The Experts below are selected from a list of 3741 Experts worldwide ranked by ideXlab platform
Doung Socheat - One of the best experts on this subject based on the ideXlab platform.
-
Bacterial Larvicide, Bacillus Thuringiensis Israelensis Strain AM 65-52 Water Dispersible Granule Formulation Impacts Both Dengue Vector, Aedes aegypti (L.) Population Density and Disease Transmission in Cambodia.
PLOS Neglected Tropical Diseases, 2016Co-Authors: To Setha, Seleena Benjamin, Ngan Chantha, Doung SocheatAbstract:A multi-phased study was conducted in Cambodia from 2005–2011 to measure the impact of larviciding with the bacterial larvicide, Bacillus Thuringiensis Israelensis (Bti), a water dispersible granule (WG) formulation on the vector, Aedes aegypti (L.) and the epidemiology. In our studies, all in-use containers were treated at 8 g/1000 L, including smaller containers and animal feeders which were found to contribute 23% of Ae aegypti pupae. The treated waters were subjected to routine water exchange activities. Pupal production was suppressed by an average 91% for 8 weeks. Pupal numbers continued to remain significantly lower than the untreated commune (UTC) for 13 weeks post treatment in the peak dengue vector season (p 50% of the household in the UTC harbored ≥11 mosquitoes per home. The adult population continued to remain at significantly much lower numbers in the Bti treated commune than in the UTC for 10–12 weeks post treatment (p
-
efficacy of Bacillus Thuringiensis Israelensis vectobac wg and dt formulations against dengue mosquito vectors in cement potable water jars in cambodia
Southeast Asian Journal of Tropical Medicine and Public Health, 2007Co-Authors: To Setha, Ngan Chantha, Doung SocheatAbstract:This study reports the evaluation of Bacillus Thuringiensis Israelensis (Bti), a biological larvicide, in cement jars holding river, well and rain water. Two Bti formulations, VectoBac WG and VectoBac DT, were evaluated in a village in Phnom Penh. Thirty-one households with cement jars supporting the colonization of Ae.aegypti immatures were chosen. In each house 3 jars were aligned next to each another and filled with the same type of water. One of the 3 jars was treated with VectoBac WG at 0.4 g per 50 liters, a second jar was treated with VectoBac DT at 1 tablet per 50 liters, and a third jar was an untreated control (UTC). The jars were not covered, kept outdoors and not subjected to water exchange activity. The efficacy of VectoBac to control natural Ae.aegypti infestation was measured by Ae.aegypti pupae surveillance, conducted 3 days per week for 3 months post-treatment (June-September 2004). All pupae were removed, allowed to emerge in the Cambodia National Malaria Center insectarium and the emerged adults were identified and counted. The VectoBac treatments were more effective in river water, followed by well and rain water. The VectoBac treatments significantly reduced the pupae numbers for a minimum of 3 months in the river water and 2.5 months in the well water (p 0.05). It was also observed that VectoBac WG and DT were target specific, without any adverse effects on aquatic predatory insects common in well and rain water. VectoBac WG and DT were found to be easy-to-use formulations, with no need to repackage them prior to use in the containers. The amounts of VectoBac WG and DT used were 12.5 fold less by weight than temephos (Abate 1.0% SG).
