Synthetic Chemical Pesticides Research Articles

Seed extracts as an effective strategy in the control of plant pathogens: Scalable industry bioactive compounds for sustainable agriculture

With a growing global population, maintaining sufficient agricultural production is crucial. However, agriculture faces numerous challenges today, particularly due to the undeniable impacts of climate change, which are expected to intensify pest and disease pressures. The traditional approach to combat these phytopathological issues has relied on synthetic chemical pesticides. While their use has indeed increased productivity, it is also evident their detrimental and cumulative effects on the environment, and the current negative perception of the population toward these chemicals. In response, governments are prompting the search for alternatives to synthetic pesticides, through different policies, such as the strategy From Farm to Fork in the European Union, which aims to reduce the use of chemical pesticides by 50% by 2030, among other measures. At this point, seed extracts with biocidal activity are emerging as a viable option for the control and management of various pathogenic agents, such as harmful bacteria, fungal and oomycete pathogens, and plant-parasitic nematodes. Nevertheless, it is worth mentioning that most of the studies have been only conducted under highly controlled conditions. Thus, this line of research should be still more deeply developed, including proofs under field conditions, in order to become the extensive and widespread use of these bio-products a reality. In this review, we compile the main studies focused on the use of these compounds for phytosanitary purposes, describing and analysing the key metabolites, their composition, extraction processes and the mechanisms involved in their antagonistic effects. Additionally, we analyse the primary factors contributing to the limited adoption of these extracts in the field, such as the scarcity of studies under real conditions or the possible impact on non-target organisms, and discuss future prospects for their development.

Development of an agroinfiltration-based transient hairpin RNA expression system in pak choi leaves (Brassica rapa ssp. chinensis) for RNA interference against Liriomyza sativae

The vegetable leafminer (Liriomyza sativae) is a devastating invasive pest of many vegetable crops and horticultural plants worldwide, causing serious economic loss. Conventional control strategy against this pest mainly relies on the synthetic chemical pesticides, but widespread use of insecticides easily causes insecticide resistance development and is harmful to beneficial organisms and environment. In this context, a more environmentally friendly pest management strategy based on RNA interference (RNAi) has emerged as a powerful tool to control of insect pests. Here we report a successful oral RNAi in L. sativae after feeding on pak choi (Brassica rapa ssp. chinensis) that transiently express hairpin RNAs targeting vital genes in this pest. First, potentially lethal genes are identified by searching an L. sativae transcriptome for orthologs of the widely used V-ATPase A and actin genes, then expression levels are assessed during different life stages and in different adult tissues. Interestingly, the highest expression levels for V-ATPase A are observed in the adult heads (males and females) and for actin in the abdomens of adult females. We also assessed expression patterns of the target hairpin RNAs in pak choi leaves and found that they reach peak levels 72 h post agroinfiltration. RNAi-mediated knockdown of each target was then assessed by letting adult L. sativae feed on agroinfiltrated pak choi leaves. Relative transcript levels of each target gene exhibit significant reductions over the feeding time, and adversely affect survival of adult L. sativae at 24 h post infestation in genetically unmodified pak choi plants. These results demonstrate that the agroinfiltration-mediated RNAi system has potential for advancing innovative environmentally safe pest management strategies for the control of leaf-mining species.

ETUDE DE LEFFICACITE DES BIOPESTICIDES A BASE DE GRAINESDE NEEM ET DELENTOMOPATHOGENEBEAUVERIABASSIANA(BALS.) VUILL.POUR LA GESTION DES PRINCIPAUX INSECTES RAVAGEURS DE LA CULTURE DU NIEBE DANS LA REGION DE MARADI AU SAHEL

