Mosquito larvicidal potential of silver nanoparticles synthesized using Chomelia asiatica (Rubiaceae) against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae)

Sustainable use of plastic-derived nanocarbons as a promising larvicidal and growth inhibitor agent towards control of mosquitoes

Nanoscale carbon was obtained from six widely used plastics (PET, HDPE, PVC, LDPE, PP and PP) via thermal degradation (600 °C) under inert atmosphere. The thermally degraded products were processed through bath sonication followed by lyophilisation and the same was characterized through proximate analysis, UV-Vis spectroscopy, Scanning electron micrograph (SEM) with energy dispersive X-ray (EDX) analysis, Transmission electron micrograph (TEM), Dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR). A series of aqueous solution of nanoscale carbon (5-30 mg/L) were prepared and same were used as both mosquito growth inhibitor and larvicidal agent against 3rd and 4th instar larvae of Culex pipiens. The significant percent mortality results were recorded for LDPE (p < 0.007) with average particle size of 3.01 nm and 62.95 W% of carbon and PS (p < 0.002) with average particle size of 12.80 nm and 58.73 W% of carbon against 3rd instar larvae, respectively. Similarly, for 4th instar larvae, both significant pupicidal and adulticidal activity were also recorded for PET (F = 24.0, p < 0.0001 and F = 5.73, p < 0.006), and HDPE (F = 26.0, p < 0.0001) and F = 5.30, p < 0.008). However, significant pupicidal activity were observed for PVC (F = 6.90, p < 0.003), and PS (F = 21.30, p < 0.0001). Histological, bio-chemical and microscopic studies were revealed that nanoscale carbon causes mild to severe damage of external and internal cellular integrity of larvae. However, nanoscale carbon does not exhibit any chromosomal abnormality and anatomical irregularities in Allium cepa and Cicer arietinum, respectively. Similarly, non-significant results with respect to blood cell deformation were also recorded from blood smear of Poecilia reticulata. Therefore, it can be concluded that plastic origin nanoscale carbon could be a viable sustainable nano-weapon towards control of insects.

An Investigation into the Larvicidal Activity of Biologically Synthesized Silver and Copper Oxide Nanoparticles Against Mosquito Larvae

This study is primarily focused on the synthesis of silver and copper oxide nanoparticles utilizing the extract of Ipomoea staphylina plant and their larvicidal activity against specific larvae. Notably, Anopheles stephensi and Aedes aegypti are significant disease vectors responsible for transmitting diseases such as malaria, dengue fever, Zika virus, and chikungunya (Anopheles stephensi), and dengue and Zika (Aedes aegypti). These mosquitoes have a substantial impact on urban areas, influencing disease transmission dynamics. In an effort to control these larvae, we have pursued the synthesis of a herbal-based nanomedicine derived from I. staphylina, a valuable herb in traditional medicine. Our successful synthesis of silver and CuO nanoparticles followed environmentally sustainable green chemistry methodologies. The I. staphylina plant extract played a dual role as a reducing agent and dopant, aligning with principles of sustainability. We employed X-ray diffraction (XRD) analysis to validate the nanoparticle structure and size, while field-emission scanning electron microscopy (FE-SEM) revealed well-defined nanostructures. Elemental composition was determined through energy-dispersive X-ray (EDX) analysis, and UV-visible spectroscopy provided insights into the bandgap energy (3.15 eV for silver, 1.2 eV for CuO nanoparticles). These nanoparticles exhibited robust larvicidal activity, with CuO nanoparticles surpassing silver nanoparticles in terms of LC50 and LC90 values. Moreover, the developmental toxicity of CuO and Ag NPs was evaluated in zebrafish embryos as part of non-target eco-toxicological studies conducted in a standard laboratory environment. These findings underscore the potential utility of these nanoparticles as highly effective and environmentally friendly natural pesticides, offering cost-effectiveness and ecological benefits.

