

    The High Throughput Screening System (HITSS) has been applied in insecticide behavioral response studies with various mosquito species. In general, chemical or natural compounds can produce a range of insect responses: contact irritancy, spatial repellency, knock-down, and toxicity. This study characterized these actions in essential oils derived from citronella, hairy basil, catnip, and vetiver in comparison to DEET and picaridin against Aedes aegypti and Anopheles minimus mosquito populations. Results indicated the two mosquito species exhibited significantly different (P<0.05) contact irritant escape responses between treatment and control for all tested compound concentrations, except with the minimum dose of picaridin (P>0.05) against Ae. aegypti. Spatial repellency responses were elicited in both mosquito species when exposed to all compounds, but the strength of the repellent response was dependent on compound and concentration. Data show that higher test concentrations had greatest toxic effects on both mosquito populations, but vetiver had no toxic effect on Ae. aegypti and picaridin did not elicit toxicity in either Ae. aegypti or An. minimus at any test concentration. Ultimately, this study demonstrates the ability of the HITSS assay to guide selection of effective plant essential oils for repelling, irritating, and killing mosquitoes. © 2015 The Society for Vector Ecology.

  3. Potential of mosquito fern (Azolla caroliniana Willd.) plants as a biofilter for cadmium removal from waste water

    SciTech Connect

    Sajwam, K.S.; Ornes, W.H.

    1995-12-31

    The aquatic vascular Mosquito Fern (Azolla Caroliania Willd.) was investigated as a potential biological filter for removal of Cd from waste water. Mosquito Fern plants were grown in and harvested weekly from 0.10 M Hoagland nutrient solutions containing 0.01, 0.04, and 1.03 {mu}g Cd mL{sup -1} or 0.50 M Hoagland nutrient solutions containing 0.02, 1.0, and 9.14,{mu}g Cd mL{sup -1}. Dry weights of plants significantly increased when exposed to all three Cd concentrations in 0. 10 M Hoagland solution through week three then decreased thereafter. However, in plants exposed to Cd treatments in 0.50 M Hoagland solution, dry weights increasedmore » through week one and decreased thereafter. Tissue Cd concentrations in plants grown in 0.10 M Hoagland solution increased during the first two weeks followed by decreases in week 3 and 4. However, tissue Cd increased through week 3 in plants grown in 0.50 M Hoagland solutions. Cadmium exposure to plants grown in 0.10 M Hoagland solution seemed to increase the tissue P concentrations in plants exposed to the lowest concentration of Cd. Tissue P in both control and treated plants in 0.50 M Hoagland solution seemed to increase over time with exception of the medium level (1 {mu}g Cd mL{sup -1}). These results suggest that Mosquito Fern would be useful for absorbing Cd from nutrient-rich water when the solution concentration was in the range of as low as 0.01 and as high as 9.14 {mu}g Cd mL{sup -1}. However, the harvest regime would have to be every one or two weeks to sustain plant vigor and realize maximum uptake of Cd from solution.« less

  4. Thermal and hydric aspects of environmental heterogeneity in the pitcher plant mosquito

    SciTech Connect

    Kingsolver, J.G.

    1979-12-01

    In an attempt to define environmental heteogeneity and uncertainty in a meaningful manner, thermal and hydric aspects of the microenvironment of the pitcher plant mosquito (Wyeomyia smithii) were studied. Mechanistic mass and energy balance models were developed to predict surface temperatures in a Sphagnum bog and temperatures and water losses in Sarracenia purpurea pitchers. Field tests indicate that the models predicted surface and pitcher temperatures within 2 to 3/sup 0/C, and hourly and daily water losses from pitchers to within 30%, using only basic meteorological data as inputs. Experiments and observations in a natural population of W. smithii in northernmore » Michigan, USA revealed significant differences in larval developmental rate, voltinism, and larval mortality due to microclimatic effects. The model predicts larval developmental rates and voltinism for each micmicroclimate within 10%. Water loss smulations predict, and field observations confirm, that pitcher desiccation is a function of microclimate and pitcher size, and that rainfall patterns on the order of 5 to 30 d determine desiccation patterns. Identification of the spatial and temporal scale of both the environment and the organismic (population) phenomena in question is crucial to constructing a meaningful definition of environmental heterogeneity. Thermal and hydric components of environmental variation may plan an important role in the maintenance of fitness variation in W. smithii. These results support the hypothesis of Istock (1978) that environmental uncertainty favors mixed life history strategies in Wyeomyia.« less

  5. Isolation and identification of mosquito (Aedes aegypti) biting- deterrent compounds from the native American ethnobotanical remedy plant Hierochloë odorata (Sweetgrass)

    USDA-ARS?s Scientific Manuscript database

    Ethnopharmacological relevance: Hierochloë odorata (L.) P. Beauv. (Poaceae), commonly known as sweetgrass, has documented use as an insect repellent by the Flatheads of Montana and Blackfoot of Alberta. Both the Flatheads of Montana and Blackfoot of Alberta would use braided plant material in a sac...

  6. Insecticidal, repellent and fungicidal properties of novel trifluoromethylphenyl amides

    USDA-ARS?s Scientific Manuscript database

    Twenty trifluoromethylphenyl amides were synthesized and evaluated as fungicides and as mosquito toxicants and repellents. Against Aedes aegypti larvae, (trifluoromethyl)phenyl)-3,5-dinitrobenzamide (1e) was the most toxic compound (24 h LC50 1940 nM), while against adults (trifluoromethyl)phenyl)-...

  7. Evaluation of Insecticides, Repellents, and Other Approaches to the Control of Coastal Stand Flies, Culicoides spp.

    DTIC Science & Technology

    1984-05-01

    mosquitoes and tabanids on Parris Island, SC. Mosq. News (in press). Harlan, H. J., C. E. Schreck, and D. L. Kline. 1983. Insect repellent jacket tests...Kline, J. F. Reinert, and T. L. Biery. 1984. Effects of aerial applications of naled on Culicoides biting midges, mosquitoes and tabanids on Parris

  8. Isolation and identification of mosquito (Aedes aegypti) biting deterrent fatty acids from male inflorescences of breadfruit (Artocarpus altilis (Parkinson)Fosberg)

    USDA-ARS?s Scientific Manuscript database

    Dried male inflorescences of breadfruit (Artocarpus altilis, Moraceae) are burned in communities throughout Oceania to repel flying insects, including mosquitoes. This study was conducted to identify chemicals responsible for mosquito deterrence. Various crude extracts were evaluated, and the most a...

  9. Bioefficacy of Mentha piperita essential oil against dengue fever mosquito Aedes aegypti L

    PubMed Central

    Kumar, Sarita; Wahab, Naim; Warikoo, Radhika

    2011-01-01

    Objective To assess the larvicidal and repellent potential of the essential oil extracted from the leaves of peppermint plant, Mentha piperita (M. piperita) against the larval and adult stages of Aedes aegypti (Ae. Aegypti). Methods The larvicidal potential of peppermint oil was evaluated against early fourth instar larvae of Ae. aegypti using WHO protocol. The mortality counts were made after 24 and 48 h, and LC50 and LC90 values were calculated. The efficacy of peppermint oil as mosquito repellent was assessed using the human-bait technique. The measured area of one arm of a human volunteer was applied with the oil and the other arm was applied with ethanol. The mosquito bites on both the arms were recorded for 3 min after every 15 min. The experiment continued for 3 h and the percent protection was calculated. Results The essential oil extracted from M. piperita possessed excellent larvicidal efficiency against dengue vector. The bioassays showed an LC50 and LC90 value of 111.9 and 295.18 ppm, respectively after 24 h of exposure. The toxicity of the oil increased 11.8% when the larvae were exposed to the oil for 48 h. The remarkable repellent properties of M. piperita essential oil were established against adults Ae. aegypti. The application of oil resulted in 100% protection till 150 min. After next 30 min, only 1-2 bites were recorded as compared with 8-9 bites on the control arm. Conclusions The peppermint essential oil is proved to be efficient larvicide and repellent against dengue vector. Further studies are needed to identify the possible role of oil as adulticide, oviposition deterrent and ovicidal agent. The isolation of active ingredient from the oil could help in formulating strategies for mosquito control. PMID:23569733

  10. Repellent efficacy of DEET, MyggA, neem (Azedirachta indica) oil and chinaberry (Melia azedarach) oil against Anopheles arabiensis, the principal malaria vector in Ethiopia.

    PubMed

    Abiy, Ephrem; Gebre-Michael, Teshome; Balkew, Meshesha; Medhin, Girmay

    2015-05-03

    In Ethiopia, Anopheles arabiensis is the main vector responsible for the transmission of malaria in the country and its control mainly involves application of indoor residual spraying (IRS) and use of insecticide-treated bed nets (ITNs). Although the role of repellents for reducing man-vector contact is documented in the literature, the response of An. arabiensis to repellents was not previously evaluated under field conditions in Ethiopia. The trial was conducted in Sodere village assessing the repellent activities of four repellents, of which, two of them were commercially available DEET (N, N-diethyl-1,3-methylbenzamide) and MyggA (p-methane diol) and the other two were laboratory- produced, 20% neem oil and 20% chinaberry oil. A 6 by 6 Latin square design was employed by involving six volunteers who received rotated treatments of repellents and the Ethiopian Niger seed, noog abyssinia (Guizotia abyssinia), and locally called as noog oil (diluents to the two plant oils). Each volunteer also served as control. Volunteers were positioned at a distance of 20-40 m from each other and each was treated with one of the repellents, Niger seed/noog/ oil or untreated. Landing mosquitoes were collected from dusk to down using tests tubes. The tests were done in three replicates. Both DEET and MyggA provided more than 96% protection. The mean protection time for DEET was 8 hrs while the time for MyggA was 6 hrs. Protection obtained from neem oil and chinaberry oil was almost similar (more than 70%), however, the complete protection time for neem was 3 hrs, while that of chinaberry oil was one hour. The commercial products and laboratory-produced repellents can be utilized by individuals to avoid contact with An. arabiensis in Ethiopia.

  11. Allethrin-Based Mosquito Control Device Causing Knockdown, Morbidity, and Mortality in Four Species of Field-Caught Mosquitoes (Diptera: Culicidae).

    PubMed

    Bibbs, Christopher S; Fulcher, Ali; Xue, Rui-De

    2015-07-01

    A mosquito control device marketed for spatial repellency, the ThermaCELL Mosquito Repellent Appliance, was evaluated in semifield trials against multiple field-caught species of mosquito. Using paper and mesh cages, mosquito test groups of at least 30 mosquitoes were suspended in a 2,337 cubic foot outdoor space while two ThermaCELL repellent devices were active. After 30 min of treatment, cages were moved to the laboratory to observe knockdown, morbidity, and mortality for 24 h. Species tested included Aedes atlanticus Dyar and Knab (98% average mortality), Psorophora ferox Humboldt (97% average mortality), Psorophora columbiae Dyar and Knab (96% average mortality), and Aedes taeniorhynchus Wiedemann (84% average mortality). The repellent devices showed effectiveness with high knockdown and mortality across all species tested. Mosquito control devices like the ThermaCELL Mosquito Repellent Appliance may have further practical applications to help combat viral exposures by limiting host mosquitoes. Such devices may provide a functional alternative to DEET dependence in the current state of mosquito management. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Drosophila TRPA1 channel is required to avoid the naturally occurring insect repellent citronellal.

    PubMed

    Kwon, Young; Kim, Sang Hoon; Ronderos, David S; Lee, Youngseok; Akitake, Bradley; Woodward, Owen M; Guggino, William B; Smith, Dean P; Montell, Craig

    2010-09-28

    Plants produce insect repellents, such as citronellal, which is the main component of citronellal oil. However, the molecular pathways through which insects sense botanical repellents are unknown. Here, we show that Drosophila use two pathways for direct avoidance of citronellal. The olfactory coreceptor OR83b contributes to citronellal repulsion and is essential for citronellal-evoked action potentials. Mutations affecting the Ca(2+)-permeable cation channel TRPA1 result in a comparable defect in avoiding citronellal vapor. The TRPA1-dependent aversion to citronellal relies on a G protein (Gq)/phospholipase C (PLC) signaling cascade rather than direct detection of citronellal by TRPA1. Loss of TRPA1, Gq, or PLC causes an increase in the frequency of citronellal-evoked action potentials in olfactory receptor neurons. Absence of the Ca(2+)-activated K(+) channel (BK channel) Slowpoke results in a similar impairment in citronellal avoidance and an increase in the frequency of action potentials. These results suggest that TRPA1 is required for activation of a BK channel to modulate citronellal-evoked action potentials and for aversion to citronellal. In contrast to Drosophila TRPA1, Anopheles gambiae TRPA1 is directly and potently activated by citronellal, thereby raising the possibility that mosquito TRPA1 may be a target for developing improved repellents to reduce insect-borne diseases such as malaria. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Neurophysiological and Behavioral Responses of Gypsy Moth Larvae to Insect Repellents: DEET, IR3535, and Picaridin

    DTIC Science & Technology

    2014-06-23

    fever mosquito Aedes aegypti [7] have a gustatory receptor neuron (GRN) housed within the labellar sensilla sensitive to DEET (D. melanogaster) and two...mosquito repellents against Aedes albopictus, Culex nigripalpus, and Ochlerotatus triseriatus (Diptera: Culicidae). Med Vet Entomol 41: 726–730. 6... Aedes aegypti mosquitoes in laboratory assays. Med Vet Entomol 20: 288–293. 7. Sanford JL, Shields VDC, Dickens JC (2013) Gustatory receptor neuron

  14. Generic insect repellent detector from the fruit fly Drosophila melanogaster.

    PubMed

    Syed, Zainulabeuddin; Pelletier, Julien; Flounders, Eric; Chitolina, Rodrigo F; Leal, Walter S

    2011-03-16

    Insect repellents are prophylactic tools against a number of vector-borne diseases. There is growing demand for repellents outperforming DEET in cost and safety, but with the current technologies R&D of a new product takes almost 10 years, with a prohibitive cost of $30 million dollar in part due to the demand for large-scale synthesis of thousands of test compounds of which only 1 may reach the market. R&D could be expedited and cost dramatically reduced with a molecular/physiological target to streamline putative repellents for final efficacy and toxicological tests. Using olfactory-based choice assay we show here that the fruit fly is repelled by not only DEET, but also IR3535 and picaridin thus suggesting they might have "generic repellent detector(s)," which may be of practical applications in new repellent screenings. We performed single unit recordings from all olfactory sensilla in the antennae and maxillary palps. Although the ab3A neuron in the wild type flies responded to picaridin, it was unresponsive to DEET and IR3535. By contrast, a neuron housed in the palp basiconic sensilla pb1 responded to DEET, IR3535, and picaridin, with apparent sensitivity higher than that of the DEET detectors in the mosquitoes Culex quinquefasciatus and Aedes aegypti. DmOr42a was transplanted from pb1 to the "empty neuron" and showed to be sensitive to the three insect repellents. For the first time we have demonstrated that the fruit fly avoids not only DEET but also IR3535 and picaridin, and identified an olfactory receptor neuron (ORN), which is sensitive to these three major insect repellents. We have also identified the insect repellent-sensitive receptor, DmOr42a. This generic detector fulfils the requirements for a simplified bioassay for early screening of test insect repellents.

  15. Anti-mosquito plants as an alternative or incremental method for malaria vector control among rural communities of Bagamoyo District, Tanzania

    PubMed Central

    2014-01-01

    Background Plants represent one of the most accessible resources available for mosquito control by communities in Tanzania. However, no documented statistics exist for their contribution in the management of mosquitoes and other insects except through verbal and some publications. This study aimed at assessing communities’ knowledge, attitudes and practices of using plants as an alternative method for mosquito control among selected communities in a malaria-prone area in Tanzania. Methods Questionnaires were administered to 202 respondents from four villages of Bagamoyo District, Pwani Region, in Tanzania followed by participatory rural appraisal with village health workers. Secondary data collection for plants mentioned by the communities was undertaken using different search engines such as googlescholar, PubMED and NAPRALERT. Results Results showed about 40.3% of respondents used plants to manage insects, including mosquitoes. A broad profile of plants are used, including “mwarobaini” (Azadirachta indica) (22.5%), “mtopetope” (Annona spp) (20.8%), “mchungwa/mlimau” (Citrus spp) (8.3%), “mvumbashi/uvumbati” (Ocimum spp) (7.4%), “mkorosho” (Anacadium occidentale) (7.1%), “mwembe” (5.4%) (Mangifera indica), “mpera” (4.1%) (Psidium spp) and “maganda ya nazi” (4.1%) (Cocos nucifera). Majority of respondents collected these plants from the wild (54.2%), farms (28.9%) and/or home gardens (6%). The roles played by these plants in fighting mosquitoes is reflected by the majority that deploy them with or without bed-nets (p > 0.55) or insecticidal sprays (p >0.22). Most respondents were aware that mosquitoes transmit malaria (90.6%) while few respondents associated elephantiasis/hydrocele (46.5%) and yellow fever (24.3%) with mosquitoes. Most of the ethnobotanical uses mentioned by the communities were consistent with scientific information gathered from the literature, except for Psidium guajava, which is reported for the first time in

  16. Anti-mosquito plants as an alternative or incremental method for malaria vector control among rural communities of Bagamoyo District, Tanzania.

    PubMed

    Innocent, Ester; Hassanali, Ahmed; Kisinza, William Nw; Mutalemwa, Prince Pp; Magesa, Stephen; Kayombo, Edmund

    2014-07-11

    Plants represent one of the most accessible resources available for mosquito control by communities in Tanzania. However, no documented statistics exist for their contribution in the management of mosquitoes and other insects except through verbal and some publications. This study aimed at assessing communities' knowledge, attitudes and practices of using plants as an alternative method for mosquito control among selected communities in a malaria-prone area in Tanzania. Questionnaires were administered to 202 respondents from four villages of Bagamoyo District, Pwani Region, in Tanzania followed by participatory rural appraisal with village health workers. Secondary data collection for plants mentioned by the communities was undertaken using different search engines such as googlescholar, PubMED and NAPRALERT. Results showed about 40.3% of respondents used plants to manage insects, including mosquitoes. A broad profile of plants are used, including "mwarobaini" (Azadirachta indica) (22.5%), "mtopetope" (Annona spp) (20.8%), "mchungwa/mlimau" (Citrus spp) (8.3%), "mvumbashi/uvumbati" (Ocimum spp) (7.4%), "mkorosho" (Anacadium occidentale) (7.1%), "mwembe" (5.4%) (Mangifera indica), "mpera" (4.1%) (Psidium spp) and "maganda ya nazi" (4.1%) (Cocos nucifera). Majority of respondents collected these plants from the wild (54.2%), farms (28.9%) and/or home gardens (6%). The roles played by these plants in fighting mosquitoes is reflected by the majority that deploy them with or without bed-nets (p > 0.55) or insecticidal sprays (p >0.22). Most respondents were aware that mosquitoes transmit malaria (90.6%) while few respondents associated elephantiasis/hydrocele (46.5%) and yellow fever (24.3%) with mosquitoes. Most of the ethnobotanical uses mentioned by the communities were consistent with scientific information gathered from the literature, except for Psidium guajava, which is reported for the first time in insect control. This survey has indicated some knowledge gap

  17. Dose-Dependent Behavioral Response of the Mosquito Aedes albopictus to Floral Odorous Compounds

    PubMed Central

    Hao, Huiling; Sun, Jingcheng; Dai, Jianqing

    2013-01-01

    The value of using plant volatiles as attractants for trapping and spatial repellents to protect hosts against mosquitoes has been widely recognized. The current study characterized behavioral responses of Aedes albopictus (Skuse) (Diptera: Culicidae) to different concentrations, ranging from 6 to 96%, of several common floral odorous compounds, including linalool, geraniol, citronellal, eugenol, anisaldehyde, and citral, using a wind tunnel olfactometer system. The results indicated that female mosquitoes reacted differently to different concentrations of the tested compounds, and the reactions also were different when those chemicals were tested alone or in the presence of human host odor. When tested alone, anisaldehyde was attractive at all tested concentrations, eugenol was attractive only at concentrations of 48–96%, while citronellal, linalool, citral, and geraniol were attractive at lower concentrations and repellent at higher concentrations. When tested in the presence of a human host, all compounds except for anisaldehyde at all tested concentrations showed host-seeking inhibition to certain degrees. Based on the results, it was concluded that anisaldehyde was effective in attracting Ae. albopictus when used alone but could also remarkably inhibit the host-seeking ability at a concentration of 96%, while citral, geraniol, linalool, citronellal, and eugenol are suitable as spatial repellents. PMID:24779928

  18. Arthropod repellency, especially tick (Ixodes ricinus), exerted by extract from Artemisia abrotanum and essential oil from flowers of Dianthus caryophyllum.

    PubMed

    Tunón, H; Thorsell, W; Mikiver, A; Malander, I

    2006-06-01

    A toluene extract of southernwood (Artemisia abrotanum) and the essential oil from flowers of carnation (Dianthus caryophyllum ) exerted pronounced a repellent effect both against ticks (nymphs of Ixodes ricinus) and yellow fever mosquitoes (Aedes aegypti). The most potent repellents found were coumarin and thujyl alcohol from A. abrotanum and phenylethanol from D. caryophyllum where coumarin and thujyl alcohol were also detected.

  19. 'Repel all biters': an enhanced collection of endophilic Anopheles gambiae and Anopheles arabiensis in CDC light-traps, from the Kagera Region of Tanzania, in the presence of a combination mosquito net impregnated with piperonyl butoxide and permethrin.

    PubMed

    LeClair, Corey; Cronery, Judith; Kessy, Enock; Tomás, Elsa V E; Kulwa, Yohannes; Mosha, Franklin W; Rowland, Mark; Protopopoff, Natacha; Derek Charlwood, J

    2017-08-15

    Mosquito nets containing synergists designed to overcome metabolic resistance mechanisms in vectors have been developed. These may enhance excitability in the mosquitoes and affect how they respond to CDC light-traps. Investigating the behaviour of vectors of disease in relation to novel mosquito nets is, therefore, essential for the design of sampling and surveillance systems. In an initial experiment in Muleba, Tanzania, nine bedrooms from three housing clusters were sampled. CDC light-traps were operated indoors next to occupied untreated nets (UTN), Olyset ® long lasting insecticidal net (LLIN) and Olyset Plus ® LLIN containing piperonyl butoxide (PBO) synergist. Nets were rotated daily between the nine rooms over nine nights. A further series of experiments using the nets on alternate nights in a single room was undertaken during the short rains. Anopheles gambiae s.l. were collected in CDC light-traps, a window-trap and Furvela tent-trap. Anopheles gambiae s.l. were identified to species by polymerase chain reaction (PCR). In the initial experiment 97.7% of the 310 An. gambiae s.l. were An. gambiae s.s., the remainder being Anopheles arabiensis. The number of mosquitoes collected from 81 light-trap collections was greater in the presence of an Olyset [density rate ratio 1.81, 95% CI (1.22-2.67), p = 0.003] relative to an UTN. In a second experiment, in the wet season 84% of the 180 An. gambiae s.l. identified were An. arabiensis. The number of An. gambiae s.l. collected from a light-trap compared to a tent-trap was significantly higher when an Olyset Plus net was used compared to an UTN. Survival of the mosquitoes in the window trap was not reduced by the use of an Olyset Plus net in the bedroom relative to an Olyset net. Mosquitoes entering bedrooms, even those susceptible to pyrethroids, were not killed by contact with an Olyset Plus LLIN. The enhanced numbers of An. gambiae or An. arabiensis collected in light-traps when a treated net is used requires

  20. Effects of Plant-Community Composition on the Vectorial Capacity and Fitness of the Malaria Mosquito Anopheles gambiae

    PubMed Central

    Stone, Christopher M.; Jackson, Bryan T.; Foster, Woodbridge A.

    2012-01-01

    Dynamics of Anopheles gambiae abundance and malaria transmission potential rely strongly on environmental conditions. Female and male An. gambiae use sugar and are affected by its absence, but how the presence or absence of nectariferous plants affects An. gambiae abundance and vectorial capacity has not been studied. We report on four replicates of a cohort study performed in mesocosms with sugar-poor and sugar-rich plants, in which we measured mosquito survival, biting rates, and fecundity. Survivorship was greater with access to sugar-rich plant species, and mortality patterns were age-dependent. Sugar-poor populations experienced Weibull mortality patterns, and of four populations in the sugar-rich environment, two female and three male subpopulations were better fitted by Gompertz functions. A tendency toward higher biting rates in sugar-poor mesocosms, particularly for young females, was found. Therefore, vectorial capacity was pulled in opposing directions by nectar availability, resulting in highly variable vectorial capacity values. PMID:22927493

  1. Mosquito Bites

    MedlinePlus

    ... humans. Other mosquito-borne infections include yellow fever, malaria and some types of brain infection (encephalitis). Symptoms ... carry certain diseases, such as West Nile virus, malaria, yellow fever and dengue fever. The mosquito obtains ...

  2. Heritability of Attractiveness to Mosquitoes

    PubMed Central

    Fernández-Grandon, G. Mandela; Gezan, Salvador A.; Armour, John A. L.; Pickett, John A.; Logan, James G.

    2015-01-01

    Female mosquitoes display preferences for certain individuals over others, which is determined by differences in volatile chemicals produced by the human body and detected by mosquitoes. Body odour can be controlled genetically but the existence of a genetic basis for differential attraction to insects has never been formally demonstrated. This study investigated heritability of attractiveness to mosquitoes by evaluating the response of Aedes aegypti (=Stegomyia aegypti) mosquitoes to odours from the hands of identical and non-identical twins in a dual-choice assay. Volatiles from individuals in an identical twin pair showed a high correlation in attractiveness to mosquitoes, while non-identical twin pairs showed a significantly lower correlation. Overall, there was a strong narrow-sense heritability of 0.62 (SE 0.124) for relative attraction and 0.67 (0.354) for flight activity based on the average of ten measurements. The results demonstrate an underlying genetic component detectable by mosquitoes through olfaction. Understanding the genetic basis for attractiveness could create a more informed approach to repellent development. PMID:25901606

  3. Bug repellent safety

    MedlinePlus

    The safest bug repellent is to wear proper clothing. Wear a full-brimmed hat to protect your ... Tuck pant cuffs into socks. Wear light-colored clothing. Light colors are less attractive than dark colors ...

  4. Chemical composition and assessment of larvicidal and repellent capacity of 14 Lamiaceae essential oils against Aedes albopictus.

    PubMed

    Giatropoulos, Athanassios; Kimbaris, Athanasios; Michaelakis, Αntonios; Papachristos, Dimitrios P; Polissiou, Moschos G; Emmanouel, Nickolaos

    2018-06-01

    In the current laboratory study, 14 essential oils (EOs) derived from 12 Lamiaceae plant species and their major components were screened for their larvicidal and repellent properties against Aedes albopictus, an invasive mosquito species of great medical importance. The results of toxicity bioassays revealed that the EOs from Thymus vulgaris, Ocimum basilicum, Origanum dictamnus, Origanum majorana, and Origanum vulgare, as well as their major components (terpenes), namely thymol, carvacrol, p-cymene, and γ-terpinene exerted the highest larvicidal effect. Essential oils from Mellisa officinalis, Origanum dictamus, Mentha spicata (chem. piperitenone epoxide), Origanum majorana, and Satureja thymbra were the most potent repellents, with the last two assigned as the best ones. Among the terpenes tested, piperitenone epoxide, carvacrol, thymol, and piperitenone provided the highest level of protection against Ae. albopictus adults. Chemical analysis revealed the presence of a high number of terpenes in the EOs, while in most cases, the biological action of the tested EOs and their major components was in consistency. The most effective EOs and terpenes that were identified through the current laboratory bioassays could be used as alternative agents to control larvae and repel adults of Ae. albopictus.

  5. Potential of crude seed extract of celery, Apium graveolens L., against the mosquito Aedes aegypti (L.) (Diptera: Culicidae).

    PubMed

    Choochote, Wej; Tuetun, Benjawan; Kanjanapothi, Duangta; Rattanachanpichai, Eumporn; Chaithong, Udom; Chaiwong, Prasong; Jitpakdi, Atchariya; Tippawangkosol, Pongsri; Riyong, Doungrat; Pitasawat, Benjawan

    2004-12-01

    Crude seed extract of celery, Apium graveolens, was investigated for anti-mosquito potential, including larvicidal, adulticidal, and repellent activities against Aedes aegypti, the vector of dengue haemorrhagic fever. The ethanol-extracted A. graveolens possessed larvicidal activity against fourth instar larvae of Ae. aegypti with LD50 and LD95 values of 81.0 and 176.8 mg/L, respectively. The abnormal movement observed in treated larvae indicated that the toxic effect of A. graveolens extract was probably on the nervous system. In testing for adulticidal activity, this plant extract exhibited a slightly adulticidal potency with LD50 and LD95 values of 6.6 and 66.4 mg/cm2, respectively. It showed repellency against Ae. aegypti adult females with ED50 and ED95 values of 2.03 and 28.12 mg/cm2, respectively. It also provided biting protection time of 3 h when applied at a concentration of 25 g%. Topical application of the ethanol-extracted A. graveolens did not induce dermal irritation. No adverse effects on the skin or other parts of the body of human volunteers were observed during 3 mo of the study period or in the following 3 mo, after which time observations ceased. A. graveolens, therefore, can be considered as a probable source of some biologically active compounds used in the development of mosquito control agents, particularly repellent products.