The insect pests of cowpea, Vignaunguiculata L. Walper, is one of the constraints which affect the cultivation this crop in Africa. The pod sucking bug Clavigrallatomentosicollis(Stål), the flower thripsMegallurothripssjöstedti(Trybom) and the pod borer Marucavitrata(Fabricius) are the main insect pests whose damage causes considerable yield losses on cowpea crop. In this study, neem Azadirachtaindica based biopesticides and the entomopathogenBeauveriabassiana(Bals.) Vuill were tested todeterminetheir efficiency in the management of cowpea insect pests. The trials were established in a farming environment with producers in 15 villages of the Maradiregion during three consecutive cropping seasons 2020, 2021 and 2022. The experimental design is the Fisher block with 4 treatments (Neem grain, B. bassiana, Chemical pesticide and the control without treatment) and two repetitions per site. The results for this studybiopesticide treatments (Neem grains and entomopathicfungus B. bassiana) reduced the insect pest damageof 73.21% and a yields increase of 104.12% compared to the control treatment. . Neem was effective as the synthetic chemical pesticide in the management of insect pests as it reduced the populations of M. sjöstedti, M. vitrata and C. tomentosicollis by 67.29, 70.57 and 71.26%respectively. This Neem biopesticide resulted a yield increase of 140.33% on cowpea for the three years of the study. Thus, for low-income producers, neem is an available resource that can constitute an effective and ecological alternative for managing cowpea insect pests in the Sahel.

Actinobacteria mediated synthesis of silver nanoparticles using Streptomyces diastaticus and their biological efficacy against human vector mosquitoes and agricultural insect pests

Mosquitoes and agricultural insects were harmful to both public health and crops. Prolonged use of synthetic chemical pesticides for insect pest control was associated with resistance development and negative human and ecological effects. This study investigates the larvicidal activity of Ag-NPs produced using Streptomyces diastaticus against Culex quinquefasciatus, Anopheles stephensi, Aedes aegypti, Spodoptera litura, and Plutella xylostella. UV-Vis spectroscopy, XRD, SEM-EDX, FT-IR, TEM, DLS, and Zeta potential analysis were used to characterize the biosynthesized Ag-NPs. The results showed that biosynthesized Ag-NPs were more toxic to, A. stephensi, C. quinquefasciatus, and A. aegypti with LC50 values of 15.70, 11.10, and 17.53 µg/mL, respectively. Biosynthesized Ag-NPs exhibited the highest antifeedant effects against S. litura (88.73 %) and P. xylostella (92.36 %) at 50 µg/mL concentration. The mortality bioassay revealed considerable larvicidal activity against S. litura and P. xylostella larvae at greater doses of 50 µg/mL, 80.67 and 84.05 %, respectively. Morphogenetic variations were observed on treated larvae of C. quinquefasciatus, A. aegypti, and A. stephensi, S. litura, and P. xylostella with Ag-NPs. In the present investigation the impact of Ag-NPs on the antioxidant enzymes (SOD, CAT, and GPx), the activity of each enzyme were dramatically increased with higher concentrations resulting in significant differences. The study also found that Ag-NPs inhibited the detoxifying enzyme (GST and AChE) activity of target organisms. The histological structure of the treated and untreated larvae revealed structural changes between the midgut epithelial cells. As a consequence of these findings, the S. diastaticus-mediated Ag-NPs serve as a possible, eco-friendly biopesticide and alternative to synthetic chemicals for the control of human vector mosquitoes and destructive arthropod insect pests.

Reduction potentials of chemical-synthetic pesticides – A case study using the example of an Eco-Scheme in southern Germany

Chemical-synthetic pesticides (CSPs) are associated with several negative environmental effects. The European Commission aims to reduce their use by 50% by 2030. This paper looks at the German Eco-Scheme, an agri-environmental payment scheme, for the foregoing of chemical-synthetic pesticides (CSPs) in arable crops for a one-year period. Using Baden-Württemberg in southern Germany as a case study, we investigated the suitability of the Eco-Scheme as a policy tool for CSP reduction. We used a field-based, georeferenced integrated land use model based on linear programming. Different payment levels for the Eco-Scheme were simulated. In addition, we analyzed the effect of labor availability, crop yield requirements, and market prices on Eco-Scheme implementation (uptake).The implementation potentials at €130/ha, the payment level in 2023, were limited and strongly dependent on market prices as well as potential food supply targets. The percentage decline in overall CSP use (measured in active substance mass) was even lower than the implementation in the percentage of acreage attributed to the Eco-Scheme. The implementation potentials were mainly observed on marginal sites. Higher simulated payment levels led to lower cost efficiency and dead weight losses. This trade-off between cost efficiency and effective reduction questions the suitability of the Eco-Scheme, at least for more substantial CSP reductions. To increase economic efficiency, we recommend differentiating payments based on abatement costs, for example on a crop-basis.

