Persistence of Vectobac WDG and Metoprag S-2G against Aedes aegypti larvae using a semi-field bioassay in Rio de Janeiro, Brazil

Persistence of Bacillus thuringiensis var. israelensis (Vectobac WDG) and methoprene (Metoprag S-2G) was evaluated against Aedes aegypti late third instar larvae of the Rockefeller strain in a semi-field bioassay. Tests were performed in Rio de Janeiro, using containers made of plastic, iron, concrete and asbestos, placed in a shaded area. The formulations used were 0.2 g of Vectobac-WDG and 1g of Metoprag S-2G per 100 liters of water in house storage containers. Vectobac WDG was tested twice, in March and in April/May, 2002. In March (temperature ranging from 21.5 to 39.3 ºC), 70-100% mortality was observed by the 7th day and declined abruptly thereafter. No significant differences were observed among the container types. In April/May (18.6 to 34.8 ºC) mortality was higher than 70% to 30-36 days in all cases, except in the iron container (40% mortality on the 12th day). Metoprag S-2G was evaluated in April/May, 2002, and induced mortality higher than 70% up to 15 days in the plastic and iron containers and only seven days in the concrete container. In the asbestos container, maximal mortality was achieved on day one post-treatment (66%). Our results point to a low persistence of both formulations in the weather conditions of Rio de Janeiro.

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Residual effect of two Bacillus thuringiensis var. israelensis products assayed against Aedes aegypti (Diptera: Culicidae) in laboratory and outdoors at Rio de Janeiro, Brazil

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652005000300002 ◽

2005 ◽

Vol 47 (3) ◽

pp. 125-130 ◽

Cited By ~ 18

Author(s):

José Bento Pereira Lima ◽

Nilson Vieira de Melo ◽

Denise Valle

Keyword(s):

Bacillus Thuringiensis ◽

Aedes Aegypti ◽

Vector Control ◽

Rio De Janeiro ◽

Residual Effect ◽

Dengue Vector ◽

Health Ministry ◽

Third Instar Larvae

Resistance of the dengue vector to temephos stimulated its substitution for Bacillus thuringiensis var. israelensis (Bti) since 2001 in Brazil. The persistence of the two Bti formulations employed at that time by the Health Ministry, Vectobac G and Aquabac G, was assayed under laboratory and outdoor conditions. Both formulations were tested at 0.2 g/10 liters of water, the same concentration applied in the field for vector control. The tests were done against Ae. aegypti third instar larvae (Rockefeller strain). In the laboratory, Vectobac G and Aquabac G caused at least 95% mortality until 101 and 45 days after treatment, respectively. In the outdoor assays, test containers of different materials were treated with either formulation and placed in a shaded area. Larvae were introduced each 3-6 days and mortality was recorded 24 and 48 hours later. In the first set of assays, performed in June 2001, mortality levels of 70% or more were attained for 2-5 weeks for both formulations in all containers. The exception was for the iron one that rusted, resulting in low mortality after seven days. In the second set of assays (August 2001), 70% mortality was attained for just 1-2 weeks for all the containers and both formulations.

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Screening Isolat Bacillus thuringiensis yang Berasal dari Karang Intan Kabupaten Banjar Kalsel terhadap Larva Nyamuk Aedes aegypti Instar 3

BIOSCIENTIAE ◽

10.20527/b.v7i2.183 ◽

2018 ◽

Vol 7 (2) ◽

Author(s):

Muhamat Muhamat

Keyword(s):

Bacillus Thuringiensis ◽

Aedes Aegypti ◽

Treatment Time ◽

Crystal Protein ◽

Complex Crystal ◽

Lc50 And Lc90 ◽

Third Instar Larvae

This study aimed to obtain isolates of B. thuringiensis pathogenic to larvae of mosquitoes Ae. aegypti from various habitats of mosquitoes in Karang Intan of Banjar District, South Kalimantan. The sampling has been conducted as many as 38 bags, and then isolation of B. thuringiensis was performed until obtained 15 isolates. Pathogenicity screening of 15 isolates against third instar larvae at a concentration Ae. aegypti 1x109 ccs (complex crystal protein spora)/ml obtained two pathogenic isolates, i.e. isolates MA17 and MA25-1. LC50 and LC90 for isolate MA17 with 24 hours of treatment time respectively were 2.63x109 ccs/ml and 2.04x1010 ccs/ml. LC50 and LC90 for isolate MA17 with 48 hours of treatment time respectively were 3.55x108 ccs/ml and 8.27x109 ccs/ml. LC50 and LC90 for MA25-1 isolates with 24 hours of treatment time respectively were 1.29x1010 ccs/ml and 8.51x1010 ccs/ml. LC50 and LC90 for MA25-1 isolates with 24 hours of treatment time respectively 2.88x109 ccs/ml and 2.88x1010 ccs/ml.

