Eco-friendly Insecticides Research Articles

Prodigiosin: A Potential Eco-Friendly Insecticide for Sustainable Crop Protection

Globally, insect pests adversely affect approximately 75% of the most important crops. However, the widespread use of chemical insecticides has significant drawbacks, including non-specific biological activity, toxicity to humans, detrimental effects on beneficial insects, and the rapid development of resistance. In this context, prodigiosin—a tripyrrolic secondary metabolite produced by various microorganisms—emerges as a promising alternative due to its favourable properties, such as being non-toxic, environmentally safe, non-irritant, and non-allergenic, and having non-carcinogenic potential. Prodigiosin has demonstrated insecticidal efficiency against pests at various developmental stages. Studies suggest that prodigiosin inhibits enzymes like acetylcholine esterase, protease, and acid phosphatase and induces oxidative stress. This review explores the potential of prodigiosin as an eco-friendly insecticide, discussing its production, extraction, and purification processes and its advantages, disadvantages, and mechanism of action, and future perspectives. Special emphasis is given to using non-pathogenic strains to mitigate biosafety concerns.

Evaluation of the efficacy of different eco-friendly insecticides against Whitefly on tomato under polyhouse conditions

Evaluation of the efficacy of different eco-friendly insecticides against Whitefly on tomato under polyhouse conditions

An Environmentally-Friendly RNAi Yeast-Attractive Targeted Sugar Bait Turns off the Drosophila suzukii Rbfox1 Gene

Spotted wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), are invasive vinegar flies of East Asian origin that are an increasingly global threat to the small fruit industry. It is essential that new classes of eco-friendly insecticides and cost-effective strategies for SWD control are developed. Here, we describe the preparation of a strain of RNA interference (RNAi) Saccharomyces cerevisiae expressing shRNA that specifically targets the SWD RNA-binding Fox protein 1 (Rbfox1) gene. The yeast effectively silences the SWD Rbfox1 gene, resulting in significant loss of fly neural activity. Laboratory trials demonstrated that the RNAi yeast can be mixed with soda, which functions as SWD attractive targeted sugar bait (ATSB) that can be delivered in a soda bottle feeder. The ATSB, mixed with yeast that was heat-killed prior to suspension in the ATSB, resulted in 92 ± 1% mortality of SWD flies that consumed it, yet had no impact on non-target dipterans. Rbfox.687 yeast delivered in ATSB feeders may one day be a useful component of integrated SWD control programs.

Saponin as an eco-friendly insecticide: unveiling mechanisms, challenges, and future directions

Saponin as an eco-friendly insecticide: unveiling mechanisms, challenges, and future directions

Ultrastructural changes in epithelial cells on different stages of sinantropic muscoid dipterans fed with spores of Brevibacillus laterosporus

Ultrastructural changes in epithelial cells on different stages of sinantropic muscoid dipterans fed with spores of Brevibacillus laterosporus

Toxicological investigations of biosynthesized nickel ferrites nanoparticles on midgut epithelium of Blaps polychresta as nanopesticides: Structural damages and oxidative stress.

Toxicological investigations of biosynthesized nickel ferrites nanoparticles on midgut epithelium of Blaps polychresta as nanopesticides: Structural damages and oxidative stress.

Fabrication of biosynthesized nickel ferrites nanoparticles and evaluation of their insecticidal efficacy on beetles (Blaps polychresta) testicular integrity

Green synthesis of nanoparticles has emerged as a significant strategy to develop effective and eco-friendly insecticide agents to combat insecticide resistance and preserve environmental integrity and biodiversity. This study was thus designed to fabricate novel green synthesized NiFe2O4 nanoparticles (NiFe NPs) and investigate their potential insecticidal effects for the first time using Blaps polychresta beetle as an agricultural coleopteran pest model. Therefore, we prepared NiFe NPs following the hydrothermal synthesis procedure in the presence of lemon juice. The physiochemical characteristics of NiFe NPs were investigated employing SEM, TEM, FT-IR, XRD, TGA, VSM, and UV-Vis analysis. The lowest and most effective dose of NiFe NPs against male beetles was ascertained at a concentration of 0.03 mg/g body weight, reporting 67% mortality after 48 h. To study the insecticidal impact of NiFe NPs, EDX analysis demonstrated the bioaccumulation of NiFe NPs in testicular tissues of beetles, leading to pathophysiological consequences. Precisely, the oxidative stress incited by NiFe NPs led to disturbance of the antioxidant defense system, which was defined by augmentation of lipid peroxidation and suppression of antioxidant enzymes. Furthermore, the comet assay exhibited remarkable DNA impairment, while flow cytometry analysis showed substantial cellular necrosis and apoptosis in NiFe NPs-treated beetles compared to control insects. In correlation with these findings, several aberrations in the histological and ultrastructure attributes of testicular tissues were perceived, including impaired follicular and cyst walls, deteriorated parietal cells, necrosis, and vacuolations. These results implied that NiFe NPs triggered oxidative injury in the testes, resulting in male reproductive system dysfunction. Altogether, our findings accentuate the potential application of NiFe NPs as nanopesticides, paving the way for the sustainable and cost-effective management of insect pests in agriculture.