-
EFFICACY OF Bacillus Thuringiensis Israelensis, VECTOBAC ® WG AND DT, FORMULATIONS AGAINST DENGUE MOSQUITO VECTORS IN CEMENT POTABLE WATER JARS IN CAMBODIA
The Southeast Asian journal of tropical medicine and public health, 2007Co-Authors: To Setha, Ngan Chantha, Doung SocheatAbstract:This study reports the evaluation of Bacillus Thuringiensis Israelensis (Bti), a biological larvicide, in cement jars holding river, well and rain water. Two Bti formulations, VectoBac WG and VectoBac DT, were evaluated in a village in Phnom Penh. Thirty-one households with cement jars supporting the colonization of Ae.aegypti immatures were chosen. In each house 3 jars were aligned next to each another and filled with the same type of water. One of the 3 jars was treated with VectoBac WG at 0.4 g per 50 liters, a second jar was treated with VectoBac DT at 1 tablet per 50 liters, and a third jar was an untreated control (UTC). The jars were not covered, kept outdoors and not subjected to water exchange activity. The efficacy of VectoBac to control natural Ae.aegypti infestation was measured by Ae.aegypti pupae surveillance, conducted 3 days per week for 3 months post-treatment (June-September 2004). All pupae were removed, allowed to emerge in the Cambodia National Malaria Center insectarium and the emerged adults were identified and counted. The VectoBac treatments were more effective in river water, followed by well and rain water. The VectoBac treatments significantly reduced the pupae numbers for a minimum of 3 months in the river water and 2.5 months in the well water (p 0.05). It was also observed that VectoBac WG and DT were target specific, without any adverse effects on aquatic predatory insects common in well and rain water. VectoBac WG and DT were found to be easy-to-use formulations, with no need to repackage them prior to use in the containers. The amounts of VectoBac WG and DT used were 12.5 fold less by weight than temephos (Abate 1.0% SG).
Seleena Benjamin - One of the best experts on this subject based on the ideXlab platform.
-
Wide area spray of bacterial larvicide, Bacillus Thuringiensis Israelensis strain AM65-52, integrated in the national vector control program impacts dengue transmission in an urban township in Sibu district, Sarawak, Malaysia.
PLOS ONE, 2020Co-Authors: Rezal Bohari, Seleena Benjamin, Chong Jin Hin, Asmad Matusop, Muhamad Rais Abdullah, Teoh Guat Ney, Lee Han LimAbstract:Several sites, Z-7L, Z-5 and Z-14, in Sibu district, Sarawak, Malaysia, experienced intense dengue transmission in 2014 that continued into 2015. A pilot study with Bacillus Thuringiensis Israelensis (Bti) to control Aedes aegypti (L.) and Ae. albopictus (Skuse) was evaluated in Z-7L, a densely populated site of 12 ha. Bti treatments were conducted weekly from epidemiology week (EW) 24/2015 for 4 weeks, followed by fortnight treatments for 2 months, in addition to the routine control activities. Bti was directly introduced into potable containers and the outdoor artificial and natural containers were treated via a wide area spray application method using a backpack mister. Aedes indices significantly reduced during the treatment and post treatment phases, compared to the control site, Z-5 (p
-
Bacterial Larvicide, Bacillus Thuringiensis Israelensis Strain AM 65-52 Water Dispersible Granule Formulation Impacts Both Dengue Vector, Aedes aegypti (L.) Population Density and Disease Transmission in Cambodia.
PLOS Neglected Tropical Diseases, 2016Co-Authors: To Setha, Seleena Benjamin, Ngan Chantha, Doung SocheatAbstract:A multi-phased study was conducted in Cambodia from 2005–2011 to measure the impact of larviciding with the bacterial larvicide, Bacillus Thuringiensis Israelensis (Bti), a water dispersible granule (WG) formulation on the vector, Aedes aegypti (L.) and the epidemiology. In our studies, all in-use containers were treated at 8 g/1000 L, including smaller containers and animal feeders which were found to contribute 23% of Ae aegypti pupae. The treated waters were subjected to routine water exchange activities. Pupal production was suppressed by an average 91% for 8 weeks. Pupal numbers continued to remain significantly lower than the untreated commune (UTC) for 13 weeks post treatment in the peak dengue vector season (p 50% of the household in the UTC harbored ≥11 mosquitoes per home. The adult population continued to remain at significantly much lower numbers in the Bti treated commune than in the UTC for 10–12 weeks post treatment (p
-
spray application of Bacillus Thuringiensis Israelensis bti strain am65 52 against aedes aegypti l and ae albopictus skuse populations and impact on dengue transmission in a dengue endemic residential site in malaysia
Southeast Asian Journal of Tropical Medicine and Public Health, 2012Co-Authors: A.w.a. Tan, Seleena Benjamin, H. L. Lee, Seau Rong Loke, K.h. Chooi, Mohd SofianazirunAbstract:A one year study was conducted to evaluate the impact of spray applica- tion of Bacillus Thuringiensis Israelensis (Bti), strain AM65-52 on vector populations and dengue transmission in a dengue endemic state in Malaysia. Residential sites with similar populations of Aedes aegypti (L.) and Aedes albopictus Skuse were studied. One site was treated with spray application of Bti into all outdoor target vector habitats, which consisted of natural and artificial containers. The other site was not treated. The impact of spray application was measured with an indoor and outdoor ovitrap index (OI) and epidemiologic data. Significant reductions in both Ae. aegypti and Ae. albopictus, OI were observed both indoors and outdoors, in treated sites compared to untreated sites (p<0.05). OI reduction was achieved over time in the treated area. The OI was suppressed to below 10%. This was maintained for 4 weeks into the post-treatment phase. The outdoor OI at the untreated site remained at more than 40% for 38 weeks during the evaluation period. One dengue case occurred at the Bti treatment site at the beginning of the treatment phase, but no further cases were detected during the remainder of the treatment phase. However, there was an ongoing dengue outbreak in the untreated area with 15 serologically confirmed cases during weeks 37-54. Intensive fogging operations with pyrethroids at the untreated (Bti) site had a positive impact on Ae. albopictus, but not on Ae. aegypti.