Advancing Sustainable Agriculture: A Comprehensive Review of Organic Farming Practices and Environmental Impact

Organic farming, characterized by the exclusion of synthetic fertilizers and chemical pesticides, represents a sustainable approach to agriculture. This study investigates the impact of organic farming practices on soil health, focusing on the proliferation and activity of soil microorganisms. Natural fertilizers such as farmyard manure, poultry litter, composts, green manures, and oil-free cakes were utilized to enhance soil fertility. The research reveals that these practices significantly improve soil health by fostering a robust microbiome, which is essential to the cycling of nutrients and overall health of the soil vitality. The safety and nutritional benefits of organic food products were also evaluated. Comparative analysis with conventionally grown foods indicates that organic produce contains lower levels of harmful residues such as pesticides, nitrates, metals, and antibiotics. This reduction in contaminants mitigates potential risks to human health associated with conventional farming practices. Furthermore, organic foods are found to be richer in essential nutrients, vitamins, and antioxidants, thereby offering superior nutritional value. The economic implications of organic farming were explored, highlighting its potential to enhance the economic viability of small-scale farmers. With increasing consumer awareness and demand for organic products, farmers practicing organic methods can command higher prices for their produce, thereby improving their economic sustainability and resilience. In conclusion, organic farming emerges as an environmentally friendly and economically viable alternative to conventional agriculture. By promoting soil health, reducing chemical residues in food, and meeting consumer demand for nutritious products, organic farming offers a pathway towards sustainable agricultural practices.

Molecular Characterization Reveals Biodiversity and Biopotential of Rhizobacterial Isolates of Bacillus Spp

Bacillus species appearas the most attractive plant growth-promoting rhizobacteria (PGPR) and alternative to synthetic chemical pesticides. The present study examined the antagonistic potential of spore forming-Bacilli isolated from organic farm soil samples of Allahabad, India. Eighty-seven Bacillus strains were isolated and characterized based on their morphological, plant growth promoting traits and molecular characteristics. The diversity analysis used 16S-rDNA, BOX-element, and enterobacterial repetitive intergenic consensus. Two strains, PR30 and PR32, later identified as Bacillus sp., exhibited potent in vitro antagonistic activity against Ralstonia solanaceorum. These isolates produced copious amounts of multiple PGP traits, such as indole-3-acetic acid (40.0 and 54.5 μg/mL), phosphate solubilization index (PSI) (4.4 and 5.3), ammonia, siderophore (3 and 4 cm), and 1-aminocyclopropane-1-carboxylate deaminase (8.1and 9.2 μM/mg//h) and hydrogen cyanide. These isolates were subjected to the antibiotic sensitivity test. The two potent isolates based on the higher antagonistic and the best plant growth-promoting ability were selected for plant growth-promoting response studies in tomatoe, broccoli, and chickpea. In the pot study, Bacillus subtilis (PR30 and PR31) showed significant improvement in seed germination (27–34%), root length (20–50%), shoot length (20–40%), vigor index (50–75%), carotenoid content (0.543–1.733), and lycopene content (2.333–2.646 mg/100 g) in tomato, broccoli, and chickpea. The present study demonstrated the production of multiple plant growth-promoting traits by the isolates and their potential as effective bioinoculants for plant growth promotion and biocontrol of phytopathogens.