An analysis of the current and potential market opportunities for hempseed and fibre: the case of Scotland?

BackgroundThe growing demand for eco-friendly food and industrial products have renewed interest in industrial hemp which is a low-cost, biodegradable, sustainable, and multi-purpose plant. Many countries in Europe and Asia have changed their laws to take advantage of the tremendous benefits that industrial hemp present. However, the development of the sector in Scotland is very slow due to stringent laws. The goal of the present study is to present policymakers with economic data on the current and potential market opportunities for industrial hemp, trends in new product development, and the state of the hemp supply chain. This study entails desk-based research primary and secondary data analysis. Primary data were collected from farmers in Aberdeenshire and Scottish borders, and secondary data were collected from the FAOSTATS Office of National Statistics and the Global New Product Database.ResultsThe results of this study show that the opportunities from hemp seed and fibre are vast: hemp can sequester more carbon dioxide than traditional crops can, improve soil biodiversity, extract toxins from soil through phytoremediation, be used as an eco-friendly insecticide and pesticide, and provide an excellent source of protein, fibre and micronutrient vitamins and minerals, as well as a range of bioactive phytochemicals. The GNPD reveals that over 4000 hemp-based products have been launched worldwide. However, the supply chain for Scottish-grown hemp faces significant bottlenecks. The sector lacks a well-established market route, faces a high licensing costs, lacks hemp seed-pressing centres, etc.ConclusionThis study is relevant because it is the first study to provide a comprehensive analysis of the industrial hemp sector in Scotland. This study makes time-bound recommendations to grow the hemp sector in Scotland, which include regular extension services, easy access to licences for production, the establishment of a hempseed and fibre processing plants, and seed production centre.

Chemical Composition, Larvicidal and Ovicidal Activities, and Enzyme Inhibition Capacity of Thymus serpyllum Essential Oils Against Spodoptera litura (Fabricius).

Due to their effectiveness at low doses and relative safety for non-target species, plant essential oils (EOs) are considered ideal alternatives to conventional pesticides for pest control. In this study, the chemical composition of Thymus serpyllum (T. serpyllum) EO was construed by Gas Chromatography-Mass Spectrometry (GC-MS), and its larvicidal and ovicidal activity against omnivorous pests Spodoptera litura (S. litura) was assessed. The effects of T. serpyllum EO on the activities of antioxidant detoxification enzymes were also measured. GC-MS analysis revealed that the main constituents of T. serpyllum EO were thymol (42.1%), p-cymene (22.4%), and γ-terpinene (18.6%). In the larvicidal toxicity experiment, the T. serpyllum EO demonstrated LC50 values of 0.606 and 0.664 mg/mL against the second- and third-instar larvae of S. litura, respectively, after 48 h exposure. Moreover, an EC50 value of 0.905 mg/mL was measured against S. litura eggs. In S. litura, T. serpyllum EO treatment reduced the enzymatic activity of ESTs and GST and, conversely, increased the enzymatic activity of AChE. Overall, this study demonstrated that T. serpyllum EO has the potential to be implemented as a novel eco-friendly insecticide against S. litura.