Plant-mediated synthesis of silver nanoparticles: unlocking their pharmacological potential-a comprehensive review

In recent times, nanoparticles have experienced a significant upsurge in popularity, primarily owing to their minute size and their remarkable ability to modify physical, chemical, and biological properties. This burgeoning interest can be attributed to the expanding array of biomedical applications where nanoparticles find utility. These nanoparticles, typically ranging in size from 10 to 100 nm, exhibit diverse shapes, such as spherical, discoidal, and cylindrical configurations. These variations are not solely influenced by the manufacturing processes but are also intricately linked to interactions with surrounding stabilizing agents and initiators. Nanoparticles can be synthesized through physical or chemical methods, yet the biological approach emerges as the most sustainable and eco-friendly alternative among the three. Among the various nanoparticle types, silver nanoparticles have emerged as the most encountered and widely utilized due to their exceptional properties. What makes the synthesis of silver nanoparticles even more appealing is the application of plant-derived sources as reducing agents. This approach not only proves to be cost-effective but also significantly reduces the synthesis time. Notably, silver nanoparticles produced through plant-mediated processes have garnered considerable attention in recent years due to their notable medicinal capabilities. This comprehensive review primarily delves into the diverse medicinal attributes of silver nanoparticles synthesized using plant-mediated techniques. Encompassing antimicrobial properties, cytotoxicity, wound healing, larvicidal effects, anti-angiogenesis activity, antioxidant potential, and antiplasmodial activity, the paper extensively covers these multifaceted roles. Additionally, an endeavor is made to provide an elucidated summary of the operational mechanisms underlying the pharmacological actions of silver nanoparticles.

Synergistic antibacterial and mosquitocidal effect of Passiflora foetida synthesized silver nanoparticles

Silver nanoparticles are opted to have various applications in different fields ranging from traditional medicines to culinary items. It is toxic and most effective against bacteria, fungi viruses, parasites, parasite carrying vectors such as mosquitoes and their larvae and other eukaryotic microorganisms at low concentration without any side effects and toxicity to humans. In view of these data, the present research has been investigated by synthesizing silver nanoparticles using 1mM silver nitrate and aqueous extract of Passiflora foetida. The variation of nanoparticles in size and shape concerning the concentration of extract prepared were analysed. The formation of silver nanoparticles was confirmed by colour changing from yellowish green to reddish-brown implicating the surface plasmon resonance. Further, it was concluded by obtaining an absorbance peak at 420 nm using UV-Visible spectrophotometer analysis. FTIR analysis was used to identify the capping ligands, which included alkanes, aromatic groups and nitro compounds. The average grain size of ~12 nm to 14 nm with crystalline phase was revealed by X-ray Diffraction studies. The SEM images depicted the surface morphology with agglomeration; TEM studies showed the shape of nanoparticles as spherical and hexagonal with sizes ranging from 40 nm to 100 nm and EDAX analysis confirmed the presence of elemental silver as the principal constituent. The characterized silver nanoparticles were then tested for synergistic antibacterial effects with tetracycline, and the results show that they are more active against E. coli and S. aureus, but moderately effective against B. cereus and K. pneumoniae . It also had a strong larval and pupal toxic effects on the dengue vector, Aedes aegypti with the highest mortality. As a result, silver nanoparticles could be a viable alternative for a variety of applications.

Efficacy of metal nanoparticles as a control tool against adult mosquito vectors: A review

Presently, there is a need to develop effective and novel modes of control for mosquitoes, which remain a key driver of infectious disease transmission throughout the world. Control methods for these vectors have historically relied on a limited number of active ingredients (AIs) that have not experienced significant change in usage since the mid-20th century. The resulting development of widespread insecticide resistance has consequently increased the risk for future vector-borne disease outbreaks. Recently, metal nanoparticles have been explored for potential use in mosquito control due to their demonstrated toxicity against mosquitoes at all life stages. However, the majority of studies to date have focused on the larvicidal efficacy of metal nanoparticles with few studies examining their adulticidal potential. In this review, we analyze the current literature on green synthesized metal nanoparticles and their effect on adult mosquitoes.