  6. Use of Nicotiana tabacum L extract for anti-Aedes Aegypti mosquito paint

    NASA Astrophysics Data System (ADS)

    Sandralintang, Trisiana Chrysanthi; Fauzantoro, Ahmad; Hermansyah, Heri; Jufri, Mahdi; Gozan, Misri

    2018-02-01

    This study intended to formulate mosquito repellent paints based tobacco leaf extracts-free pyrethroid substance which is safe for users. The active substance which was added to the paint as a mosquito repellent was an extract of tobacco leaves. The result of Anti-mosquito paint formulation produced was according to the Indonesia National Standard (SNI). The results of anti-Aedes Aegypti mosquito paint effectiveness test showed that 5% concentration of tobacco extract could kill half of the mosquito population (LC50) for 2 hours, the concentration of tobacco extract between 3-5% killed half the mosquito population (LC50) during 4 hours, while 1-3% and 0-1% concentration of tobacco extract killed half the mosquito population (LC50) for 6 and 24 hours, respectively.

  7. Repellents and New “Spaces of Concern” in Global Health

    PubMed Central

    Kelly, Ann H.; Koudakossi, Hermione N. Boko; Moore, Sarah J.

    2017-01-01

    ABSTRACT Today, malaria prevention hinges upon two domestic interventions: insecticide-treated bed nets and indoor residual spraying. As mosquitoes grow resistant to these tools, however, novel approaches to vector control have become a priority area of malaria research and development. Spatial repellency, a volumetric mode of action that seeks to reduce disease transmission by creating an atmosphere inimical to mosquitoes, represents one way forward. Drawing from research that sought to develop new repellent chemicals in conversation with users from sub-Saharan Africa and the United States, we consider the implications of a non-insecticidal paradigm of vector control for how we understand the political ecology of malaria. PMID:28594568

  8. Toxic and repellent activity of selected monoterpenoids (thymol, carvacrol and linalool) against the castor bean tick, Ixodes ricinus (Acari: Ixodidae).

    PubMed

    Tabari, Mohaddeseh Abouhosseini; Youssefi, Mohammad Reza; Maggi, Filippo; Benelli, Giovanni

    2017-10-15

    The castor bean tick, Ixodes ricinus, is a species of medical and veterinary importance. The use of synthetic acaricides for tick control has led to development of resistance, residues in the environment and animal products, and public health concerns. In this regard, plant essential oils and their main constituents represent an appealing alternative strategy to combat ticks. The phenols thymol and carvacrol and the alcohol linalool are monoterpenoids occurring in essential oils of several aromatic and medicinal plants, such as thyme, oregano, savory, lavender and coriander. Recent studies have shown toxicity of these monoterpenoids against selected mosquito vectors and other arthropod pests. However, information on their bioactivity on I. ricinus is not available. On this basis, here we evaluated the ovicidal, larvicidal and repellency effects of these compounds against I. ricinus. Concentrations of 0.25, 0.5, 1, 2 and 5% were sprayed on the egg masses, then hatching rates were noted. Larvicidal assays were conducted on unengorged larvae, following the larval packet technique. The repellency was determined by measuring the vertical migration behavior of ticks in laboratory conditions. Carvacrol and thymol at all concentrations tested led to a significant hatching decrease, showing an efficacy higher than permethrin, whereas linalool did not cause any significant effect. In the larvae treated with carvacrol and thymol (1, 2 and 5%), mortality rates reached 100% after 24h, showing a larvicidal efficacy higher than permethrin, whereas no effect was seen in the larval groups treated with linalool. Carvacrol and thymol at all concentrations tested showed >90% repellency on I. ricinus. Linalool was scarcely effective (50.24% repellency) only at the concentration of 5%. Overall, based on these results, the phenols carvacrol and thymol can be considered as candidate ingredients for the development of novel acaricidal formulations to control the populations of I. ricinus

  9. Deep sequencing revealed molecular signature of horizontal gene transfer of plant like transcripts in the mosquito Anopheles culicifacies: an evolutionary puzzle

    PubMed Central

    Sharma, Punita; Das De, Tanwee; Sharma, Swati; Kumar Mishra, Ashwani; Thomas, Tina; Verma, Sonia; Kumari, Vandana; Lata, Suman; Singh, Namita; Valecha, Neena; Chand Pandey, Kailash; Dixit, Rajnikant

    2015-01-01

    In prokaryotes, horizontal gene transfer (HGT) has been regarded as an important evolutionary drive to acquire and retain beneficial genes for their survival in diverse ecologies. However, in eukaryotes, the functional role of HGTs remains questionable, although current genomic tools are providing increased evidence of acquisition of novel traits within non-mating metazoan species. Here, we provide another transcriptomic evidence for the acquisition of massive plant genes in the mosquito, Anopheles culicifacies. Our multiple experimental validations including genomic PCR, RT-PCR, real-time PCR, immuno-blotting and immuno-florescence microscopy, confirmed that plant like transcripts (PLTs) are of mosquito origin and may encode functional proteins. A comprehensive molecular analysis of the PLTs and ongoing metagenomic analysis of salivary microbiome provide initial clues that mosquitoes may have survival benefits through the acquisition of nuclear as well as chloroplast encoded plant genes. Our findings of PLTs further support the similar questionable observation of HGTs in other higher organisms, which is still a controversial and debatable issue in the community of evolutionists. We believe future understanding of the underlying mechanism of the feeding associated molecular responses may shed new insights in the functional role of PLTs in the mosquito. PMID:26998230

  10. Efficacy of topical permethrin as repellent against Aedes aegypti's bites.

    PubMed

    Miot, Hélio Amante; Ferreira, Daniela Pinho; Mendes, Fabiana Guandalini; Carrenho, Flávia Roberta Hernandes; de Oliveira Amui, Isabela; Carneiro, Carlos Augusto Sá; Madeira, Newton Goulart

    2008-07-15

    Mosquitoes are the most important vectors of infectious diseases and their bites are related to several adverse skin reactions. Permethrin impregnated clothes are an efficient strategy against arthropods' bites; however, its topical efficacy as a repellent has not been well established. We studied the response to permethrin lotion 5 percent and N,N-Diethyl-meta-toluamide (DEET) spray 50 percent applied to the unprotected forearms of 10 volunteers. Each arm was exposed to 20 female mosquitoes of Aedes aegypti. We performed 71 bilateral comparative measurements evaluating the timing for the first bites. The average times for the arm without the product, with permethrin 5 percent, and with DEET 50 percent were: 7.9 seconds, 336.2 seconds and 7512.1 seconds. The results showed a significant difference between repellency times between either product and unprotected controls. In addition, there was a significant difference in time to first bite between permethrin and DEET treated arms (p<0.01). Permethrin affords some repellent activity against Aedes aegypti bites in this experimental setting. However, permethrin's profile of repellency was significantly inferior to that of DEET.

  11. Nectar Theft and Floral Ant-Repellence: A Link between Nectar Volume and Ant-Repellent Traits?

    PubMed Central

    Ballantyne, Gavin; Willmer, Pat

    2012-01-01

    As flower visitors, ants rarely benefit a plant. They are poor pollinators, and can also disrupt pollination by deterring other flower visitors, or by stealing nectar. Some plant species therefore possess floral ant-repelling traits. But why do particular species have such traits when others do not? In a dry forest in Costa Rica, of 49 plant species around a third were ant-repellent at very close proximity to a common generalist ant species, usually via repellent pollen. Repellence was positively correlated with the presence of large nectar volumes. Repellent traits affected ant species differently, some influencing the behaviour of just a few species and others producing more generalised ant-repellence. Our results suggest that ant-repellent floral traits may often not be pleiotropic, but instead could have been selected for as a defence against ant thieves in plant species that invest in large volumes of nectar. This conclusion highlights to the importance of research into the cost of nectar production in future studies into ant-flower interactions. PMID:22952793

  12. Ultra low concentration deltamethrin loaded patch development and evaluation of its repellency against dengue vector Aedes (S) albopictus

    PubMed Central

    2013-01-01

    Background Mosquito repellents and emanators confer protection against mosquito bites through spatial action of emanated vapours which are released into the adjoining environment. Synthetic insecticides released into the environment in ultra low volume vapour phase deter the mosquitoes from biting humans in a protected space. Methods Formulation patches were prepared using the solvent evaporation method over a backing membrane and using Dibutylphthalate (DBT) as a plasticizer. The effect of formulation variables on the deltamethrin release from the patch matrices were studied under accelerated conditions, whereas, HPLC was used for quantitative estimation of deltamethrin. The prepared patch formulations were subjected to physicochemical studies, such as, deltamethrin content, thickness, weight variation, percent moisture content, moisture uptake, surface area and surface pH determination. Deltamethrin-polymer interaction and compatibility was ascertained using DSC and FT-IR, while surface morphology and deltamethrin distribution in the patch were studied using SEM technique. Repellent activity of the patch formulations was evaluated against Ae. albopictus mosquitoes. Results Blends of polymeric combinations of polyvinylpyrrolidone (PVP) and ethyl-cellulose (EC) with admixture of deltamethrin provided prolonged repellent activity against Ae. albopictus mosquitoes. Physicochemical characterisation indicated the suitability of deltamethrin patch formulation with the polymeric combinations of PVP and EC. Patches were very effective against laboratory reared Ae. albopictus mosquitoes. No significant difference was observed between the performance of test patches and commercially available repellent cream Mosqshield®. Conclusion Deltamethrin loaded patches provided effective repellency against Ae. albopictus mosquitoes. The study emphasised that deltamethrin released to the environment in low concentration could be an excellent spatial repellent against hematophagous

  13. Evolutionary divergence of core and post-translational circadian clock genes in the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Tormey, Duncan; Colbourne, John K; Mockaitis, Keithanne; Choi, Jeong-Hyeon; Lopez, Jacqueline; Burkhart, Joshua; Bradshaw, William; Holzapfel, Christina

    2015-10-06

    Internal circadian (circa, about; dies, day) clocks enable organisms to maintain adaptive timing of their daily behavioral activities and physiological functions. Eukaryotic clocks consist of core transcription-translation feedback loops that generate a cycle and post-translational modifiers that maintain that cycle at about 24 h. We use the pitcher-plant mosquito, Wyeomyia smithii (subfamily Culicini, tribe Sabethini), to test whether evolutionary divergence of the circadian clock genes in this species, relative to other insects, has involved primarily genes in the core feedback loops or the post-translational modifiers. Heretofore, there is no reference transcriptome or genome sequence for any mosquito in the tribe Sabethini, which includes over 375 mainly circumtropical species. We sequenced, assembled and annotated the transcriptome of W. smithii containing nearly 95 % of conserved single-copy orthologs in animal genomes. We used the translated contigs and singletons to determine the average rates of circadian clock-gene divergence in W. smithii relative to three other mosquito genera, to Drosophila, to the butterfly, Danaus, and to the wasp, Nasonia. Over 1.08 million cDNA sequence reads were obtained consisting of 432.5 million nucleotides. Their assembly produced 25,904 contigs and 54,418 singletons of which 62 % and 28 % are annotated as protein-coding genes, respectively, sharing homology with other animal proteomes. The W. smithii transcriptome includes all nine circadian transcription-translation feedback-loop genes and all eight post-translational modifier genes we sought to identify (Fig. 1). After aligning translated W. smithii contigs and singletons from this transcriptome with other insects, we determined that there was no significant difference in the average divergence of W. smithii from the six other taxa between the core feedback-loop genes and post-translational modifiers. The characterized transcriptome is sufficiently complete and of

  14. Aquatic insect predators and mosquito control.

    PubMed

    Shaalan, Essam Abdel-Salam; Canyon, Deon V

    2009-12-01

    Mosquitoes are serious biting pests and obligate vectors of many vertebrate pathogens. Their immature larval and pupal life stages are a common feature in most tropical and many temperate water bodies and often form a significant proportion of the biomass. Control strategies rely primarily on the use of larvicides and environmental modification to reduce recruitment and adulticides during periods of disease transmission. Larvicides are usually chemical but can involve biological toxins, agents or organisms. The use of insect predators in mosquito control has been exploited in a limited fashion and there is much room for further investigation and implementation. Insects that are recognized as having predatorial capacity with regard to mosquito prey have been identified in the Orders Odonata, Coleoptera, Diptera (primarily aquatic predators), and Hemiptera (primarily surface predators). Although their capacity is affected by certain biological and physical factors, they could play a major role in mosquito control. Furthermore, better understanding for the mosquitoes-predators relationship(s) could probably lead to satisfactory reduction of mosquito-borne diseases by utilizing either these predators in control programs, for instance biological and/or integrated control, or their kairomones as mosquitoes' ovipoisting repellents. This review covers the predation of different insect species on mosquito larvae, predator-prey-habitat relationships, co-habitation developmental issues, survival and abundance, oviposition avoidance, predatorial capacity and integrated vector control.

  15. Repellency of essential oil of Piper aduncum against Aedes albopictus in the laboratory.

    PubMed

    Misni, Norashiqin; Sulaiman, Sallehudin; Othman, Hidayatulfathi; Omar, Baharudin

    2009-12-01

    The repellent activity of Piper aduncum essential oil against Aedes albopictus was investigated under laboratory conditions with human volunteers. The lowest median effective dose (ED50) value was 1.5 microg/cm2 at 60 sec of exposure when compared to 90 sec (2.1 microg/cm2) and 120 sec (1.8 microg/cm2) of exposure. At 0.4 g, the essential oil gave a high protection (95.2%) against Ae. albopictus bites or landing at 2 h postapplication. The percentage of protection was reduced to 83.3% after 4 h, 64.5% after 6 h, and 51.6% after 8 h postapplication. As a comparison, treatment with 10% deet gave 100% protection against mosquito biting/landing for 4 h postapplication. There was no significant difference in percentage protection reduction between the plant extract and the commercial product deet, respectively (P = 0.739). The essential oil, which was not as good as deet, still gave moderate protection against Ae. albopictus biting even until 4 h postapplication. In conclusion, the P. aduncum essential oil has the potential to be used as a repellent against the dengue/dengue hemorrhagic fever vector, Ae. albopictus.

  16. Toxicity, repellency and flushing out in Triatoma infestans (Hemiptera: Reduviidae) exposed to the repellents DEET and IR3535

    PubMed Central

    Reynoso, Mercedes M.N.; Seccacini, Emilia A.; Calcagno, Javier A.; Zerba, Eduardo N.

    2017-01-01

    DEET and IR3535 are insect repellents present worldwide in commercial products; their efficacy has been mainly evaluated in mosquitoes. This study compares the toxicological effects and the behavioral responses induced by both repellents on the blood-sucking bug Triatoma infestans Klug (Hemiptera: Reduviidae), one of the main vectors of Chagas disease. When applied topically, the Median Lethal Dose (72 h) for DEET was 220.8 µg/insect. Using IR3535, topical application of 500 µg/insect killed no nymphs. The minimum concentration that produced repellency was the same for both compounds: 1,15 µg/cm2. The effect of a mixture DEET:IR3535 1:1 was similar to that of their pure components. Flushing out was assessed in a chamber with a shelter containing groups of ten nymphs. The repellents were aerosolized on the shelter and the number of insects leaving it was recorded for 60 min. During that time, 0.006 g/m3 of the positive control tetramethrin flushed out 76.7% of the nymphs, while 1.76 g/m3 of DEET or IR3535 flushed out 30 and 0%, respectively. The concentrations required for both compounds to produce toxicity or flushing out are too high to have any practical applications. However, they showed a promising repellency. Additional research should be done to evaluate their possible use for personal protection against T. infestans bites. PMID:28533956

  17. Assessment of the repellent effect of citronella and lemon eucalyptus oil against South African Culicoides species.

    PubMed

    Venter, Gert J; Labuschagne, Karien; Boikanyo, Solomon N B; Morey, Liesl

    2014-08-08

    The use of insect repellents to reduce the attack rate of Culicoides species (Diptera:Ceratopogonidae) should form part of an integrated control programme to combat African horse sickness and other diseases transmitted by these blood-feeding midges. In the present study the repellent effects of a commercially available mosquito repellent, a combination of citronella and lemon eucalyptus oils, on Culicoides midges was determined. The number of midges collected with two 220 V Onderstepoort traps fitted with 8 W 23 cm white light tubes and baited with peel-stick patches, each containing 40 mg of active ingredient, was compared with that of two unbaited traps. Two trials were conducted and in each trial the four traps were rotated in two replicates of a 4 x 4 randomised Latin square design. Although more midges were collected in the baited traps, the mean number in the baited and unbaited traps was not significantly different. This mosquito repellent did not influence either the species composition or the physiological groups of Culicoides imicola Kieffer. The higher mean numbers in the baited traps, although not statistically significant, may indicate that this mosquito repellent might even attract Culicoides midges under certain conditions.

  18. Remarkable repellency of Ligusticum sinense (Umbelliferae), a herbal alternative against laboratory populations of Anopheles minimus and Aedes aegypti (Diptera: Culicidae).

    PubMed

    Sanghong, Rukpong; Junkum, Anuluck; Chaithong, Udom; Jitpakdi, Atchariya; Riyong, Doungrat; Tuetun, Benjawan; Champakaew, Daruna; Intirach, Jitrawadee; Muangmoon, Roongtawan; Chansang, Arpaporn; Pitasawat, Benjawan

    2015-08-07

    For personal protection against mosquito bites, user-friendly natural repellents, particularly from plant origin, are considered as a potential alternative to applications currently based on synthetics such as DEET, the standard chemical repellent. This study was carried out in Thailand to evaluate the repellency of Ligusticum sinense hexane extract (LHE) against laboratory Anopheles minimus and Aedes aegypti, the primary vectors of malaria and dengue fever, respectively. Repellent testing of 25% LHE against the two target mosquitoes; An. minimus and Ae. aegypti, was performed and compared to the standard repellent, DEET, with the assistance of six human volunteers of either sex under laboratory conditions. The physical and biological stability of LHE also was determined after keeping it in conditions that varied in temperature and storage time. Finally, LHE was analysed chemically using the qualitative GC/MS technique in order to demonstrate a profile of chemical constituents. Ethanol preparations of LHE, with and without 5% vanillin, demonstrated a remarkably effective performance when compared to DEET in repelling both An. minimus and Ae. aegypti. While 25% LHE alone provided median complete-protection times against An. minimus and Ae. aegypti of 11.5 (9.0-14.0) hours and 6.5 (5.5-9.5) hours, respectively, the addition of 5% vanillin increased those times to 12.5 (9.0-16.0) hours and 11.0 (7.0-13.5) hours, respectively. Correspondingly, vanillin added to 25% DEET also extended the protection times from 11.5 (10.5-15.0) hours to 14.25 (11.0-18.0) hours and 8.0 (5.0-9.5) hours to 8.75 (7.5-11.0) hours against An. minimus and Ae. aegypti, respectively. No local skin reaction such as rash, swelling or irritation was observed during the study period. Although LHE samples kept at ambient temperature (21-35°C), and 45°C for 1, 2 and 3 months, demonstrated similar physical characteristics, such as similar viscosity and a pleasant odour, to those that were fresh and

  19. Oviposition deterrent and skin repellent activities of Solanum trilobatum leaf extract against the malarial vector Anopheles stephensi.

    PubMed Central

    Rajkumar, S.; Jebanesan, A.

    2005-01-01

    The leaf extract of Solanum trilobatum (Solanaceae) was tested under laboratory conditions for oviposition deterrent and skin repellent activities against the adult mosquito Anopheles stephensi. Concentrations of 0.01, 0.025, 0.05, 0.075 and 0.1% reduced egg laying by gravid females from 18 to 99% compared to ethanol-treated controls. In skin repellent tests, concentrations of 0.001, 0.005, 0.01, 0.015, and 0.02 % provided 70 to 120 minutes protection against mosquito bites, whereas the ethanol control provided only 2.2 minutes of protection. Both oviposition deterrent and skin repellent activity were dose dependent. The results suggest that the leaf extract of S. trilobatum is an effective oviposition deterrent and skin repellent against An. stephensi. PMID:16341247

  20. Quantification through TLC-densitometric analysis, repellency and anticholinesterase activity of the homemade extract of Indian cloves.

    PubMed

    Affonso, Raphael S; Lima, Josélia A; Lessa, Bruno M; Caetano, João V O; Obara, Marcos T; Nóbrega, Andréa B; Nepovimova, Eugenie; Musilek, Kamil; Kuca, Kamil; Slana, Gláucia B C A; França, Tanos C C

    2018-02-01

    The rise of the mosquitoes-transmitted diseases, like dengue, zika and chikungunya in Brazil in the last years has increased concerns on protection against mosquitoes bites. However, the prohibitive prices of the commercially available repellents for the majority of the Brazilian population has provoked a search for cheaper solutions, like the use of the homemade ethanolic extract of Indian clove (Syzygium aromaticum L.) as repellent, which has been reported as quite efficient by the local press. In order to verify this, we performed here the quantification of the main components of this extract through high-performance thin-layer chromatography (HPTLC)-densitometry and evaluated its efficiency as a repellent and its acetylcholinesterase (AChE) inhibition capacity. Our results have proved HPTLC-densitometry as an efficient and appropriate method for this quantification and confirmed the repellency activity, as well as its capacity of AChE inhibition. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Insecticidal and Repellent Activity of Siparuna guianensis Aubl. (Negramina) against Aedes aegypti and Culex quinquefasciatus

    PubMed Central

    Aguiar, Raimundo Wagner Souza; dos Santos, Suetonio Fernandes; da Silva Morgado, Fabricio; Ascencio, Sergio Donizeti; de Mendonça Lopes, Magnólia; Viana, Kelvinson Fernandes; Didonet, Julcemar; Ribeiro, Bergmann Morais

    2015-01-01

    This study investigated the toxic effects of essential oils isolated from Siparuna guianensis against Aedes aegypti, Culex quinquefasciatus (eggs, larvae, pupae, and adult) and Aedes albopictus (C6/36) cells. The oviposition-deterring activity, egg viability, and repellence activity in the presence of different essential oils concentrations were determined. The essential oils showed high toxicity to all developmental stages of A. aegypti and C. quinquefasciatus. Furthermore, the oils also showed high repellent activity towards the adult stage of mosquitoes (0.025 to 0.550 μg/cm2 skin conferred 100% repellence up to 120 min) and in contact with cultured insect cells (C6/36) induced death possibly by necrosis. The results presented in this work show the potential of S. guianensis essential oils for the development of an alternative and effective method for the natural control of mosquitoes in homes and urban areas. PMID:25646797

  2. Replicate phylogenies and post-glacial range expansion of the pitcher-plant mosquito, Wyeomyia smithii, in North America.

    PubMed

    Merz, Clayton; Catchen, Julian M; Hanson-Smith, Victor; Emerson, Kevin J; Bradshaw, William E; Holzapfel, Christina M

    2013-01-01

    Herein we tested the repeatability of phylogenetic inference based on high throughput sequencing by increased taxon sampling using our previously published techniques in the pitcher-plant mosquito, Wyeomyia smithii in North America. We sampled 25 natural populations drawn from different localities nearby 21 previous collection localities and used these new data to construct a second, independent phylogeny, expressly to test the reproducibility of phylogenetic patterns. Comparison of trees between the two data sets based on both maximum parsimony and maximum likelihood with Bayesian posterior probabilities showed close correspondence in the grouping of the most southern populations into clear clades. However, discrepancies emerged, particularly in the middle of W. smithii's current range near the previous maximum extent of the Laurentide Ice Sheet, especially concerning the most recent common ancestor to mountain and northern populations. Combining all 46 populations from both studies into a single maximum parsimony tree and taking into account the post-glacial historical biogeography of associated flora provided an improved picture of W. smithii's range expansion in North America. In a more general sense, we propose that extensive taxon sampling, especially in areas of known geological disruption is key to a comprehensive approach to phylogenetics that leads to biologically meaningful phylogenetic inference.

  3. Essential oil composition and larvicidal activity of six Mediterranean aromatic plants against the mosquito Aedes albopictus (Diptera: Culicidae).

    PubMed

    Conti, Barbara; Canale, Angelo; Bertoli, Alessandra; Gozzini, Francesca; Pistelli, Luisa

    2010-11-01

    Laboratory bioassays on insecticidal activity of essential oils (EOs) extracted from six Mediterranean plants (Achillea millefolium, Lavandula angustifolia, Helichrysum italicum, Foeniculum vulgare, Myrtus communis, and Rosmarinus officinalis) were carried out against the larvae of the Culicidae mosquito Aedes albopictus. The chemical composition of the six EOs was also investigated. Results from applications showed that all tested oils had insecticidal activity, with differences in mortality rates as a function of both oil and dosage. At the highest dosage (300 ppm), EOs from H. italicum, A. millefolium, and F. vulgare caused higher mortality than the other three oils, with mortality rates ranging from 98.3% to 100%. M. communis EO induced only 36.7% larval mortality at the highest dosage (300 ppm), a similar value to those recorded at the same dosage by using R. officinalis and L. angustifolia (51.7% and 55%, respectively). Identified compounds ranged from 91% to 99%. The analyzed EOs had higher content of monoterpenoids (80-99%) than sesquiterpenes (1-15%), and they can be categorized into three groups on the basis of their composition. Few EOs showed the hydrocarbon sesquiterpenes, and these volatile compounds were generally predominant in comparison with the oxygenated forms, which were detected in lower quantities only in H. italicum (1.80%) and in M. communis (1%).

  4. The Efficacy of Some Commercially Available Insect Repellents for Aedes aegypti (Diptera: Culicidae) and Aedes albopictus (Diptera: Culicidae)

    PubMed Central

    Rodriguez, Stacy D.; Drake, Lisa L.; Price, David P.; Hammond, John I.; Hansen, Immo A.

    2015-01-01

    Reducing the number of host-vector interactions is an effective way to reduce the spread of vector-borne diseases. Repellents are widely used to protect humans from a variety of protozoans, viruses, and nematodes. DEET (N,N-Diethyl-meta-toluamide), a safe and effective repellent, was developed during World War II. Fear of possible side effects of DEET has created a large market for “natural” DEET-free repellents with a variety of active ingredients. We present a comparative study on the efficacy of eight commercially available products, two fragrances, and a vitamin B patch. The products were tested using a human hand as attractant in a Y-tube olfactometer setup with Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse), both major human disease vectors. We found that Ae. albopictus were generally less attracted to the test subject’s hand compared with Ae, aegypti. Repellents with DEET as active ingredient had a prominent repellency effect over longer times and on both species. Repellents containing p-menthane-3,8-diol produced comparable results but for shorter time periods. Some of the DEET-free products containing citronella or geraniol did not have any significant repellency effect. Interestingly, the perfume we tested had a modest repellency effect early after application, and the vitamin B patch had no effect on either species. This study shows that the different active ingredients in commercially available mosquito repellent products are not equivalent in terms of duration and strength of repellency. Our results suggest that products containing DEET or p-menthane-3,8-diol have long-lasting repellent effects and therefore provide good protection from mosquito-borne diseases. PMID:26443777

  5. Repelling Point Bosons

    SciTech Connect

    McGuire, J. B.