Comparative analysis of active period and oxidative stress of DDVP and ginger (Zingiber officinale) oil on Indian meal moth (Plodia interpunctella Hübner) infesting maize grain

BackgroundIndian meal moth (Plodia interpunctella) is a significant pest infesting stored grains, particularly maize. Over time, synthetic insecticides have been employed to control insect. The residual effects posed on non-target organisms have called for replacement of synthetic insecticides with botanicals. This study therefore aimed at comparing the insecticidal consistency and oxidative stress invoked by dichlorvos (DDVP) and the oil extract of ginger (Zingiber officinale) on Indian meal moth infesting maize. Disinfested maize grains were treated with DDVP and ginger oil extract separately. Adults P. interpunctella were introduced to the treated grains daily using complete replacement method. The percentage mortality was calculated daily for 10 d. Furthermore, the oxidative stress caused by DDVP and ginger oil extract on the moth was evaluated by measuring the level of some oxidative stress biomarkers such as glutathione S-transferase, superoxide dismutase, glutathione peroxidase (GPx), and catalase (CAT) activity in the exposed insects.ResultsPreliminary results indicated that both DDVP and ginger oil extract exhibited insecticidal properties against Indian meal moth infesting maize. However, the insecticidal (active) period of ginger oil extract was found to be longer than that of DDVP. Nevertheless, DDVP provoked greater oxidative stress in the exposed moth.ConclusionsGinger oil extract and DDVP show potential for controlling Indian meal moth infestations in stored maize. Yet, ginger oil offers a longer-lasting effect on pest suppression and control. Consequently, it could be a replacement or synergistic insecticide with DDVP to provide ecofriendly insecticide application.

Molecular Docking Assessment of Limonoids from Cameroonian Entandrophragma Species as Potential Inhibitors of Anopheles gambiae Acetylcholinesterase (AChE)

Malaria remains one of the great killers in tropical regions of the world due to the transmission of the Plasmodium parasite by the bites of the female mosquito Anopheles. The resistance of this species to synthetic insecticides contributes to an increase in the incidence of malaria and therefore necessitates the development of new potent and eco-friendly insecticides. In this study, twelve previously reported limonoids from four Entandrophragma species collected in Cameroon have been computationally evaluated for their Anopheles gambiae AChE inhibitory activity. The docking procedure was carried out through Molecular Operating Environment 2019.01 (MOE), while the UCSF Chimera program was used to model the docking results based on interactions between proteins and ligands, and molecular dynamics trajectories were analyzed using the GROMACS 2021.1 tool. Entandrophragmin and encandollens B and C with docking scores ranging from −6.45 to −7.28 kcal/mol were the most promising hits compared to the reference azadirachtin (−6.22 kcal/mol) and were further evaluated for their mechanism of action. Subsequent evaluation classified encandollen C as the best candidate for the development of new potent eco-friendly insecticides based on its lower average RMSD and RMSF and its compactness over a 150 ns duration with acetylcholinesterase.

Efficacy of Aqueous and Ethanolic Extracts of <i>Myrtus communis</i> Against <i>Aphis fabae</i> Scopoli on Faba Bean

The efficicacy of the ethanolic and the cold aqueous extracts of the Myrtus communis plant was evaluated against the nymphs of been aphid Aphis fabae. The results showed the superiority of the cold aqueous extract over the ethanolic extract. The mortality rate of nymphs reached 100% at a concentration of 20 mg/ ml for the periods 24, 48, and 72 hr, with the ethanolic extract, the highest mortality was at a concentration of 20 mg/ ml (70, 90, and 100%) for the periods of 24, 48, and 72 hr, respectively. Thus, cold aqueous and ethanolic extract of M. communis can be used as safe and ecofriendly insecticide to control Aphis fable.

Contact Toxicity and Repellent Effects of Essential Oils from Toddalia asiatica Against Two Stored-Product Insects.

Insect infestations continually endanger stored goods, underscoring the significance of discovering eco-friendly insecticides for pest management. Essential oils (EOs) from different parts of Toddalia asiatica (leaf, fruit and branch) were extracted by hydrodistillation and analyzed by GC-MS. Carvene, p-cymene and muurolene are the principal compounds of T. asiatica leaf (TAL), T. asiatica fruit (TAF) and T. asiatica branch (TAB) EO respectively. Our work aimed to assess the contact toxicity and repellent effects of EOs on two storage pests, Tribolium castaneum and Lasioderma serricorne. All tested EOs exhibited obvious contact toxicity, especially, TAL EO against T. castaneum (33.48 μg/adult) and TAF EO against L. serricorne (16.42 μg/adult). Repellency tests revealed that TAL and TAF EOs, at a concentration of 78.63 nL/cm2, achieved nearing 100 % efficiency against T. castaneum. These results suggest that EOs of T. asiatica could be used as effective botanical insecticides for managing stored-product insects.