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Susceptibility of Aedes aegypti larvae to temephos and Bacillus thuringiensis var israelensis in integrated control

Revista de Saúde Pública ◽

10.1590/s0034-89101991000300004 ◽

1991 ◽

Vol 25 (3) ◽

pp. 184-187 ◽

Cited By ~ 13

Author(s):

Carlos Fernando S. de Andrande ◽

Maurício Modolo

Keyword(s):

Bacillus Thuringiensis ◽

Aedes Aegypti ◽

Integrated Control ◽

Integrated Treatment ◽

Fourth Instar ◽

Two Agents ◽

Lethal Time ◽

Third Instar Larvae

The susceptibility of field collected Aedes aegypti larvae was evaluated in terms of median lethal time (LT50) and final mortality, when treated with temephos, Bacillus thuringiensis var israelensis as well as mixtures of these two agents. Third instar larvae were shown to be more susceptible than early and late fourth instar ones to the entomopathogen. Survival of some individuals when exposed to temephos suggest possible resistance. Temporal synergism in early fourth instar larvae was detected when they were exposed to mixtures of Bti-temephos. The possibility of this integrated treatment is commented on.

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Toxicity and residual control of Plutella xylostella L. (Lepidoptera: Plutellidae) with Bacillus thuringiensis Berliner and insecticides

Ciência Rural ◽

10.1590/s0103-84782012000800001 ◽

2012 ◽

Vol 42 (8) ◽

pp. 1335-1340 ◽

Cited By ~ 1

Author(s):

Carla Pedroso de Moraes ◽

Luis Amilton Foerster

Keyword(s):

Bacillus Thuringiensis ◽

Plutella Xylostella ◽

Diamondback Moth ◽

Growth Inhibitor ◽

Weather Conditions ◽

Larval Population ◽

Resistant Population ◽

Cruciferous Plants ◽

Residual Control ◽

Third Instar Larvae

Plutella xylostella L. is the most important worldwide pest of cruciferous plants and indiscriminate use of insecticides has led to the resistance of the species to different groups. This research was conducted to compare the toxicity and persistence of two strains of Bacillus thuringiensis to P. xylostella larvae. Concentrations between 125 and 500g 100L-1 of water of the commercial products were evaluated and compared to the insect growth inhibitor diflubenzuron and to the neurotoxic pyrethroid deltamethrin. The efficacy of the insecticides was compared between treated plants kept indoor greenhouse and outdoor. Third instar larvae were more susceptible to B. thuringiensis than first instar ones. Agree and Dipel showed similar control rates of third instars until 10 days after treatment, but on the 15th day, Agree was significantly more efficient than Dipel. Both B. thuringiensis formulations showed a reduction in mortality after 10 days when the treated plants were exposed to natural weather conditions in comparison to the same treatments kept inside greenhouse. Dimilin (100g 100L-1 of water) and deltamethrin (30ml of commercial product 100L-1 of water) were not efficient to control third instar larvae of P. xylostella. This inefficiency cannot be attributed to a resistant population of P. xylostella since the larval population used in the experiments was not subjected to insecticide pressure, once the crop was organically cultivated all year round. The results showed that both formulations of B. thuringiensis are sound alternatives for the control of the diamondback moth in organically conducted cruciferous crops, considering the high residual control provided under subtropical weather conditions.