    2011-12-01

    There is a body of conventional wisdom that holds that a solvable quantum problem, by virtue of its solvability, is pathological and thus irrelevant. It has been difficult to refute this view owing to the paucity of theoretical constructs and experimental results. Recent experiments involving equivalent ions trapped in a spatial conformation of extreme anisotropic confinement (longitudinal extension tens, hundreds or even thousands of times transverse extension) have modified the view of relevancy, and it is now possible to consider systems previously thought pathological, in particular point Bosons that repel in one dimension. It has been difficult for the experimentalistsmore » to utilize existing theory, mainly due to long-standing theoretical misunderstanding of the relevance of the permutation group, in particular the non-commutativity of translations (periodicity) and transpositions (permutation). This misunderstanding is most easily rectified in the case of repelling Bosons.« less

  6. Larvicidal Efficacy of Different Plant Parts of Railway Creeper, Ipomoea cairica Extract Against Dengue Vector Mosquitoes, Aedes albopictus (Diptera: Culicidae) and Aedes aegypti (Diptera: Culicidae)

    PubMed Central

    AhbiRami, Rattanam; Zuharah, Wan Fatma; Thiagaletchumi, Maniam; Subramaniam, Sreeramanan; Sundarasekar, Jeevandran

    2014-01-01

    Abstract Natural insecticides from plant origin against mosquito vectors have been the main concern for research due to their high level of eco-safety. Control of mosquitoes in their larval stages are an ideal method since Aedes larvae are aquatic, thus it is easier to deal with them in this habitat. The present study was specifically conducted to explore the larvicidal efficacy of different plant parts of Ipomoea cairica (L.) or railway creeper crude extract obtained using two different solvents; methanol and acetone against late third-stage larvae of Aedes albopictus (Skuse) and Aedes aegypti (L.) (Diptera: Culicidae). Plant materials of I. cairica leaf, flower, and stem were segregated, airdried, powdered, and extracted using Soxhlet apparatus. Larvicidal bioassays were performed by using World Health Organization standard larval susceptibility test method for each species which were conducted separately for different concentration ranging from 10 to 450 ppm. Both acetone and methanol extracts showed 100% mortality at highest concentration tested (450 ppm) after 24 h of exposure. Results from factorial ANOVA indicated that there were significant differences in larvicidal effects between mosquito species, solvent used and plant parts ( F  = 5.71, df = 2, P  < 0.05). The acetone extract of I. cairica leaf showed the most effective larvicidal action in Ae. aegypti with LC 50 of 101.94 ppm followed by Ae. albopictus with LC 50 of 105.59 ppm compared with other fractions of I. cairica extract obtained from flower, stem, and when methanol are used as solvent. The larvae of Ae. aegypti appeared to be more susceptible to I. cairica extract with lower LC 50 value compared with Ae. albopictus ( F  = 8.83, df = 1, P  < 0.05). Therefore, this study suggests that the acetone extract of I. cairica leaf can be considered as plant-derived insecticide for the control of Aedes mosquitoes. This study quantified the larvicidal property of I

  7. A low-cost repellent for malaria vectors in the Americas: results of two field trials in Guatemala and Peru

    PubMed Central

    Moore, Sarah J; Darling, Samuel T; Sihuincha, Moisés; Padilla, Norma; Devine, Gregor J

    2007-01-01

    Background The cost of mosquito repellents in Latin America has discouraged their wider use among the poor. To address this problem, a low-cost repellent was developed that reduces the level of expensive repellent actives by combining them with inexpensive fixatives that appear to slow repellent evaporation. The chosen actives were a mixture of para-menthane-diol (PMD) and lemongrass oil (LG). Methods To test the efficacy of the repellent, field trials were staged in Guatemala and Peru. Repellent efficacy was determined by human-landing catches on volunteers who wore the experimental repellents, control, or 15% DEET. The studies were conducted using a balanced Latin Square design with volunteers, treatments, and locations rotated each night. Results In Guatemala, collections were performed for two hours, commencing three hours after repellent application. The repellent provided >98% protection for five hours after application, with a biting pressure of >100 landings per person/hour. The 15% DEET control provided lower protection at 92% (p < 0.0001). In Peru, collections were performed for four hours, commencing two hours after repellent application. The PMD/LG repellent provided 95% protection for six hours after application with a biting pressure of >46 landings per person/hour. The 20% DEET control provided significantly lower protection at 64% (p < 0.0001). Conclusion In both locations, the PMD/LG repellent provided excellent protection up to six hours after application against a wide range of disease vectors including Anopheles darlingi. The addition of fixatives to the repellent extended its longevity while enhancing efficacy and significantly reducing its cost to malaria-endemic communities. PMID:17678537

  8. Malaria infection in mosquitoes decreases the personal protection offered by permethrin-treated bednets.

    PubMed

    Thiévent, Kevin; Hofer, Lorenz; Rapp, Elise; Tambwe, Mgeni Mohamed; Moore, Sarah; Koella, Jacob C

    2018-05-04

    Insecticides targeting adult mosquitoes are the main way of controlling malaria. They work not only by killing mosquitoes, but also by repelling and irritating them. Indeed their repellent action gives valuable personal protection against biting mosquitoes. In the context of malaria control this personal protection is especially relevant when mosquitoes are infectious, whereas to protect the community we would prefer that the mosquitoes that are not yet infectious are killed (so, not repelled) by the insecticide. As the infectious stage of malaria parasites increases the motivation of mosquitoes to bite, we predicted that it would also change their behavioural response to insecticides. With two systems, a laboratory isolate of the rodent malaria Plasmodium berghei infecting Anopheles gambiae and several isolates of P. falciparum obtained from schoolchildren in Tanzania that infected Anopheles arabiensis, we found that mosquitoes harbouring the infectious stage (the sporozoites) of the parasite were less repelled by permethrin-treated nets than uninfected ones. Our results suggest that, at least in the laboratory, malaria infection decreases the personal protection offered by insecticide-treated nets at the stage where the personal protection is most valuable. Further studies must investigate whether these results hold true in the field and whether the less effective personal protection can be balanced by increased community protection.

  9. Laboratory and field evaluation of the impact of exercise on the performance of regular and polymer-based deet repellents.

    PubMed

    Schofield, Steven; Tepper, Martin; Gadawski, Randy

    2007-11-01

    Studies were done in Manitoba, Canada, to evaluate the impact of exercise on repellent performance against mosquitoes. Two products containing the active ingredient N,N-diethyl-3-methylbenzamide (deet) were tested; one product was a polymer-based cream (3M Ultrathon Insect Repellent) and the other product was an alcohol-based pump spray formulation (Muskol Insect Repellent). Assessments were done in the laboratory using Aedes aegypti (L.) and in the field with naturally occurring populations of mosquitoes. Repellent was applied to the forearms (laboratory) or a lower leg (field) of test subjects at 1.5 g of test product per 600 cm2 surface area (0.75 or 0.83 mg deet/cm2). For a given test day, subjects exercised or did not. Exposure to mosquito attack was for 1 min at 30-min intervals in laboratory procedures, and it was continuous in field tests. Performance was measured as complete protection time (CPT). Moderate levels of physical activity resulted in a >40% decline in mean CPT, from 468 to 267 min in the laboratory experiments and from 359 to 203 min in field tests. Repellent product did not affect the magnitude of the decline. Mean biting pressure during field trials was 21.3 bites per min, and mosquito collections were made up primarily of Ochlerotatus sticticus (Meigen) and Aedes vexans (Meigen).

  10. Repellent activity of herbal essential oils against Aedes aegypti (Linn.) and Culex quinquefasciatus (Say.)

    PubMed Central

    Sritabutra, Duangkamon; Soonwera, Mayura

    2013-01-01

    Objective To determine the mosquito repellent activity of herbal essential oils against female Aedes aegypti and Culex quinquefasciatus. Methods On a volunteer's forearm, 0.1 mL of each essential oil was applied to 3 cm×10 cm of exposed skin. The protection time was recorded for 3 min after every 30 min. Results Essential oil from clove oil in olive oil and in coconut oil gave the longest lasting period of 76.50 min and 96.00 min respectively against Aedes aegypti. The citronella grass oil in olive oil, citronella grass oil in coconut oil and lemongrass oil in coconut oil exhibited protection against Culex quinquefasciatus at 165.00, 105.00, and 112.50 min respectively. Conclusions The results clearly indicated that clove, citronella and lemongrass oil were the most promising for repellency against mosquito species. These oils could be used to develop a new formulation to control mosquitoes.

  11. Eco-friendly larvicides from Indian plants: Effectiveness of lavandulyl acetate and bicyclogermacrene on malaria, dengue and Japanese encephalitis mosquito vectors.

    PubMed

    Govindarajan, Marimuthu; Benelli, Giovanni

    2016-11-01

    Mosquitoes (Diptera: Culicidae) are a key threat for millions of people and animals worldwide, since they act as vectors for devastating pathogens and parasites, including malaria, dengue, Japanese encephalitis, filiariasis and Zika virus. Mosquito young instars are usually targeted using organophosphates, insect growth regulators and microbial agents. Indoor residual spraying and insecticide-treated bed nets are also employed. However, these chemicals have negative effects on human health and the environment and induce resistance in a number of vectors. In this scenario, newer and safer tools have been recently implemented to enhance mosquito control. The concrete potential of screening plant species as sources of metabolites for entomological and parasitological purposes is worthy of attention, as recently elucidated by the Y. Tu's example. Here we investigated the toxicity of Heracleum sprengelianum (Apiaceae) leaf essential oil and its major compounds toward third instar larvae of the malaria vector Anopheles subpictus, the arbovirus vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. GC-MS analysis showed that EO major components were lavandulyl acetate (17.8%) and bicyclogermacrene (12.9%). The EO was toxic to A. subpictus, A. albopictus, and C. tritaeniorhynchus, with LC50 of 33.4, 37.5 and 40.9µg/ml, respectively. Lavandulyl acetate was more toxic to mosquito larvae if compared to bicyclogermacrene. Their LC50 were 4.17 and 10.3µg/ml for A. subpictus, 4.60 and 11.1µg/ml for A. albopictus, 5.11 and 12.5µg/ml for C. tritaeniorhynchus. Notably, the EO and its major compounds were safer to three non-target mosquito predators, Anisops bouvieri, Diplonychus indicus and Gambusia affinis, with LC50 ranging from 206 to 4219µg/ml. Overall, this study highlights that H. sprengelianum EO is a promising source of eco-friendly larvicides against three important mosquito vectors with moderate toxicity against non-target aquatic

  12. Feasibility of repellent use in a context of increasing outdoor transmission: a qualitative study in rural Tanzania.

    PubMed

    Sangoro, Onyango; Kelly, Ann H; Mtali, Sarah; Moore, Sarah J

    2014-09-02

    Extensive employment of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) has substantially reduced malaria morbidity and mortality in sub-Saharan Africa. These tools target indoor resting and biting vectors, and may select for vectors that bite and rest outdoors. Thus, to significantly impact this residual malaria transmission outdoors, tools targeting outdoor transmission are required. Repellents, used for personal protection, offer one solution. However, the effectiveness of this method hinges upon its community acceptability. This study assessed the feasibility of using repellents as a malaria prevention tool in Mbingu village, Ulanga, Southern Tanzania. Change in knowledge, attitude and practice (KAP) in relation to repellent use was assessed before and after the implementation of a cluster randomized clinical trial on topical repellents in rural Tanzania where repellent and placebo lotion were provided free of charge to 940 households for a period of 14 months between July 2009 and August 2010. Compliance, defined as the number of evenings that participants applied the recommended dose of repellent every month during the study period, was assessed using questionnaires, administered monthly during follow up of participants in the clinical trial. Focus group discussions (FGDs) were conducted in the same community three years later to assess the community's KAP in relation to repellents and preference to different repellent formats. At baseline, only 0.32% (n=2) households in the intervention arm and no households in the control arm had ever used topical repellents. During follow-up surveys, significantly more households, 100% (n=457) in intervention arm relative to the control, 84.03% (n=379), (p=<0.001) perceived the repellent to be effective.Post-study, 99.78% (n=462) and 99.78% (n=463), (p=0.999) in the intervention and control arms respectively, were willing to continue repellent use. Mosquito nuisance motivated repellent use. From

  13. Identifying the effective concentration for spatial repellency of the dengue vector Aedes aegypti

    PubMed Central

    2012-01-01

    Background Current efforts are underway to quantify the chemical concentration in a treated air space that elicits a spatial repellent (deterrent) response in a vector population. Such information will facilitate identifying the optimum active ingredient (AI) dosage and intervention coverage important for the development of spatial repellent tools – one of several novel strategies being evaluated for vector-borne disease control. This study reports initial findings from air sampling experiments conducted under field conditions to describe the relationship between air concentrations of repellent AIs and deterrent behavior in the dengue vector, Aedes aegypti. Methods Air samples were taken inside and outdoors of experimental huts located in Pu Tuey Village, Kanchanaburi Province, Thailand in conjunction with mosquito behavioral evaluations. A mark-release-recapture study design using interception traps was used to measure deterrency of Ae. aegypti against 0.00625% metofluthrin coils and DDT-treated fabric (2g/m2) within separate experimental trials. Sentinel mosquito cohorts were positioned adjacent to air sampling locations to monitor knock down responses to AI within the treated air space. Air samples were analyzed using two techniques: the U.S. Environmental Protection Agency (USEPA) Compendium Method TO-10A and thermal desorption (TD). Results Both the USEPA TO-10A and TD air sampling methods were able to detect and quantify volatized AIs under field conditions. Air samples indicated concentrations of both repellent chemicals below thresholds required for toxic responses (mortality) in mosquitoes. These concentrations elicited up to a 58% and 70% reduction in Ae. aegypti entry (i.e., deterrency) into treated experimental huts using metofluthrin coils and DDT-treated fabric, respectively. Minimal knock down was observed in sentinel mosquito cohorts positioned adjacent to air sampling locations during both chemical evaluations. Conclusions This study is the first

  14. Essential oils of medicinal plants from the central andes of Argentina: chemical composition, and antifungal, antibacterial, and insect-repellent activities.

    PubMed

    Lima, Beatriz; López, Sandra; Luna, Lorena; Agüero, María B; Aragón, Liliana; Tapia, Alejandro; Zacchino, Susana; López, María L; Zygadlo, Julio; Feresin, Gabriela E

    2011-05-01

    The antifungal, antibacterial, and insect-repellent activities of the essential oils (EOs) of Acantholippia seriphioides, Artemisia mendozana, Gymnophyton polycephalum, Satureja parvifolia, Tagetes mendocina, and Lippia integrifolia, collected in the Central Andes area, province of San Juan, Argentina, were investigated. The dermatophytes Microsporum gypseum, Trichophyton mentagrophytes, and T. rubrum were inhibited by the EOs of G. polycephalum, L. integrifolia, and S. parvifolia, with minimum inhibitory concentrations (MICs) between 31.2 and 1000 μg/ml. Moreover, all EOs presented moderate activity against the bacteria tested, and the L. integrifolia and G. polycephalum EOs showed excellent repellent properties against Triatoma infestans, the Chagas disease vector, with repellency values between 60 and 100%. The A. seriphioides, G. polycephalum, and L. integrifolia EOs, obtained by hydrodistillation, were characterized by GC-FID and GC/MS analyses. The highest number of components (40) was identified in L. integrifolia EO, which, along with that of A. seriphioides, contained important amounts of oxygenated monoterpenes (44.35 and 29.72%, resp.). Thymol (27.61%) and carvacrol (13.24%) were the main components of A. seriphioides EO, and borneol, lippifoli-1(6)-en-5-one, and terpinen-4-ol (>8.5%) were the principal compounds of L. integrifolia EO. These results support the idea that oxygenated monoterpenes are the bioactive fractions of the EOs. Finally, the study shows that these Andean species might be used to treat superficial fungal infections and to improve the local Chagas disease situation by vector-control. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

  15. Thermoperiodism and the thermal environment of the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Bradshaw, William E

    1980-07-01

    Wyeomyia smithii Coq. (Diptera: Culicidae) completes its pre-adult development only within leaves of the purple pitcher-plant, Sarracenia purpurea. Between early June and mid-October in northern New York State, the daily temperature cycle in leaves lagged the photic cycle by 0-6 h and exhibited a mean daily amplitude of 14.5°C.Thermoperiod acts as a potent zeitgeber. At constant temperatures, W. smithii respond to the shorter dark period of a symmetric skeleton photoperiod as "day". However, a superimposed thermoperiod having the thermophase coincident with the longer dark period overrides this tendancy. Thermoperiods may also perturb the photoperiodic clock but W. smithii compensate for the range of phase relationships between the photic and thermal cycles observed in nature.Compared with constant temperatures, W. smithii develop more slowly but exhibit a 7-fold increase in fecundity when reared under fluctuating temperatures. The net result is a 50% greater capacity for increase in the latter regimen. These results suggest that maximum fitness in W. smithii is achieved through the action of, and not despite, thermal heterogeneity.

  16. A repellent net as a new technology to protect cabbage crops.

    PubMed

    Martin, T; Palix, R; Kamal, A; Delétré, E; Bonafos, R; Simon, S; Ngouajio, M

    2013-08-01

    Floating row covers or insect-proof nets with fine mesh are effective at protecting vegetable crops against aphids but negatively impact plant health, especially under warm conditions. Furthermore, in control of cabbage insect pests, aphid parasitoids cannot enter the fine-mesh nets, leading to frequent aphid outbreaks. To surmount these difficulties, a 40-mesh-size repellent net treated with alphacypermethrin was studied in laboratory and field tests. Results showed both irritant and repellent effects of the alphacypermethrin-treated net on Myzus persicae (Sulzer) (Hemiptera: Aphididae) and its parasitoid Aphidius colemani (Haliday) (Hymenoptera: Braconidae). Under field conditions, there were no pests on cabbage protected with the repellent net. The repellent net allowed combining a visual and repellent barrier against aphids. Because of this additive effect, repellent nets allowed covering cabbage permanently with adequate protection against all pests.

  17. Chemosensory Responses to the Repellent Nepeta Essential Oil and Its Major Component Nepetalactone by Aedes aegypti (Diptera: Culicidae), a Vector of Zika Virus.

    PubMed

    Sparks, Jackson T; Bohbot, Jonathan D; Ristic, Mihailo; Mišic, Danijela; Skoric, Marijana; Mattoo, Autar; Dickens, Joseph C

    2017-07-01

    Nepeta essential oil (Neo; catnip) and its major component, nepetalactone, have long been known to repel insects including mosquitoes. However, the neural mechanisms through which these repellents are detected by mosquitoes, including the yellow fever mosquito Aedes aegypti (L.), an important vector of Zika virus, were poorly understood. Here we show that Neo volatiles activate olfactory receptor neurons within the basiconic sensilla on the maxillary palps of female Ae. aegypti. A gustatory receptor neuron sensitive to the feeding deterrent quinine and housed within sensilla on the labella of females was activated by both Neo and nepetalactone. Activity of a second gustatory receptor neuron sensitive to the feeding stimulant sucrose was suppressed by both repellents. Our results provide neural pathways for the reported spatial repellency and feeding deterrence of these repellents. A better understanding of the neural input through which female mosquitoes make decisions to feed will facilitate design of new repellents and management strategies involving their use. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  18. Mosquito Bites

    MedlinePlus

    ... spreading to the United States. One factor is climate change, which makes the conditions in some parts of ... United States. How can I prevent mosquito bites? Use an insect ... DEET, picaridin, IR3535, oil of lemon eucalyptus, or para-menthane-diol. It ...

  19. Repellent effect of some household products on fly attraction to cadavers.

    PubMed

    Charabidze, Damien; Bourel, Benoit; Hedouin, Valery; Gosset, Didier

    2009-08-10

    The most common task of a forensic entomologist is to determine an accurate minimum post-mortem interval (PMI) using necrophagous fly larvae found on carrion. More often, blowflies (Diptera: Calliphoridae) are the first insects to detect the cadaver and, if the circumstances are favourable, to leave eggs on the body. However, several studies reveal that products such as gas or paint found on the cadaver induce a delay in the colonisation of the body, leading to an under-estimate of the PMI. Six common household products (gas, mosquito citronella repellent, perfume, bleach, hydrochloric acid and soda) were added to dead rats (Rattus norvegicus) in a field (Lille Forensic Institute, France). The presence of necrophagous flies was checked at regular intervals during 1 month. This experiment was repeated at the same period for four consecutive years. Results clearly showed the repellent effect of three of the six tested substances: gas (petroleum spirit), perfume and mosquito citronella repellent, which resulted in a mean delay of several days in the appearance of the first Dipteran species. Experiments were then carried out in controlled conditions in order to confirm previous observations. An olfactometer was specially designed to observe the behaviour of female Calliphora vicina (Diptera: Calliphoridae) in response to mice (Mus musculus) cadaver odour stimuli combined with household products. Dead mouse odour was a strong attractive stimulus for most of the tested individuals. Furthermore, it was noticed that the presence of mosquito citronella repellent, perfume, hydrochloric acid and paradichlorobenzene produced a significant repellent effect on female flies. All these results together confirm the repellent effect of some household products on flies and the necessity for forensic entomologists to consider this hypothesis when estimating the PMI.

  20. Oleoresin Capsicum has Potential as a Rodent Repellent in Direct Sedding Longleaf Pine

    Treesearch

    James P. Barnett

    1998-01-01

    Direct seeding of southern pines has been a versatile and inexpensive alternative to planting on many reforestation sites across the South. Successful direct seeding has required that seeds be coated with thiram to repel birds, and with endrin to repel rodents. Endrin, which is extremely toxic, is no longer produced in the United States. Therefore, a substitute is...

  1. Sharks senses and shark repellents.

    PubMed

    Hart, Nathan S; Collin, Shaun P

    2015-01-01

    Despite over 70 years of research on shark repellents, few practical and reliable solutions to prevent shark attacks on humans or reduce shark bycatch and depredation in commercial fisheries have been developed. In large part, this deficiency stems from a lack of fundamental knowledge of the sensory cues that drive predatory behavior in sharks. However, the widespread use of shark repellents is also hampered by the physical constraints and technical or logistical difficulties of deploying substances or devices in an open-water marine environment to prevent an unpredictable interaction with a complex animal. Here, we summarize the key attributes of the various sensory systems of sharks and highlight residual knowledge gaps that are relevant to the development of effective shark repellents. We also review the most recent advances in shark repellent technology within the broader historical context of research on shark repellents and shark sensory systems. We conclude with suggestions for future research that may enhance the efficacy of shark repellent devices, in particular, the continued need for basic research on shark sensory biology and the use of a multi-sensory approach when developing or deploying shark repellent technology. © 2014 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  2. Superhydrophobic Blood-Repellent Surfaces.

    PubMed

    Jokinen, Ville; Kankuri, Esko; Hoshian, Sasha; Franssila, Sami; Ras, Robin H A

    2018-06-01

    Superhydrophobic surfaces repel water and, in some cases, other liquids as well. The repellency is caused by topographical features at the nano-/microscale and low surface energy. Blood is a challenging liquid to repel due to its high propensity for activation of intrinsic hemostatic mechanisms, induction of coagulation, and platelet activation upon contact with foreign surfaces. Imbalanced activation of coagulation drives thrombogenesis or formation of blood clots that can occlude the blood flow either on-site or further downstream as emboli, exposing tissues to ischemia and infarction. Blood-repellent superhydrophobic surfaces aim toward reducing the thrombogenicity of surfaces of blood-contacting devices and implants. Several mechanisms that lead to blood repellency are proposed, focusing mainly on platelet antiadhesion. Structured surfaces can: (i) reduce the effective area exposed to platelets, (ii) reduce the adhesion area available to individual platelets, (iii) cause hydrodynamic effects that reduce platelet adhesion, and (iv) reduce or alter protein adsorption in a way that is not conducive to thrombus formation. These mechanisms benefit from the superhydrophobic Cassie state, in which a thin layer of air is trapped between the solid surface and the liquid. The connections between water- and blood repellency are discussed and several recent examples of blood-repellent superhydrophobic surfaces are highlighted. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. High-Throughput Mosquito and Fly Bioassay System for Natural and Artificial Substrates Treated with Residual Insecticides

    DTIC Science & Technology

    2013-03-01

    1989. Evaluation of the cotton fabric model for screening topical mosquito repellents . J Am Mosq Control Assoc 5:73–76. WHO [World Health Organization...institutions, research libraries, and research funders in the common goal of maximizing access to critical research. High-Throughput Mosquito and Fly Bioassay...A. Allan , Todd W. Walker , Christopher J. Geden , Jerome A. Hogsette , and Kenneth J. Linthicum Source: Journal of the American Mosquito Control

  4. A push-pull system to reduce house entry of malaria mosquitoes

    PubMed Central

    2014-01-01

    Background Mosquitoes are the dominant vectors of pathogens that cause infectious diseases such as malaria, dengue, yellow fever and filariasis. Current vector control strategies often rely on the use of pyrethroids against which mosquitoes are increasingly developing resistance. Here, a push-pull system is presented, that operates by the simultaneous use of repellent and attractive volatile odorants. Method/Results Experiments were carried out in a semi-field set-up: a traditional house which was constructed inside a screenhouse. The release of different repellent compounds, para-menthane-3,8-diol (PMD), catnip oil e.o. and delta-undecalactone, from the four corners of the house resulted in significant reductions of 45% to 81.5% in house entry of host-seeking malaria mosquitoes. The highest reductions in house entry (up to 95.5%), were achieved by simultaneously repelling mosquitoes from the house (push) and removing them from the experimental set-up using attractant-baited traps (pull). Conclusions The outcome of this study suggests that a push-pull system based on attractive and repellent volatiles may successfully be employed to target mosquito vectors of human disease. Reductions in house entry of malaria vectors, of the magnitude that was achieved in these experiments, would likely affect malaria transmission. The repellents used are non-toxic and can be used safely in a human environment. Delta-undecalactone is a novel repellent that showed higher effectiveness than the established repellent PMD. These results encourage further development of the system for practical implementation in the field. PMID:24674451

  5. Evaluation of 15 Local Plant Species as Larvicidal Agents Against an Indian Strain of Dengue Fever Mosquito, Aedes aegypti L. (Diptera: Culicidae)

    PubMed Central

    Kumar, Sarita; Wahab, Naim; Mishra, Monika; Warikoo, Radhika

    2012-01-01

    The adverse effects of chemical insecticides-based intervention measures for the control of mosquito vectors have received wide public apprehension because of several problems like insecticide resistance, resurgence of pest species, environmental pollution, toxic hazards to humans, and non-target organisms. These problems have necessitated the need to explore and develop alternative strategies using eco-friendly, environmentally safe, bio-degradable plant products which are non-toxic to non-target organisms too. In view of this, 15 plant species were collected from local areas in New Delhi, India. Different parts of these plants were separated, dried, mechanically grinded, and sieved to get fine powder. The 200 g of each part was soaked in 1000 mL of different solvents separately and the crude extracts, thus formed, were concentrated using a vacuum evaporator at 45°C under low pressure. Each extract was screened to explore its potential as a mosquito larvicidal agent against early fourth instars of dengue vector, Aedes aegypti using WHO protocol. The preliminary screening showed that only 10 plants possessed larvicidal potential as they could result in 100% mortality at 1000 ppm. Further evaluation of the potential larvicidal extracts established the hexane leaf extract of Lantana camara to be most effective extract exhibiting a significant LC50 value of 30.71 ppm while the Phyllanthus emblica fruit extract was found to be least effective with an LC50 value of 298.93 ppm. The extracts made from different parts of other five plants; Achyranthes aspera, Zingiber officinalis, Ricinus communis, Trachyspermum ammi, and Cassia occidentalis also possessed significant larvicidal potential with LC50 values ranging from 55.0 to 74.67 ppm. Other three extracts showed moderate toxicity against A. aegypti larvae. Further investigations would be needed to isolate and identify the primary component responsible for the larvicidal efficiency of the effective plants

  6. Isolongifolenone: A Novel Sesquiterpene Repellent of Ticks and Mosquitoes

    DTIC Science & Technology

    2009-01-01

    Invasive Insect Biocontrol and Behavior Laboratory, Beltsville Agricultural Research Center-West, Beltsville, MD 20705. 2 Corresponding author, e-mail...AND ADDRESS(ES) U.S. Department of Agriculture -Agricultural Research Center,Invasive Insect Biocontrol and Behavior Laboratory,Beltsville

  7. Skin-Applied Repellent Ingredients

    EPA Pesticide Factsheets

    Active ingredients in EPA-registered insect repellents include catnip oil, oil of citronella, DEET, IR 3535, picaridin, oil of lemon eucalyptus, and 2-undecanone. Find fact sheets and pesticide regulatory information.

  8. Dihydronepetalactones deter feeding activity by mosquitoes, stable flies, and deer ticks.

    PubMed

    Feaster, John E; Scialdone, Mark A; Todd, Robin G; Gonzalez, Yamaira I; Foster, Joseph P; Hallahan, David L

    2009-07-01

    The essential oil of catmint, Nepeta cataria L., contains nepetalactones, that, on hydrogenation, yield the corresponding dihydronepetalactone (DHN) diastereomers. The DHN diastereomer (4R,4aR,7S,7aS)-4,7-dimethylhexahydrocyclopenta[c]pyran-1(3H)-one, DHN 1) was evaluated as mosquito repellent, as was the mixture of diastereomers {mostly (4S,4aR,7S,7aR)-4,7-dimethylhexahydrocyclopenta[c]pyran-1(3H)-one, DHN 2} present after hydrogenation of catmint oil itself. The repellency of these materials to Aedes aegypti L. and Anopheles albimanus Wiedemann mosquitoes was tested in vitro and found to be comparable to that obtained with the well-known insect repellent active ingredient N,N-diethyl-3-methylbenzamide (DEET). DHN 1 and DHN 2 also repelled the stable fly, Stomoxys calcitrans L., in this study. DHN 1, DHN 2, and p-menthane-3,8-diol (PMD), another natural monoterpenoid repellent, gave comparable levels of repellency against An. albimanus and S. calcitrans. Laboratory testing of DHN 1 and DHN 2 using human subjects with An. albimanus mosquitoes was carried out. Both DHN 1 and DHN 2 at 10% (wt:vol) conferred complete protection from bites for significant periods of time (3.5 and 5 h, respectively), with DHN2 conferring protection statistically equivalent to DEET. The DHN 1 and DHN 2 diastereomers were also efficaceous against black-legged tick (Ixodes scapularis Say) nymphs.

  9. Do insect repellents induce drift behaviour in aquatic non-target organisms?

    PubMed

    Fink, Patrick; Moelzner, Jana; Berghahn, Ruediger; von Elert, Eric

    2017-01-01

    Synthetic insect repellents are compounds applied to surfaces to discourage insects, mainly mosquitoes, from landing on those surfaces. As some of these repellents have repeatedly been detected in surface waters at significant concentrations, they may also exert repellent effects on aquatic non-target organisms. In running water systems, aquatic invertebrates actively enter downstream drift in order to avoid unfavourable environmental conditions. We thus tested the hypothesis that the widely used insect repellents DEET (N,N-Diethyl-m-toluamide), EBAAP (3-[N-butyl-N-acetyl]-aminopropionic acid ethyl ester) and Icaridin (1-piperidinecarboxylic acid 2-(2-hydroxyethyl)-1-methylpropyl ester) induce downstream drift behaviour in the aquatic invertebrates Gammarus pulex (Crustacea, Amphipoda) and Cloeon dipterum (Insecta, Ephemeroptera), using a laboratory-scale drift assay. We found no clear increase in the drift behaviour of both invertebrate species across a concentration gradient of eight orders of magnitude and even beyond maximum environmental concentrations for any of the three repellents. We found no evidence for a direct drift-inducing activity of insect repellents on aquatic non-target organisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Evaluation of four commercial natural products for repellency and toxicity against the lone star tick, Amblyomma americanum (Acari: Ixodidae).