-
Spray application of Bacillus Thuringiensis Israelensis (Bti strain AM65-52) against Aedes aegypti (L.) and Ae. albopictus Skuse populations and impact on dengue transmission in a dengue endemic residential site in Malaysia.
The Southeast Asian journal of tropical medicine and public health, 2012Co-Authors: A.w.a. Tan, Seleena Benjamin, H. L. Lee, Seau Rong Loke, K.h. Chooi, Mohd Sofian-azirunAbstract:A one year study was conducted to evaluate the impact of spray applica- tion of Bacillus Thuringiensis Israelensis (Bti), strain AM65-52 on vector populations and dengue transmission in a dengue endemic state in Malaysia. Residential sites with similar populations of Aedes aegypti (L.) and Aedes albopictus Skuse were studied. One site was treated with spray application of Bti into all outdoor target vector habitats, which consisted of natural and artificial containers. The other site was not treated. The impact of spray application was measured with an indoor and outdoor ovitrap index (OI) and epidemiologic data. Significant reductions in both Ae. aegypti and Ae. albopictus, OI were observed both indoors and outdoors, in treated sites compared to untreated sites (p
-
Aedes albopictus control with spray application of Bacillus Thuringiensis Israelensis, strain AM 65-52.
The Southeast Asian journal of tropical medicine and public health, 2010Co-Authors: Patrick H Y Lam, Chia S Boon, Ng Y Yng, Seleena BenjaminAbstract:A Bacillus Thuringiensis Israelensis (Bti) formulation, VectoBac ® WG (strain AM 65-52), was evaluated for mosquito control in a training area with dense veg- etation. Bti was spray applied to target Aedes albopictus larval habitats of 130 ha once every 2 weeks using a motorized back pack mist blower, Stihl ® SR420, and a vehicle mounted ultra low volume generator (ULV), IGEBA ® U40. Ovitrap index (OI) and larval density (LD) were used to measure the efficacy of larviciding. In the Bti treated area the OI and LD significantly decreased with time (p < 0.05); OI decreased from 84.3 ± 1.7 to 27.5 ± 2.5 (%) and LD decreased from 27.9 ± 1.5 to 3.2 ± 1.8 larvae per ovitrap by 3 months from the start of treatment. During the same period of time there was no significant reduction in OI and LD at the untreated site which was under a conventional mosquito control program. This large scale study indicates larvicidal spraying with Bti of natural breeding sites, was able to reduce Ae. albopictus adult density. This significant reduction was not achieved with conventional manual application methods.
Susanto G. Nugroho - One of the best experts on this subject based on the ideXlab platform.