Assessing the effectiveness, biosafety, and resident’s perception of a micro-encapsulated propoxur paint against Aedes aegypti: a field trial in a dengue-affected community of Sonora, Mexico

Mosquito-borne diseases remain a major public health concern in the Region of the Americas. Concerning dengue, Mexico ranked as the third American country with the highest number of cases in 2023, following Brazil and Peru. In this sense, the development and production of safer, eco-friendly, cost-effective, more efficient, and target-specific insecticides have become essential in disease control strategies. This study aimed to assess the effectiveness and safety of indoor micro-encapsulated propoxur paint against Aedes aegypti, estimate residents' exposure via cholinesterase levels, and gauge resident perceptions in the rural village Poblado Miguel Alemán (PMA), Sonora, Mexico. Houses in PMA were organised into four blocks for a field trial, with different treatments on interior walls: 1) full insecticide paint coverage; 2) insecticide paint applied up to 1 meter; 3) full indoor residual spraying; and 4) no treatment (control). Mosquito surveys were conducted before and after interventions. Blood samples from residents were analysed for cholinesterase levels, while perceptions were gathered through a questionnaire. Aedes resting density correlated closely with the paint formulation and coverage. Full-surface insecticide paint showed the greatest reduction. Both paint interventions notably impacted Aedes breeding, with substantial reductions in House Index (20.1% IP, 31.2% IP 1 m) and Container Index (51.8% IP, 61.7% IP 1 m) compared to the control over one year. Post-intervention blood cholinesterase activity remained within acceptable limits. Over 80% of residents expressed satisfaction with the interventions. The use of propoxur paint proves to be a safe, effective, and well-accepted method for decreasing Ae. aegypti populations in urban areas.

Effect of Three Novel Thiazolidiones on the Development, Reproduction, and Trehalase Activity of Spodoptera frugiperda (Lepidoptera: Noctuidae)

Spodoptera frugiperda was used to investigate its role as a trehalase inhibitor of three new thiothiazolidone compounds—6d, 6e, and 6f. The development and reproduction of S. frugiperda were investigated to evaluate the potential of these compounds as a novel pesticide for pest control. Compounds 6d, 6e, and 6f were injected into larvae and female pupae. Molecular changes in trehalose and chitin metabolism genes were monitored. Pupal trehalase activity, the female pupal emergence rate, ovarian development, and SfVg and SfVgR gene expression levels were assessed. The results revealed that all three compounds significantly inhibited trehalase activity in the larvae. The expression of TRE was significantly downregulated, and compounds 6d and 6f significantly downregulated the expression of TRE2. Treated larvae exhibited significantly decreased survival rates and a higher incidence of abnormalities. The egg production and hatching rates were markedly diminished by the inhibitors, and the ovaries displayed blackening and clumping. These compounds exhibit promise as eco-friendly insecticides, but further experiments are required to test their multifaceted capabilities.

Entomopathogenic fungi against the dengue vector Aedes aegypti: laboratory and semifield assessment

Aedes aegypti, in addition to its association with arboviruses of significant public health concern, poses a considerable challenge to the scientific community, which is actively working to devise innovative strategies to address this threat. Entomopathogenic fungi (EPF) are important bioagents for insect pest control. This study aimed to evaluate the virulence of EPF against Ae. aegypti larvae and adults under laboratory and semifield conditions. Conidia powder from M. anisopliae CG 153 or B. bassiana CG 479, at concentrations ranging from 1×105 to 1×108 conidia/mL, was tested against larvae (N=30) under laboratory conditions, while conidia suspension was used against adults (N=30) via the impregnated filter paper method. Survival curves were compared using the Log-rank test. Both isolates exhibited virulence against larvae and adults, with survival rates ranging from 0% to 64% and 20% to 76%, respectively. Subsequently, both fungi, at a concentration of 107 conidia/mL, were tested against larvae (N=60) and adults (N=60) under laboratory and semifield conditions. Under semifield conditions, larvae and adults showed survival rates ranging from 12% to 35% and 5% to 20%, respectively. The semifield tests produced promising results in decreasing mosquito survival rates. Consequently, this study concludes that the isolates M. anisopliae CG153 and B. bassiana CG 479 have the potential to serve as eco-friendly insecticides against mosquitoes, thus warranting further exploration in the bioprospecting of EPF-based products.