    PubMed

    Machtinger, Erika T; Li, Andrew Y

    2017-12-01

    Lone star ticks are aggressive ectoparasites of domestic and wild animals, as well as humans. These ticks can transmit many pathogens that cause disease including Erhlichia and tularemia. Common compounds used for personal protection and area sprays are N-diethyl-3-methyl benzamide (DEET) and permethrin, but public concern over personal and environmental safety require the development of new, safer products. In the current study, four commercially available products (Wondercide, Essentria IC 3 , Vet's Best, and Mosquito Barrier) were tested for both repellent and toxic effects against lone star tick nymphs and adults. Overall, all four products were more effective against nymphs than against adults. Wondercide and Essentria IC 3 were as toxic to nymphs as permethrin at concentrations of 3.13% and higher, and as repellent as DEET at all concentrations. Nymphs were also repelled by Mosquito Barrier and Vet's Best, but these products had about half or less of the repellent effects of Wondercide and Essentria IC 3 at most of the concentrations. Adult ticks were repelled similarly by all products at all tested concentrations, but at lower levels than nymphs. Toxicity of the four tested products on adults was similar at concentrations of 12.5% and below, less than half of what was observed with permethrin with declining effectiveness as concentrations decreased. Overall, these four products may offer a natural way to repel lone star ticks, but further field testing is needed to determine rates of application and residual activity.

  11. Residual Efficacy of Field-Applied Permethrin, d-Phenothrin, and Resmethrin on Plant Foliage Against Adult Mosquitoes

    DTIC Science & Technology

    2008-01-01

    Kerst WC. 1997. Residue levels of pyrethrins and piperonyl butoxide in soil and runoff water. J Environ Sci Health B 32:621–644. Antonious GF, Snyder JC...Patel GA. 2001. Pyrethrins and piperonyl butoxide residues on potato leaves and in soil under field conditions. J Environ Sci Health B 36:261–271... metabolism of the pyrethroids cis- and trans- cypermethrin in rainbow trout, Salmo gairdneri. Xenobiotica 17:1175–1193. Foster WA. 1995. Mosquito sugar feeding

  12. Comparative analysis of mosquito (Diptera: Culicidae: Aedes aegypti Liston) responses to the insecticide Temephos and plant derived essential oil derived from Piper betle L.

    PubMed

    Vasantha-Srinivasan, Prabhakaran; Senthil-Nathan, Sengottayan; Ponsankar, Athirstam; Thanigaivel, Annamalai; Edwin, Edward-Sam; Selin-Rani, Selvaraj; Chellappandian, Muthiah; Pradeepa, Venkatraman; Lija-Escaline, Jalasteen; Kalaivani, Kandaswamy; Hunter, Wayne B; Duraipandiyan, Veeramuthu; Al-Dhabi, Naif Abdullah

    2017-05-01

    Resistance to treatments with Temephos or plant derived oil, Pb-CVO, between a field collected Wild Strain (WS) and a susceptible Laboratory Strain (LS) of Ae. aegypti were measured. The Temephos (0.1mg/L) showed the greatest percentage of mosquito mortality compared to Pb-CVO (1.5mg/L) in LS Ae. aegypti. However, WS Ae. aegypti was not significantly affected by Temephos (0.1mg/L) treatment compare to the Pb-CVO (1.5mg/L). However, both strains (LS and WS) when treated with Pb-CVO (1.5mg/L) displayed steady larval mortality rate across all instars. The LC 50 of Temephos was 0.027mg in LS, but increased in WS to 0.081mg/L. The LC 50 of Pb-CVO treatment was observed at concentrations of 0.72 and 0.64mg/L for LS and WS strains respectively. The enzyme level of α- and β-carboxylesterase was reduced significantly in both mosquito strains treated with Pb-CVO. Whereas, there was a prominent deviation in the enzyme ratio observed between LS and WS treated with Temephos. The GST and CYP450 levels were upregulated in the LS, but decreased in WS, after treatment with Temephos. However, treatment with Pb-CVO caused both enzyme levels to increase significantly in both the strains. Visual observations of the midgut revealed cytotoxicity from sub-lethal concentrations of Temephos (0.04mg/L) and Pb-CVO (1.0mg/L) in both strains of Ae. aegypti compared to the control. The damage caused by Temephos was slightly less in WS compared to LS mosquito strains. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Mosquito cytogenetics

    PubMed Central

    Kitzmiller, James B.

    1963-01-01

    Although an intensified interest in mosquito cytogenetics in the past decade has produced a number of contributions to knowledge on this subject, the available information is still superficial and limited to a few mosquito species only. The author of this review summarizes the research done in this field between 1953 and 1962. The following are some of the achievements and some of the gaps that remain to be filled. Karyotypes of several species of Anopheles, Aedes and Culex conform to the general pattern 2n=6, with heterosomes distinguishable only in Anopheles. At least three different karyotypes are present in Anopheles. Salivary gland chromosome maps are now available for several anopheline species, but are still lacking for Culex and Aedes. No precise correlation may yet be made between the frequency of chromosomal aberrations and the degree of insecticide-resistance. Sexual differences in the salivary X-chromosomes have been reported for several species of Anopheles. Chromosomal polymorphism is common in some anophelines, but rare in others. Chromosomal mutation has been induced by means of X-rays. In his conclusions, the author stresses that prospects are especially good for evolutionary and genetic studies involving chromosomal polymorphism. PMID:14058227

  14. Comparative efficacy of IR3535 and deet as repellents against adult Aedes aegypti and Culex quinquefasciatus.

    PubMed

    Cilek, J E; Petersen, J L; Hallmon, C E

    2004-09-01

    Arm-in-cage laboratory evaluations of 2 proprietary formulations of the mosquito repellents IR3535 and N,N-diethyl-3-methylbenzamide (deet; aqueous cream, hydroalcoholic spray) were made with 10 and 20% concentrations of each repellent. Also, 4 commercially available products containing IR3535 (Expedition insect repellent 20.07% active ingredient [AI], Bug Guard Plus with SPF30 sunscreen 7.5% AI, Bug Guard Plus with SPF15 sunscreen 7.5% AI, and Bug Guard Plus 7.5% AI) were tested. All comparisons were made on an equal formulation or concentration basis. Eight volunteers tested all formulations or products 3 times against laboratory-reared, Aedes aegypti and Culex quinquefasciatus mosquitoes (6-10 days old). Products were applied to a forearm at the rate of 0.002 g/cm2. The other forearm was not treated and served as a control. Elapsed time to 1st and 2nd consecutive bite was recorded. Mean protection time (i.e., time to 1st bite) with proprietary formulations of IR3535 were comparable to those of deet, with 20% concentrations providing greater protection against Ae. aegypti (3 h) and Cx. quinquefasciatus (6 h). Mean protection time for commercial products containing IR3535 ranged from nearly 90 to 170 min for Ae. aegypti and 3.5 to 6.5 h for Cx. quinquefasciatus. Mean time to the 2nd bite was similar to time to 1st bite for each mosquito species, product, and formulation.

  15. Insecticidal, repellent and fungicidal properties of novel trifluoromethylphenyl amides.

    PubMed

    Tsikolia, Maia; Bernier, Ulrich R; Coy, Monique R; Chalaire, Katelyn C; Becnel, James J; Agramonte, Natasha M; Tabanca, Nurhayat; Wedge, David E; Clark, Gary G; Linthicum, Kenneth J; Swale, Daniel R; Bloomquist, Jeffrey R

    2013-09-01

    Twenty trifluoromethylphenyl amides were synthesized and evaluated as fungicides and as mosquito toxicants and repellents. Against Aedes aegypti larvae, N-(2,6-dichloro-4-(trifluoromethyl)phenyl)-3,5-dinitrobenzamide (1e) was the most toxic compound (24 h LC50 1940 nM), while against adults N-(2,6-dichloro-4-(trifluoromethyl)phenyl)-2,2,2-trifluoroacetamide (1c) was most active (24 h LD50 19.182 nM, 0.5 μL/insect). However, the 24 h LC50 and LD50 values of fipronil against Ae. aegypti larvae and adults were significantly lower: 13.55 nM and 0.787 × 10(-4) nM, respectively. Compound 1c was also active against Drosophila melanogaster adults with 24 h LC50 values of 5.6 and 4.9 μg/cm(2) for the Oregon-R and 1675 strains, respectively. Fipronil had LC50 values of 0.004 and 0.017 μg/cm(2) against the two strains of D. melanogaster, respectively. In repellency bioassays against female Ae. aegypti, 2,2,2-trifluoro-N-(2-(trifluoromethyl)phenyl)acetamide (4c) had the highest repellent potency with a minimum effective dosage (MED) of 0.039 μmol/cm(2) compared to DEET (MED of 0.091 μmol/cm(2)). Compound N-(2-(trifluoromethyl)phenyl)hexanamide (4a) had an MED of 0.091 μmol/cm(2) which was comparable to DEET. Compound 4c was the most potent fungicide against Phomopsis obscurans. Several trends were discerned between the structural configuration of these molecules and the effect of structural changes on toxicity and repellency. Para- or meta- trifluoromethylphenyl amides with an aromatic ring attached to the carbonyl carbon showed higher toxicity against Ae. aegypti larvae, than ortho- trifluoromethylphenyl amides. Ortho- trifluoromethylphenyl amides with trifluoromethyl or alkyl group attached to the carbonyl carbon produced higher repellent activity against female Ae. aegypti and Anopheles albimanus than meta- or para- trifluoromethylphenyl amides. The presence of 2,6-dichloro- substitution on the phenyl ring of the amide had an influence on larvicidal and repellent

  16. Green synthesis of selenium nanoparticles conjugated Clausena dentata plant leaf extract and their insecticidal potential against mosquito vectors.

    PubMed

    Sowndarya, P; Ramkumar, G; Shivakumar, M S

    2017-12-01

    Mosquitoes are major vectors for the transmission of many diseases like chikungunya, malaria, dengue, zika, etc. worldwide. In the present study, selenium nanoparticles (SeNPs) were synthesized from Clausena dentata and were tested for their larvicidal efficacy against the fourth-instar larvae of Anopheles stephensi, Aedes Aegypti, and Culex quinquefasciatus. The synthesized nanoparticles were characterized using UV-Vis spectroscopy, Fourier Transform Infrared Radiation (FTIR) spectroscopy, EDaX, and SEM. The results recorded from UV-Vis spectroscopy show the peak absorption spectrum at 420 nm. In FTIR, the maximum peak value is 2922.25 cm -1 assigned to N-H group (amide group). In EDaX analysis shows peak around 72.64 which confirm the binding intensity of selenium. In SEM analysis, the synthesized SeNPs sizes were ranging from 46.32 nm to 78.88 nm. The synthesized SeNPs produced high mortality with very low concentration (LC 50 ) were 240.714 mg/L; 104.13 mg/L, and 99.602 mg/L for A. stephensi, A. Aegypti, and C. quinquefasciatus, respectively. These results suggest that the C. dentata leaf extract-mediated biosynthesis of SeNPs has the potential to be used as an ideal ecofriendly approach toward the control of mosquito vectors at early stages.

  17. Larvicidal and Adulticidal Activity of Chroman and Chromene Analogues against Susceptible and Permethrin-Resistant Mosquito Strains.

    PubMed

    Meepagala, Kumudini M; Estep, Alden S; Becnel, James J

    2016-06-22

    Mosquitoes play a major role as vectors that transmit parasitic and viral diseases worldwide, especially in tropical and subtropical countries. Mosquito borne diseases not only affect humans but they also affect livestock in many parts of the world. They carry diseases that are lethal to dogs and horses. Dog heartworm disease (Dirofilaria immitis) is a parasitic disease spread through mosquitoes. This disease is not limited to dogs, but it can affect other animals and humans as well. Eastern equine encephalitis (EEE) and West Nile virus (WNV) are also mosquito borne diseases that affect the central nervous system of horses and cause severe complications and death. Emergence of resistance among mosquitoes to current pesticides has increased the importance of the search for alternate compounds that are effective and environmentally benign with diverse modes of actions than those that are commercially available. Aedes aegypti mosquitoes are the primary vector for transmission of Zika viral fever, yellow fever, dengue fever, and chikungunya. Mosquito control is currently the best strategy to prevent mosquito borne diseases. There are numerous approaches for control of potentially dangerous mosquito populations. These approaches include the use of adulticides (insecticides), larvicides, and, to a limited extent, the use of repellents. Our previous studies have shown the mosquito repellent activity of chromenes. In the present study, we demonstrate larvicidal and adulticidal activity of chroman and chromene analogues against a permethrin susceptible laboratory strain as well as activity against a permethrin-resistant strain of Aedes aegypti.

  18. Altered behavioral responses of Sindbis virus-infected Aedes aegypti (Diptera: Culicidae) to DEET and non-DEET based insect repellents.

    PubMed

    Qualls, Whitney A; Day, Jonathan F; Xue, Rui-de; Bowers, Doria F

    2012-06-01

    Changes in the time to first bite (TFB) and the bloodfeeding behavior of adult female Aedes aegypti (L.) mosquitoes following dissemination of Sindbis virus (SINV) were observed after exposure to repellents with the active ingredients (AI) DEET, picaridin, 2-undecanone (2-U), and oil of lemon eucalyptus. Dissemination of SINV significantly decreased (P<0.0001) the TFB of DEET (15%) and picaridin (15%) by 46% and 37%, respectively. Significant (P<0.0001) changes in activation, probing, and engorgement times were observed in SINV infected mosquitoes after exposure to the four repellents compared to uninfected mosquitoes. Taken together, a decrease in TFB and time to complete the four bloodfeeding stages will lessen the prey-status, and enhance both the chances of mosquito survival and arbovirus transmission. Published by Elsevier B.V.

  19. 7 CFR 3201.61 - Animal repellents.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Animal repellents. 3201.61 Section 3201.61... Designated Items § 3201.61 Animal repellents. (a) Definition. Products used to aid in deterring animals that... animal repellents. By that date, Federal agencies that have the responsibility for drafting or reviewing...

  20. 7 CFR 3201.61 - Animal repellents.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Animal repellents. 3201.61 Section 3201.61... Designated Items § 3201.61 Animal repellents. (a) Definition. Products used to aid in deterring animals that... animal repellents. By that date, Federal agencies that have the responsibility for drafting or reviewing...

  1. 7 CFR 3201.61 - Animal repellents.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Animal repellents. 3201.61 Section 3201.61... Designated Items § 3201.61 Animal repellents. (a) Definition. Products used to aid in deterring animals that... animal repellents. By that date, Federal agencies that have the responsibility for drafting or reviewing...

  2. Aerodynamic repellency of impacting liquids

    NASA Astrophysics Data System (ADS)

    Gauthier, Anaïs; Bouillant, Ambre; Clanet, Christophe; Quéré, David

    2018-05-01

    Impacting liquids can be reflected by moving solid plates, provided the surface is fast enough. We describe and model here the threshold speed of bouncing, in particular as a function of the impact velocity of the incoming liquid. We also demonstrate that the aerodynamic force responsible for the nonwetting behavior induces an oblique rebound, which contributes to the liquid removal. In summary, this situation repels viscous, low surface tension drops of any size, all kinds of cases where repellency is impossible to achieve by other means.

  3. Optimization of pyrethroid and repellent on fabrics against Stegomyia albopicta (=Aedes albopictus) using a microencapsulation technique.

    PubMed

    Yao, T-T; Wang, L-K; Cheng, J-L; Hu, Y-Z; Zhao, J-H; Zhu, G-N

    2015-03-01

    A new approach employing a combination of pyrethroid and repellent is proposed to improve the protective efficacy of conventional pyrethroid-treated fabrics against mosquito vectors. In this context, the insecticidal and repellent efficacies of commonly used pyrethroids and repellents were evaluated by cone tests and arm-in-cage tests against Stegomyia albopicta (=Aedes albopictus) (Diptera: Culicidae). At concentrations of LD50 (estimated for pyrethroid) or ED50 (estimated for repellent), respectively, the knock-down effects of the pyrethroids or repellents were further compared. The results obtained indicated that deltamethrin and DEET were relatively more effective and thus these were selected for further study. Synergistic interaction was observed between deltamethrin and DEET at the ratios of 5 : 1, 2 : 1, 1 : 1 and 1 : 2 (but not 1 : 5). An optimal mixing ratio of 7 : 5 was then microencapsulated and adhered to fabrics using a fixing agent. Fabrics impregnated by microencapsulated mixtures gained extended washing durability compared with those treated with a conventional dipping method. Results indicated that this approach represents a promising method for the future impregnation of bednet, curtain and combat uniform materials. © 2014 The Royal Entomological Society.

  4. Comparison of Field and Laboratory-Based Tests for Behavioral Response of Aedes aegypti (Diptera: Culicidae) to Repellents.

    PubMed

    Sathantriphop, Sunaiyana; Kongmee, Monthathip; Tainchum, Krajana; Suwansirisilp, Kornwika; Sanguanpong, Unchalee; Bangs, Michael J; Chareonviriyaphap, Theeraphap

    2015-12-01

    The repellent and irritant effects of three essential oils-clove, hairy basil, and sweet basil-were compared using an excito-repellency test system against an insecticide-resistant strain of Aedes aegypti (L.) females from Pu Teuy, Kanchanaburi Province. DEET was used as the comparison standard compound. Tests were conducted under field and controlled laboratory conditions. The most marked repellent effect (spatial noncontact assay) among the three test essential oils was exhibited by sweet basil, Ocimum basilicum L. (53.8% escaped mosquitoes in 30-min exposure period) under laboratory conditions while hairy basil, Ocimum americanum L. and clove, Syzygium aromaticum (L.) Merill et. L.M. Perry from laboratory tests and sweet basil from field tests were the least effective as repellents (0-14%). In contrast, the contact assays measuring combined irritancy (excitation) and repellency effects found the best contact irritant response to hairy basil and DEET in field tests, whereas all others in laboratory and field were relatively ineffective in stimulating mosquitoes to move out the test chambers (0-5.5%). All three essential oils demonstrated significant differences in behavioral responses between field and laboratory conditions, whereas there was no significant difference in contact and noncontact assays for DEET between the two test conditions (P > 0.05). © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Mosquito activity of a series of chalcones and 2-pyrazoline derivatives against Aedes aegypti

    USDA-ARS?s Scientific Manuscript database

    Aedes aegypti (L.) (Diptera: Culicidae) transmit pathogens to humans, leading to diseases such as yellow fever and dengue fever. Repellents and insecticides are two common interventions to reduce mosquito biting and thereby disease risk. However, overreliance on a chemical or class of chemicals c...

  6. Declining malaria, rising of dengue and Zika virus: insights for mosquito vector control.

    PubMed

    Benelli, Giovanni; Mehlhorn, Heinz

    2016-05-01

    The fight against mosquito-borne diseases is a challenge of huge public health importance. To our mind, 2015 was an extraordinary year for malaria control, due to three hot news: the Nobel Prize to Youyou Tu for the discovery of artemisinin, the development of the first vaccine against Plasmodium falciparum malaria [i.e. RTS,S/AS01 (RTS,S)], and the fall of malaria infection rates worldwide, with special reference to sub-Saharan Africa. However, there are major challenges that still deserve attention, in order to boost malaria prevention and control. Indeed, parasite strains resistant to artemisinin have been detected, and RTS,S vaccine does not offer protection against Plasmodium vivax malaria, which predominates in many countries outside of Africa. Furthermore, the recent outbreaks of Zika virus infections, occurring in South America, Central America and the Caribbean, represent the most recent of four arrivals of important arboviruses in the Western Hemisphere, over the last 20 years. Zika virus follows dengue (which slyly arrived in the hemisphere over decades and became more aggressive in the 1990s), West Nile virus (emerged in 1999) and chikungunya (emerged in 2013). Notably, there are no specific treatments for these arboviruses. The emerging scenario highlights that the effective and eco-friendly control of mosquito vectors, with special reference to highly invasive species such as Aedes aegypti and Aedes albopictus, is crucial. The concrete potential of screening plant species as sources of metabolites for parasitological purposes is worthy of attention, as elucidated by the Y. Tu's example. Notably, plant-borne molecules are often effective at few parts per million against Aedes, Ochlerotatus, Anopheles and Culex young instars, can be used for the rapid synthesis of mosquitocidal nanoformulations and even employed to prepare cheap repellents with low human toxicity. In addition, behaviour-based control tools relying to the employ of sound traps and the

  7. Mosquito, adult (image)

    MedlinePlus

    This illustration shows an adult southern house mosquito. This mosquito feeds on blood and is the carrier of many diseases, such as encephalitis, West Nile, dengue fever, yellow fever, and others. ( ...

  8. Repellency to ticks (Acari: Ixodidae) of extracts of nigella sativa L.(Ranunculaceae) and the anti-inflammatory DogsBestFriend™

    USDA-ARS?s Scientific Manuscript database

    Motivated by observations that the canine anti-inflammatory cream DogsBestFriend™ (DBF) appeared to deter flies, mosquitoes, and ticks from treated animals, repellent efficacy bioassays using four species of ticks were conducted with three extracts of Nigella sativa L. (Ranunculaceae), a constituent...

  9. Laboratory trials of fatty acids as repellents or antifeedants against houseflies, horn flies and stable flies (Diptera: Muscidae).

    PubMed

    Mullens, Bradley A; Reifenrath, William G; Butler, Sarah M

    2009-12-01

    Straight-chain, saturated fatty acids (particularly C8, C9 and C10) have some known behavioral effects on insects such as mosquitoes, and were tested in combination for potential repellency/antifeedant activity in bioassays against three significant muscoid flies of medical/veterinary importance: houseflies, horn flies and stable flies. Mixtures of C8, C9 and C10 (1:1:1; 15% total actives in formulation) were highly repellent to houseflies and horn flies at or below 1 mg formulation cm(-2). Repellency time varied from < 1 day for houseflies to usually at least 3 days for horn flies. Individual longer-chain-length fatty acids were tested, and C11 repelled houseflies for up to 5-8 days, while C12 lasted 2 days. Minimum statistically significant repellency levels of the C8, C9 and C10 mixture (3 h after application) against horn flies were 0.06-0.12 mg cm(-2). A liquid formulation of the 15% C8, C9 and C10 mixture in a silicone oil carrier (at 2.8 mg AI cm(-2)) was highly repellent against hungry stable flies in a blood-feeding membrane bioassay for at least 8 h. The low toxicity and reasonable activity and persistence of these carboxylic acids make them good candidates for development as protective materials against pest flies in livestock settings. (c) 2009 Society of Chemical Industry.

  10. Modified mosquito landing boxes dispensing transfluthrin provide effective protection against Anopheles arabiensis mosquitoes under simulated outdoor conditions in a semi-field system.

    PubMed

    Andrés, Marta; Lorenz, Lena M; Mbeleya, Edgar; Moore, Sarah J

    2015-06-24

    Efforts to control malaria vectors have primarily focused on scaling-up of long-lasting insecticidal nets (LLINs) and indoor residual spraying. Although highly efficient against indoor-biting and indoor-resting vectors, these interventions have lower impact on outdoor-biting mosquitoes. Innovative vector control tools are required to prevent outdoor human-mosquito contacts. In this work, the potential of spatial repellents, delivered in an active system that requires minimal user compliance, to provide personal protection against exophagic mosquitoes active in the early evening was explored. A device previously used as an odour-baited lure and kill apparatus, the mosquito landing box (MLB), was modified to dispense the volatile synthetic pyrethroid, transfluthrin, as a spatial repellent. The MLB has an active odour-dispensing mechanism that uses a solar-powered fan and switches on at dusk to provide long duration dispensing of volatile compounds without the need for the user to remember to employ it. Two MLBs were located 5 m from a human volunteer to investigate the repellent effects of a transfluthrin 'bubble' created between the MLBs. Transfluthrin was emanated from polyester strips, hanging inside the MLB odour-dispensing unit. A fully randomized cross-over design was performed in a large, semi-field, screened cage to assess the effect of the repellent against laboratory-reared Anopheles arabiensis mosquitoes under ambient outdoor conditions. The knock-down capacity of the transfluthrin-treated strips was also evaluated at different time points up to 3 weeks after being impregnated to measure duration of efficacy. The protective transfluthrin bubble provided 68.9% protection against An. arabiensis bites under these simulated outdoor conditions. Volatile transfluthrin caused low mortality among mosquitoes in the semi-field system. Transfluthrin-treated strips continued to knock down mosquitoes in laboratory tests, 3 weeks after impregnation, although this effect

  11. A community-wide study of malaria reduction: evaluating efficacy and user-acceptance of a low-cost repellent in northern Ghana.

    PubMed

    Dadzie, Samuel; Boakye, Daniel; Asoala, Victor; Koram, Kwadwo; Kiszewski, Anthony; Appawu, Maxwell

    2013-02-01

    NO MAS (NM) mosquito repellent was evaluated in two farming villages (4 km apart) in the Kassena Nankana district of northern Ghana. We determined its efficacy against local malaria vectors, degree of user acceptance, and its effect on malaria prevalence in households using insecticide-treated bed nets. The average protective efficacy of NM against Anopheles mosquitoes over 9 hours was 89.6%. Controls averaged 86 bites/person/night versus 9 bites/person/night with the use of NM. Use of repellent was associated with a decrease of absolute malaria prevalence by 19.2% in the repellent village and by 6.5% in the control village (45.5 to 26.3, and 29.5 to 23.0, respectively). The user-acceptance rate of NM repellent was 96.1%. Ten percent (10%) of repellent users reported irritation as the main adverse effect during the period. Eighty-five percent (85%) of the users found the odor of NM appealing and 87% reported no inconvenience in applying the repellent daily.

  12. Mosquito Life Cycle

    EPA Pesticide Factsheets

    Knowing the stages of the mosquito's life will help you prevent mosquitoes around your home and help you choose the right pesticides for your needs, if you decide to use them. All mosquito species go through four distinct stages during their live cycle.

  13. MAN, MOSQUITOES AND MICROBES.

    ERIC Educational Resources Information Center

    SCHOONOVER, ROBERT A.

    THE CONTROL OF MOSQUITOES IS A MATTER OF INCREASING CONCERN IN THE STATE OF FLORIDA. A BRIEF DESCRIPTION OF THE LIFE CYCLE, VARIOUS SPECIES, CONTROL, AND DESCRIPTION OF DISEASES TRANSMITTED BY THE MOSQUITO WAS PRESENTED. THE ARTICLE CONCLUDED THAT MOSQUITO CONTROL IS NOT ONLY A HEALTH PROBLEM, BUT ALSO A MATTER OF IMPROVED ECONOMICS IN RELATION TO…

  14. Pre-treatment of Stegomyia aegypti mosquitoes with a sublethal dose of imidacloprid impairs behavioural avoidance induced by lemon oil and DEET.

    PubMed

    Thany, S H; Tong, F; Bloomquist, J R

    2015-03-01

    The present study was conducted to determine whether imidacloprid can impair the avoidance behaviour of the mosquito Stegomyia aegypti. Laboratory investigations using a T-maze apparatus showed that St. aegypti mosquitoes present long term avoidance behaviour when they are exposed to repetitive trials with lemon oil and DEET. The present study tested the effect of a sublethal dose of imidacloprid on the avoidance behaviour of St. aegypti mosquitoes over a 48 h period. Data suggest that 0.5 ng of imidacloprid/mosquito reduces the avoidance behaviour of mosquitoes exposed to lemon oil, on the first day of exposure, after the second trial; whereas imidacloprid affected DEET repellency only the first day of exposure, after the second trial. Imidacloprid was toxic against St. aegypti mosquitoes, and at sublethal doses was able to impair the repellency induced by lemon oil and DEET. The present data were consistent with the finding that St. aegypti mosquitoes exhibit long term avoidance behaviour, and treatment of mosquitoes with a sublethal dose of imidacloprid under DEET application can affect the repellency of DEET against St. aegypti. © 2014 The Royal Entomological Society.

  15. Pre-West Nile virus outbreak: perceptions and practices to prevent mosquito bites and viral encephalitis in the United States.

    PubMed

    Herrington, James E

    2003-01-01

    Mosquitoes can transmit over 100 of the viruses that can cause encephalitis, meningitis, and hemorrhagic disease in humans (Chin 2000; Gubler 1996; Monath 1989). While much is known about the ecology, epidemiology, and clinical manifestations of the arboviral encephalitides (Campbell et al. 2002; Centers for Disease Control and Prevention 1997; Gubler 1998; Hayes 1989; Hubálek and Halouzka 1999), little empirical research exists regarding the U.S. population's knowledge of mosquitoes and arboviral encephalitis, particularly prior to the U.S. outbreak of West Nile virus (WNV) in 1999. A nationally representative 55-item survey instrument was successfully administered to 1,500 adults in the United States and an additional 250 adults in six states in the Northeast (Connecticut, Delaware, New Jersey, New York, Pennsylvania, and Rhode Island) regarding mosquitoes and mosquito-borne viral encephalitis. A summary outcome measure for mosquito bite prevention was created. Analyses revealed that the following were statistically significant predictors of behaviors taken to prevent mosquito bites: being concerned about being bitten by mosquitoes, perceived effectiveness of staying indoors in late afternoon and early evening was protective, perceived effectiveness that mosquito repellent is not harmful to health, owning dogs and/or cats as pets, being married, and being > or = 18-44 years old. Being concerned about being bitten by mosquitoes was the most robust predictor of behavioral action to prevent mosquito bites (OR = 7.3; 95% CI = 4.3, 12.2). Observed misperceptions and inadequate knowledge regarding insect repellents suggest increased promotion of the safety and efficacy of DEET-containing insect repellents is warranted.