-
Pengaruh Bacillus Thuringiensis Israelensis Sebagai Larvasida Vektor Demam Berdarah Dengue (DBD) Terhadap Ikan Guppy (Poecilia reticulata)
University of Halu Oleo, 2019Co-Authors: Apriyani Nita, Setyaningrum Endah, Susanto G. NugrohoAbstract:ABSTRAK Penyakit tular vektor merupakan salah satu masalah kesehatan masyarakat yang utama di Indonesia, diantaranya penyakit Demam Berdarah Dengue (DBD) yang ditularkan oleh Aedes aegypti. Untuk mengurangi efek negatif insektisida, dewasa ini pemberantasan vektor diupayakan dengan penggunaan agen biologi yaitu menggunakan Bacillus Thuringiensis Israelensis (Bti) yang lebih ramah lingkungan dan tidak menyebabkan resisten vektor. Selain harus efektif membunuh larva nyamuk, Bti juga harus tidak membahayakan biota perairan lainnya yang sehabitat seperti ikan Guppy (Poecilia reticulata). Oleh karena itu, penelitian ini bertujuan untuk mengetahui pengaruh Bti terhadap mortalitas ikan Guppy sebagai organisme non target vektor DBD. Penelitian ini dilakukan di Laboratorium Zoologi, Jurusan Biologi, Fakultas Matematika dan Ilmu pengetahuan Alam, Universitas Lampung. Dilaksanakan pada Desember – Februari 2019. Metode penelitian yang digunakan adalah eksperimental skala laboratoris berupa Rancangan Acak Lengkap (RAL) yaitu konsentrasi Bti sebagai perlakuan dengan empat kali ulangan. Perlakuan yang diuji yaitu kontrol ( tidak diberi Bti), dan pemberian Bti dengan konsentrasi 20 ppm, 40 ppm, 60 ppm, 80 pmm, dan 100 ppm. Hasil penelitian menunjukkan pemberian Bti pada konsentrasi berbeda tidak berpengaruh terhadap kematian ikan Guppy dan tidak berpengaruh secara signifikan terhadap pertumbuhan berat total ikan Guppy.Kata kunci : Demam Berdarah Dengue (DBD), Bacillus Thuringiensis Israelensis, ikan Guppy
-
Pengaruh Bacillus Thuringiensis Israelensis Sebagai Larvasida Vektor Demam Berdarah Dengue (DBD) Terhadap Benur Udang Vaname (Litopenaeus vannamei)
University of Halu Oleo, 2019Co-Authors: Suryaningkunti, Jeany Audina, Setyaningrum Endah, Susanto G. NugrohoAbstract:ABSTRAKPenyakit endemis yang menyebabkan angka kematian tertinggi hampir di seluruh provinsi di Indonesia adalah demam berdarah dengue (DBD). Vektor utama dalam penyebaran penyakit DBD adalah nyamuk Aedes aegypti. Usaha pembibitan udang banyak dikembangkan di Lampung namun usahanya tidak diikuti dengan penyelamatan lingkungan, sehingga muncul wabah DBD dari usaha pembibitan tersebut. Salah satu pengendalian vektor penyakit DBD dengan menggunakan larvasida Bti. Selain harus efektif membunuh larva nyamuk, Bti juga harus aman bagi organisme non target seperti udang vaname (Litopenaeus vannamei).Tujuan dari penelitian ini untuk mengetahui pengaruh Bti sebagai larvasida vektor DBD terhadap mortalitas benur udang vaname (L. vannamei). Penelitian ini dilaksanakan pada bulan November sampai Desember 2018 di Laboratorium Zoologi II, Jurusan Biologi, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Lampung. Metode yang digunakan adalah Rancangan Acak Lengkap (RAL). Perlakuan yang diberikan yaitu kontrol (tidak diberi Bti), dan penambahan Bti 20 ppm, 40 ppm, 60 ppm, 80 ppm, serta 100 ppm. Parameter yang diamati adalah mortalitas benur udang vaname (L. vannamei), pertumbuhan berupa berat dan panjang, kelulushidupan serta kualitas air selama pemeliharaan. Data pertumbuhan yang diperoleh dianalisis dengan ANOVA, sedangkan data persentase mortalitas, kelulushidupan dan kualitas air yang diperoleh dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa Bti dengan berbagai konsentrasi tidak memberikan pengaruh secara nyata terhadap pertumbuhan (p>0,05), persentase mortalitas dan kelulushidupan benur udang vaname (L. vannamei) sehingga larvasida tersebut dapat digunakan untuk pemberantasan vektor DBD pada hatchery dan tambak udang vaname.Kata kunci : Bacillus Thuringiensis Israelensis, benur udang vaname (L. vannamei), pertumbuhan, mortalitas, kelulushidupa
To Setha - One of the best experts on this subject based on the ideXlab platform.