Using predatory species and entomopathogenic fungi as alternatives to chemical pesticides in green bean field

BackgroundGreen bean, Phaseolus vulgaris L. (Fam.: Leguminosae) is a widely consumed grain legume prized for its edible seeds and pods. It is susceptible to infestations with various pests as insects and mites throughout the growing season. In this study, the efficacy of the predatory species, Chrysoperla carnea (Stephens), Phytoseiulus persimilis Athias-Henriot and the entomopathogenic fungus (EPF) Metarhizium anisopliae (Hypocreales: Clavicipitaceae), as well as conventional pesticides, Mospilan and Vertimec, were evaluated against the most important pests, mainly the whitefly, Bemisia tabaci (Genn.) and the two-spotted spider mite, Tetranychus urticae Koch, infesting the green beans cultivated at two locations Giza and El-Menoufia Governorates in Egypt.ResultsThe findings demonstrate that treatments using C. carnea and M. anisopliae effectively reduced the whitefly population, while pesticide treatments were comparatively less effective. In the Giza plots, at the end of the experiments, the use of both M. anisopliae and C. carnea showed high reductions in whitefly population (85.57 and 84.87%), respectively, while in El-Menoufia, C. carnea (97.74%) was the most effective treatment followed by M. anisopliae (90.32%). Pesticide treatment in this case yielded a reduction rate of (22.76 and 59.67%) in Giza and El-Menoufia plots, respectively. However, for spider mite control, P. persimilis proved to be the most effective treatment in Giza and El-Menoufia plots, reducing the spider mite population to 98.44 and 96.14%, respectively. Metarhizium anisopliae treatment also displayed moderate effectiveness, with reduction rates of 75.62 and 75.37% in Giza and El-Menoufia plots, respectively. In comparison, pesticide treatment showed low effectiveness, with reduction rates of only 23.92 and 53.16% in the two locations, respectively.ConclusionApplications of the predator, C. carnea and the EPF, M. anisopliae were highly effective in reducing the population of whitefly, while the predator mite P. persimilis proved to be the most effective for controlling the spider mites. Overall, the study suggests that biocontrol agents, such as the predators and the EPF, can be considered as alternatives to synthetic chemical pesticides for controlling pests infesting green beans.

Enhancing arthropod occurrence in wheat cropping systems: the role of non-chemical pest management and nitrogen optimization

This study analyzes arthropod biomass and abundance to track the changes in arthropod occurrence in relation to pesticide use in three winter wheat cropping systems managed at different intensities (organic, conventional, and hybrid). Arthropod occurrence was surveyed using three collection tools: sweeping nets, eclector traps, and yellow traps. Sampling was conducted over three years from 2020 to 2022 with 588 samples collected. The wet weight of the captured organisms was determined and arthropod abundance calculated. The application of a NOcsPS (no chemical-synthetic pesticides) strategy, a new hybrid cultivation method realized with optimized use of nitrogen fertilizers but without chemical-synthetic pesticides, showed a higher arthropod occurrence and performed more convincingly regarding produced arthropod biomass and abundance than the other cropping variants. The results also demonstrate a dependence of the obtained insect indices on the collection method. Although arthropod biomass and abundance correlated for all collection methods, the combination of various methods as well as multiple procedures of sample analysis gives a more realistic and comprehensive view of the impact of the wheat cultivation systems on the arthropod fauna than one-factor analyses.

Phytochemical screening and antimicrobial activities of Guizotia abyssinica L. leaf and flower extracts

Sustainable agricultural systems demand less or no use of synthetic chemicals, which have various adverse effects on the environment and human health. In this context, studies on phytochemicals with antimicrobial and antioxidant properties hold great promise to suppress plant diseases and, thereby, reducing the application of synthetic chemical pesticides. Such an alternative approach requires screening and identification of bioactive compounds from various plant species. In the present study, Guizotia abyssinica L., an oilseed crop plant that usually requires less water with no pesticide inputs to grow, was screened for its potential antioxidant and antimicrobial phytochemicals. The methanolic and aqueous extracts of leaves and flowers of G. abyssinica were tested for their polyphenol content (total phenols and flavonoids) and antioxidant potential. The antioxidant and free radical scavenging activities of both methanolic and aqueous extracts were higher in comparison to many previously reported plant extracts. Furthermore, leaf extracts of G. abyssinica have shown slightly higher antioxidant activity than flower extracts. In vitro antimicrobial studies confirmed the inhibitory effect of methanolic extracts of leaves and flowers against phytopathogens like Xanthomonas oryzae RR24, Fusarium sp. and Alternaria sp. The chemical nature and composition of these crude extracts were analyzed by Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography Mass Spectrometry (GC-MS). Approximately, 28 bioactive compounds detected in GC-MS were predicted to have antimicrobial activity. Based on our results, we conclude that the extracts derived from G. abyssinica have demonstrated remarkable efficacy in inhibiting the proliferation of phytopathogens, thus exhibiting immense potential in promoting sustainable agricultural practices.