Green Nano-Biotechnology: A New Sustainable Paradigm to Control Dengue Infection

Dengue is a growing mosquito-borne viral disease prevalent in 128 countries, while 3.9 billion people are at high risk of acquiring the infection. With no specific treatment available, the only way to mitigate the risk of dengue infection is through controlling of vector, i.e., Aedes aegypti. Nanotechnology-based prevention strategies like biopesticides with nanoformulation are now getting popular for preventing dengue fever. Metal nanoparticles (NPs) synthesized by an eco-friendly process, through extracts of medicinal plants have indicated potential anti-dengue applications. Green synthesis of metal NPs is simple, cost-effective, and devoid of hazardous wastes. The recent progress in the phyto-synthesized multifunctional metal NPs for anti-dengue applications has encouraged us to review the available literature and mechanistic aspects of the dengue control using green-synthesized NPs. Furthermore, the molecular bases of the viral inhibition through NPs and the nontarget impacts or hazards with reference to the environmental integrity are discussed in depth. Till date, major focus has been on green synthesis of silver and gold NPs, which need further extension to other innovative composite nanomaterials. Further detailed mechanistic studies are required to critically evaluate the mechanistic insights during the synthesis of the biogenic NPs. Likewise, detailed analysis of the toxicological aspects of NPs and their long-term impact in the environment should be critically assessed.

Phytochemical analysis and fabrication of silver nanoparticles using Acacia catechu: An efficacious and ecofriendly control tool against selected polyphagous insect pests

Globally, the farmers are struggling with polyphagous insect pest, and it is the number one enemy of agri-products, which made plenty of economic deterioration. Spodoptera litura and Helicoverpa armigera are the agronomically important polyphagous pests. Most of the farmers are predominately dependent on synthetic chemical insecticides (SCIs) for battle against polyphagous pets. As a result, the broad spectrum usage of SCIs led a lot of detrimental outcomes only inconsequently the researchers search the former-friendly phyto-pesticidal approach. In the present investigation, leaf ethanol extract (LEE) and silver nanoparticles (AgNPs) of A. catechu (Ac) were subjected to various spectral (TLC, CC, UV, FTIR, XRD and SEM) analyses. Larval and pupal toxicity of A. catechu Ac-LEE and Ac-AgNPs were tested against selected polyphagous insect pests. The significant larval and pupal toxicity were experimentally proven, and the highest toxicity noticed in AgNPs than Ac-LEE. The larval and pupal toxicity of Ac-AgNPs tested against S. litura and H. armigera LC50/LC90 values were 71.04/ 74.78, 85.33/ 88.91 µg/mL and 92.57/ 96.21 and 124.43/ 129.95 µg/mL respectively. Ac-AgNPs could be potential phyto-pesticidal effectiveness against selected polyphagous insect pests. In globally, it is significantly sufficient ratification giving towards the prevention of many unauthorized SCPs.

Design and development of porous terracotta disc: An eco-friendly novel control agent for mosquito larvae

In the present work, we synthesized silver nanoparticles supported by rice husk by hydrothermal treatment, as-synthesized silver nanoparticles rice husk (AgNPs-RH) bio-composite mixed with potter clay thoroughly, molded, dried into a disc-shaped before firing and applying as a point of use larvicidal agent. As designed, porous terracotta disc (PTD) infused with AgNPs-RH-biocomposite were characterized by UV spectrophotometer, Fourier-transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction analysis and energy-dispersive X-ray spectroscopy. The amount of silver ions released from the PTD was also found to be within the prescribed limit of 0.1 ppm-level. Later we dropped the PTD and tested its larvicidal activity against the IV^th instar larva stage of Aedes, Anopheles and Culex species. We found 100% larvicidal mortality in 24 h of exposure to the designed PTD and the amount of silver released from the porous disc was found to be 0.0343 ppm. Further from the histopathological studies of dead larvae revealed that the silver ions from the PTD have substantially damaged the exoskeleton of larvae.