  16. The mode of action of spatial repellents and their impact on vectorial capacity of Anopheles gambiae sensu stricto.

    PubMed

    Ogoma, Sheila B; Ngonyani, Hassan; Simfukwe, Emmanuel T; Mseka, Antony; Moore, Jason; Maia, Marta F; Moore, Sarah J; Lorenz, Lena M

    2014-01-01

    Malaria vector control relies on toxicity of insecticides used in long lasting insecticide treated nets and indoor residual spraying. This is despite evidence that sub-lethal insecticides reduce human-vector contact and malaria transmission. The impact of sub-lethal insecticides on host seeking and blood feeding of mosquitoes was measured. Taxis boxes distinguished between repellency and attraction inhibition of mosquitoes by measuring response of mosquitoes towards or away from Transfluthrin coils and humans. Protective effective distance of coils and long-term effects on blood feeding were measured in the semi-field tunnel and in a Peet Grady chamber. Laboratory reared pyrethroid susceptible Anopheles gambiae sensu stricto mosquitoes were used. In the taxis boxes, a higher proportion of mosquitoes (67%-82%) were activated and flew towards the human in the presence of Transfluthrin coils. Coils did not hinder attraction of mosquitoes to the human. In the semi-field Tunnel, coils placed 0.3 m from the human reduced feeding by 86% (95% CI [0.66; 0.95]) when used as a "bubble" compared to 65% (95% CI [0.51; 0.76]) when used as a "point source". Mosquitoes exposed to coils inside a Peet Grady chamber were delayed from feeding normally for 12 hours but there was no effect on free flying and caged mosquitoes exposed in the semi-field tunnel. These findings indicate that airborne pyrethroids minimize human-vector contact through reduced and delayed blood feeding. This information is useful for the development of target product profiles of spatial repellent products that can be used to complement mainstream malaria vector control tools.

  17. Factors influencing the use of topical repellents: implications for the effectiveness of malaria elimination strategies

    PubMed Central

    Gryseels, Charlotte; Uk, Sambunny; Sluydts, Vincent; Durnez, Lies; Phoeuk, Pisen; Suon, Sokha; Set, Srun; Heng, Somony; Siv, Sovannaroth; Gerrets, René; Tho, Sochantha; Coosemans, Marc; Peeters Grietens, Koen

    2015-01-01

    In Cambodia, despite an impressive decline in prevalence over the last 10 years, malaria is still a public health problem in some parts of the country. This is partly due to vectors that bite early and outdoors reducing the effectiveness of measures such as Long-Lasting Insecticidal Nets. Repellents have been suggested as an additional control measure in such settings. As part of a cluster-randomized trial on the effectiveness of topical repellents in controlling malaria infections at community level, a mixed-methods study assessed user rates and determinants of use. Repellents were made widely available and Picaridin repellent reduced 97% of mosquito bites. However, despite high acceptability, daily use was observed to be low (8%) and did not correspond to the reported use in surveys (around 70%). The levels of use aimed for by the trial were never reached as the population used it variably across place (forest, farms and villages) and time (seasons), or in alternative applications (spraying on insects, on bed nets, etc.). These findings show the key role of human behavior in the effectiveness of malaria preventive measures, questioning whether malaria in low endemic settings can be reduced substantially by introducing measures without researching and optimizing community involvement strategies. PMID:26574048

  18. Synthesis and characterization of methyltrihydroxysilane water repellent

    NASA Astrophysics Data System (ADS)

    Abidin, A. Z.; Harjandi, M. N.; Wirawan, V.; Suharno, S. M.

    2018-03-01

    Methyltrihydroxysilane (CH3Si (OH)3) as a water repellent has been synthesized from trichloromethylsilane and ethanol by varying their composition, reaction condition, and the addition of nanosilica. The properties of the material have been characterized using FTIR for identification of raw materials and water repellent product, SEM for identification of water repellent coating surface, and tensiometer for measurement of water repellent contact angle. The FTIR spectra confirm the reaction of the water-repellent formation. The water repellent product was applied by spraying or dip coating on the automotive window surface. This study shows that the best ethanol composition is 91% and the best contact angle of synthesized water repellent material is 149,46°. This contact angle is higher than that of a commercial product, which shows it as a property of the superhydrophobic material. Water repellency properties increase as the composition of trichloromethylsilane increases. It shows that the increasing of trichloromethylsilane composition can also increase methyltrihydroxysilane formation. However, glass surface becomes opaque as the composition of trichloromethylsilane increase because methyltrihydroxysilane will create the Si-O-Si layer that has a white color. The addition of nanomaterial also increases the surface roughness, but a binder is required to bind nanomaterial to the water-repellent layer. For an application, dip coating has better water repellency than spraying. This is because dip coating method creates more homogenous nanomaterial precipitation on the surface. On the other hand, the level of transparency is worse. Therefore, the water repellent of trichloromethylsilane is recommended for applications that do not need clarity such bathroom glass wall.

  19. Larvicidal and repellent activity of tetradecanoic acid against Aedes aegypti (Linn.) and Culex quinquefasciatus (Say.) (Diptera:Culicidae).

    PubMed

    Sivakumar, R; Jebanesan, A; Govindarajan, M; Rajasekar, P

    2011-09-01

    To investigate the larvicidal and repellent efficacy of tetradecanoic acid against Aedes aegypti (Ae. aegypti) L. and Culex quinquefasciatus (Cx. quinquefasciatus) Say (Diptera: Culicidae). Larvicidal efficacy of tetradecanoic acid was tested at various concentrations against the early third instar larvae of Ae. aegypti and Cx. quinquefasciatus. The repellent activity was determined against two mosquito species at three concentrations viz., 1.0,2.5 and 5.0 ppm under the laboratory conditions. The tetradecanoic acid was found to be more effective against Cx. quinquefasciatus than Ae. aegypti larvae. The LC(50) values were 14.08 ppm and 25.10 ppm, respectively. Tetradecanoic acid showed lesser repellency against Ae. aegypti and Cx. quinquefasciatus. The highest repellency was observed in higher concentration of 5.0 mg/cm(2) provided 100% protection up to 60 and 90 min against Ae. aegypti and Cx. quinquefasciatus respectively. From the results it can be concluded the tetradecanoic acid is a potential for controlling Cx. quinquefasciatus and Ae. aegypti mosquitoes. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  20. Laboratory and semi-field evaluations of two (transfluthrin) spatial repellent devices against Aedes aegypti (L.) (Diptera: Culicidae).

    PubMed

    McPhatter, Lee P; Mischler, Paula D; Webb, Meiling Z; Chauhan, Kamal; Lindroth, Erica J; Richardson, Alec G; Debboun, Mustapha

    2017-01-01

    Two transfluthrin-based spatial repellent products (Raid Dual Action Insect Repellent and Home Freshener and Raid Shield (currently not commercially available), SC Johnson, Racine WI) were evaluated for spatial repellent effects against female Aedes aegypti (L.) mosquitoes under laboratory (wind tunnel) and semi-field (outdoor enclosure) conditions. The placement of either product in the wind tunnel significantly reduced host-seeking behaviors. The mean baseline (control) landing counts for the Raid Dual Action and Raid Shield were reduced by 95% and 74% respectively. Mean probing counts for the Raid Dual Action were reduced by 95%, while the probing counts for the Raid Shield were decreased by 69%. Baseline blood-feeding success was significantly reduced for both treatments: Raid Dual Action (100%) and Raid Shield (96%). Semi-field evaluations were conducted in outdoor enclosures at the Navy Entomology Center of Excellence, Jacksonville, Florida. A moderate reduction in mosquito entry into military style tents resulted when either product was placed near the tent opening. The Raid Shield reduced mosquito entry into tents by 88%, while the Dual Action decreased entry by 66%.

  1. Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi (Diptera: Culicidae).

    PubMed

    Govindarajan, M; Mathivanan, T; Elumalai, K; Krishnappa, K; Anandan, A

    2011-01-01

    To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria (E. coronaria) and Caesalpinia pulcherrima (C. pulcherrima) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi). The ovicidal activity was determined against three mosquito species at various concentrations ranging from 50-450 ppm under the laboratory conditions. The hatch rates were assessed 48 h after treatment. The repellent efficacy was determined against three mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm(2) under the laboratory conditions. The crude extract of E. coronaria exerted zero hatchability (100% mortality) at 250, 200 and 150 ppm for Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The crude extract of C. pulcherrima exerted zero hatchability (100% mortality) at 375, 300 and 225 ppm for Cx. quinquefasciatus, Ae. aegypti and An. Stephensi, respectively. The methanol extract of E. coronaria found to be more repellenct than C. pulcherrima extract. A higher concentration of 5.0 mg/cm(2) provided 100% protection up to 150, 180 and 210 min against Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The results clearly showed that repellent activity was dose dependent. From the results it can be concluded the crude extracts of E. coronaria and C. pulcherrima are an excellent potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.

  2. Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi (Diptera: Culicidae)

    PubMed Central

    Govindarajan, M; Mathivanan, T; Elumalai, K; Krishnappa, K; Anandan, A

    2011-01-01

    Objective To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria (E. coronaria) and Caesalpinia pulcherrima (C. pulcherrima) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi). Methods The ovicidal activity was determined against three mosquito species at various concentrations ranging from 50-450 ppm under the laboratory conditions. The hatch rates were assessed 48 h after treatment. The repellent efficacy was determined against three mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm2 under the laboratory conditions. Results The crude extract of E. coronaria exerted zero hatchability (100% mortality) at 250, 200 and 150 ppm for Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The crude extract of C. pulcherrima exerted zero hatchability (100% mortality) at 375, 300 and 225 ppm for Cx. quinquefasciatus, Ae. aegypti and An. Stephensi, respectively. The methanol extract of E. coronaria found to be more repellenct than C. pulcherrima extract. A higher concentration of 5.0 mg/cm2 provided 100% protection up to 150, 180 and 210 min against Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The results clearly showed that repellent activity was dose dependent. Conclusions From the results it can be concluded the crude extracts of E. coronaria and C. pulcherrima are an excellent potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes. PMID:23569723

  3. Preventing Superinfection in Malaria Spreads with Repellent and Medical Treatment Policy

    NASA Astrophysics Data System (ADS)

    Fitri, Fanny; Aldila, Dipo

    2018-03-01

    Malaria is a kind of a vector-borne disease. That means this disease needs a vector (in this case, the anopheles mosquito) to spread. In this article, a mathematical model for malaria disease spread will be discussed. The model is constructed as a seven-dimensional of a non-linear ordinary differential equation. The interventions of treatment for infected humans and use of repellent are included in the model to see how these interventions could be considered as alternative ways to control the spread of malaria. Analysis will be made of the disease-free equilibrium point along with its local stability criteria, construction of the next generation matrix which followed with the sensitivity analysis of basic reproduction number. We found that both medical treatment and repellent intervention succeeded in reducing the basic reproduction number as the endemic indicator of the model. Finally, some numerical simulations are given to give a better interpretation of the analytical results.

  4. Stratifying repellent-treated pine seed.

    Treesearch

    T.A. Harrington

    1960-01-01

    Germinative capacity of loblolly, shortleaf, and Virginia pine may be seriously reduced if the seed is repellent-coated and then stratified when fresh. In contrast, cold storage for a few months may largely forestall damage from later repellent treatment and stratification.

  5. Tips to Prevent Mosquito Bites

    MedlinePlus

    ... mosquitoes using insecticides. Use Structural Barriers Cover all gaps in walls, doors, and windows to prevent mosquitoes ... into pants and pants into socks to cover gaps in your clothing where mosquitoes can get to ...

  6. Naturally occurring bioactive compounds from four repellent essential oils against Bemisia tabaci whiteflies.

    PubMed

    Deletre, Emilie; Chandre, Fabrice; Barkman, Barbara; Menut, Chantal; Martin, Thibaud

    2016-01-01

    In tropical countries, netting is an effective sustainable tool for protecting horticultural crops against Lepidoptera, although not against small pests such as Bemisia tabaci, while smaller mesh netting can be used in temperate regions. A solution is to combine a net with a repellent. Previously we identified repellent essential oils: lemongrass (Cymbopogon citratus), cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and citronella (Cymbopogon winternarius). The present study was designed to identify the active compounds of these essential oils, characterise their biological activity and examine their potential for coating nets. We investigated the efficiency and toxicity of nets dipped in different solutions. We then studied the repellent effect with an olfactometer and the irritant effect by videotracking. Geraniol and citronellol were the most promising net coatings owing to their repellent effect. The repellency, irritancy or toxicity varied with the product and concentration, and these features were independent, indicating that the repellent and the irritant/toxic mechanisms were not the same. The combined effects of these different compounds account for the bioactivity of the mixture, suggesting interactions between the compounds. This new sustainable strategy for protecting vegetable crops against whiteflies is discussed, in addition to the use of companion plants that could produce such bioactive compounds. © 2015 Society of Chemical Industry.

  7. Larvicidal and repellent activity of the essential oil of Coriandrum sativum L. (Apiaceae) fruits against the filariasis vector Aedes albopictus Skuse (Diptera: Culicidae).

    PubMed

    Benelli, Giovanni; Flamini, Guido; Fiore, Giulia; Cioni, Pier Luigi; Conti, Barbara

    2013-03-01

    The essential oils of many Apiaceae species have been already studied for their insecticidal and repellent properties against insect pests. In this research, the essential oil (EO) extracted from the fruits of Coriandrum sativum L. (Apiaceae) was evaluated for the first time for its larvicidal and repellent activities against the most invasive mosquito worldwide, Aedes albopictus Skuse (Diptera: Culicidae). The chemical composition of C. sativum EO was investigated by gas chromatography with electron impact mass spectrometry analysis. Coriander EO was mainly composed by monoterpene hydrocarbons and oxygenated monoterpenes, with linalool (83.6 %) as the major constituent. C. sativum EO exerted toxic activity against A. albopictus larvae: LC(50) was 421 ppm, while LC(90) was 531.7 ppm. Repellence trials highlighted that C. sativum EO was a good repellent against A. albopictus, also at lower dosages: RD(50) was 0.0001565 μL/cm(2) of skin, while RD(90) was 0.002004 μL/cm(2). At the highest dosage (0.2 μL/cm(2) of skin), the protection time achieved with C. sativum essential oil was higher than 60 min. This study adds knowledge about the chemical composition of C. sativum EO as well as to the larvicidal and repellent activity exerted by this EO against A. albopictus. On this basis, we believe that our findings could be useful for the development of new and safer products against the Asian tiger mosquito.

  8. Molecular Basis of N,N-Diethyl-3-Methylbenzamide (DEET) in Repelling the Common Bed Bug, Cimex lectularius

    PubMed Central

    Liu, Feng; Xia, Xiaoming; Liu, Nannan

    2017-01-01

    As the most extensively used chemical repellent, N,N-diethyl-3-methylbenzamide (DEET) displayed repellency to a wide range of insects, including the common bed bug, Cimex lectularius. While the neuronal or molecular basis involved in DEET's repellency have been majorly focused on mosquitos and fruit flies, DEET's repellency to the common bed bug is largely unreached. To gain new insights into the cellular and molecular mechanisms in DEET's repellency to the common bed bug, we characterized the neuronal response of bed bugs to DEET, identified the olfactory receptors targeted by DEET and demonstrated the interfering effect of DEET on bed bug's responses to human odorants. High doses of DEET were required for activating the olfactory receptor neurons in the sensilla of bed bugs and at least three DEET-sensitive receptors were functionally deciphered. These DEET-sensitive receptors presented even more sensitive to certain botanical terpenes/terpenoids which also displayed repellency at varying levels for bed bugs. In addition, DEET produced a blocking effect on the neuronal responses of bed bugs to specific human odors and showed inhibitory effect on the function of odorant receptors in responding to certain human odors. Taken together, our results indicate that DEET may function as a stimulus that triggers avoidance behaviors and a molecular “confusant” for interrupting the host odor recognition in the odorant receptors of bed bugs. The receptors that coincidently responded to both synthetic DEET and botanical terpenes/terpenoids suggested that DEET probably target on receptors that originally responded to terpenes/terpenoids. This study gave novel insight into the mechanisms of DEET's repellency to bed bugs and also provided valuable information for developing new reagents for bed bug control. PMID:28676765

  9. Molecular Basis of N,N-Diethyl-3-Methylbenzamide (DEET) in Repelling the Common Bed Bug, Cimex lectularius.

    PubMed

    Liu, Feng; Xia, Xiaoming; Liu, Nannan

    2017-01-01

    As the most extensively used chemical repellent, N,N-diethyl-3-methylbenzamide (DEET) displayed repellency to a wide range of insects, including the common bed bug, Cimex lectularius . While the neuronal or molecular basis involved in DEET's repellency have been majorly focused on mosquitos and fruit flies, DEET's repellency to the common bed bug is largely unreached. To gain new insights into the cellular and molecular mechanisms in DEET's repellency to the common bed bug, we characterized the neuronal response of bed bugs to DEET, identified the olfactory receptors targeted by DEET and demonstrated the interfering effect of DEET on bed bug's responses to human odorants. High doses of DEET were required for activating the olfactory receptor neurons in the sensilla of bed bugs and at least three DEET-sensitive receptors were functionally deciphered. These DEET-sensitive receptors presented even more sensitive to certain botanical terpenes/terpenoids which also displayed repellency at varying levels for bed bugs. In addition, DEET produced a blocking effect on the neuronal responses of bed bugs to specific human odors and showed inhibitory effect on the function of odorant receptors in responding to certain human odors. Taken together, our results indicate that DEET may function as a stimulus that triggers avoidance behaviors and a molecular "confusant" for interrupting the host odor recognition in the odorant receptors of bed bugs. The receptors that coincidently responded to both synthetic DEET and botanical terpenes/terpenoids suggested that DEET probably target on receptors that originally responded to terpenes/terpenoids. This study gave novel insight into the mechanisms of DEET's repellency to bed bugs and also provided valuable information for developing new reagents for bed bug control.

  10. Assessment of the repellent effect of Lippia alba essential oil and major monoterpenes on the cattle tick Rhipicephalus microplus.

    PubMed

    Lima, A da Silva; Carvalho, J F de; Peixoto, M G; Blank, A F; Borges, L M F; Costa Junior, L M

    2016-03-01

    The control of Rhipicephalus microplus (Ixodida: Ixodidae) is achieved using synthetic acaricides. However, resistant tick populations are widespread around the world. Plant essential oils can act as repellents, keeping ticks away from hosts and decreasing the selection pressure on synthetic acaricides. The aim of this study was to evaluate the in vitro repellent effect of Lippia alba essential oil on R. microplus larvae. Leaves from two L. alba genotypes maintained under the same agronomic and environmental conditions were collected. Essential oil was extracted by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC-MS). The major monoterpenes detected in the chemical analysis were commercially acquired and tested. For the repellency test, a glass rod was vertically fixed to measure active climbing of approximately 30 R. microplus larvae aged 14-21 days in response to essential oils and monoterpenes. Repellency was evaluated at 1 h, 3 h and 5 h after treatment. Variation in repellent action was detected between the genotypes. The major monoterpenes identified in the essential oils (limonene and carvone) showed low repellent effects in comparison with intact essential oils. Thus, the present results showed that L. alba essential oil contains bioactive compounds with great repellent activity against ticks that varies according to the plant genotype. © 2015 The Royal Entomological Society.

  11. Perceived nuisance of mosquitoes on the Isle of Sheppey, Kent, UK.

    PubMed

    Hutchinson, Robert A; Lindsay, Steve W

    2006-09-01

    Little is known about the biting nuisance of mosquitoes in the UK, despite the high numbers found in some locations. A telephone questionnaire survey was used to determine the perceived nuisance of biting insects on the Isle of Sheppey, Kent, a place notorious for mosquitoes. Two hundred randomly selected individuals were interviewed and asked if they suffered from mosquito bites. If they answered yes, they were asked to describe where and when they were bitten, and what measures they took against mosquitoes. Forty-six percent of respondents completed the questionnaire. Of those, 50% reported being bitten by mosquitoes, mostly outside during the summer. Seventy percent said that most biting occurred during the evening and night. Of those respondents who protected themselves against biting (27), most used repellents (70%), with the remainder changing their behaviour to avoid mosquitoes, including closing or screening windows (33%), wearing thicker clothes (7%) and spraying insecticide (4%). One person slept under a bednet in summer (4%). This study provides evidence that on the Isle of Sheppey mosquitoes are considered a major nuisance by a sizeable proportion of the population. Since there is growing interest in the threat posed by new and emerging diseases in the UK, health authorities will need to make substantial efforts to inform and reassure the public about the threats posed by mosquitoes in areas where they are common.

  12. Insecticidal and repellent activities of insecticide-sucrose solutions to Culex pipiens molestus (Diptera: Culicidae) under laboratory and field conditions.

    PubMed

    Shin, Ehyun; Park, Chan; Ahn, Young-Joon; Lee, Dong-Kyu; Chang, Kyu-Sik

    2011-06-01

    Culex pipiens molestus Forskal has been reported as a dominant species in underground structures of urban areas in the Republic of Korea (ROK) during all seasons and becomes bothersome to humans in late autumn and winter. Most Cx. pipiens molestus in septic tanks are controlled in the ROK using larvicides such as Bt and IGR. However, there are a number of problems associated with larvicides, such as high cost and requirement for frequent use. In the present work, a new control method for Cx. pipiens molestus in septic tanks by using mixtures of sucrose solution with insecticides was investigated. The insecticidal and repellent activities of ten insecticides were evaluated for best control of Cx. pipiens molestus in septic tanks. Firstly, differences in susceptibilities to insecticides were evaluated in topical assays by forced direct contact bioassay and in a screened wire cage by free direct contact bioassay. The difference in insecticide susceptibility in the mosquitoes was the result of repellency by the insecticides. In three septic tanks, the density of Culex mosquitoes was sharply reduced by a deltamethrin-sucrose solution kit. The results demonstrated the potential for mosquito control by deltamethrin-sucrose solution, and the study offers basic information related to mosquito control in septic tanks. Copyright © 2011 Society of Chemical Industry.

  13. Evolutionarily conserved odorant receptor function questions ecological context of octenol role in mosquitoes

    PubMed Central

    Dekel, Amir; Pitts, Ronald J.; Yakir, Esther; Bohbot, Jonathan D.

    2016-01-01

    Olfaction is a key insect adaptation to a wide range of habitats. In the last thirty years, the detection of octenol by blood-feeding insects has been primarily understood in the context of animal host-seeking. The recent discovery of a conserved octenol receptor gene in the strictly nectar-feeding elephant mosquito Toxorhynchites amboinensis (TaOr8) suggests a different biological role. Here, we show that TaOR8 is a functional ortholog of its counterparts in blood-feeding mosquitoes displaying selectivity towards the (R)-enantiomer of octenol and susceptibility to the insect repellent DEET. These findings suggest that while the function of OR8 has been maintained throughout mosquito evolution, the context in which this receptor is operating has diverged in blood and nectar-feeding mosquitoes. PMID:27849027

  14. Angelica sinensis (Umbelliferae) with proven repellent properties against Aedes aegypti, the primary dengue fever vector in Thailand.

    PubMed

    Champakaew, D; Junkum, A; Chaithong, U; Jitpakdi, A; Riyong, D; Sanghong, R; Intirach, J; Muangmoon, R; Chansang, A; Tuetun, B; Pitasawat, B

    2015-06-01

    Botanical resources with great diversity in medicinal and aromatic plants are a rich and reliable source for finding insect repellents of plant origin, which are widely popular among today's consumers. Although some herbal-based repellents have been proven comparable to or even better than synthetics, commercially available natural repellents generally tend to be expensive, with short-lived effectiveness. This critical flaw leads to ongoing research for new and effective repellents, which provide longer protection against vector and nuisance-biting insects, while remaining safe, user friendly, and reasonably priced. This study aimed to evaluate the repellent activity of plant-derived products against the primary dengue vector, Aedes aegypti, by following the human bait technique of World Health Organization guidelines. Preliminary laboratory screening tests for repellency of 33 plant species clearly demonstrated Angelica sinensis as the most effective repellent from each kind of extracted product, with its essential oil and ethanolic extract having median complete protection times of 7.0 h (6.0-7.5) and 2.5 h (2.0-2.5), respectively. Due to its low yield (0.02 %), pungent smell, and little cause of irritation, A. sinensis essential oil did not qualify as a candidate for further repellent assessment. However, subsequent extractions of A. sinensis with different organic solvents of increasing polarity provided four extractants with varying degrees of repellency against A. aegypti. The hexane extract of A. sinensis provided excellent repellency, with a median complete protection time of 7.5 h (6.5-8.5), which was longer than that of ethanol (2.5, 2.0-2.5 h), acetone (1.75, 0.5-2.5 h), and methanol extracts (0.5, 0-1.0 h). By being the most effective product, A. sinensis hexane extract gave significant protection comparable to that of its essential oil and the standard synthetic repellent, N,N-diethyl-3-methylbenzamide (DEET: 6.25, 5.0-6.5 h). Qualitative gas

  15. General Information about Mosquitoes

    MedlinePlus

    ... they can use without posing unreasonable risk to human health and the environment. State and local government agencies play a critical role in protecting public health from mosquito-borne ... use of pesticides for mosquito control is appropriate for their area. ...

  16. Relationship between chemical structure and rat repellency

    USGS Publications Warehouse

    Bellack, E.; DeWitt, J.B.; Treichler, R.

    1953-01-01

    Repellent activity is defined as the activity of a compound in preventing consumption of, or gnawing attacks upon, foodstuffs or articles containing or treated with the candidate substance. Data are presented on repellency indices of 2700 compounds, and it is shown that repellency is associated with specific functional groups attached to alkyl, aryl, or heterocyclic nuclei. Functional groups containing nitrogen, sulfur or halogens are most active, with amines, imides, thiocyanates and thiocarbamates forming some of the most active classes. Activity of any functional group may be affected by molecular weight, unsaturation, or spatial configuration of the nucleus, or by the presence of additional substituent groups.

  17. Field evaluation of the efficacy of proprietary repellent formulations with IR3535 and picaridin against Aedes aegypti.

    PubMed

    Naucke, T J; Kröpke, R; Benner, G; Schulz, J; Wittern, K P; Rose, A; Kröckel, U; Grünewald, H W

    2007-06-01

    Seven proprietary repellent formulations (3 hydro-alcoholic spray solutions and 4 skin lotions) with active ingredient IR3,535 (ethyl butylacetylaminopropionate, EBAAP) or Picaridin (hydroxyethyl isobutyl piperidine carboxylate, KBR 3,023, Bayrepel) were tested in a field study on 10 test persons over a period of 10 h for their efficacy at preventing bites. The tests were conducted in Belo Horizonte, Brazil on field populations of the yellow fever mosquito Aedes aegypti. The concentration of the active substances ranged from 10% to 20%. All the tested samples provided lasting protection (time to first bite) over several hours: ranging from 5 h 20 min to 6 h 50 min with a mean of approximately 6 h. The longest protection until the second bite (=first confirmation bite) was approximately 7 h 40 min, whereas the shortest protection was 6 h 50 min. The longest protection until the third bite (=second confirmation bite) was 8 h 35 min, whereas the shortest protection was 7 h 40 min. In the control tests in which none of the samples were applied, the mean times until the first, second and third bites were 26, 46 and 59 min, respectively. The basis for this field study was provided by two American guidelines, which have the greatest international acceptance. The first is a draft guideline from the Environmental Protection Agency (EPA (United States Environmental Protection Agency), Product performance test guidelines. OPPTS 810.3700. Insect repellents for human skin and outdoor premises. Public Draft, 1999) and the second is a standard from the American Society for Testing and Materials (ASTM (American Society for Testing and Materials International), E 939-94 (reapproved 2,000): standard test method of field testing topical applications of compounds as repellents for medically important and pest arthropods (including insects, ticks, and mites): I. Mosquitoes, 2,000). Both guidelines recommend measuring the duration of protection until the first and second bites and also

  18. Field assessment of a novel spatial repellent for malaria control: a feasibility and acceptability study in Mondulkiri, Cambodia.