Laboratory evaluation of different eco-friendly insecticides against the Egyptian fluted scale, Icerya aegyptiaca

Lac cultivation is generally carried out on a limited number of indigenous tree species found scattered in forests and cultivable land. Recent studies show that Flemingia semialata Roxb. (Leguminosae) is an excellent bushy host plant for the cultivation of the kusmi strain of lac insects. The present investigation was carried out with the objective of getting acquainted with the different eco-friendly insecticides under laboratory evaluation against the Egyptian fluted scale, Icerya aegyptica. Maximum nymphal mortality of 81.67 per cent and 78.34 per cent was observed at 0.2 per cent Pestoguard and Neemazal after 12 days of treatment, which is statistically at par with each other. 51.67 per cent mortality was achieved after 12 days of treatment at 1 per cent Uro-insecticide and Green mealikil, which is a microbial pesticide that is also effective against the Egyptian fluted scale, Icerya aegyptiaca. The mortality percentage was low after 1, 3 days and seven days, but it gradually increased after 12 days of treatment, obtaining 48.34% mortality, which is statistically at par with Uro-insecticide. All the eco-friendly insecticides used in the present experiment (Uroinsecticides, Pestoguard, green mealikil and neemazal) are effective in controlling the population of Icerya aegyptiaca. Unlike Malathion and Imidacloprid, they don’t have a quick knockdown effect; however, the mortality due to exposure significantly increases as there is an increase in days or duration of application, and they are safe for the lac insect.

Rational Design of Triazinone Derivatives with Low Bee Toxicity Based on the Binding Mechanism of Neonicotinoids to Apis mellifera.

Bees, one of the most vital pollinators in the ecosystem and agriculture, are currently threatened by neonicotinoids. To explore the molecular mechanisms of neonicotinoid toxicity to bees, the different binding modes of imidacloprid, thiacloprid, and flupyradifurone with nicotinic acetylcholine receptor (nAChR) α1β1 and cytochrome P450 9Q3 (CYP9Q3) were studied using homology modeling and molecular dynamics simulations. These mechanisms provided a basis for the design of compounds with a potential low bee toxicity. Consequently, we designed and synthesized a series of triazinone derivatives and assessed their bioassays. Among them, compound 5a not only displayed substantially insecticidal activities against Aphis glycines (LC50 = 4.40 mg/L) and Myzus persicae (LC50 = 6.44 mg/L) but also had low toxicity to Apis mellifera. Two-electrode voltage clamp recordings further confirmed that compound 5a interacted with the M. persicae nAChR α1 subunit but not with the A. mellifera nAChR α1 subunit. This work provides a paradigm for applying molecular toxic mechanisms to the design of compounds with low bee toxicity, thereby aiding the future rational design of eco-friendly nicotinic insecticides.

Bioactivities of essential oil extracted from Elsholtzia densa Benth. And its main components against Tribolium castaneum eggs and pupae

Bioactivities of essential oil extracted from Elsholtzia densa Benth. And its main components against Tribolium castaneum eggs and pupae

Bioassay Study of Azadirachtin And Plumbagin on Pericallia ricini (Lepidoptera: Arctiidae)

In recent years, the overuse of commercially obtainable synthetic pesticides against phytophagous insects has augmented their bioaccumulation in the biosphere, foremost to increased resistance and reduced soil biodiversity. Moreover, extreme uses of insecticides enter various environmental resources as an outcome of overflow, initiating deleterious health problems to agriculturalists and consumers of agricultural products. Hence, more attention is being paid towards the expansion of substitute eco-friendly insecticides that will help in an effective pest management system and also prevent longstanding exposure that causes diseases. As a result, important ecologically friendly and harmless alternative practice strategies to artificial compounds are essential. Azadirachtin and plumbagin (phytoproducts) have been identified as an extraordinary biocontrol agent with low toxicity and high efficacy among many plant products for latent chemotherapeutic compounds in plant pest and disease management systems. The biocidal effectiveness of neem is attributed to its azadirachtin active ingredient, which affect some metabolic processes in insects such as protein synthesis, deviations in biological fitness, reduced sexual communication, and chitin synthesis. Similarly, Plumbagin (Napthaquinones) have established substantial attention in agricultural chemistry because of a novel action mode, extremely high activity against a broad spectrum of insects, low acute toxicity to mammals, and environmentally benign characteristics. The present study indicated that Azadirachtin and Plumbagin can be significant alternatives to Chemical insecticides for Pericallia ricini control in short-cycle crops.