Biocontrol of mosquito vectors through herbal-derived silver nanoparticles: prospects and challenges

Mosquitoes spread several life-threatening diseases such as malaria, filaria, dengue, Japanese encephalitis, West Nile fever, chikungunya, and yellow fever and are associated with millions of deaths every year across the world. However, insecticides of synthetic origin are conventionally used for controlling various vector-borne diseases but they have various associated drawbacks like impact on non-targeted species, negative effects on the environment, and development of resistance in vector species by alteration of the target site. Plant extracts, phytochemicals, and their nanoformulations can serve as ovipositional attractants, insect growth regulators, larvicides, and repellents with least effects on the environment. Such plant-derived products exhibit broad-spectrum resistance against various mosquito species and are relatively cheaper, environmentally safer, biodegradable, easily accessible, and are non-toxic to non-targeted organisms. Therefore, in this review article, the current knowledge of phytochemical sources exhibiting larvicidal activity and their variations in response to solvents used for their extraction is underlined. Also, different methods such as physical, chemical, and biological for silver nanoparticle (AgNPs) synthesis, their mechanism of synthesis using plant extract, their potent larvicidal activity, and the possible mechanism by which these particles kill mosquito larvae are discussed. In addition, constraints related to commercialization of nanoherbal products at government and academic or research level and barriers from laboratory experiments to field trial have also been discussed. This comprehensive information can be gainfully employed for the development of herbal larvicidal formulations and nanopesticides against insecticide-resistant vector species in the near future. Graphical abstract.

Bio-nanoparticle assembly: a potent on-site biolarvicidal agent against mosquito vectors

Background: Vector-borne diseases such as malaria, dengue, yellow fever, encephalitis and filariasis are considered serious human health concerns in the field of medical entomology. Controlling the population of mosquito vectors is one of the best strategies for combating such vector-borne diseases. However, the use of synthetic insecticides for longer periods of time increases mosquito resistance to the insecticides. Recently, the search for new environmentally friendly and efficient insecticides has attracted major attention globally. With the evolution of material sciences, researchers have reported the effective control of such diseases using various sustainable resources. The present investigation demonstrates a potent on-site biolarvicidal agent against different mosquito vectors such as Aedes albopictus, Anopheles stephensi and Culex quinquefasciatus. Methods: Stable and photo-induced colloidal silver nanoparticles were generated via the surface functionalization of the root extract of Cyprus rotundas. Characterizations of the nanoparticles were performed using assorted techniques, such as UV-visible spectroscopy, FTIR spectroscopy, DLS and HRTEM. The bioefficacy of the synthesized nanoparticles was investigated against different species of mosquito larvae through the evaluation of their life history trait studies, fecundity and hatchability rate of the treated larvae. Histopathological and polymerase chain reaction-random amplified polymorphic DNA (RAPD) analyses of the treated larvae were also examined to establish the cellular damage. Results: The synthesized nanoparticles showed remarkable larvicidal activity against mosquito larvae in a very low concentration range (0.001–1.00) mg L⁻¹. The histopathological study confirmed that the present nanoparticles could easily enter the cuticle membrane of mosquito larvae and subsequently obliterate their complete intestinal system. Furthermore, RAPD analysis of the treated larvae could assess the damage of the DNA banding pattern. Conclusion: The present work demonstrates a potent biolarvicidal agent using sustainable bioresources of the aqueous Cyprus rotundas root extract. The results showed that the synthesized nanoparticles were stable under different physiological conditions such as temperature and photo-induced oxidation. The effectiveness of these materials against mosquito larvae was quantified at very low dose concentrations. The present biolarvicidal agent can be considered as an environmentally benign material to control the mosquito vectors with an immense potential for on-site field applications.

The present work demonstrates a potent and stable biolarvicidal agent using sustainable bioresources. The synthesized nanomaterials can control the mosquito vectors at a very low concentration range (0.01–1.00 mg L⁻¹) for on-site field applications.