-
Bacterial Larvicide, Bacillus Thuringiensis Israelensis Strain AM 65-52 Water Dispersible Granule Formulation Impacts Both Dengue Vector, Aedes aegypti (L.) Population Density and Disease Transmission in Cambodia.
PLOS Neglected Tropical Diseases, 2016Co-Authors: To Setha, Seleena Benjamin, Ngan Chantha, Doung SocheatAbstract:A multi-phased study was conducted in Cambodia from 2005–2011 to measure the impact of larviciding with the bacterial larvicide, Bacillus Thuringiensis Israelensis (Bti), a water dispersible granule (WG) formulation on the vector, Aedes aegypti (L.) and the epidemiology. In our studies, all in-use containers were treated at 8 g/1000 L, including smaller containers and animal feeders which were found to contribute 23% of Ae aegypti pupae. The treated waters were subjected to routine water exchange activities. Pupal production was suppressed by an average 91% for 8 weeks. Pupal numbers continued to remain significantly lower than the untreated commune (UTC) for 13 weeks post treatment in the peak dengue vector season (p 50% of the household in the UTC harbored ≥11 mosquitoes per home. The adult population continued to remain at significantly much lower numbers in the Bti treated commune than in the UTC for 10–12 weeks post treatment (p
-
efficacy of Bacillus Thuringiensis Israelensis vectobac wg and dt formulations against dengue mosquito vectors in cement potable water jars in cambodia
Southeast Asian Journal of Tropical Medicine and Public Health, 2007Co-Authors: To Setha, Ngan Chantha, Doung SocheatAbstract:This study reports the evaluation of Bacillus Thuringiensis Israelensis (Bti), a biological larvicide, in cement jars holding river, well and rain water. Two Bti formulations, VectoBac WG and VectoBac DT, were evaluated in a village in Phnom Penh. Thirty-one households with cement jars supporting the colonization of Ae.aegypti immatures were chosen. In each house 3 jars were aligned next to each another and filled with the same type of water. One of the 3 jars was treated with VectoBac WG at 0.4 g per 50 liters, a second jar was treated with VectoBac DT at 1 tablet per 50 liters, and a third jar was an untreated control (UTC). The jars were not covered, kept outdoors and not subjected to water exchange activity. The efficacy of VectoBac to control natural Ae.aegypti infestation was measured by Ae.aegypti pupae surveillance, conducted 3 days per week for 3 months post-treatment (June-September 2004). All pupae were removed, allowed to emerge in the Cambodia National Malaria Center insectarium and the emerged adults were identified and counted. The VectoBac treatments were more effective in river water, followed by well and rain water. The VectoBac treatments significantly reduced the pupae numbers for a minimum of 3 months in the river water and 2.5 months in the well water (p 0.05). It was also observed that VectoBac WG and DT were target specific, without any adverse effects on aquatic predatory insects common in well and rain water. VectoBac WG and DT were found to be easy-to-use formulations, with no need to repackage them prior to use in the containers. The amounts of VectoBac WG and DT used were 12.5 fold less by weight than temephos (Abate 1.0% SG).
-
EFFICACY OF Bacillus Thuringiensis Israelensis, VECTOBAC ® WG AND DT, FORMULATIONS AGAINST DENGUE MOSQUITO VECTORS IN CEMENT POTABLE WATER JARS IN CAMBODIA
The Southeast Asian journal of tropical medicine and public health, 2007Co-Authors: To Setha, Ngan Chantha, Doung SocheatAbstract:This study reports the evaluation of Bacillus Thuringiensis Israelensis (Bti), a biological larvicide, in cement jars holding river, well and rain water. Two Bti formulations, VectoBac WG and VectoBac DT, were evaluated in a village in Phnom Penh. Thirty-one households with cement jars supporting the colonization of Ae.aegypti immatures were chosen. In each house 3 jars were aligned next to each another and filled with the same type of water. One of the 3 jars was treated with VectoBac WG at 0.4 g per 50 liters, a second jar was treated with VectoBac DT at 1 tablet per 50 liters, and a third jar was an untreated control (UTC). The jars were not covered, kept outdoors and not subjected to water exchange activity. The efficacy of VectoBac to control natural Ae.aegypti infestation was measured by Ae.aegypti pupae surveillance, conducted 3 days per week for 3 months post-treatment (June-September 2004). All pupae were removed, allowed to emerge in the Cambodia National Malaria Center insectarium and the emerged adults were identified and counted. The VectoBac treatments were more effective in river water, followed by well and rain water. The VectoBac treatments significantly reduced the pupae numbers for a minimum of 3 months in the river water and 2.5 months in the well water (p 0.05). It was also observed that VectoBac WG and DT were target specific, without any adverse effects on aquatic predatory insects common in well and rain water. VectoBac WG and DT were found to be easy-to-use formulations, with no need to repackage them prior to use in the containers. The amounts of VectoBac WG and DT used were 12.5 fold less by weight than temephos (Abate 1.0% SG).
