Toxicity of Trewia nudiflora-mediated silver nanoparticles on mosquito larvae and non-target aquatic fauna

Toxin Reviews ◽  
2021 ◽  
pp. 1-12
Author(s):  
Venkattan Esan ◽  
Chakkaravarthy Elanchezhiyan ◽  
Shahid Mahboob ◽  
Khalid A. Al-Ghanim ◽  
Fahad Al-Misned ◽  
...  
Author(s):  
Aparajita Gogoi ◽  
Shyama Prasad Biswas

Background: It is widely reported that exotic larvicidal fishes like Gambusia and Poecilia have adverse impact on the native aquatic fauna. The present study highlights the efficacy of two colourful native murrels, primarily designated as ornamental fish, Channa bleheri and Channa stewartii as biocontrol agent of mosquito larvae. Methods: Live specimens of Channa bleheri and C. stewartii, collected from the wetlands of Tinsukia district of Upper Assam, were assessed for their larvivorous potential at individual and group levels during day and night by dividing the specimens into two size groups. After 12 hour and 24 hour starvation, the test specimens (mean size for small group 8.67 - 9.17 cm and that of large group 11.63-13.27 cm) were given known number of mosquito larvae and recorded the consumption rate. Result: The predation rate varied from 33.3±4.36 to 71.6±5.15/min for Channa bleheri and that of C. stewartii from 16.3±0.95 to 68.2±2.77/min. In both species, smaller sized specimens were better performers as predators. Predation rate at 12 and 24 hrs of starvation and between day and night proved that these native murrels are excellent predators of mosquito larvae.


2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Sarita Ashok Bhutada

Mosquitoes are one of the most medically significant groups of vectors, having an ability to transmit parasites and pathogens that can have devastating impacts on humans. In this study, chitosan nanoparticles were synthesized from chitosan polymer by ionic gelation method. The chitin was first extracted from Saccharomyces cerevisiae and then deacetylated to chitosan. Silver nanopartcals were also prepared and the presence and characterization was investigated by scanning electron microscopy (SEM). The comparative study of the larvicidal activity of chitosan nanoparticles and silvers was also studied which shows chitosan nanoparticles started  mortality at higher concentrations, it showed uniform rise in mortality of mosquito larvae than silver nanoparticles. 


2020 ◽  
Vol 8 (2) ◽  
pp. 126
Author(s):  
Wilson Lamayi Danbature ◽  
Zaccheus Shehu ◽  
Muhammad Mustapha Adam ◽  
Ahmed Mohammed Bello

One of the objectives of nanotechnology is to synthesize effective nanoinsecticides in a bid to reduce the prevalence of the numerous diseases caused by mosquitoes. This synthesis is even more vital in cases where phytochemicals from plants extracts are used as reducing agents. In this study, phytochemical screening of aqueous sprout extract of Palmyra palm (Borassus aethiopum) was performed, in accordance with some established methods and the results confirmed the presence of alkaloids, flavonoids, saponins, coumarins, glycosides, tannins, phenols as well as quinines, however, sterols, steroids and terpenoids were not detected. Subsequently, the sprout extract was used as a reducing agent in the synthesis of silver nanoparticles (AgNPs). Characterization with Fourier transform infrared and Ultraviolet-visible spectrometry was then carried out to confirm the synthesis. In addition, the AgNPs were further analyzed for larvicidal potency against 1st, 2nd 3rd and 4th instars Culex quinquefasciatus mosquito larvae, at interval concentrations of 5, 10, 20, 25 and 50 ppm. The LC50 and LC90 values discovered to be 9.103 ppm and 134.463 ppm with a correlation of 0.815, as well as 10.316 ppm and 118.810 ppm with a correlation of 0.801, for the 1st and 2nd instars, respectively. Meanwhile, the 3rd and 4th instars had LC50 and LC90 values of 17.585 ppm and 179.052 ppm, respectively, with a correlation of 0.807. This study provides a basis for extracting and analyzing the reduction potential of the phytochemicals present in the sprout extract, as well as the application of AgNPs, in controlling mosquito larvae population.


2019 ◽  
Vol 107 (3) ◽  
pp. 305
Author(s):  
Mengmei Geng ◽  
Yuting Long ◽  
Tongqing Liu ◽  
Zijuan Du ◽  
Hong Li ◽  
...  

Surface-enhanced Raman Scattering (SERS) fiber probe provides abundant interaction area between light and materials, permits detection within limited space and is especially useful for remote or in situ detection. A silver decorated SERS fiber optic probe was prepared by hydrothermal method. This method manages to accomplish the growth of silver nanoparticles and its adherence on fiber optic tip within one step, simplifying the synthetic procedure. The effects of reaction time on phase composition, surface plasmon resonance property and morphology were investigated by X-ray diffraction analysis (XRD), ultraviolet-visible absorption spectrum (UV-VIS absorption spectrum) and scanning electron microscope (SEM). The results showed that when reaction time is prolonged from 4–8 hours at 180 °C, crystals size and size distribution of silver nanoparticles increase. Furthermore, the morphology, crystal size and distribution density of silver nanoparticles evolve along with reaction time. A growth mechanism based on two factors, equilibrium between nucleation and growth, and the existence of PVP, is hypothesized. The SERS fiber probe can detect rhodamin 6G (R6G) at the concentration of 10−6 M. This SERS fiber probe exhibits promising potential in organic dye and pesticide residue detection.


ENTOMON ◽  
2019 ◽  
Vol 44 (2) ◽  
pp. 117-126
Author(s):  
Rhitayu Chakraborti ◽  
Probir Kumar Bandyopadhyay

Study to assess the larvicidal property of Lantana camara leaves against Aedes triseriatus larvae found that the ethyl acetate extract had profound larvicidal action with the crude extract having a LC50 value of 409.831ppm. GC-MS analysis of the ethyl acetate extract confirmed the presence of twenty-one compounds out of which beta-caryophyllene covered the highest percentage of the chromatogram area. Further tests with beta-caryophyllene against the mosquito larvae proved it to be the active ingredient of L. Camara with a LC50 value of 104.243ppm.


Author(s):  
S. Rezaei-Zarchi ◽  
M. Taghavi-Foumani ◽  
S. Razavi Sheshdeh ◽  
M. Negahdary ◽  
G. Rahimi

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