Plant extracts for developing mosquito larvicides: From laboratory to the field, with insights on the modes of action

In the last decades, major research efforts have been done to investigate the insecticidal activity of plant-based products against mosquitoes. This is a modern and timely challenge in parasitology, aimed to reduce the frequent overuse of synthetic pesticides boosting resistance development in mosquitoes and causing serious threats to human health and environment. This review covers the huge amount of literature available on plant extracts tested as mosquito larvicides, particularly aqueous and alcoholic ones, due to their easy formulation in water without using surfactants. We analysed results obtained on more than 400 plant species, outlining that 29 of them have outstanding larvicidal activity (i.e., LC₅₀ values below 10 ppm) against major vectors belonging to the genera Anopheles, Aedes and Culex, among others. Furthermore, synergistic and antagonistic effects between plant extracts and conventional pesticides, as well as among selected plant extracts are discussed. The efficacy of pure compounds isolated from the most effective plant extracts and - when available - their mechanism of action, as well as the impact on non-target species, is also covered. These belong to the following class of secondary metabolites: alkaloids, alkamides, sesquiterpenes, triterpenes, sterols, flavonoids, coumarins, anthraquinones, xanthones, acetogenonins and aliphatics. Their mode of action on mosquito larvae ranges from neurotoxic effects to inhibition of detoxificant enzymes and larval development and/or midugut damages. In the final section, current drawbacks as well as key challenges for future research, including technologies to synergize efficacy and improve stability - thus field performances - of the selected plant extracts, are outlined. Unfortunately, despite the huge amount of laboratory evidences about their efficacy, only a limited number of studies was aimed to validate their efficacy in the field, nor the epidemiological impact potentially arising from these vector control operations has been assessed. This strongly limits the development of commercial mosquito larvicides of botanical origin, at variance with plant-borne products developed in the latest decades to kill or repel other key arthropod species of medical and veterinary importance (e.g., ticks and lice), as well as mosquito adults. Further research on these issues is urgently needed.

Comparison Between Insecticidal Activity of <i>Lantana camara</i> Extract and its Synthesized Nanoparticles Against Anopheline mosquitoes

BACKGROUND AND OBJECTIVE

Malaria is still a severe health problem especially in developing countries which occur and young children are the most affected. The present study was designed to compare the insecticidal potential of Lantana camara leaves extract alone and its synthesized nanoparticles against Anopheles multicolor.

MATERIALS AND METHODS

Copper nanoparticles CuNPs were synthesized by green bio-reduction method using aqueous extract of leaves of Lantana camara plant. The CuNPs formation was confirmed by ultraviolet visible spectrophotometer (UV-VIS) and Transitional Electron Microscopy (TEM). The application of L. camara extract and its synthesized CuNPs on different stages of A. multicolor were adopted.

RESULTS

The biosynthesized CuNPs were spherical with the average sizes of 11-17.8 nm. The highest insecticidal effect (100% of larval mortality) achieved at high dose (140 ppm) of L. camara leaves extract alone comparing with that occur at low dose (20 ppm) of CuNPs synthesized L. camara leaves. The LC50 and LC90 for the 4 instar larvae were 63.5 and 119.9 ppm for plant extract alone compared to 12.6 and 18.4 ppm for CuNPs preparation.

CONCLUSION

So, this study proved that CuNPs preparation of L. camara leaves is highly efficient compared to the plant extract alone and more economic as less quantities were used. Also, awareness against invasion of Anopheles mosquito vectors with effective preventive measures to protect from malaria infection.

Nanosilver crystals capped with Bauhinia acuminata phytochemicals as new antimicrobials and mosquito larvicides

To develop novel nanoformulated insecticides and antimicrobials, herein we produced Ag nanoparticles (AgNPs) using the Bauhinia acuminata leaf extract. This unexpensive aqueous extract acted as a capping and reducing agent for the formation of AgNPs. We characterized B. acuminata-synthesized AgNPs by UV-vis and FTIR spectroscopy, XRD and TEM analyses. UV-vis spectroscopy analysis of B. acuminata-synthesized AgNPs showed a peak at 441.5 nm. FTIR shed light on functional groups from the phytoconstituents involved in nanosynthesis. XRD of B. acuminata-synthesized AgNPs suggested a face-centered cubic structure, with a highly crystalline nature. TEM of B. acuminata-synthesized AgNPs revealed mean size of 25 nm, with round shape. AgNPs tested at 60 μg/mL inhibited the growth of 5 bacteria and 3 fungal pathogens. In the insecticidal assays on important mosquito species, LC₅₀ of the aqueous extract of B. acuminata leaves on the larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus were 204.07, 226.02, and 249.24 μg/mL, respectively. The B. acuminata-synthesized AgNPs exhibited higher larvicidal efficacy, with LC₅₀ values of 24.59, 27.19, and 30.19 μg/mL, respectively. Therefore, herein we developed a single-step, reliable, inexpensive, and environmentally non-toxic synthesis process to obtain AgNPs with high bioactivity against pathogens and vectors. Given the effective antimicrobial and larvicidal activity, nanoparticles fabricated using plant extracts and extremely low concentrations of trace elements, such as silver, can be exploited for multipurpose activities. Our results pointed out that B. acuminata-synthesized AgNPs have a promising potential in antimicrobial food packaging, as well as a foliar spray to control plant pathogens in the field, and to synergize the efficacy of fungicidal and larvicidal formulations.