Pendampingan Demplot Teknik Budidaya Bawang Merah pada Musim Hujan Secara Ramah Lingkungan

Background: Shallot cultivation in the rainy season faces the constraints of more severe plant disease problems. Utilization of mixed biopestisda Trichoderma harzianum, Bacillus sp. B8 and Pseudomonas flourescens P8 as well as proper cultivation techniques have not been adopted by farmers. It is necessary to assist farmers in implementing the technology The objectives of the activity are: assisting farmers in implementing the shallot cultivation technology package appropriately, increasing the quantity and quality of crop production, and increasing farmers' income through increasing farm efficiency. Method: The farmers participating in the activity are members of the farmer group "Lestari" Tambak Sogra Village, Sumbang District, Banyumas Regency. Technology transfer method through demplot assistance. The biopesticide technology package and environmental manipulation are compared to the conventional package of synthetic chemical pesticides. Data on the growth and yield of technological plot crops compared to conventional plots. The large number of farmers who can independently apply the technology is observed. Results: mentoring activities showed that farmer group members were able to independently implement technology packages. The use of biopesticides and proper cultivation techniques can produce growth and yield equivalent to the use of synthetic chemical pesticides. Conclusion: 80% partner farmers can apply technology packages, the use of biopesticides is able to substitute the use of synthetic chemical pesticides, technology packages are able to increase 5.9% of shallot bulbs and reduce 75% production costs.

Toxicological, biological, and biochemical impacts of the egyptian lavender (Lavandula multifida L.) essential oil on two lepidopteran pests

The use of essential oils as an eco-friendly tool in pest management stems from their natural origin and the presence of bioactive compounds that exhibit pesticidal properties, offering a sustainable alternative to synthetic chemical pesticides. This study explores the toxicity of Lavandula multifida (lavender) essential oil (EO), as a botanical pesticide against two widespread and destructive Noctuidae pests, Spodoptera littoralis (Boisd.) and Agrotis ipsilon (Hufnagel). GC-MS was employed to characterize 23 compounds in the EO, with 1,3,3-trimethyl-2-oxabicyclo [2.2.2] octane (eucalyptol) (39.84%), being the primary component. The leaf dipping technique was utilized to assess the toxicity of the EO to both insects. At 96 hours post-treatment, the LC50 of lavender EO to S. littoralis and A. ipsilon larvae were 2.350 and 2.991 mg · ml–1, respectively. Concerning its biological effect, both concentrations of the EO (LC15 and LC50) significantly shortened the duration of the larval (to 15.24 and 14.23 days) and pupal (to 11.19 and 10.55 days) stages of S. littoralis. Biochemical assays revealed that the LC50 of lavender EO significantly inhibited α-esterase activity in S. littoralis at 72- and 96 hours post-treatment (0.031 and 0.063 mmol · min–1 · mg–1), and A. ipsilon at 96 hours post-treatment (0.129 mmol · min–1 · mg–1 protein). Given its significant toxicological, biological, and biochemical effects on S. littoralis, it is suggested that lavender EO could be considered for use in integrated pest management strategies while ensuring its safe application to protect non-target organisms.

Biological Approaches for Sustainable Pest and Disease Management in Pulse Crops

Pulse crops, including lentils, peas, chickpeas, and beans, play a crucial role in addressing global food security and nutritional needs. However, their production is often hampered by various pests and diseases, leading to significant yield losses. Conventional pest and disease management practices, heavily reliant on synthetic chemical pesticides, have raised concerns about environmental sustainability, human health, and the development of resistance in target organisms. In recent years, biological approaches have emerged as promising alternatives for sustainable pest and disease management in pulse crops. This review provides a comprehensive overview of various biological control strategies, including the use of beneficial microorganisms, plant extracts, and other eco-friendly methods. The review discusses the mode of action, efficacy, and potential applications of these approaches in combating major pests and diseases affecting pulse crops. Additionally, it highlights the challenges and future prospects of integrating biological control methods into integrated pest and disease management programs. By adopting these sustainable practices, pulse crop production can be enhanced while minimizing the environmental footprint and promoting long-term ecological balance. The review serves as a valuable resource for researchers, extension specialists, and stakeholders in the agricultural sector, emphasizing the importance of biological approaches in achieving sustainable and resilient pulse crop production systems.