Norbert Becker - One of the best experts on this subject based on the ideXlab platform.
-
Biological larviciding against malaria vector mosquitoes with Bacillus Thuringiensis Israelensis (Bti) - Long term observations and assessment of repeatability during an additional intervention year of a large-scale field trial in rural Burkina Faso
Global Health Action, 2020Co-Authors: Peter Dambach, Norbert Becker, Volker Winkler, Till Bärnighausen, Issouf Traoré, Saidou Ouedraogo, Ali Sié, Rainer Sauerborn, Valérie R. LouisAbstract:The first line of malaria vector control to date mainly relies on the use of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS). For integrated vector management, targeting the vector larvae with biological larvicides such as Bacillus Thuringiensis Israelensis (Bti) can be an effective additional mainstay. This study presents data from the second intervention year of a large-scale trial on biological larviciding with Bti that was carried out in 127 rural villages and a semi-urban town in Burkina Faso. Here we present the reductions in malaria mosquitoes that were achieved by continuing the initial interventions for an additional year, important to assess sustainability and repeatability of the results from the first intervention year. Larviciding was performed applying two different larviciding choices ((a) treatment of all environmental breeding sites, and (b) selective treatment of those that were most productive for Anopheles larvae indicated by remote sensing based risk maps). Adult Anopheles spp. mosquito abundance was reduced by 77.4% (full treatment) and 63.5% (guided treatment) compared to the baseline year. The results showed that malaria vector abundance can be dramatically reduced using biological larviciding and that this effect can be achieved and maintained over several consecutive transmission seasons.
-
Effect of biological larviciding with Bacillus Thuringiensis Israelensis for malaria control on non-target vector mosquito species in rural Burkina Faso – A cluster randomized trial
2019Co-Authors: Peter Dambach, Till Bärnighausen, Issouf Traoré, Saidou Ouedraogo, Ali Sié, Rainer Sauerborn, Anges Yadouleton, Martin Dambach, Patricia Korir, Norbert BeckerAbstract:Abstract Background: Biological larviciding is an additional tool that can help address the current dilemma in malaria control, namely vector resistances to pyrethroids and shifting of biting activity to times when people are not protected. Although malaria interventions primarily target Anopheles mosquitoes, there might be an impact on populations of other mosquito genera that share the same breeding sites. In this study we research to what extent Culex and Aedes mosquitoes, the primary vectors of numerous zoonotic diseases, are affected by larviciding interventions against malaria mosquitoes. Methods: We researched the impact of different larviciding choices with Bacillus Thuringiensis Israelensis on non-target mosquitoes in 127 rural villages and a semi-urban town in a health district in Northwestern Burkina Faso. All villages were distributed into a total of three study arms with different larviciding choices: full, selective and untreated control. Geographically close villages were distributed into clusters to avoid contamination between treated and untreated villages. Adult mosquitoes were captured in light traps inside and outside houses during the rainy seasons of a baseline and an intervention year. A negative binomial regression was used to determine the reductions achieved through larviciding among different mosquito genera.Results: Larviciding interventions against malaria showed only limited or no impact against Culex mosquitoes, while against Aedes, reductions of up to 34% were achieved when all detected breeding sites in the public space were treated. While the semi-urban setting showed high abundance of Culex, in the rural villages we captured more Aedes. Conclusions: Future larviciding programs should be evaluated for including the treatment of Aedes and Culex breeding habitats. Since the major cost components of such programs are labor and transport, other disease vectors could be targeted at little additional cost.