Fabrication of highly effective mosquito nanolarvicides using an Asian plant of ethno-pharmacological interest, Priyangu (Aglaia elaeagnoidea): toxicity on non-target mosquito natural enemies

Mosquitoes threaten the lives of humans, livestock, pets and wildlife around the globe, due to their ability to vector devastating diseases. Aglaia elaeagnoidea, commonly known as Priyangu, is widely employed in Asian traditional medicine and pest control. Medicinal activities include anti-inflammatory, analgesic, anticancer, and anesthetic actions. Flavaglines, six cyclopenta[b]benzofurans, a cyclopenta[bc]benzopyran, a benzo[b]oxepine, and an aromatic butyrolactone showed antifungal properties, and aglaroxin A and rocaglamide were effective to control moth pests. Here, we determined the larvicidal action of A. elaeagnoidea leaf aqueous extract. Furthermore, we focused on Priyangu-mediated synthesis of Ag nanoparticles toxic to Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi. The plant extract and the nanolarvicide were tested on three mosquito vectors, following the WHO protocol, as well as on three non-target mosquito predators. Priyangu-synthesized Ag nanoparticles were characterized by spectroscopic (UV, FTIR, XRD, and EDX) and microscopic (AFM, SEM, and TEM) analyses. Priyangu extract toxicity was moderate on Cx. quinquefasciatus (LC₅₀ 246.43; LC₉₀ 462.09 μg/mL), Ae. aegypti (LC₅₀ 229.79; LC₉₀ 442.71 μg/mL), and An. stephensi (LC₅₀ 207.06; LC₉₀ 408.46 μg/mL), respectively, while Priyangu-synthesized Ag nanoparticles were highly toxic to Cx. quinquefasciatus (LC₅₀ 24.91; LC₉₀ 45.96 μg/mL), Ae. aegypti (LC₅₀ 22.80; LC₉₀ 43.23 μg/mL), and An. stephensi (LC₅₀ 20.66; LC₉₀ 39.94 μg/mL), respectively. Priyangu extract and Ag nanoparticles were found safer to non-target larvivorous fishes, backswimmers, and waterbugs, with LC₅₀ ranging from 1247 to 37,254.45 μg/mL, if compared to target pests. Overall, the current research represents a modern approach integrating traditional botanical pesticides and nanotechnology to the control of larval populations of mosquito vectors, with negligible toxicity against non-target including larvivorous fishes, backswimmers, and waterbugs.

A facile and rapid method for green synthesis of Achyranthes aspera stem extract-mediated silver nano-composites with cidal potential against Aedes aegypti L