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Larvicidal toxicity and parasporal inclusion of native Bacillus thuringiensis BK5.2 against Aedes aegypti

Journal of Basic and Clinical Physiology and Pharmacology ◽

10.1515/jbcpp-2020-0472 ◽

2021 ◽

Vol 32 (4) ◽

pp. 379-384

Author(s):

Salamun ◽

Fatimah ◽

Ahmad Fauzi ◽

Seling N. Praduwana ◽

Ni’matuzahroh

Keyword(s):

Electron Microscope ◽

Bacillus Thuringiensis ◽

Aedes Aegypti ◽

National Park ◽

Probit Analysis ◽

Morphological Observation ◽

Region Detection ◽

Transmission Electron ◽

Lethal Time ◽

Third Instar Larvae

Abstract Objectives Native Bacillus thuringiensis BK5.2, isolated from soil of Baluran National Park, East Java, Indonesia, has been shown to be toxic against Aedes aegypti larvae. This study aims to determine the strength and the speed of the toxicity of B. thuringiensis BK5.2 against A. aegypti larvae in lethal concentration (LC) and lethal time (LT), as well as detection of toxin structure and parasporal inclusion. Methods LC values were determined by the mortality of A. aegypti third instar larvae after 24 and 48 h exposure to five various concentrations of B. thuringiensis BK5.2, while LT values were determined based on the mortality of A. aegypti third instar larvae due to exposure to LC90 concentration at 0; 0.5; 1; 2; 4; 8; 10; 20; 24; and 48 h. Larvicidal toxicity was determined based on value of LC50 and LC90 (CFU/mL), as well as LT50 and LT90 (hours) analysed with Probit analysis. Parasporal inclusion was detected using transmission electron microscope (TEM) and scanning electron microscope (SEM). Results Based on bioassay, LC50 and LC90 values were 11.6 × 106 and 22.7 × 106 CFU/mL, respectively, at 24 h exposure, as well as 8.3 × 106 and 15.4 × 106 CFU/mL, respectively, at 48 h exposure, while the value of LT50 and LT90 were 19.0 and 26.6 h, respectively. Morphological observation of the dead larvae showed there was damage on abdomen and thorax region. Detection by TEM and SEM showed there was cuboidal parasporal inclusion. Conclusions Native B. thuringiensis BK5.2 has high toxicity against A. aegypti larvae and detected flatcuboidal toxin in parasporal inclusion.

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Avaliação do acesso aos criadouros do aedes aegypti por agentes de saúde do programa saúde da família no município do Rio de Janeiro

Revista Baiana Saúde Pública ◽

10.22278/2318-2660.2008.v32.n2.a1403 ◽

1970 ◽

Vol 32 (2) ◽

pp. 151

Author(s):

Eduardo Dias Wermeling

Keyword(s):

Aedes Aegypti ◽

Rio De Janeiro

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Characterization of a novel Bacillus thuringiensis toxin active against Aedes aegypti larvae

Acta Tropica ◽

10.1016/j.actatropica.2021.106088 ◽

2021 ◽

pp. 106088

Author(s):

Jiangyu Wu ◽

Li Wei ◽

Jiali He ◽

Kang Fu ◽

Xinxin Li ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Aedes Aegypti ◽

Bacillus Thuringiensis Toxin

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A STANDARDIZED BIOASSAY FOR LARVICIDAL ACTIVITY OF BACILLUS THURINGIENSIS IN SUNFLOWER MOTH HOMOEOSOMA ELECTELLUM (LEPIDOPTERA: PHYCITIDAE)

The Canadian Entomologist ◽

10.4039/ent11715-1 ◽

1985 ◽

Vol 117 (1) ◽

pp. 15-22 ◽

Cited By ~ 4

Author(s):

R. G. Lidstone ◽

D. W. Goerzen ◽

G. G. Khachatourians

Keyword(s):

Bacillus Thuringiensis ◽

Larvicidal Activity ◽

Standard Test ◽

Mortality Curve ◽

Bioassay Technique ◽

Sunflower Moth ◽

Homoeosoma Electellum ◽

Third Instar Larvae

AbstractA standard test for the larvicidal activity of Bacillus thuringiensis (B.t.) against the larvae of the sunflower moth Homoeosoma electellum (Hulst) has been developed. Bioassay parameters investigated include diet preparation, concentration of B.t., effect of formaldehyde, and method of pathogen incorporation in diet. The LC50 for seconded third-instar larvae is 1.24 μg of Dipel® WP ml−1 or 19.8 IU B.t. ml−1 pathogen-incorporated diet. Layering of a pathogen-suspension upon the surface of the diet was not a reliable bioassay technique for H. electellum. The addition of formaldehyde in the diet reduced the slope of the dose–mortality curve but did not change the LC50.

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