    PubMed

    Liverani, Marco; Charlwood, Jacques Derek; Lawford, Harriet; Yeung, Shunmay

    2017-10-13

    Large-scale use of insecticide-treated nets and indoor residual spraying have contributed to a significant decrease in malaria transmission worldwide. Further reduction and progress towards elimination, however, require complementary control measures which can address the remaining gaps in protection from mosquito bites. Following the development of novel pyrethroids with high knockdown effects on malaria vectors, programmatic use of spatial repellents has been suggested as one potential strategy to fill the gaps. This report explores social and contextual factors that may influence the relevance, uptake and sustainable use of a spatial repellent in two remote villages in Mondulkiri province, Cambodia, with endemic malaria transmission. The repellent consisted of polyethylene emanators, held in an open plastic frame and impregnated with 10% metofluthrin. In a baseline survey, 90.9% of households in Ou Chra (n = 30/33) and 96.6% in Pu Cha (n = 57/59) were interviewed. Behavioural data were collected for all household occupants (n = 448). In both villages, there were times and places in which people remained exposed to mosquito bites. Prior to the installation of the repellent, 50.6 and 59.5% of respondents noted that bites occurred "very often" inside the house and in the outdoor area surrounding the house, respectively. Indoor biting was reported to occur more frequently in the evening, followed by at night, while outdoor biting occurred more frequently in the early morning. In a follow-up survey, spatial repellents were well received in both villages, although 63.2% of respondents would not replace bed nets with repellents. Most participants (96.6%) were willing to use the product again; the mean willingness to pay was US$ 0.3 per unit. A preference for local procurement methods emerged. Widespread use of spatial repellents would not fill all protective gaps, but, if their entomological efficacy can be ascertained, outdoor application has the potential to

  19. Cosmicflows-3: Cold Spot Repeller?

    SciTech Connect

    Courtois, Hélène M.; Graziani, Romain; Dupuy, Alexandra

    The three-dimensional gravitational velocity field within z ∼ 0.1 has been modeled with the Wiener filter methodology applied to the Cosmicflows-3 compilation of galaxy distances. The dominant features are a basin of attraction and two basins of repulsion. The major basin of attraction is an extension of the Shapley concentration of galaxies. One basin of repulsion, the Dipole Repeller, is located near the anti-apex of the cosmic microwave background dipole. The other basin of repulsion is in the proximate direction toward the “Cold Spot” irregularity in the cosmic microwave background. It has been speculated that a vast void might contributemore » to the amplitude of the Cold Spot from the integrated Sachs–Wolfe effect.« less

  20. Protective efficacy of menthol propylene glycol carbonate compared to N, N-diethyl-methylbenzamide against mosquito bites in Northern Tanzania.

    PubMed

    Kweka, Eliningaya J; Munga, Stephen; Mahande, Aneth M; Msangi, Shandala; Mazigo, Humphrey D; Adrias, Araceli Q; Matias, Jonathan R

    2012-09-05

    The reduction of malaria parasite transmission by preventing human-vector contact is critical in lowering disease transmission and its outcomes. This underscores the need for effective and long lasting arthropod/insect repellents. Despite the reduction in malaria transmission and outcomes in Tanzania, personal protection against mosquito bites is still not well investigated. This study sought to determine the efficacy of menthol propylene glycol carbonate (MR08), Ocimum suave as compared to the gold standard repellent N, N-diethyl-methylbenzamide (DEET), either as a single dose or in combination (blend), both in the laboratory and in the field against Anopheles gambiae s.l and Culex quinquefasciatus. In the laboratory evaluations, repellents were applied on one arm while the other arm of the same individual was treated with a base cream. Each arm was separately exposed in cages with unfed female mosquitoes. Repellents were evaluated either as a single dose or as a blend. Efficacy of each repellent was determined by the number of mosquitoes that landed and fed on treated arms as compared to the control or among them. In the field, evaluations were performed by human landing catches at hourly intervals from 18:00  hr to 01:00  hr. A total of 2,442 mosquitoes were collected during field evaluations, of which 2,376 (97.30%) were An. gambiae s.l while 66 (2.70%) were Cx. quinquefaciatus. MR08 and DEET had comparatively similar protective efficacy ranging from 92% to 100 for both single compound and blends. These findings indicate that MR08 has a similar protective efficacy as DEET for personal protection outside bed nets when used singly and in blends. Because of the personal protection provided by MR08, DEET and blends as topical applicants in laboratory and field situations, these findings suggest that, these repellents could be used efficiently in the community to complement existing tools. Overall, Cx. quinquefasciatus were significantly prevented from blood

  1. Repellent and Larvicidal Activity of the Essential Oil From Eucalyptus nitens Against Aedes aegypti and Aedes albopictus (Diptera: Culicidae).

    PubMed

    Alvarez Costa, Agustín; Naspi, Cecilia V; Lucia, Alejandro; Masuh, Héctor M

    2017-05-01

    Dengue, chikungunya, and yellow fever are important vector-borne diseases transmitted by female mosquitoes when they feed on humans. The use of repellents based on natural products is an alternative for personal protection against these diseases. Application of chemicals with larvicidal activity is another strategy for controlling the mosquito population. The repellent and larvicidal activities of the essential oil from Eucalyptus nitens were tested against Aedes aegypti and Aedes albopictus, the main vectors of these arboviruses. The essential oil was extracted by hydrodistillation and then analyzed by gas chromatography-mass spectrometry. The main components of Eucalyptus nitens essential oil were found to be terpenes such as 1,8-cineole and p-cymene, followed by β-triketones and alkyl esters. The repellent activity of the essential oil against both species was significantly higher when compared with the main component, 1,8-cineole, alone. These results indicate that the repellent effect of E. nitens is not due only to the main component, 1,8-cineole, but also that other compounds may be responsible. Aedes aegypti was found to be more tolerant to the essential oil larvicidal effects than Ae. albopictus (Ae. aegypti LC50 = 52.83 ppm, Ae. albopictus LC 50 = 28.19 ppm). The repellent and larvicidal activity could be associated to the presence of cyclic β-triketones such as flavesone, leptospermone, and isoleptospermone. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Can topical insect repellents reduce malaria? A cluster-randomised controlled trial of the insect repellent N,N-diethyl-m-toluamide (DEET) in Lao PDR.

    PubMed

    Chen-Hussey, Vanessa; Carneiro, Ilona; Keomanila, Hongkham; Gray, Rob; Bannavong, Sihamano; Phanalasy, Saysana; Lindsay, Steven W

    2013-01-01

    Mosquito vectors of malaria in Southeast Asia readily feed outdoors making malaria control through indoor insecticides such as long-lasting insecticidal nets (LLINs) and indoor residual spraying more difficult. Topical insect repellents may be able to protect users from outdoor biting, thereby providing additional protection above the current best practice of LLINs. A double blind, household randomised, placebo-controlled trial of insect repellent to reduce malaria was carried out in southern Lao PDR to determine whether the use of repellent and long-lasting insecticidal nets (LLINs) could reduce malaria more than LLINs alone. A total of 1,597 households, including 7,979 participants, were recruited in June 2009 and April 2010. Equal group allocation, stratified by village, was used to randomise 795 households to a 15% DEET lotion and the remainder were given a placebo lotion. Participants, field staff and data analysts were blinded to the group assignment until data analysis had been completed. All households received new LLINs. Participants were asked to apply their lotion to exposed skin every evening and sleep under the LLINs each night. Plasmodium falciparum and P. vivax cases were actively identified by monthly rapid diagnostic tests. Intention to treat analysis found no effect from the use of repellent on malaria incidence (hazard ratio: 1.00, 95% CI: 0.99-1.01, p = 0.868). A higher socio-economic score was found to significantly decrease malaria risk (hazard ratio: 0.72, 95% CI: 0.58-0.90, p = 0.004). Women were also found to have a reduced risk of infection (hazard ratio: 0.59, 95% CI: 0.37-0.92, p = 0.020). According to protocol analysis which excluded participants using the lotions less than 90% of the time found similar results with no effect from the use of repellent. This randomised controlled trial suggests that topical repellents are not a suitable intervention in addition to LLINs against malaria amongst agricultural populations in

  3. Can Topical Insect Repellents Reduce Malaria? A Cluster-Randomised Controlled Trial of the Insect Repellent N,N-diethyl-m-toluamide (DEET) in Lao PDR

    PubMed Central

    Chen-Hussey, Vanessa; Carneiro, Ilona; Keomanila, Hongkham; Gray, Rob; Bannavong, Sihamano; Phanalasy, Saysana; Lindsay, Steven W.

    2013-01-01

    Background Mosquito vectors of malaria in Southeast Asia readily feed outdoors making malaria control through indoor insecticides such as long-lasting insecticidal nets (LLINs) and indoor residual spraying more difficult. Topical insect repellents may be able to protect users from outdoor biting, thereby providing additional protection above the current best practice of LLINs. Methods and Findings A double blind, household randomised, placebo-controlled trial of insect repellent to reduce malaria was carried out in southern Lao PDR to determine whether the use of repellent and long-lasting insecticidal nets (LLINs) could reduce malaria more than LLINs alone. A total of 1,597 households, including 7,979 participants, were recruited in June 2009 and April 2010. Equal group allocation, stratified by village, was used to randomise 795 households to a 15% DEET lotion and the remainder were given a placebo lotion. Participants, field staff and data analysts were blinded to the group assignment until data analysis had been completed. All households received new LLINs. Participants were asked to apply their lotion to exposed skin every evening and sleep under the LLINs each night. Plasmodium falciparum and P. vivax cases were actively identified by monthly rapid diagnostic tests. Intention to treat analysis found no effect from the use of repellent on malaria incidence (hazard ratio: 1.00, 95% CI: 0.99–1.01, p = 0.868). A higher socio-economic score was found to significantly decrease malaria risk (hazard ratio: 0.72, 95% CI: 0.58–0.90, p = 0.004). Women were also found to have a reduced risk of infection (hazard ratio: 0.59, 95% CI: 0.37–0.92, p = 0.020). According to protocol analysis which excluded participants using the lotions less than 90% of the time found similar results with no effect from the use of repellent. Conclusions This randomised controlled trial suggests that topical repellents are not a suitable intervention in addition to LLINs

  4. Using Insect Repellents Safely and Effectively

    MedlinePlus

    ... Directory Planning, Budget and Results Jobs and Internships Headquarters Offices Regional Offices Labs and Research Centers Related ... repellent product label. This registration number means the company provided EPA with technical information on the effectiveness ...

  5. Regulation of Skin-Applied Repellents

    EPA Pesticide Factsheets

    Before they can be marketed, most insect repellents must be registered by EPA, which indicates they have been evaluated and approved for human safety and effectiveness when applied according to label instructions.

  6. Formation of Soil Water Repellency by Laboratory Burning and Its Effect on Soil Evaporation

    NASA Astrophysics Data System (ADS)

    Ahn, Sujung; Im, Sangjun

    2010-05-01

    Fire-induced soil water repellency can vary with burning conditions, and may lead to significant changes in soil hydraulic properties. However, isolation of the effects of soil water repellency from other factors is difficult, particularly under field conditions. This study was conducted to (i) investigate the effects of burning using different plant leaf materials and (ii) of different burning conditions on the formation of soil water repellency, and (iii) isolate the effects of the resulting soil water repellency on soil evaporation from other factors. Burning treatments were performed on the surface of homogeneous fully wettable sand soil contained in a steel frame (60 x 60 cm; 40 cm depth). As controls a sample without a heat treatment, and a heated sample without fuel, were also used. Ignition and heat treatments were carried out with a gas torch. For comparing the effects of different burning conditions, fuel types included oven-dried pine needles (fresh needles of Pinus densiflora), pine needle litter (litter on a coniferous forest floor, P. densiflora + P. rigida), and broad-leaf litter (Quercus mongolica + Q. aliena + Prunus serrulata var. spontanea + other species); fuel loads were 200 g, 300 g, and 500 g; and heating duration was 40 s, 90 s and 180 s. The heating duration was adjusted to control the temperature, based on previous experiments. The temperature was measured continuously at 3-second intervals and logged with two thermometers. After burning, undisturbed soil columns were sampled for subsequent experiments. Water Drop Penetration Time (WDPT) test was performed at every 1 mm depth of the soil columns to measure the severity of soil water repellency and its vertical extent. Soil water repellency was detected following all treatments. As the duration of heating increased, the thickness of the water repellent layer increased, whilst the severity of soil water repellency decreased. As regards fuel amount, the most severe soil water repellency was

  7. Trends in insect repellent formulations: A review.

    PubMed

    Tavares, Melanie; da Silva, Márcio Robert Mattos; de Oliveira de Siqueira, Luciana Betzler; Rodrigues, Raphaela Aparecida Schuenck; Bodjolle-d'Almeida, Lolita; Dos Santos, Elisabete Pereira; Ricci-Júnior, Eduardo

    2018-03-25

    The use of natural and synthetic repellents, marketed in different pharmaceutical forms, is growing in the world due to the emerging vector-borne viral diseases as Dengue, Zika, Chikungunya, Yellow Fever and Malaria. The choice of the ideal formulation will depend on a series of factors to be analyzed: type of repellent active (natural or synthetic), pharmaceutical forms (spray, lotion, cream, gel), action time duration (short or long), environment of exposure and the user (adult, pregnant women, children, newborn). The most used repellents are DEET, IR3535 (Ethyl Butylacetylaminopropionate) (EB), Icaridin (Picaridin) and essential oils, each of them presenting advantages and disadvantages. DEET is the oldest and the most powerful repellent available in the market, thus being the reference standard. For this reason, there are many classic formulations available in the market containing the chemical component DEET in spray forms and lotions. However, due to its toxicity, DEET is not recommended for children up to 6 months and pregnant women. DEET has been an option along with other market-shared products as IR3535 and Icaridin (Picaridin), which present less toxicity in their composition. IR3535 is the less toxic and may be prescribed for children over 6 months of age and pregnant women so that they have been the best option because of the lower toxicity levels presented. IR3535 is the one that has the lowest toxicity level among the three options and may be prescribed for children above 6 months of age and pregnant women. Icaridin is as potent as DEET, but less toxic, and has the advantage of having the long-lasting action among the aforementioned repellents. The new formulations have been based on controlled release systems (CRS). The CRSs for repellents comprise polymer micro/nanocapsules, micro/solid lipid nanoparticles, nanoemulsions/microemulsions, liposomes/niosomes, nanostructured hydrogels and cyclodextrins. There are many formulations based on micro

  8. Application study of evolutionary operation methods in optimization of process parameters for mosquito coils industry

    NASA Astrophysics Data System (ADS)

    Ginting, E.; Tambunanand, M. M.; Syahputri, K.

    2018-02-01

    Evolutionary Operation Methods (EVOP) is a method that is designed used in the process of running or operating routinely in the company to enables high productivity. Quality is one of the critical factors for a company to win the competition. Because of these conditions, the research for products quality has been done by gathering the production data of the company and make a direct observation to the factory floor especially the drying department to identify the problem which is the high water content in the mosquito incense coil. PT.X which is producing mosquito coils attempted to reduce product defects caused by the inaccuracy of operating conditions. One of the parameters of good quality insect repellent that is water content, that if the moisture content is too high then the product easy to mold and broken, and vice versa if it is too low the products are easily broken and burn shorter hours. Three factors that affect the value of the optimal water content, the stirring time, drying temperature and drying time. To obtain the required conditions Evolutionary Operation (EVOP) methods is used. Evolutionary Operation (EVOP) is used as an efficient technique for optimization of two or three variable experimental parameters using two-level factorial designs with center point. Optimal operating conditions in the experiment are stirring time performed for 20 minutes, drying temperature at 65°C, and drying time for 130 minutes. The results of the analysis based on the method of Evolutionary Operation (EVOP) value is the optimum water content of 6.90%, which indicates the value has approached the optimal in a production plant that is 7%.

  9. Physicians, Primary Caregivers and Topical Repellent: All Under-Utilised Resources in Stopping Dengue Virus Transmission in Affected Households.

    PubMed

    Nguyen, Nguyet Minh; Whitehorn, James S; Luong Thi Hue, Tai; Nguyen Thanh, Truong; Mai Xuan, Thong; Vo Xuan, Huy; Nguyen Thi Cam, Huong; Nguyen Thi Hong, Lan; Nguyen, Hoa L; Dong Thi Hoai, Tam; Nguyen Van Vinh, Chau; Wolbers, Marcel; Wills, Bridget; Simmons, Cameron P; Carrington, Lauren B

    2016-05-01

    Primary health care facilities frequently manage dengue cases on an ambulatory basis for the duration of the patient's illness. There is a great opportunity for specific messaging, aimed to reduce dengue virus (DENV) transmission in and around the home, to be directly targeted toward this high-risk ambulatory patient group, as part of an integrated approach to dengue management. The extent however, to which physicians understand, and can themselves effectively communicate strategies to stop focal DENV transmission around an ambulatory dengue case is unknown; the matter of patient comprehension and recollection then ensues. In addition, the effectiveness of N,N-diethyl-3-methylbenzamide (DEET)-based insect repellent in protecting dengue patients from Aedes aegypti mosquitoes' bites has not been investigated. A knowledge, attitude and practice (KAP) survey, focusing on the mechanisms of DENV transmission and prevention, was performed using semi-structured questionnaires. This survey was targeted towards the patients and family members providing supportive care, and physicians routinely involved in dengue patient management in Southern Vietnam. An additional clinical observational study was conducted to measure the efficacy of a widely-used 13% DEET-based insect repellent to repel Ae. aegypti mosquitoes from the forearms of dengue cases and matched healthy controls. Among both the physician (n = 50) and patient (n = 49) groups there were several respondents lacking a coherent understanding of DENV transmission, leading to some inappropriate attitudes and inadequate acute preventive practices in the household. The application of insect repellent to protect patients and their relatives from mosquito bites was frequently recommended by majority of physicians (78%) participating in the survey. Nevertheless, our tested topical application of 13% DEET conferred only ~1hr median protection time from Ae. aegypti landing. This is notably shorter than that advertised on the

  10. The repellency of lemongrass oil against stable flies, tested using video tracking

    PubMed Central

    Baldacchino, Frédéric; Tramut, Coline; Salem, Ali; Liénard, Emmanuel; Delétré, Emilie; Franc, Michel; Martin, Thibaud; Duvallet, Gérard; Jay-Robert, Pierre

    2013-01-01

    Lemongrass oil (Cymbopogon citratus) is an effective repellent against mosquitoes (Diptera: Culicidae) and house flies (Diptera: Muscidae). In this study, its effectiveness was assessed on stable flies (Diptera: Muscidae) in laboratory conditions. First, we demonstrated that lemongrass oil is an active substance for antennal olfactory receptor cells of Stomoxys calcitrans as indicated by a significant increase in the electroantennogram responses to increasing doses of lemongrass oil. Feeding-choice tests in a flight cage with stable flies having access to two blood-soaked sanitary pads, one of which was treated with lemongrass oil, showed that stable flies (n = 24) spent significantly more time in the untreated zone (median value = 218.4 s) than in the treated zone (median value = 63.7 s). No stable flies fed on the treated pad, whereas nine fed on the untreated pad. These results suggest that lemongrass oil could be used as an effective repellent against stable flies. Additional studies to confirm its spatial repellent and feeding deterrent effects are warranted. PMID:23759542

  11. Synergistic insecticidal and repellent effects of combined pyrethroid and repellent-impregnated bed nets using a novel long-lasting polymer-coating multi-layer technique.

    PubMed

    Faulde, Michael K; Nehring, Oliver

    2012-08-01

    and 2,139 mg/m(2) etofenprox LLIRN, for 72 weeks with the 5,002 mg/m(2) DEET and 2,349 mg/m(2) etofenprox LLIRN, for 63 weeks with the 3,590 mg/m(2) DEET and 1,208 mg/m(2) permethrin LLRN, and for 61 weeks with the 4,711 mg/m(2) DEET and 702 mg/m(2) etofenprox LLIRN. Because 100 % bite protection with up to 75 % quicker contact toxicity of pyrethroids were documented, synergistic toxicological and repellent effects of multi-layer polymer-coating LLIRNs may overcome LLIN-triggered selection pressure for development of new kdr- and metabolic pyrethroid resistances while simultaneously increasing protective efficacy also against kdr- and metabolic pyrethroid-resistant mosquitoes substantially due to the repellent-induced effects of LLIRNs thus indicating that this approach is a promising new candidate for future bed net, curtain, and window screen impregnation aiming at optimized prevention from mosquito-borne diseases.

  12. Behaviors Related to Mosquito-Borne Diseases among Different Ethnic Minority Groups along the China-Laos Border Areas.

    PubMed

    Wu, Chao; Guo, Xiaofang; Zhao, Jun; Lv, Quan; Li, Hongbin; McNeil, Edward B; Chongsuvivatwong, Virasakdi; Zhou, Hongning

    2017-10-15

    Background : In China, mosquito-borne diseases are most common in the sub-tropical area of Yunnan province. The objective of this study was to examine behaviors related to mosquito-borne diseases in different ethnic minority groups and different socioeconomic groups of people living in this region. Methods : A stratified two-stage cluster sampling technique with probability proportional to size was used in Mengla County, Xishuangbanna Prefecture, Yunnan. Twelve villages were used to recruit adult (≥18 years old) and eight schools were used for children (<18 years old). A questionnaire on behaviors and environment variables related to mosquito-borne diseases was devised. Results : Multiple correspondence analysis (MCA) grouped 20 behaviors into three domains, namely, environmental condition, bed net use behaviors, and repellent use behaviors, respectively. The Han ethnicity had the lowest odds of rearing pigs, their odds being significantly lower than those of Yi and Yao. For bed net use, Dai and other ethnic minority groups were less likely to use bed nets compared to Yi and Yao. The odds of repellent use in the Han ethnicity was lower than in Yi, but higher than in Dai. The Dai group was the most likely ethnicity to use repellents. Farmers were at a higher risk for pig rearing and not using repellents. Education of less than primary school held the lowest odds of pig rearing. Those with low income were at a higher risk for not using bed nets and repellent except in pig rearing. Those with a small family size were at a lower risk for pig rearing. Conclusion : Different ethnic and socioeconomic groups in the study areas require different specific emphases for the prevention of mosquito-borne diseases.

  13. Behaviors Related to Mosquito-Borne Diseases among Different Ethnic Minority Groups along the China-Laos Border Areas

    PubMed Central

    Wu, Chao; Guo, Xiaofang; Zhao, Jun; Lv, Quan; Li, Hongbin; McNeil, Edward B.; Chongsuvivatwong, Virasakdi; Zhou, Hongning

    2017-01-01

    Background: In China, mosquito-borne diseases are most common in the sub-tropical area of Yunnan province. The objective of this study was to examine behaviors related to mosquito-borne diseases in different ethnic minority groups and different socioeconomic groups of people living in this region. Methods: A stratified two-stage cluster sampling technique with probability proportional to size was used in Mengla County, Xishuangbanna Prefecture, Yunnan. Twelve villages were used to recruit adults (≥18 years old) and eight schools were used for children (<18 years old). A questionnaire on behaviors and environment variables related to mosquito-borne diseases was devised. Results: Multiple correspondence analysis (MCA) grouped 20 behaviors into three domains, namely, environmental condition, bed net use behaviors, and repellent use behaviors, respectively. The Han ethnicity had the lowest odds of rearing pigs, their odds being significantly lower than those of Yi and Yao. For bed net use, Dai and other ethnic minority groups were less likely to use bed nets compared to Yi and Yao. The odds of repellent use in the Han ethnicity was lower than in Yi, but higher than in Dai. The Dai group was the most likely ethnicity to use repellents. Farmers were at a higher risk for pig rearing and not using repellents. Education of less than primary school held the lowest odds of pig rearing. Those with low income were at a higher risk for not using bed nets and repellent except in pig rearing. Those with a small family size were at a lower risk for pig rearing. Conclusion: Different ethnic and socioeconomic groups in the study areas require different specific emphases for the prevention of mosquito-borne diseases. PMID:29036937

  14. Control of deer damage with chemical repellents in regenerating hardwood stands

    Treesearch

    Brian J. MacGowan; Larry Severeid; Fred, Jr. Skemp

    2004-01-01

    Wildlife damage can be a major problem in natural tree regeneration or tree plantings. In the North Central Hardwoods region, white-tailed deer (Odocoileus virginianus) are a significant cause of damage to hardwood seedlings. We evaluated the use of a combination of chemical repellents (Hinder®, Tree Guard®, chicken eggs, and...

  15. Improving rangeland seeding success in post-fire water repellent soil using surfactant seed coating technology

    USDA-ARS?s Scientific Manuscript database

    Severe disturbance from catastrophic wildfires often requires that native plant materials be reintroduced through reseeding, but the success rate of these restoration efforts in arid environments is notoriously low. Post-fire soil water repellency can limit reseeding success by decreasing soil moist...

  16. Greek Pinus essential oils: larvicidal activity and repellency against Aedes albopictus (Diptera: Culicidae).

    PubMed

    Koutsaviti, Katerina; Giatropoulos, Athanassios; Pitarokili, Danae; Papachristos, Dimitrios; Michaelakis, Antonios; Tzakou, Olga

    2015-02-01

    The needle volatiles metabolites of seven Pinus spp.: Pinus nigra (3 samples), Pinus stankewiczii, Pinus brutia, Pinus halepensis, Pinus canariensis, Pinus pinaster and Pinus strobus from Greece were determined by gas chromatography and gas chromatography-mass spectrometry. P. nigra and P. canariensis essential oils were dominated by α-pinene (24.9-28.9 % and 15 %, respectively) and germacrene D (20.3-31.9 % and 55.8 %, respectively), whereas P. brutia and P. strobus by α-pinene (20.6 % and 31.4 %, respectively) and β-pinene (31.7 % and 33.6 %, respectively). P. halepensis and P. pinaster oils were characterized by β-caryophyllene (28.5 % and 22.5 %, respectively). Finally, β-pinene (31.4 %), germacrene D (23.3 %) and α-pinene (17.5 %) were the most abundant compounds in the needle oil of P. stankewiczii. Additionally the larvicidal and repellent properties of their essential oils were evaluated against Aedes albopictus, a mosquito of great ecological and medical importance. The results of bioassays revealed that repellent abilities of the tested essential oils were more potent than their larvicidal activities. The essential oils of P. brutia, P. halepensis and P. stankewiczii presented considerable larvicidal activity (LC50 values 67.04 mgL(-1) and 70.21 mgL(-1), respectively), while the others were weak to inactive against larvae. The essential oils of P. halepensis, P. brutia, and P. stankewiczii presented a high repellent activity, even at the dose of 0.2 μL cm(-2), while in the dose of 0.4 μL cm(-2), almost all the tested EOs displayed protection against the mosquito.

  17. Effectiveness of Gel Repellents on Feral Pigeons

    PubMed Central

    Stock, Birte; Haag-Wackernagel, Daniel

    2013-01-01

    Simple Summary Feral pigeons live in close association in urban areas. They constitute serious health risks to humans and also lead to high economic loss due to costly damage to buildings, historic monuments, statues and even vegetation. While numerous avian repellent systems are regularly introduced onto the market, scientific proof of efficacy and their use from the point of view of animal welfare is lacking. Therefore, two avian gel repellents were studied on free-living feral pigeons in this study. The focus was set on repellent efficacy and animal welfare concerns. This study’s aim is to contribute to a better understanding of feral pigeon management in our cities. Abstract Millions of feral pigeons (Columba livia) live in close association with the human population in our cities. They pose serious health risks to humans and lead to high economic loss due to damage caused to buildings. Consequently, house owners and city authorities are not willing to allow pigeons on their buildings. While various avian repellents are regularly introduced onto the market, scientific proof of efficacy is lacking. This study aimed at testing the effectiveness of two avian gel repellents and additionally examined their application from animal welfare standpoint. The gels used an alleged tactile or visual aversion of the birds, reinforced by additional sensory cues. We mounted experimental shelves with the installed repellents in a pigeon loft and observed the behavior of free-living feral pigeons towards the systems. Both gels showed a restricted, transient repellent effect, but failed to prove the claimed complete effectiveness. Additionally, the gels’ adhesive effect remains doubtful in view of animal welfare because gluing of plumage presents a risk to feral pigeons and also to other non-target birds. This study infers that both gels lack the promised complete efficacy, conflict with animal welfare concerns and are therefore not suitable for feral pigeon management in

  18. Repellence produced by monoterpenes on Rhodnius prolixus (Hemiptera: Reduviidae) decreases after continuous exposure to these compounds.

    PubMed

    Lutz, Alejandra; Sfara, Valeria; Alzogaray, Raúl Adolfo

    2014-01-01

    Botanical monoterpenes are secondary metabolites present in essential oils produced by plants. Some of them are insect repellents. The bloodsucking bug Rhodnius prolixus Ståhl (Hemiptera: Reduviidae) is one of the main vectors of Chagas disease in the north of South America and some countries in Central America. In this study, we studied the repellence produced by two monoterpenes, menthyl acetate and geraniol, on fifth instar nymphs of R. prolixus. In the absence of other stimuli, both menthyl acetate and geraniol produced a repellent effect from 740 μg/cm(2) and 74 μg/cm(2), respectively. Pre-exposure to each monoterpene reduced the repellent activity produced by the same substance. Additionally, pre-exposure to one monoterpene decreased the behavioral response of the nymphs to the other one. The repellent effect of both monoterpenes also decreased when nymphs' antennae were previously treated with the nitric oxide donor S-nitroso-N-acetyl-cysteine. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  19. Repellence Produced by Monoterpenes on Rhodnius prolixus (Hemiptera: Reduviidae) Decreases After Continuous Exposure to These Compounds

    PubMed Central

    Lutz, Alejandra; Sfara, Valeria; Alzogaray, Raúl Adolfo

    2014-01-01

    Abstract Botanical monoterpenes are secondary metabolites present in essential oils produced by plants. Some of them are insect repellents. The bloodsucking bug Rhodnius prolixus Ståhl (Hemiptera: Reduviidae) is one of the main vectors of Chagas disease in the north of South America and some countries in Central America. In this study, we studied the repellence produced by two monoterpenes, menthyl acetate and geraniol, on fifth instar nymphs of R. prolixus . In the absence of other stimuli, both menthyl acetate and geraniol produced a repellent effect from 740 μg/cm 2 and 74 μg/cm 2 , respectively. Pre-exposure to each monoterpene reduced the repellent activity produced by the same substance. Additionally, pre-exposure to one monoterpene decreased the behavioral response of the nymphs to the other one. The repellent effect of both monoterpenes also decreased when nymphs’ antennae were previously treated with the nitric oxide donor S-nitroso-N-acetyl-cysteine. PMID:25525113

  20. Insecticidal and insect-repellent activities of essential oils from Verbenaceae and Anacardiaceae against Rhizopertha dominica.