Aedes aegypti L. is the primary vector associated with transmission of globally concerned diseases; Zika, yellow fever, dengue and Chikungunya. Present study investigates an efficient, alternative and comparative approach for mosquito control which is safe to environment and non-target organisms. The silver nano-composites (AgNCs) were synthesized from the aqueous stem extract of Achyranthes aspera (AASE) using different concentration of aqueous silver nitrate (AgNO₃). The synthesis was tracked by UV-vis spectrophotometer and particle size analyser (DLS). The evaluation of their larvicidal potential against early fourth instars of Ae. aegypti showed significant potency, the toxicity increasing with the concentration of silver nitrate. The 24, 48 and 72 h bioassays resulted in respective LC₅₀ values of 26.693, 1.113 and 0.610 μg/mL (3 mM AASE-AgNO₃) 9.119, 0.420 and 0.407 μg/mL (4 mM AASE-AgNO₃) and that of 4.283, 0.3 and 0.248 μg/mL (5 mM AASE-AgNO₃). Keeping in view the significantly high larvicidal efficiency at lower concentration of silver nitrate, the 4 mM nano-composites were selected over 5 mM composites for further biophysical characterization carried out by X-ray Diffraction (XRD), Fourier transform infrared spectrometer (FTIR), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) spectroscopy and Transmission electron microscopy (TEM). SEM and TEM confirmed the synthesis of spherical poly-dispersed AgNCs with average size ranging from 1-30 nm. Characterization through XRD showed the crystalline face-centered-cubic (fcc) structure of AgNCs with the highest intense peak obtained at 2θ value of 31.82°. FT-IR data suggests complex nature of AgNCs showing clearly defined peaks in different ranges. The present investigations recommend AgNCs of A. aspera stems as a low-cost and eco-friendly alternative to chemical insecticides for mosquito control.

Ipomoea batatas (Convolvulaceae)-mediated synthesis of silver nanoparticles for controlling mosquito vectors of Aedes albopictus, Anopheles stephensi, and Culex quinquefasciatus (Diptera:Culicidae)

We proposed an effective and eco-friendly control of dengue, malaria, and filariasis-causing vectors. We tested Ipomoea batatas leaves-mediated silver nanoparticles (AgNPs) against first to fourth instar larvae and adults of Aedes albopictus, Anopheles stephensi, and Culex quinquefasciatus at different concentrations. The synthesized AgNPs showed broad spectrum of larvicidal and adulticidal effects after 48 h of exposure. The characterization of synthesized AgNPs was done using various spectral and microscopy analyses. The maximum efficacy was observed in synthesized AgNPs against the adult of Ae. albopictus with the LC₅₀ and LC₉₀ values were 10.069 and 15.657 μg/mL, respectively, followed by others.

Mosquito larvicidal activity of cadmium nanoparticles synthesized from petal extracts of marigold (Tagetes sp.) and rose (Rosa sp.) flower

Mosquitoes are blood-thirsty insects and serve as the most important vectors for spreading most notorious diseases such as malaria, yellow fever, dengue fever, and filariasis. The extensive use of synthetic mosquito repellent has resulted in resistance in mosquitoes. Therefore, the development of a reliable, eco-friendly processes for the synthesis of nano dimensional materials is an utmost important aspect of nanotechnology. In the present study, authors report absolute green synthesis of cadmium nanoparticles using marigold and rose flower petal extract. The characterization of nanomaterials was done by using UV-Vis, SEM, FTIR and fluorescent spectrophotometer analysis. Finally cadmium nanoparticles were also evaluated for their larvicidal activity of mosquito. Marigold flower petal extract shows 100 % mortality after 72 h of incubation with 10 ppm of Cd-nanoparticles. No mortality was observed in the control. Therefore, out of two flower petal mediated nanoparticles, only marigold showed better performance towards mosquito larvicidal activity than rose petal extracts. This is the first report on mosquito larvicidal activity of flower-petal mediated cadmium nanoparticles. Thus, the use of marigold petal extract to synthesize cadmium nanoparticles is a rapid, ecofriendly, and a single-step approach and the CdNps formed can be potential mosquito larvicidal agents.

One-pot green synthesis of silver nanocrystals using Hymenodictyon orixense: a cheap and effective tool against malaria, chikungunya and Japanese encephalitis mosquito vectors?

Mosquitoes are important vectors of malaria, dengue, Zika virus and many other parasites and pathogens of public health relevance.

Size-controlled fabrication of silver nanoparticles using the Hedyotis puberula leaf extract: toxicity on mosquito vectors and impact on biological control agents

As a low-cost and eco-friendly control tool, Ag nanoparticles were fabricated usingHedyotis puberulaaqueous extract as a reducing and capping agent and showed potent activity against malaria and arbovirus vectors with low biotoxicity against non-target aquatic organisms.