Farmers’ Knowledge, Perceptions, and Management Practices of False Codling Moth (Thaumatotibia leucotreta) in Smallholder Capsicum sp. Cropping Systems in Kenya

False codling moth (FCM) Thaumatotibia leucotreta Meyrick (Lepidoptera: Tortricidae) is currently the main pest of phytosanitary concern in international trade, causing rejection and decline of horticultural produce from Kenya exported to the European Union (EU). Overreliance on synthetic insecticides to control this pest is ineffective and unsustainable in the long run, whereas continuous use of pesticides results in high levels of residues in the produce. To gather farmers’ knowledge, attitudes, and practices used by smallholder farmers to manage this pest, a field survey was carried out in 10 Capsicum sp. (Solanales: Solanaceae)-producing counties in Kenya. Data were collected using semi-structured questionnaires administered through face-to-face interviews and focus group discussions involving 108 individual farmers, 20 key informants, and 10 focus group discussions. The majority of the respondents (83.33%) were aware of the FCM infesting Capsicum sp. About three quarters of the farmers (76.85%) reported yield losses and unmarketable quality of FCM-infested Capsicum sp. Most farmers interviewed (99.07%) used insecticides as a management tool. In contrast, only 39.81% of the farmers applied integrated pest management strategies including use of biological control agents and intercropping with repellent plants to control this pest. The results show that FCM is perceived as a significant threat to the horticultural industry of Kenya. Training needs for smallholder farmers and key informants to avoid overreliance on synthetic chemical pesticides and to maintain export goals to the EU where identified.

Bacillus velezensis LY7 promotes pepper growth and induces resistance to Colletotrichum scovillei

Anthracnose of pepper (Capsicum annuum L), caused by Colletotrichum scovillei, is one of the three major diseases of pepper that seriously impact yield and quality. As an alternative to the use of synthetic chemical pesticides, a variety of endophytic bacteria have been reported to be potential biocontrol agents with the ability to improve disease resistance and abiotic stress tolerance in host plants. However, the mechanisms of action by which these different bacterial biocontrol agents inhibit the onset and development of disease, in some cases, remains unclear. In the present study, the potential use of the endophytic bacterial strain Bacillus velezensis LY7, originally isolated from pepper leaves, as a biocontrol agent was evaluated. More specifically, the ability of LY7 to control anthracnose in pepper and promote growth was assessed in pot experiments in a greenhouse and in vitro assays. Results indicated that the use of B. velezensis LY7 enhanced the synthesis of jasmonic acid and other hormones in pepper plants, as well as increased disease resistance and plant growth. A 200 × dilution of LY7 fermentation broth reduced disease incidence up to 90.70 %, while also enhancing plant growth. The mechanism of action of LY7 was also evaluated. Results indicated that LY7 secreted an antibiotic protein possessing a cupin domain OS. RNA-sequence analysis of the transcriptome of C. scovillei at several timepoints after exposure to LY7 (24, 48, and 72 h) revealed the up- and down-regulation of several genes. More specifically, LY7 induced the expression of genes associated with biosynthesis pathways and transcription factors involved in anthracnose pathogenicity. Our results indicate that the LY7 strain of induces hormone synthesis in pepper plants that results in enhanced disease resistance and promotes growth, as well as enhances stress tolerance by enhancing antioxidant and defense-related enzyme activity. These results demonstrate the potential of using LY7 for the biocontrol of anthracnose in pepper plants.

