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

1991 ◽  
Vol 25 (3) ◽  
pp. 184-187 ◽  
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.

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

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.

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

BIOSCIENTIAE ◽  
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.

scholarly journals Pemanfaatan Jeruk Purut (Citrus Hystrix) Sebagai Biolarvasida

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Titik Lestari
Keyword(s):  
Essential Oil ◽  
Literature Review ◽  
Aedes Aegypti ◽  
Research Methods ◽  
Chemical Compound ◽  
Mosquito Vector ◽  
The Third ◽  
Chemical Content ◽  
Lethal Time ◽  
Third Instar Larvae

Absctract: Citrus hystrix, Biolarvicides. Insectisides and pestisides were used as larvicides to control mosquito vector Aedes aegypti particularly. Some research suggested there had been a larvae resistance to pesticides. Biolarvicides with basic ingredients plant was another alternative that can be used. Lime (Citrus hystrix) was one of plants that often used as biolarvicides, both lits fruit and leaves. This paper aimed to know about chemical compound in lime and its potential as biolarvicidal. Research methods was literature review from several research journals. The results showed that the presence of coumpounds were essential oil, flavonoids, saponins, terpeesn, limonoids, citronellal, linalool, citronellol, acetate citronelil, kariofilin and geraniol. LC50 of lime leaves as biolarvicides againts the third instar larvae of Aedes aegypti was 279.882 ppm, biolarvicides oxicity values (LC90) was 4000 ppm with the lethal time (LT90) was 12.67 hours. Based on results of this study concluded that the presence of the chemical content of Citrus hystrix plant potential as biolarvicides.

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

2005 ◽  
Vol 47 (1) ◽  
pp. 7-12 ◽  
Author(s):  
José Bento Pereira Lima ◽  
Nilson Vieira de Melo ◽  
Denise Valle
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Rio De Janeiro ◽  
Weather Conditions ◽  
Post Treatment ◽  
Field Bioassay ◽  
Storage Containers ◽  
Third Instar Larvae

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.

scholarly journals Evaluation of a new formulation of Bacillus thuringiensis israelensis

2010 ◽  
Vol 70 (4) ◽  
pp. 1109-1113 ◽  
Author(s):  
J. Lopes ◽  
OMN. Arantes ◽  
MA. Cenci
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Fourth Instar ◽  
State University ◽  
Local Production ◽  
Liquid Formulation ◽  
Bacillus Thuringiensis Israelensis ◽  
Commercial Products ◽  
New Formulation

The aim of this study was to determine the potency (ITU) and efficacy of a liquid formulation of Bacillus thuringiensis israelensis developed by the State University of Londrina named BioUel, against early fourth instar larvae of Aedes aegypti and Culex quinquefasciatus. The ITU/mg of BioUel was 960, the LC50 was of 0.271 (± 0.39) ppm, and the LC95 was 0.634 (± 0.099) ppm, in larvae of C. quinquefasciatus. In A. aegypti larvae, LC50 was 0.332 (± 0.042) ppm and LC95 was 0.694 (± 0.073) ppm. The ITU level of BioUel and its control results were similar to most commercial products tested. Stability was of approximately 90 days, which allows for local production.

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

2005 ◽  
Vol 47 (3) ◽  
pp. 125-130 ◽  
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.

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

Acta Tropica ◽  
2021 ◽  
pp. 106088
Author(s):  
Jiangyu Wu ◽  
Li Wei ◽  
Jiali He ◽  
Kang Fu ◽  
Xinxin Li ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Bacillus Thuringiensis Toxin

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

1985 ◽  
Vol 117 (1) ◽  
pp. 15-22 ◽  
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.

ENCAPSULATION OF RHABDITOID NEMATODES IN MOSQUITOES

1962 ◽  
Vol 40 (7) ◽  
pp. 1269-1275 ◽  
Author(s):  
Joan F. Bronskill
Keyword(s):  
Aedes Aegypti ◽  
Endemic Species ◽  
Body Cavity ◽  
Fourth Instar ◽  
The Body ◽  
Histological Structure ◽  
Adult Tissue ◽  
Defence Reaction ◽  
Blood Sinus

In third and fourth instar larvae of Aedes aegypti (L.), juveniles of the rhabditoid, DD136, penetrate the blood sinus and cardial epithelium of the proventriculus to enter the body cavity of the host, where they complete their development. By 5 hours, a thick capsule developed about many of the ensheathed immature adults of DD136 within the body cavity of A. aegypti larvae. This rapid defence reaction of the mosquito to DD136, which has both a melanin and a cellular manifestation, occurs both in the exotic mosquito A. aegypti and in the two endemic species tested, Aedes stimulans (Walker) and Aedes trichurus (Dyar). The resistance of A. stimulans to an endemic rhabditoid, possibly of the Diplogasteridae, is also similar. The histological structure of the capsule is not affected during metamorphosis in A. aegypti; however, during histogenesis of adult tissue displacement and (or) distortion of some tissues and organs may be caused by the presence of the capsule within the host's body cavity. The activity of the adult A. aegypti is normal when this distortion or displacement is minor. Though usually encapsulated DD136 are retained within the body cavity of A. aegypti during metamorphosis, sometimes they are partially or completely expelled from the host's body cavity at the time of molting.

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