    PubMed

    Benzi, Verónica S; Murrayb, Ana P; Ferrero, Adriana A

    2009-09-01

    Essential oils extracted from leaves of Aloysia polystachya and A. citriodora (Verbenaceae) and from leaves and fruits of Schinus molle var. areira (Anacardiaceae) were tested for their repellent and toxic activities against adults of Rhizopertha dominica (Coleoptera: Bostrichidae). Topical application and filter paper assays were employed for contact toxicity studies; filter paper impregnation was also used for fumigant and repellent assays. In topical tests A. polystachya was as effective as S. molle leaves. In the case of repellent assays, A. citriodora was the most effective oil based on the class scale. A. polystachya was the most toxic plant on contact toxicity by filter paper assay (LC50 26.6 mg/cm2). Fumigant toxicity was only evaluated with fruits and leaves of S. molle, and no significant differences were found between them. Published data are included to compare the fumigant toxicity of S. molle with that of A. citridora and A. polystachya.

  1. The Effect of Early Mosquito Insecticides Exposure on Spraque Dawley Rat Testis: A Histopathological Feature Towards Malignancy?

    NASA Astrophysics Data System (ADS)

    Indah Winarni, Tri; Auzan Aziman, Milzam; Abshar Andar, Anindyo; Pawitra, Ika

    2017-02-01

    The incidence of health problems associated with endocrine-disruption have increased. Many studies suggesting that endocrine disruptor chemicals (EDC) do contribute to cancer through estrogen-related receptors. Many chemicals have EDCs properties including insecticides. Early life exposure to EDCs can increased the risk of testicular cancer have been reported in the last decade. This study was aimed to determine the effect of insecticides exposure on histopathological tumor cell development of germ and Leydig cell. True experiment research design with posttest only control group design was applied. Sprague Dawley (SD) rat (n = 25) were randomly divided into 5 groups (control group, 25 mg β estradiol 3-benzoate, spiral mosquito coil repellent, 3 ml of liquid mosquito repellent, and 4 ml of liquid mosquito repellent). The exposure were administered for 20 days started at aged 3 days. At the age of 100 days (older adult), testis was stained using Hematoxyllin Eosin (HE) and histological features predicting malignancy were observed. The number of tumor cell development in both testicular germ cells and Leydig cells significantly increased in all treated group compared to those of control and the changes towards malignancy were also observed in all treated group. Exposure to mosquito insecticides causes significant changes in testicular germ and Leydig cell histological features that leads to malignancy.

  2. Repellency of selected chemicals against the bed bug (Hemiptera: Cimicidae).

    PubMed

    Wang, Changlu; Lü, Lihua; Zhang, Aijun; Liu, Chaofeng

    2013-12-01

    In recent years, the common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), became a major public health concern in urban communities. Bed bugs are notoriously difficult to control, and their bites are not tolerated by most people. The public has an urgent need for materials and methods to reduce bed bug introduction and bites during work, travel, or sleep. A repellent product will help achieve these goals by discouraging and preventing bed bugs from moving to a protected area. We evaluated the repellency of three commercially available insect repellent or control materials and five nonregistered materials with the goal of identifying safe and effective bed bug repellents. The two commercial repellent products that contained 7% picaridin or 0.5% permethrin had little repellency against bed bugs. N,N-diethyl-m-toluamide (DEET), the most commonly used insect repellent, provided a high level of repellency against bed bugs. When a host cue (carbon dioxide) was present, the minimum DEET concentration to repel > or = 94% of the bed bugs for a9-h period was 10%. The longevity of repellency of DEET was concentration dependent. At 25% concentration, DEET-treated fabric surface remained highly repellent to bed bugs for a 14-d period. However, DEET has a strong smell and dissolves certain plastic materials. Therefore, we evaluated several odorless, noncorrosive, and potentially effective repellents. Isolongifolenone and isolongifolanone, two natural products and recently reported insect repellents, exhibited strong repellent property against bed bugs but at significantly lower levels than DEET. Three novel potential repellent compounds discovered by Bedoukian Research Inc. (Danbury, CT) exhibited similar level of repellency and longevity as DEET for repelling bed bugs. These nonirritant and odorless compounds are promising candidates as alternatives to DEET for reducing the spread of bed bugs and bed bug bites.

  3. Repellent and deterrent effects of SS220, Picaridin, and Deet suppress human blood feeding by Aedes aegypti, Anopheles stephensi, and Phlebotomus papatasi.

    PubMed

    Klun, Jerome A; Khrimian, Ashot; Debboun, Mustapha

    2006-01-01

    A series of behavioral tests with Aedes aegypti (L.), Anopheles stephensi Liston, mosquitoes, and the sand fly Phlebotomus papatasi Scopoli in the presence of Deet, SS220, and Picaridin topically applied to the skin of human volunteers showed that the insects were deterred from feeding on and repelled from surfaces emanating the compounds. When offered a 12- or 24-cm2 area of skin, one-half treated with compound and one-half untreated, the insects fed almost exclusively on untreated skin. The sand flies and mosquitoes did not at any time physically contact chemically treated surfaces. When treated and untreated skin areas were covered with cloth, insects contacted, landed, and bit only through cloth covering untreated skin. These observations provided evidence that the compounds deterred feeding and repelled insects from treated surfaces primarily as a result of olfactory sensing. When cloth, one-half untreated and one-half treated with chemical, was placed over untreated skin, insects only touched and specifically bit through the untreated cloth. This showed that the activity of the chemicals does not involve a chemical x skin interaction. In the presence of any of the three chemicals, no matter how they were presented to the insects, overall population biting activity was reduced by about one-half relative to controls. This reduction showed a true repellent effect for the compounds. Results clearly showed that Deet, SS220, and Picaridin exert repellent and deterrent effects upon the behavior of mosquitoes and sand flies. Heretofore, the combined behavioral effects of these compounds upon mosquito and sand fly behavior were unknown. Moreover, protection afforded by Deet, SS220, and Picaridin against the feeding of these three disease vectors on humans is mechanistically a consequence of the two chemical effects.

  4. Spatial Repellency and the Field Evaluation of a Push-Pull Strategy for the Control of Malaria Vectors in Northern Belize, Central America

    DTIC Science & Technology

    2014-09-18

    monitoring of knocked down mosquitoes. To control for residual chemical contamination from repellent treatments, all huts and interception traps were...to discontinue any ongoing trial if the institution is found to have contravened any of the above conditions. 7. The applicant shall cover food ...albopictus (Skuse) from Selangor, Malaysia . Trap Biomed 30:220-30 31. Cherington E, Ek E, Cho P, Burgess F, Hernandez B, et al. 2010. Forest Cover and

  5. Joint Statement on Insect Repellents by EPA and CDC

    EPA Pesticide Factsheets

    The EPA and the CDC are recommending the public to use insect repellents and take other precautions to avoid biting insects that carry serious diseases. This statement discusses diseases of concern, government roles, and repellent selection and use.

  6. Repellence and toxicity of Schinus molle extracts on Blattella germanica.

    PubMed

    Ferrero, A A; Chopa, C Sánchez; González, J O Werdin; Alzogaray, R A

    2007-06-01

    The biological activities of ethanol and petroleum ether extracts from leaves and fruits of Schinus molle against adults of Blattella germanica were examined by repellence test and topical application. All extracts produced significant repellent effect and mortality.

  7. Water repellent soils: a state-of-the-art

    Treesearch

    Leonard F. DeBano

    1981-01-01

    Water repellency in soils was first described by Schreiner and Shorey (1910), who found that some soils in California could not be wetted and thereby were not suitable for agriculture. Waxy organic substances were responsible for the water repellency. Other studies in the early 1900's on the fairy ring phenomenon suggested that water repellency could be caused by...

  8. Ceramic coatings for water-repellent textiles

    NASA Astrophysics Data System (ADS)

    Colleoni, C.; Esposito, F.; Guido, E.; Migani, V.; Trovato, V.; Rosace, G.

    2017-10-01

    In recent years, ceramic coatings have been widely studied for their potential performance in many scientific and technological fields. Ceramic coatings are also used as a textile-finishing agent to impart several properties such as anti-bacterial, anti-abrasion, flame retardant. In this study, fluoro free water repellent finishings have been developed to assess the features of the silica films on the textile fabrics. The water repellency of the treated samples has been evaluated by different tests such as water contact angle, water uptake and drop test.

  9. Physicians, Primary Caregivers and Topical Repellent: All Under-Utilised Resources in Stopping Dengue Virus Transmission in Affected Households

    PubMed Central

    Nguyen, Nguyet Minh; Whitehorn, James S.; Luong Thi Hue, Tai; Nguyen Thanh, Truong; Mai Xuan, Thong; Vo Xuan, Huy; Nguyen Thi Cam, Huong; Nguyen Thi Hong, Lan; Nguyen, Hoa L.; Dong Thi Hoai, Tam; Nguyen Van Vinh, Chau; Wolbers, Marcel; Wills, Bridget; Simmons, Cameron P.; Carrington, Lauren B.

    2016-01-01

    Background Primary health care facilities frequently manage dengue cases on an ambulatory basis for the duration of the patient’s illness. There is a great opportunity for specific messaging, aimed to reduce dengue virus (DENV) transmission in and around the home, to be directly targeted toward this high-risk ambulatory patient group, as part of an integrated approach to dengue management. The extent however, to which physicians understand, and can themselves effectively communicate strategies to stop focal DENV transmission around an ambulatory dengue case is unknown; the matter of patient comprehension and recollection then ensues. In addition, the effectiveness of N,N-diethyl-3-methylbenzamide (DEET)-based insect repellent in protecting dengue patients from Aedes aegypti mosquitoes’ bites has not been investigated. Methodology A knowledge, attitude and practice (KAP) survey, focusing on the mechanisms of DENV transmission and prevention, was performed using semi-structured questionnaires. This survey was targeted towards the patients and family members providing supportive care, and physicians routinely involved in dengue patient management in Southern Vietnam. An additional clinical observational study was conducted to measure the efficacy of a widely-used 13% DEET-based insect repellent to repel Ae. aegypti mosquitoes from the forearms of dengue cases and matched healthy controls. Principal Findings Among both the physician (n = 50) and patient (n = 49) groups there were several respondents lacking a coherent understanding of DENV transmission, leading to some inappropriate attitudes and inadequate acute preventive practices in the household. The application of insect repellent to protect patients and their relatives from mosquito bites was frequently recommended by majority of physicians (78%) participating in the survey. Nevertheless, our tested topical application of 13% DEET conferred only ~1hr median protection time from Ae. aegypti landing. This is

  10. The repellent and persistent toxic effects of essential oils against the poultry red mite, Dermanyssus gallinae.

    PubMed

    Nechita, I S; Poirel, M T; Cozma, V; Zenner, L

    2015-12-15

    The economic impact of the poultry red mite, Dermanyssus gallinae, the lack of new acaricides, the occurrence of resistance and tighter legislation have all led to the need to find new ways to control this pest. One promising alternative method of control focuses on employing repellent and/or toxic effects of selected plant essential oils against D. gallinae. Ten essential oils (basil, thyme, coriander, eucalyptus, lavender, lemon, fir tree, oregano, mint, and juniper) were tested for the persistence of toxic and repellent effects. In filter-paper toxicity bioassays against D. gallinae, the best results were observed for lavender (more than 97% mortality after 48 and 72 h) and thyme (84% at 72 h) at a dose of 0.12 mg/cm(2). In addition, two oils showed significant persistent toxic effects 15 and 30 days post application to filter papers. Thyme was the most effective (100% mortality at 72 h), followed by lavender (nearly 80% mortality after 72 h). Out of the ten oils tested for their repellent effect, thyme was the strongest, with nearly 80% of the tested area avoided by mites; oregano caused a 60% avoidance and lavender exhibited an effect close to 40%. All other oils exhibited a repellent effect of less than 30%. None of the experiments showed a repellent effect for HM (commercial alimentary oil) or negative controls. We found that the thyme and lavender essential oils exhibited promising results when tested in vitro for toxic and repellent effects against D. gallinae; thus, we suggest that future experiments focus on in vivo tests using these oils in farm units. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Repellent activity of essential oils and some of their individual constituents against Tribolium castaneum herbst.

    PubMed

    Caballero-Gallardo, Karina; Olivero-Verbel, Jesús; Stashenko, Elena E

    2011-03-09

    A tool for integrated pest management is the use of essential oils (EOs) and plant extracts. In this study, EOs from Tagetes lucida , Lepechinia betonicifolia , Lippia alba , Cananga odorata , and Rosmarinus officinalis , species grown in Colombia, were analyzed by gas chromatography-mass spectrometry. These oils as well as several of their constituents were tested for repellent activity against Tribolium castaneum , using the area preference method. The main components (>10%) found in EOs were methylchavicol, limonene/α-pinene, carvone/limonene, benzyl acetate/linalool/benzyl benzoate, and α-pinene, for T. lucida, L. betonicifolia, L. alba, C. odorata, and R. officinalis, respectively. All EOs were repellent, followed a dose-response relationship, and had bioactivity similar to or better than that of commercial compound IR3535. EOs from C. odorata and L. alba were the most active. Compounds from EOs, such benzyl benzoate, β-myrcene, and carvone, showed good repellent properties. In short, EOs from plants cultivated in Colombia are sources of repellents against T. castaneum.

  12. Application of minidisk infiltrometer to estimate soil water repellency

    NASA Astrophysics Data System (ADS)

    Alagna, Vincenzo; Iovino, Massimo; Bagarello, Vincenzo; Mataix-Solera, Jorge; Lichner, Ľubomír

    2016-04-01

    Soil water repellency (SWR) reduces affinity of soils to water resulting in detrimental implication for plants growth as well as for hydrological processes. During the last decades, it has become clear that SWR is much more widespread than formerly thought, having been reported for a wide variety of soils, land uses and climatic conditions. The repellency index (RI), based on soil-water to soil-ethanol sorptivity ratio, was proposed to characterize subcritical SWR that is the situation where a low degree of repellency impedes infiltration but does not prevent it. The minidisk infiltrometer allows adequate field assessment of RI inherently scaled to account for soil physical properties other than hydrophobicity (e.g., the volume, connectivity and the geometry of pores) that directly influence the hydrological processes. There are however some issues that still need consideration. For example, use of a fixed time for both water and ethanol sorptivity estimation may lead to inaccurate RI values given that water infiltration could be negligible whereas ethanol sorptivity could be overestimated due to influence of gravity and lateral diffusion that rapidly come into play when the infiltration process is very fast. Moreover, water and ethanol sorptivity values need to be determined at different infiltration sites thus implying that a large number of replicated runs should be carried out to obtain a reliable estimate of RI for a given area. Minidisk infiltrometer tests, conducted under different initial soil moisture and management conditions in the experimental sites of Ciavolo, Trapani (Italy) and Javea, Alicante (East Spain), were used to investigate the best applicative procedure to estimate RI. In particular, different techniques to estimate the water, Sw, and ethanol, Se, sorptivities were compared including i) a fixed 1-min time interval, ii) the slope of early-time 1D infiltration equation and iii) the two-term transient 3D infiltration equation that explicitly

  13. Thermodynamics of cell adhesion. II. Freely mobile repellers.

    PubMed Central

    Torney, D C; Dembo, M; Bell, G I

    1986-01-01

    The equilibrium adhesion of a cell or vesicle to a substrate is analyzed in a theoretical model in which two types of mobile molecules in the cell membrane are of interest: receptors that can form bonds with fixed ligands in the substrate and repellers that repel the substrate. If the repulsion between the repeller molecule and substrate is greater than kT, there is substantial redistribution of the repellers from the contact area. Coexisting equilibrium states are observed having comparable free energies (a) with unstretched bonds and repeller redistribution and (b) with stretched bonds and partial redistribution. PMID:3955182

  14. Neurophysiological Study of Vector Responses to Repellents.

    DTIC Science & Technology

    1979-08-01

    The Al sensilla responded weakly or not at all to oviposition site attractants and the repellent series. Citronellol and geraniol induced a decrease...612 - 0/++ -- ++/0 + + 0 SRI-C6 - 0/-- - /++ ++ 0 0 2504-5 0/- 0 0 0 0 Citronellol 0/++ 0 - 0 Geraniol 0 - - 0 0 Naphthalene 0 0 0 0 Juglone + + +4

  15. Water repellency and dimensional stability of wood

    Treesearch

    Roger M. Rowell; W. Bart Banks

    1985-01-01

    A discussion of the interaction between wood and water makes clear the distinction between water repellency of wood (a rate of change) and dimensional stability (a level of equilibrium). A review of methods of treating wood follows, leading to comparison of their effectiveness, description of test procedures to evaluate treatments, and discussion of deficiencies of the...

  16. Effects of soil water repellency on microbial community structure and functions in Mediterranean pine forests

    NASA Astrophysics Data System (ADS)

    Lozano, Elena; Grayston, Sue J.; Mataix-Solera, Jorge; Arcenegui, Victoria; Jimenez-Pinilla, Patricia; Mataix-Beneyto, Jorge

    2015-04-01

    results suggest a possible influence of SWR on microbial structure and its activity in soils. References: Lozano, E., García-Orenes, F., Bárcenas-Moreno, G., Jiménez-Pinilla, P., Mataix-Solera, J., Arcenegui, V., Morugán-Coronado, A., Mataix-Beneyto, J., 2014. Relationships between soil water repellency and microbial community composition under different plant species in a Mediterranean semiarid forest. J. Hydrol. Hydromech., 62, 101-107 Müller, K., Deurer, M., Newton, P.C.D., 2010. Is there a link between elevated atmospheric carbon dioxide concentration, soil water repellency and soil carbon mineralization? Agric. Ecosyst. Environ., 139, 98-109. Acknowledgements: to the "Ministerio de Economía and Competitividad" of Spanish Government for finance the POSTFIRE project (CGL2013- 47862-C2-1-R), Generalitat Valenciana for PhD grant, and Spanish Soil Science Society and FUEGORED for their support.

  17. Arbovirus Prevalence in Mosquitoes, Kenya

    PubMed Central

    Sutherland, Laura J.; Muiruri, Samuel; Muchiri, Eric M.; Gray, Laurie R.; Zimmerman, Peter A.; Hise, Amy G.; King, Charles H.

    2011-01-01

    Few studies have investigated the many mosquito species that harbor arboviruses in Kenya. During the 2006–2007 Rift Valley fever outbreak in North Eastern Province, Kenya, exophilic mosquitoes were collected from homesteads within 2 affected areas: Gumarey (rural) and Sogan-Godud (urban). Mosquitoes (n = 920) were pooled by trap location and tested for Rift Valley fever virus and West Nile virus. The most common mosquitoes trapped belonged to the genus Culex (75%). Of 105 mosquito pools tested, 22% were positive for Rift Valley fever virus, 18% were positive for West Nile virus, and 3% were positive for both. Estimated mosquito minimum infection rates did not differ between locations. Our data demonstrate the local abundance of mosquitoes that could propagate arboviral infections in Kenya and the high prevalence of vector arbovirus positivity during a Rift Valley fever outbreak. PMID:21291594

  18. Management of water repellency in Australia, and risks associated with preferential flow, pesticide concentration and leaching

    NASA Astrophysics Data System (ADS)

    Blackwell, P. S.

    2000-05-01

    The three most westerly states of southern Australia have the largest area of water repellent soils, which limit agricultural production, of any country in the world. Simplified principles of the problems caused by repellency and the principles of soil management solutions are considered and related to experimental evidence. The phenomena of diverted soil water flow and isolated dry soil can explain most of the problems caused by repellency. Plant adaptation, soil or hydrophobic removal, reduced soil drying, reduced surface tension, water harvesting, avoidance, masking and, perhaps, water movement along dead root systems are the main soil management principles. Dead roots may play a role in zero till cropping systems, allowing more uniform wetting of dry hydrophobic soil at the base of a dead plant and along the dendritic pattern of the dead root system. Application of these management principles, especially water harvesting, avoidance and masking (by the use of deep trenching, furrow sowing methods or claying), have made a considerable improvement to sustainability and productivity of farming systems on the water repellent soils of Australia. Evidence is selected to assess risks of preferential flow, pesticide concentration and leaching for different agricultural soil management methods. All management methods can have some risks, but claying seems to have the least risk and furrowing the highest risk of encouraging preferential flow, pesticide concentration and leaching. It is suggested we have insufficient information and understanding to quantify the risks of groundwater contamination for different environments, farming systems and soil management methods to control repellency. There is an urgent need to develop quantified guidelines to minimise any possible groundwater contamination hazard for the extensive areas using farming systems with furrows and increasing amounts of pesticide and fertiliser.

  19. Failure of interior residual sprays as protection against mosquitoes in military-issued two-man tents.

    PubMed

    Morrow, Meredith G; Johnson, Richard N; Polanco, Jorge; Claborn, David M

    2010-12-01

    Most studies on interior (or indoor) residual spraying (IRS) have been targeted on permanent/semipermanent structures. We measured the utility of a portable field bioassay, which can be set up quickly to determine the best chemical repellent or irritant for use as an IRS during an emergency or military situation when displaced persons are temporarily housed in tents. If the bioassay were used over an extended period of time, it would also offer a unique way to monitor vector susceptibility and would be able to determine which chemical is most efficient in individual populations. In total, 2193 mosquitoes belonging to seven species in five genera were collected over the study period. No statistical differences were found between any of the treatments, control, and standard tents utilizing the 4 x 4 Latin square design. Therefore, we conclude that IRS with these tested chemicals in military-issued two-person tents are not effective or significant at stopping mosquito entrance. Further studies on implementation of a portable, field bioassay should include utilizing different mosquito traps in the bioassay and looking at the difference between contact irritants and spatial repellents in different-sized tents, as spatial repellency may be more important in smaller-sized tents.

  20. Attractiveness of volatiles from different body parts to the malaria mosquito Anopheles coluzzii is affected by deodorant compounds

    PubMed Central

    Verhulst, Niels O.; Weldegergis, Berhane T.; Menger, David; Takken, Willem

    2016-01-01

    Mosquitoes display biting preferences among different sites of the human body. In addition to height or convection currents, body odour may play a role in the selection of these biting sites. Previous studies have shown that skin emanations are important host-finding cues for mosquitoes. In this study, skin emanations were collected from armpits, hands and feet; the volatile profiles were analysed and tested for their attractiveness to the malaria mosquito Anopheles coluzzii. Skin emanations collected from armpits were less attractive to An. coluzzii compared to hands or/and feet. The difference may have been caused by deodorant residues, which were found in the armpit samples and not in those of hands and feet. In a subsequent experiment, volunteers were asked to avoid using skincare products for five days, and thereafter, no differences in attractiveness of the body parts to mosquitoes were found. The detected deodorant compound isopropyl tetradecanoate inhibited mosquito landings in a repellent bioassay. It is concluded that the volatiles emanated from different body parts induced comparable levels of attraction in mosquitoes, and that skincare products may reduce a person’s attractiveness to mosquitoes. PMID:27251017

  1. Attractiveness of volatiles from different body parts to the malaria mosquito Anopheles coluzzii is affected by deodorant compounds.

    PubMed

    Verhulst, Niels O; Weldegergis, Berhane T; Menger, David; Takken, Willem

    2016-06-01

    Mosquitoes display biting preferences among different sites of the human body. In addition to height or convection currents, body odour may play a role in the selection of these biting sites. Previous studies have shown that skin emanations are important host-finding cues for mosquitoes. In this study, skin emanations were collected from armpits, hands and feet; the volatile profiles were analysed and tested for their attractiveness to the malaria mosquito Anopheles coluzzii. Skin emanations collected from armpits were less attractive to An. coluzzii compared to hands or/and feet. The difference may have been caused by deodorant residues, which were found in the armpit samples and not in those of hands and feet. In a subsequent experiment, volunteers were asked to avoid using skincare products for five days, and thereafter, no differences in attractiveness of the body parts to mosquitoes were found. The detected deodorant compound isopropyl tetradecanoate inhibited mosquito landings in a repellent bioassay. It is concluded that the volatiles emanated from different body parts induced comparable levels of attraction in mosquitoes, and that skincare products may reduce a person's attractiveness to mosquitoes.

  2. Repellent and fumigant toxicity of essential oil from Thymus persicus against Tribolium castaneum and Callosobruchus maculatus.

    PubMed

    Moharramipour, S; Taghizadeh, A; Meshkatalsadat, M H; Talebi, A A; Fathipour, Y

    2008-01-01

    Repellent and insecticidal activity of the essential oil extracted from Thymus persicus (Roniger ex Reach. F.) Jalas was evaluated against two stored-product beetles Tribolium castaneum (Herbst) and Callosobruchus maculatus (F.). Dry flowering aerial parts of the plant were subjected to hydro distillation using a modified Clevenger-type apparatus. The repellent and fumigant toxicity were tested against 1-7 days old adult beetles at 27 +/- 1 degrees C and 65 +/- 5% RH in dark condition. The repellency on C. maculatus and T. castaneum at highest concentration (2 microL/mL acetone) was 82.40% and 70.40% respectively. Fumigation bioassays showed that C. maculatus adults were significantly more susceptible (LC50 = 2.39 microL/L air) to the essential oil than T. castaneum adults (LC50 = 234.42 microL/L air). It could be concluded that T. persicus may have potential for applications in management of stored-product pests because of its safety, strong repellency and fumigant toxicity.

  3. N,N-diethyl phenylacetamide (DEPA): A safe and effective repellent for personal protection against hematophagous arthropods.

    PubMed

    Kalyanasundaram, Muthuswami; Mathew, Nisha

    2006-05-01

    Repellents play an important role in protecting humans from the bites of insect pests. An effective and safe repellent will be useful in reducing human-vector contact and thereby help in the interruption of vector borne disease transmission. Because of the unavailability of m-toluic acid in India for the manufacture of N,N-diethyl m-toluamide (DEET), there is a need to develop an alternate effective and safe insect repellent. In total, 120 substituted amides were synthesized and tested for repellency at 1.0 mg/cm2 under laboratory conditions. Among these amides, N,N-diethyl phenylacetamide (DEPA), applied at 1.0 mg/cm2 in different oil bases, was found to exhibit promising repellency (6-8 h) in the laboratory when tested against Aedes aegypti (L.) The repellent DEPA was evaluated on army personnel in comparison with dimethylphthalate (DMP) and DEET against mosquitoes, black flies, and land leeches under field condition in the North-East Frontier area of India. Both DEPA and DEET displayed broad-spectrum repellency. DEPA was more effective than DMP against all test organisms. However, no significant difference was noticed between DEPA and DEET for repellency at 0.25 and 0.5 mg/cm2 against black flies and mosquitoes. DMP was the least effective among the three compounds in the field studies. The relative potency of DEPA in comparison with DEET and DMP for repellency against Phlebotomine sand flies also was determined. At 0.1 mg/cm2, both DEPA and DEET were found to be equally effective with a protection time from 4.37 +/- 0.08 to 4.45 +/- 0.15 h. Both compounds were significantly more effective than DMP. At 0.2 mg/cm2, DEPA and DEET provided protection times of 6.52 +/- 0.08 and 7.15 +/- 0.15 h, respectively. DEPA was formulated into a vanishing cream, a pharmacologically safe polymer-based liquid, and a liposphere lotion. The vanishing cream and the two-polymer liquid formulations enhanced protection times from 4.4 to 6.5 and 7.13 h, respectively, compared with an

  4. Composition and repellency of the essential oils of Evodia calcicola Chun ex Huang and Evodia trichotoma (Lour.) Pierre against three stored product insects.

    PubMed

    Yang, Kai; You, Chun-Xue; Wang, Cheng-Fang; Guo, Shan-Shan; Li, Yin-Ping; Wu, Yan; Geng, Zhu-Feng; Deng, Zhi-Wei; Du, Shu-Shan

    2014-01-01

    During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oils of Evodia calcicola and Evodia trichotoma leaves were found to possess strong repellency against the red flour beetle Tribolium castaneum adults, the cigarette beetle Lasioderma serricorne adults and the booklouse Liposcelis bostrychophila. The two essential oils obtained by hydrodistillation were investigated by GC-MS. The main components of E. calcicola essential oil were identified to be (-)-β-pinene (44.02%), β-phellandrene (20.93%), ocimene (16.49%), and D-limonene (9.87%). While the main components of the essential oil of E. trichotoma were D-limonene (69.55%), 1R-a-pinene (11.48%), caryophyllene (2.80%) and spathulenol (2.24%). Data showed that T. castaneum was the most sensitive than other two stored product insects. Compared with the positive control, DEET (N, N-diethyl-3- methylbenzamide), the two essential oils showed the same level repellency against the red flour beetle. However, the essential oil of E. trichotoma showed the same level repellency against the cigarette beetle, while E. calcicola essential oil possessed the less level repellency against L. serricorne, relative to the positive control, DEET. Moreover, the two crude oils also exhibited strong repellency against L. bostrychophila, but lesser level repellency than the positive control, DEET. Thus, the essential oils of E. calcicola and E. trichotoma may be potential to be developed as a new natural repellent in the control of stored product insects.