Comparative immunotoxicity of bees, apis mellifera (hymenoptera: apidae), exposed to natural and synthetic xenobiotics

The objective of this study was to compare the effects of natural and synthetic chemical pesticides, thereby examining the supposed selectivity of these natural compounds on Apis mellifera bees. The LC50 values used in the bioassays were obtained from the research by Souza et al. (2023) and are as follows: Karate® (13.4 µL/100 mL), Limonene compound (1,440 µL/100 mL), and Roundup® (712,290 µL/100 mL). However, as reported by these authors, a concentration of 250 µL/100 ml was used for Azamax®. These LC50 values, along with a concentration of 250 µL/100 mL of Azamax®, were employed in immunohistochemical analyzes using the TUNEL method and PCNA in the midgut of bees. Immunological assessments (nitric oxide, phenoloxidase, and oxidative stress markers TBARS and GSH) were also conducted on adult worker bees. The xenobiotic treatments did not reveal apoptosis or cell proliferation. Nonetheless, we observed epithelial degeneration, marked by the presence of vacuolated cells, suggesting a necrotic process. Except for the Limonene compound, all substances induced oxidative stress, leading to increased levels of TBARS. Although there were no differences in GSH levels, we observed alterations in the immune system of these insects, characterized by increased phenoloxidase activity and NO2 levels. Based on the acquired results, it is possible to conclude that caution should be exercised when using chemical pesticides in agriculture, whether they are of synthetic or natural origin, as they have the potential to cause irreversible histopathological and immunological damage. This study also underscores the importance of conducting more comprehensive investigations into the impact of natural products on the physiology of pollinator insects.

Phytochemical Analysis of Some Selected Indigenous Plants in Eastern Region of Sri Lanka used for Minimizing Insect Damage on Stored Grains during Storage

Grains are precious food in developing countries but are tragically susceptible to attack by several stored insects. Thus, grain productions often fall below demand. As the resistance of pests against synthetic chemical pesticides and residues in foods increased, consumers‘ awareness turned toward food and environmental safety. The studies conducted in Sri Lanka revealed that the botanical pesticides are being used to minimize these problems and have the potential to battle against pests on stored grains during storage. Further the reference in Sri Lanka evidenced that the botanical pesticides are readily available, inexpensive, easily biodegradable and low toxic to non-target organisms. With this concept the present study has been undertaken to analyze the secondary metabolites, known as phytochemicals that possess antioxidant or anti insecticidal properties, which are much safe, eco-friendly and can combat with the man-made chemicals in controlling the storage pests. The study was carried out to find the presence of phytochemicals namely, alkaloid, flavonoid, phenol, tannin, steroids, cardiac glycosides, terpenoid, saponine and reducing sugars in an aqueous extract of some selected indigenous plants, which are available in Eastern Region of Sri Lanka namely; Capsicum annuum (Chilli), Citrus aurantiifolia (Lime) Piper nigrum (Pepper), Azadiracta indica (Neem), Moringa oleifera (Moringa) Eucalyptus globules (Eucalyptus), Justicia adhatoda (Adhathodai) Annona reticulate (Annona), Cymbopogan citratus (Lemon grass) Vitex trifolia (Nochchi), Ocimum tenuiflorium (Thulsi), Lantenna camera(Nayunni), Eichhornia crassipes (Water hayasinth), Tagetes erecta (Marigold) piper longum (Thipilli) and Achyranthes aspera (Nayuruvi), that have pesticidal properties. The leaves of selected crops were dried at room temperature for a period of one week and grounded in to fine powder to take 10 g of powder from each to prepare 200 ml of water extract using electro thermal soxhlet for 36 hours and analyses qualitatively by the standard scientific procedures. The results showed that the water extract of Neem, Moringa and Thulsi contained all the above tested phytochemicals. The flavonoid was observed in all tested crops except Thipilil, which contained only phenol and tannin. Further Pepper, Eucalyptus, Lemon grass, Annona, and Chilli did not show alkaloids where Annona had only flavonoid, phenol and tannin. Nochchi showed all the phytochemicals except cardiac glycosides and terpenoid. The study confirmed the strength of tested crops in utilizing them in the pest management programme at storage because of the presence of one or more groups of the major insecticidal components like, alkaloids and flavonoids. The study also exposes the way for further studies related to the impact of individual plant insecticidal components against storage pests. 
 Keywords: Aalkaloids, Aqueous, Extract, Grains and phytochemical

Formulation of Mentha piperita-Based Nanobiopesticides and Assessment of the Pesticidal and Antimicrobial Potential.