-
Field Efficacy of Granular Formulations of Bacillus Thuringiensis Israelensis - Strain Am65-52 Against Floodwater Mosquitoes in Poland and Germany
Journal of the American Mosquito Control Association, 2010Co-Authors: Katarzyna Rydzanicz, Peter Dechant, Norbert BeckerAbstract:Abstract This paper presents results of studies evaluating the efficacy of various granular formulations of VectoBac® (Bacillus Thuringiensis Israelensis de Barjac [Bti] H-14 strain AM65-52) against immature mosquitoes in 2 distinct habitats in Poland and Germany. Meadows intermittently flooded with sewage water in the city of Wroclaw, Poland, provide ideal habitats for immature stages of Aedes caspius, Ae. vexans, and Culex pipiens pipiens. Helicopter applications of VectoBac G and VectoBac TP sand granules (VectoBac TP-SG) at rates of 5 and 10 kg/ha to the meadows resulted in between 70.9% and 97.4% larval mortality. In Germany, some swampy woodlands in the upper Rhine Valley provide ideal habitats for snowmelt mosquitoes, Aedes cantans, Ae. punctor, Ae. rusticus, and Ae. communis. Ground applications of VectoBac G, VectoBac TP-SG, and VectoBac WG IcyPearls (VectoBac WG-IP) were made to these habitats when the water temperature was ∼7°C. Larval mortality at 7-day post-application ranged from 90.9% (Vect...
-
Sterilization of Bacillus Thuringiensis Israelensis products by gamma radiation.
Journal of the American Mosquito Control Association, 2002Co-Authors: Norbert BeckerAbstract:This study examines the effect of routine gamma radiation based on cobalt 60 on the viability, mosquito larvicidal activity, and density of Bacillus spores in the soil. Although 1 g of unirradiated powder of Bacillus Thuringiensis Israelensis (Bti) contains on average 6.2 × 10 9 spores, no spores survived radiation doses of 20.6 kGy and higher. Radiation at a dose of 20-25 kGy caused a 20-30% reduction in the effectiveness of Bti powder against mosquito larvae. In areas treated with unirradiated Bti material on average twice a year, soil contained 700,000 to 44 million spores per gram. In areas treated with irradiated Bti products, either no Bti spores or fewer than 100,000 were found per gram of soil. A radiation dose of 25 kGy fulfills the requirements of killing all spores in a Bti product and maintaining the effectiveness of the product in routine treatments. No viable spores remain in water used for household purposes or irrigation of garden areas when irradiated Bti fizzy tablets are used in water containers. Irradiation of Bti products fulfills the requirements of drinking water regulations and thus allows these products to be used widely.
-
Community based dengue control in Columbia: people's knowledge and practice and the potential contribution of the biological larvicide Bti (Bacillus Thuringiensis Israelensis).
Tropical medicine and parasitology : official organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft fur Technische Zusammenar, 1995Co-Authors: Axel Kroeger, Dehlinger U, Burkhardt G, Atehortua W, Anaya H, Norbert BeckerAbstract:A study on dengue control was undertaken in a poor urban area in Cucuta, Colombia. The first objective was to describe people's knowledge, attitudes and practices regarding dengue fever, the transmission of the disease and possible preventive measures. The second objective was to analyse the infestation of the community with Aedes aegypti larvae, and the third objective to test the efficacy of Bti (Bacillus Thuringiensis Israelensis) with respect to the level and duration of reduction of Ae. aegypti larvae in water tanks. It was found that people had a very fragmentary knowledge about dengue and about the necessary protective measures which did not lead them to any action. The infestation of water containers, particularly the larger tanks, was very high (house index = 61 ; Breteau index = 96). The application of Bti in water tanks led to satisfactory results : For one month and longer, the water tanks treated with Bti were free of mosquito larvae. The effect was reduced by a lower dose, washing the tanks and a less potent formulation. People's acceptance of Bti was higher than that of temephos. Further studies are necessary to confirm the utility of Bti in dengue control.