  5. Fumigant and Repellent Activity of Limonene Enantiomers Against Tribolium confusum du Val.

    PubMed

    Malacrinò, A; Campolo, O; Laudani, F; Palmeri, V

    2016-10-01

    The use of pesticides, as carried out in the last 50 years, caused several negative environmental and human health consequences, leading to the development of alternative techniques to control pests, such as the use of compounds of plant origin. In this study, we assessed the fumigant and repellent activity of both the enantiomers of limonene, a monoterpene usually found in many plant species, against Tribolium confusum du Val. We tested both molecules at different doses, air temperatures, and in absence and presence of flour. R-(+)-limonene resulted more effective than S-(-)-limonene; indeed, it was able to reach 100% of efficacy at a concentration of 85 mg/L air when tested at different temperatures without flour. Data showed a positive relationship between efficacy and temperature, and a negative effect of the presence of debris on the bioactivity of limonene. Furthermore, repellency trials reported a higher activity of R-(+)-limonene compared to the other enantiomer.

  6. Mosquito Avoidance Practices and Knowledge of Arboviral Diseases in Cities with Differing Recent History of Disease

    PubMed Central

    Haenchen, Steven D.; Hayden, Mary H.; Dickinson, Katherine L.; Walker, Kathleen; Jacobs, Elizabeth E.; Brown, Heidi E.; Gunn, Jayleen K. L.; Kohler, Lindsay N.; Ernst, Kacey C.

    2016-01-01

    As the range of dengue virus (DENV) transmission expands, an understanding of community uptake of prevention and control strategies is needed both in geographic areas where the virus has recently been circulating and in areas with the potential for DENV introduction. Personal protective behaviors such as the use of mosquito repellent to limit human–vector contact and the reduction of vector density through elimination of oviposition sites are the primary control methods for Aedes aegypti, the main vector of DENV. Here, we examined personal mosquito control measures taken by individuals in Key West, FL, in 2012, which had experienced a recent outbreak of DENV, and Tucson, AZ, which has a high potential for introduction but has not yet experienced autochthonous transmission. In both cities, there was a positive association between the numbers of mosquitoes noticed outdoors and the overall number of avoidance behaviors, use of repellent, and removal of standing water. Increased awareness and perceived risk of DENV were associated with increases in one of the most effective household prevention behaviors, removal of standing water, but only in Key West. PMID:27527634

  7. Lessons from mosquitoes' painless piercing.

    PubMed

    Gurera, Dev; Bhushan, Bharat; Kumar, Navin

    2018-05-18

    Arthropods are the largest group of the living organisms. They attack other organisms by biting, stinging, or piercing and sucking. Among various medically important arthropods, which feed on living hosts, mosquitoes' piercing spread viruses which have been reported to cause the highest number of deaths annually. The primary cause of the deaths is malaria, which is spread by infected mosquitoes' piercing. This study aims at elucidating lessons from mosquitoes' painless piercing. Mosquitoes pierce using their fascicle, which is a bundle of coherently functioning six stylets. Based on experiments and available literature, it is presented that mosquitoes painlessly pierce using a combination of the numbing, the fascicle's serrated design, the vibratory actuation, and the graded and frequency-dependent mechanical properties of the labrum. Based on this understanding, a mosquito-inspired microneedle design has also been proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Percutaneous penetration and pharmacodynamics: Wash-in and wash-off of sunscreen and insect repellent.

    PubMed

    Rodriguez, Jocelyn; Maibach, Howard I

    2016-01-01

    Increased awareness of skin cancer and mosquito-transmitted diseases has increased use of insect repellents and sunscreens. The challenge in setting recommendations for use and reapplication, especially when used concomitantly, lies in finding the balance between applying a durable product effective in withstanding natural and physical factors such as water, sweat, temperature and abrasion, while limiting percutaneous absorption and decreasing risk of potential dermal and systemic toxicity. Inorganic sunscreens show no or little percutaneous absorption or toxic effects in comparison to organic sunscreens, which show varying levels of dermal penetration and cutaneous adverse effects. An alternative to N,N-diethyl-m-toluamide (DEET), the traditional gold standard compound in insect repellents, picaridin appears as efficacious, has lower risk of toxicity, and when used simultaneously with sunscreen may decrease percutaneous absorption of both compounds. Conversely, combined use of DEET and sunscreen results in significantly higher absorption of both compounds. It is important to increase consumer awareness of "washing in" of various compounds leading to increased risk of toxicity, as well as differences in reapplication need due to "washing off" caused by water, sweat and abrasion. Although much remains to be studied, to maximize efficacy and decrease toxicity, contemporary research tools, including dermatopharmokinetics, should aid these prospective advances.

  9. Sulfate turpentine: a resource of tick repellent compounds.

    PubMed

    Schubert, Fredrik; Pålsson, Katinka; Santangelo, Ellen; Borg-Karlson, Anna-Karin

    2017-07-01

    Compounds with tick (Ixodes ricinus) repellent properties were isolated from sulfate turpentine consisting of Norway spruce (80%) and Scots pine (20%) from southern Sweden. The turpentine was divided into two fractions by distillation under reduced pressure resulting in one monoterpene hydrocarbon fraction and a residual containing higher boiling terpenoids. The monoterpene fraction was further oxidized with SeO 2 to obtain oxygenated monoterpenes with potential tick repellent properties. The oxidized fraction and the high boiling distillation residual were each separated by medium pressure liquid chromatography. The fractions were tested for tick repellency and the compounds in those with highest tick repellency were identified by GC-MS. The fractions with highest repellency contained, mainly (-)-borneol, and mixtures of (+)- and (-)-1-terpineol and terpinen-4-ol. The enantiomers of borneol showed similar tick repellent properties.

  10. Differential Attraction of Malaria Mosquitoes to Volatile Blends Produced by Human Skin Bacteria

    PubMed Central

    Verhulst, Niels O.; Andriessen, Rob; Groenhagen, Ulrike; Bukovinszkiné Kiss, Gabriella; Schulz, Stefan; Takken, Willem; van Loon, Joop J. A.; Schraa, Gosse; Smallegange, Renate C.

    2010-01-01

    The malaria mosquito Anopheles gambiae sensu stricto is mainly guided by human odour components to find its blood host. Skin bacteria play an important role in the production of human body odour and when grown in vitro, skin bacteria produce volatiles that are attractive to A. gambiae. The role of single skin bacterial species in the production of volatiles that mediate the host-seeking behaviour of mosquitoes has remained largely unknown and is the subject of the present study. Headspace samples were taken to identify volatiles that mediate this behaviour. These volatiles could be used as mosquito attractants or repellents. Five commonly occurring species of skin bacteria were tested in an olfactometer for the production of volatiles that attract A. gambiae. Odour blends produced by some bacterial species were more attractive than blends produced by other species. In contrast to odours from the other bacterial species tested, odours produced by Pseudomonas aeruginosa were not attractive to A. gambiae. Headspace analysis of bacterial volatiles in combination with behavioural assays led to the identification of six compounds that elicited a behavioural effect in A. gambiae. Our results provide, to our knowledge, the first evidence for a role of selected bacterial species, common on the human skin, in determining the attractiveness of humans to malaria mosquitoes. This information will be used in the further development of a blend of semiochemicals for the manipulation of mosquito behaviour. PMID:21209854

  11. Structure-activity relationship studies on the mosquito toxicity and biting deterrency of callicarpenal derivatives.

    PubMed

    Cantrell, Charles L; Klun, Jerome A; Pridgeon, Julia; Becnel, James; Green, Solomon; Fronczek, Frank R

    2009-04-01

    Callicarpenal (=13,14,15,16-tetranorclerod-3-en-12-al=[(1S,2R,4aR,8aR)-1,2,3,4,4a,7,8,8a-octahydro-1,2,4a,5-tetramethylnaphthalen-1-yl]acetaldehyde; 1) has previously demonstrated significant mosquito bite-deterring activity against Aedes aegypti and Anopheles stephensi in addition to repellent activity against host-seeking nymphs of the blacklegged tick, Ixodes scapularis. In the present study, structural modifications were performed on callicarpenal (1) in an effort to understand the functional groups necessary for maintaining and/or increasing its activity and to possibly lead to more effective insect control agents. All modifications in this study targeted the C(12) aldehyde or the C(3) alkene functionalities or combinations thereof. Mosquito biting deterrency appeared to be influenced most by C(3) alkene modification as evidenced by catalytic hydrogenation that resulted in a compound having significantly less effectiveness than 1 at a test amount of 25 nmol/cm2. Oxidation and/or reduction of the C(12) aldehyde did not diminish mosquito biting deterrency, but, at the same time, none of the modifications were more effective than 1 in deterring mosquito biting. Toxicities of synthesized compounds towards Ae. aegypti ranged from an LD50 value of 2.36 to 40.11 microg per mosquito. Similarly, LD95 values ranged from a low of 5.59 to a high of 104.9 microg.

  12. Mosquito Lagoon environmental resources inventory

    NASA Technical Reports Server (NTRS)

    Provancha, Jane A.; Hall, Carlton R.; Oddy, Donna M.

    1992-01-01

    This document provides a synopsis of biotic and abiotic data collected in the Mosquito Lagoon area in relation to water quality. A holistic ecological approach was used in this review to allow for summaries of climate, land use, vegetation, geohydrology, water quality, fishes, sea turtles, wading birds, marine mammals, invertebrates, shellfish, and mosquito control. The document includes a bibliographic database list of 157 citations that have references to the Mosquito Lagoon, many of which were utilized in development of the text.

  13. Larvicidal and repellent properties of Streptomyces sp. VITJS4 crude extract against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae).

    PubMed

    Naine, S Jemimah; Devi, C Subathra

    2014-01-01

    The aim of the present study was to assess the larvicidal and repellent properties of marine Streptomyces sp. VITJS4 crude extracts. The marine soil samples were collected from the Puducherry coast, Tamil Nadu, India. The isolate Streptomyces sp. VITJS4 was taxonomically characterized and identified. The ethyl acetate crude extract tested for larvicidal property showed 100% mortality for all the 3 species after 24 h exposure against the early fourth instar larvae of malarial vector--Anopheles stephensi at 50% and 90% lethal concentration (LC50 = 132.86, LC90 396.14 ppm); dengue vector--Aedes aegypti (LC50 = 112.78, LC90 336.42 ppm) and filariasis vector--Culex quinquefasciatus (LC50 = 156.53, LC90 468.37 ppm). The Streptomyces sp. VITJS4 solvent extracts of hexane, ethyl acetate, benzene, chloroform and methanol were tested for repellent activity against A. stephensi, A. aegypti and C. quinquefasciatus. The ethyl acetate extract showed complete protection for 210 min at 6 mg/cm2 against these mosquito bites. The crude extract was analyzed further for Fourier Transform-infrared spectroscopy (FT-IR) analysis. In addition to the importance of bioactive compounds, the utilization of Streptomyces sp. VITJS4 crude extracts revealed effective larvicidal and repellent activity against the vectors, which perhaps represents a promising tool in the management of mosquito control.

  14. Utility of wire cages, tree shelters, and repellants to minimize herbivory to oak by white-tailed deer

    Treesearch

    James N. Kochenderfer; W.Mark Ford

    2008-01-01

    We evaluated the efficacy of exclusion cages and commercially available repellants in deterring white-tailed deer (Odocoileus virginianus) herbivory on northern red oak (Quercus rubra) and chestnut oak (Q. montana) stump sprouts and planted red oak seedlings following a commercial clearcut harvest in West...

  15. ORAL INSECT REPELLENTS - INSECT TASTE RECEPTORS AND THEIR ACTION,

    DTIC Science & Technology

    CULICIDAE, * CHEMORECEPTORS ), INSECT REPELLENTS, ELECTROPHYSIOLOGY, STIMULATION(PHYSIOLOGY), ELECTROLYTES(PHYSIOLOGY), BLOOD, INGESTION(PHYSIOLOGY), REPRODUCTION(PHYSIOLOGY), NUTRITION, ENTOMOLOGY, AEDES, MOUTH

  16. Rodent-repellent studies. III. Advanced studies in the evaluation of chemical repellents

    USGS Publications Warehouse

    Bellack, E.; DeWitt, J.B.

    1949-01-01

    In order to bridge the gap between preliminary screening of chemicals for potential rodent repellency and the application ofthese compounds to paper cartons, more advanced studies in the evaluation ofpromising materials have been carried out. These studies have resulted in: (1) a modification of the food acceptance technique which eliminates doubtful compounds and also provides a closer analogy to the ultimate goal, and (2) a method for rapidly testing chemicals incorporated in paper. When the results of these latter tests are expressed as a function of time, it can be shown that a distinct correlation exists between the deterrency exhibited by treated paper and the repellency of treated food.

  17. Insecticidal, acaricidal and repellent effects of DEET- and IR3535-impregnated bed nets using a novel long-lasting polymer-coating technique.

    PubMed

    Faulde, Michael K; Albiez, Gunther; Nehring, Oliver

    2010-03-01

    A novel long-lasting repellent-treated net (LLRTN) has been designed by binding the skin repellents N,N-diethyl-m-toluamide (DEET), or IR3535, onto the fibres of bed net fabric using a new polymer-coating technique. The repellent toxicological effectiveness and residual activity of a factory-based repellent-impregnated fabric has been evaluated by laboratory testing against adult Aedes aegypti mosquitoes and nymphal Ixodes ricinus ticks. By using this repellent-embedding impregnation technique, concentrations exceeding 10 g/m(2) could be achieved with one single polymer layer. Both DEET- and IR3535-impregnated fabrics revealed a dose-dependent insecticidal as well as acaricidal activity. One hundred percent knockdown times of DEET-treated bed nets ranged from 187.5 +/- 31.8 to 27.5 +/- 3.5 min against A. aegypti, and between 214 +/- 47 and 22.6 +/- 5 min against nymphal I. ricinus, linked to a DEET concentration of 1.08 and 10.58 g/m(2), respectively. With IR3535, A. aegypti produced dose-dependent 100% knockdown times varying from 87.5 +/- 10.6 to 57.5 +/- 3.5 min and between 131.4 +/- 6.5 and 33.8 +/- 5 min against nymphal I. ricinus, respectively, linked to concentrations between 1.59 and 10.02 g/m(2). One hundred percent repellency measured by complete landing and biting protection of impregnated fabric by using the arm-in-cage test could be achieved at DEET concentrations exceeding 3.7 to 3.9 g/m(2), and for IR3535 concentrations over 10 g/m(2). One hundred percent landing and biting protection could be preserved with DEET-treated fabrics for 29 weeks at an initial concentration of 4.66 g/m(2), 54 weeks at 8.8 g/m(2), 58 weeks at 9.96 g/m(2) and 61 weeks at 10.48 g/m(2) for DEET, and 23 weeks for IR3535-treated fabric at a concentration of 10.02 g/m(2). Unlike repellent-treated fabric, a brand of a commercially available long-lasting insecticide-treated net tested containing 500 mg permethrin/m(2) did not protect from mosquito bites. First results on

  18. Effect of treated wastewater application on soil water repellency of sandy soil with olive trees and grass cover

    NASA Astrophysics Data System (ADS)

    Diamantis, V.; Ziogas, A.; Giougis, J.; Pliakas, F.; Diamantis, I.

    2009-04-01

    Soil water repellency has received significant attention due to water scarcity and increasing demand of irrigation water worldwide. The objective of this study was to examine the effects of treated wastewater application on soil water repellency of a repellent sandy soil with olive trees and grass cover. Secondary effluent from a municipal wastewater treatment plant was applied directly on the field on a 4×2 m plot. Freshwater and a mixture of freshwater:wastewater (1:1) were used in subsequent plots for comparison. A total of 62 water applications were performed between March 2006 and July 2008. The soil receiving the mixture of freshwater:wastewater exhibited the highest wettability. The soil water repellency after the first year of wastewater application decreased in the respective plot compared with the soil under natural conditions. The higher values of the WDPT were determined on the freshwater irrigated plot. The field-moist samples on all plots revealed high wettability because the moisture content of the soil was maintained above the critical soil water content. The results of this study reveal that short-term application of treated municipal wastewater does not induce soil water repellency.

  19. Identification of insecticidal principals from cucumber seed oil against the yellow fever mosquito, Aedes aegypti

    USDA-ARS?s Scientific Manuscript database

    The yellow fever mosquito, Aedes aegypti, is one of the most medically important mosquito species due to its ability to spread viruses of yellow fever, dengue fever and Zika in humans. In this study, the insecticidal activity of seventeen plant essential oils were evaluated to toxicity by topical a...

  20. Mosquito ovicidal properties of Ageratina adenophora (Family: Asteraceae) against filariasis vector, Culex quinquefasciatus (Diptera: Culicidae)

    USDA-ARS?s Scientific Manuscript database

    Mosquito-borne diseases with an economic impact create loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates. Mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. Extracts from plants may be alternativ...

  1. Broad Surveys of DNA Viral Diversity Obtained through Viral Metagenomics of Mosquitoes

    PubMed Central

    Ng, Terry Fei Fan; Willner, Dana L.; Lim, Yan Wei; Schmieder, Robert; Chau, Betty; Nilsson, Christina; Anthony, Simon; Ruan, Yijun; Rohwer, Forest; Breitbart, Mya

    2011-01-01

    Viruses are the most abundant and diverse genetic entities on Earth; however, broad surveys of viral diversity are hindered by the lack of a universal assay for viruses and the inability to sample a sufficient number of individual hosts. This study utilized vector-enabled metagenomics (VEM) to provide a snapshot of the diversity of DNA viruses present in three mosquito samples from San Diego, California. The majority of the sequences were novel, suggesting that the viral community in mosquitoes, as well as the animal and plant hosts they feed on, is highly diverse and largely uncharacterized. Each mosquito sample contained a distinct viral community. The mosquito viromes contained sequences related to a broad range of animal, plant, insect and bacterial viruses. Animal viruses identified included anelloviruses, circoviruses, herpesviruses, poxviruses, and papillomaviruses, which mosquitoes may have obtained from vertebrate hosts during blood feeding. Notably, sequences related to human papillomaviruses were identified in one of the mosquito samples. Sequences similar to plant viruses were identified in all mosquito viromes, which were potentially acquired through feeding on plant nectar. Numerous bacteriophages and insect viruses were also detected, including a novel densovirus likely infecting Culex erythrothorax. Through sampling insect vectors, VEM enables broad survey of viral diversity and has significantly increased our knowledge of the DNA viruses present in mosquitoes. PMID:21674005

  2. Repellence of the main components from the essential oil of Glycosmis lucida Wall. ex Huang against two stored product insects.

    PubMed

    Guo, Shan-Shan; Zhang, Wen-Juan; Yang, Kai; Liang, Jun-Yu; You, Chun-Xue; Wang, Cheng-Fang; Li, Yin-Ping; Geng, Zhu-Feng; Deng, Zhi-Wei; Du, Shu-Shan

    2017-05-01

    A screening of Chinese medicinal herbs and wild plants for agrochemicals was carried out; the essential oil of Glycosmis lucida leaves was found to possess significant repellent activity against Tribolium castaneum and Liposcelis bostrychophila. It was found that the main components included elixene (19.81%), spathulenol (10.68%), anethole (12.05%), verbenone (10.32%) followed by β-caryophyllene (6.87%). The essential oil, anethole and verbenone were strongly repellent against T. castaneum (96, 86 and 94%, respectively, at 15.73 nL cm -2 ) and L. bostrychophila (100, 68 and 72%, respectively, at 31.58 nL cm -2 ) after a 2h treatment. The results indicate that anethole and verbenone had the potential to be developed as natural repellents for control of stored product insects.

  3. Wetting properties of fungi mycelium alter soil infiltration and soil water repellency in a γ-sterilized wettable and repellent soil.

    PubMed

    Chau, Henry Wai; Goh, Yit Kheng; Vujanovic, Vladimir; Si, Bing Cheng

    2012-12-01

    Soil water repellency (SWR) has a drastic impact on soil quality resulting in reduced infiltration, increased runoff, increased leaching, reduced plant growth, and increased soil erosion. One of the causes of SWR is hydrophobic fungal structures and exudates that change the soil-water relationship. The objective of this study was to determine whether SWR and infiltration could be manipulated through inoculation with fungi. The effect of fungi on SWR was investigated through inoculation of three fungal strains (hydrophilic -Fusarium proliferatum, chrono-amphiphilic -Trichoderma harzianum, and hydrophobic -Alternaria sp.) on a water repellent soil (WR-soil) and a wettable soil (W-soil). The change in SWR and infiltration was assessed by the water repellency index and cumulative infiltration respectively. F. proliferatum decreased the SWR on WR-soil and slightly increased SWR in W-soil, while Alternaria sp. increased SWR in both the W-soil and the WR-soil. Conversely T. harzianum increased the SWR in the W-soil and decreased the SWR in the WR-soil. All strains showed a decrease in infiltration in W-soil, while only the F. proliferatum and T. harzianum strain showed improvement in infiltration in the WR-soil. The ability of fungi to alter the SWR and enmesh soil particles results in changes to the infiltration dynamics in soil. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  4. Repellency Effects of Essential Oils of Myrtle (Myrtus communis), Marigold (Calendula officinalis) Compared with DEET against Anopheles stephensi on Human Volunteers.

    PubMed

    Tavassoli, M; Shayeghi, M; Abai, Mr; Vatandoost, H; Khoobdel, M; Salari, M; Ghaderi, A; Rafi, F

    2011-01-01

    Malaria and leishmaniasis are two most significant parasitic diseases which are endemic in Iran. Over the past decades, interest in botanical repellents has increased as a result of safety to human. The comparative efficacy of essential oils of two native plants, myrtle (Myrtus communis) and marigold (Calendula officinalis) collected from natural habitats at southern Iran was compared with DEET as synthetic repellent against Anopheles stephensi on human subjects under laboratory condition. Essential oils from two species of native plants were obtained by Clevenger-type water distillation. The protection time of DEET, marigold and myrtle was assessed on human subject using screened cage method against An. stephensi. The effective dose of 50% essential oils of two latter species and DEET were determined by modified ASTM method. ED(50) and ED(90) values and related statistical parameters were calculated by probit analysis. The protection time of 50% essential oils of marigold and myrtle were respectively 2.15 and 4.36 hours compared to 6.23 hours for DEET 25%. The median effective dose (ED(50)) of 50% essential oils was 0.1105 and 0.6034 mg/cm(2) respectively in myrtle and marigold. The figure for DEET was 0.0023 mg/cm(2). This study exhibited that the repellency of both botanical repellents was generally lower than DEET as a synthetic repellent. However the 50% essential oil of myrtle showed a moderate repellency effects compared to marigold against An. stephensi.

  5. Repellency Effects of Essential Oils of Myrtle (Myrtus communis), Marigold (Calendula officinalis) Compared with DEET against Anopheles stephensi on Human Volunteers

    PubMed Central

    Tavassoli, M; Shayeghi, M; Abai, MR; Vatandoost, H; Khoobdel, M; Salari, M; Ghaderi, A; Rafi, F

    2011-01-01

    Background: Malaria and leishmaniasis are two most significant parasitic diseases which are endemic in Iran. Over the past decades, interest in botanical repellents has increased as a result of safety to human. The comparative efficacy of essential oils of two native plants, myrtle (Myrtus communis) and marigold (Calendula officinalis) collected from natural habitats at southern Iran was compared with DEET as synthetic repellent against Anopheles stephensi on human subjects under laboratory condition. Methods: Essential oils from two species of native plants were obtained by Clevenger-type water distillation. The protection time of DEET, marigold and myrtle was assessed on human subject using screened cage method against An. stephensi. The effective dose of 50% essential oils of two latter species and DEET were determined by modified ASTM method. ED50 and ED90 values and related statistical parameters were calculated by probit analysis. Results: The protection time of 50% essential oils of marigold and myrtle were respectively 2.15 and 4.36 hours compared to 6.23 hours for DEET 25%. The median effective dose (ED50) of 50% essential oils was 0.1105 and 0.6034 mg/cm2 respectively in myrtle and marigold. The figure for DEET was 0.0023 mg/cm2. Conclusion: This study exhibited that the repellency of both botanical repellents was generally lower than DEET as a synthetic repellent. However the 50% essential oil of myrtle showed a moderate repellency effects compared to marigold against An. stephensi. PMID:22808414

  6. Effects of wildfire on soil water repellency in pine and eucalypt forest in central Portugal

    NASA Astrophysics Data System (ADS)

    Faria, Sílvia; Eufemia Varela, María.; Keizer, Jan Jacob

    2010-05-01

    Soil water repellency is a naturally occurring phenomenon that can be intensified by soil heating during fires. Fire-induced or -enhanced water repellency, together with the loss of plant cover, is widely regarded as a key factor in increased surface runoff and accelerated erosion in recently burnt areas. The present study is part of the EROSFIRE-II project, whose main aim is to assess and predict post-wildfire hydrological and erosion processes at multiple spatial scales, ranging from micro-plot (< 1 m2) to small catchments (< 1 km2). This work concerns the occurrence and severity of topsoil water repellency in the two forest types occurring in the Colmeal study area, i.e. Maritime Pine and eucalypt stands The objectives are: (i) to clarify the role of wildfire, by comparing recently burnt and adjacent long unburned stands; (ii) to determine the temporal patterns in repellency, through monthly measurements during the first year following the wildfire, and relate them to soil moisture variations in particular. The Colmeal study area is located in the Lousã mountain range in central Portugal. The wildfire occurred in August 2008 and consumed a total area of about 70 ha. Within the burnt area, two slopes were selected with the same parent material (schist) but different forest types (Pinus pinaster and Eucaliptus globulus). In addition, two similar but long unburned slopes were selected in the immediate surroundings. For a period of 10 months, starting November 2008, water repellency and moisture content of the 0-5 cm topsoil layer were measured in the field at monthly intervals. Repellency was measured using the ‘Molarity of an Ethanol Droplet' (MED) test, soil moisture content using a DECAGON EC5 sensor. The results revealed a very strong repellency (ethanol classes 6-7) at all four sites during the first sampling period in November 2008, suggesting that the immediate wildfire effects were minor for both forest types. In the subsequent 5 to 6 months, however

  7. The influence of compost addition on the water repellency of brownfield soils

    NASA Astrophysics Data System (ADS)

    Whelan, Amii; Kechavarzi, Cedric; Sakrabani, Ruben; Coulon, Frederic; Simmons, Robert; Wu, Guozhong

    2010-05-01

    Compost application to brownfield sites, which can facilitate the stabilisation and remediation of contaminants whilst providing adequate conditions for plant growth, is seen as an opportunity to divert biodegradable wastes from landfill and put degraded land back into productive use. However, although compost application is thought to improve soil hydraulic functioning, there is a lack of information on the impact of large amounts of compost on soil water repellency. Water repellency in soils is attributed to the accumulation of hydrophobic organic compounds released as root exudates, fungal and microbial by-products and decomposition of organic matter. It has also been shown that brownfield soils contaminated with petroleum-derived organic contaminants can exhibit strong water repellency, preventing the rapid infiltration of water and leading potentially to surface run off and erosion of contaminated soil. However, hydrophobic organic contaminants are known to become sequestrated by partitioning into organic matter or diffusing into nano- and micropores, making them less available over time (ageing). The effect of large amounts of organic matter addition through compost application on the water repellency of soils contaminated with petroleum-derived organic contaminants requires further investigation. We characterised the influence of compost addition on water repellency in the laboratory by measuring the Water Drop Penetration Time (WDPT), sorptivity and water repellency index through infiltration experiments on soil samples amended with two composts made with contrasting feedstocks (green waste and predominantly meat waste). The treatments consisted of a sandy loam, a clay loam and a sandy loam contaminated with diesel fuel and aged for 3 years, which were amended with the two composts at a rate equivalent to 750t/ha. In addition core samples collected from a brownfield site, amended with compost at three different rates (250, 500 and 750t/ha) in 2007, were

  8. Effective delivery of a nematode-repellent peptide using a root-cap-specific promoter.

    PubMed

    Lilley, Catherine J; Wang, Dong; Atkinson, Howard J; Urwin, Peter E

    2011-02-01

    The potential of the MDK4-20 promoter of Arabidopsis thaliana to direct effective transgenic expression of a secreted nematode-repellent peptide was investigated. Its expression pattern was studied in both transgenic Arabidopsis and Solanum tuberosum (potato) plants. It directed root-specific β-glucuronidase expression in both species that was chiefly localized to cells of the root cap. Use of the fluorescent timer protein dsRED-E5 established that the MDK4-20 promoter remains active for longer than the commonly used constitutive promoter CaMV35S in separated potato root border cells. Transgenic Arabidopsis lines that expressed the nematode-repellent peptide under the control of either AtMDK4-20 or CaMV35S reduced the establishment of the beet cyst nematode Heterodera schachtii. The best line using the AtMDK4-20 promoter displayed a level of resistance >80%, comparable to that of lines using the CaMV35S promoter. In transgenic potato plants, 94.9 ± 0.8% resistance to the potato cyst nematode Globodera pallida was achieved using the AtMDK4-20 promoter, compared with 34.4 ± 8.4% resistance displayed by a line expressing the repellent peptide from the CaMV35S promoter. These results establish the potential of the AtMDK4-20 promoter to limit expression of a repellent peptide whilst maintaining or even improving the efficacy of the cyst-nematode defence. © 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  9. Evaluation of mosquito responses to pyrethroid insecticides topically applied to sheep.

    PubMed

    Johnson, G D; Goosey, H B; Rolston, M G; Miller, W L; Hokit, D G; Redden, R R; Kott,