The excessive use of synthetic pesticides has detrimental impacts on humans, non-target organisms, and the environment. Insect pest management strategies are shifting toward biopesticides, which can provide a feasible and environmentally friendly green solution to the pest problem. The key objective of the present research work was the preparation of Mentha piperita-based nanobiopesticides with enhanced stability, solubility, and pesticidal potential. Nanobiopesticides based on the Mentha piperita extract were prepared using the antisolvent precipitation method. The central composite design of response surface methodology (RSM) was utilized to optimize different process parameters, e.g., the amounts of the stabilizer and plant extract. The nanosuspension of Mentha piperita prepared with the stabilizer SLS showed a particle size of 259 nm and a polydispersity index of 0.61. The formulated biopesticides in the form of nanosuspensions showed good antibacterial activities as compared to the Mentha piperita extract against two phytopathogenic bacterial strains, Clavibacter michiganensis and Pseudomonas syringae. The M. piperita nanosuspension had higher antifungal efficacy against A. niger and F. oxysporum than the Mentha piperita extract. The M. piperita extract and its nanosuspensions were tested for pesticidal activity against the stored-grain insects Tribolium castaneum and Sitophilus oryzae. Mentha piperita-based nanobiopesticides demonstrated significantly high (p < 0.05) average mortality of 84.4% and 77.7% against Tribolium castaneum and Sitophilus oryzae, respectively. Mentha piperita-based nanobiopesticides showed enhanced pesticidal potential and could be used as a good alternative to synthetic chemical pesticides.

Bio-Pesticides: Essential for Controlling Insect Pests

In the context of India's agricultural landscape, where synthetic chemical pesticides have played a significant role, this exploration underscores the pressing need for sustainable alternatives. Biopesticides, sourced from natural materials, emerge as pivotal tools in eco-friendly pest management. The diverse types of biopesticides, their current utilization in India, and the potential for expanded adoption are discussed. Despite constituting a mere 3% of total pesticides, the intrinsic qualities of biopesticides, exemplified by Neem-based products, present a promising avenue for sustainable pest control. The significance of India's biodiversity and traditional knowledge is highlighted, suggesting their potential in shaping innovative biopesticides. With a growing emphasis on organic farming, there is a foreseeable shift towards increased acceptance and integration of biopesticides in Indian agriculture.

Soil treatment with Beauveria and Metarhizium to control fall armyworm, Spodoptera frugiperda, during the soil-dwelling stage

Fall armyworm, Spodoptera frugiperda is an invasive polyphagous pest and has annually invaded Korea since it was first reported in 2019. This pest has already acquired resistance to synthetic chemical pesticides. To minimize the damage caused by S. frugiperda, alternative control methods with different mode of action should be developed. In this study, we assessed the virulence of native entomopathogenic fungi against S. frugiperda and investigated application methods to effectively control the target insect. We obtained 93 fungal isolates and assayed their pathogenicity against second instar larvae. Of the 93 isolates, 34 isolates caused high mortality. Based on their virulence, conidial productivity, and thermotolerance, ten isolates were selected for quantitative bioassays. In the bioassays using leaf dipping, all isolate treatments showed high virulence against second instar larvae, but only two isolates, Beauveria bassiana JEF-492 and Sf83 caused 93.3% and 86.7% mortality against fourth instar larvae, respectively. Given the soil-dwelling pupal stage, drenching the soil with Metarhizium anisopliae JEF-157 and B. bassiana JEF-492 from the selected isolates reduced the survival rate of pupae by up to 80% under laboratory conditions. The M. anisopliae JEF-157 and B. bassiana JEF-492 cultured on barley and rice showed high conidial productivity and thermotolerance. Our results show that soil application of M. anisopliae JEF-157 and B. bassiana JEF-492 targeting pupal stage could be effectively combined with the spray on the leaf-dwelling larval stage when the isolates encounter unfavorable abiotic stress on the leaves.