Insecticidal Activity Research Articles

Engineering a novel entomopathogenic strain Pseudomonas chlororaphis for efficient production of double-stranded RNAs and pest control.

RNA interference (RNAi)-based pesticides are emerging as the next generation of pest control solutions. We have previously identified Pseudomonas chlororaphis strain R3-3, which exhibits toxicity towards Plagiodera versicolora. We engineered a mutant strain derived from R3-3, named P. chlororaphis BM, through knocking out the RNase III gene and incorporating a T7 RNA polymerase expression system to boost dsRNA production. We revealed that P. chlororaphis BM produced comparable amounts of dsRNA to the strain E. coli HT115 (DE3) while maintaining its insecticidal activity. Importantly, insect feeding bioassays demonstrated that P. chlororaphis BM expressing dsRNA targeted β-Actin (encoding β-actin protein) of P. versicolora and Srp54K (encoding signal recognition particle protein 54 k) of Henosepilachna vigintioctopunctata exhibited enhanced insecticidal efficacy compared to E. coli HT115 (DE3). The development of P. chlororaphis BM, a novel dsRNA-expressing bacterium, holds promise for pest management due to its robust dsRNA production and sustained insecticidal activity. This research paves the way for leveraging biocontrol bacteria in RNAi-based pest management strategies. © 2025 Society of Chemical Industry.

Natural Biphenyl-Type Neolignans as Resources of Pesticide Candidates: Assembly, Insecticidal Potency, and Cytotoxicity of Honokiol/Magnolol Analogues of Isoxazoline Hybridization via [3 + 2] Dipolar Cycloaddition.

Currently, the development of novel pesticides remains a crucial initiative to address the challenges of agricultural pest management. In pursuit of agrochemical candidates derived from plant natural products (NPs), 76 novel isoxazoline-hybridized honokiol/magnolol analogues were assembled via a [3 + 2] dipolar cycloaddition reaction, and their pesticidal potency and cytotoxicity were evaluated. Bioassays revealed that 13 compounds (5d, 6k, 7b-d, 7f, 7g, 8d-f, 13f, 15d, and 16h) exhibited superior larvicidal activity against Plutella xylostella Linnaeus with LC50 values in the range of 1.75-5.87 μg/mL, outperforming the botanical insecticide rotenone (LC50 = 26.7 μg/mL). Particularly, compounds 7c, 8d, and 15d showed over 11-fold higher larvicidal activity against P. xylostella than against rotenone. Meanwhile, compounds 5i, 6g, 7a, and 8a displayed better growth inhibitory effects on Mythimna separata Walker (LC50 = 0.13, 0.25, 0.34, and 0.35 mg/mL, respectively) compared to rotenone (LC50 = 0.53 mg/mL). Further greenhouse potted-plant assays revealed that compounds 8d and 15d showed superior in vivo control efficacy against P. xylostella compared to rotenone and comparable to tolfenpyrad and also demonstrated good protective effects on plants. Toxicity tests disclosed that these potent compounds exhibited moderate cytotoxicity to the human keratinocyte cell line (HaCaT), indicating a considerably favorable safety profile for skin exposure. Structure-activity relationship (SAR) analysis illustrated the importance of the exposed hydroxyls and newly introduced isoxazoline scaffolds in enhancing the insecticidal activity of these compounds. The novel scaffold, excellent insecticidal potency, and good safety profile position these compounds reported herein as promising leads for further pesticide candidates development. Furthermore, the present work offers valuable insights for advancing the NP-inspired agrochemical innovation.

Knockdown and insecticidal activities of pyrethrum, dimefluthrin and meperfluthrin against Aedes aegypti and Aedes albopictus

Knockdown and insecticidal activities of pyrethrum, dimefluthrin and meperfluthrin against Aedes aegypti and Aedes albopictus

Molecular characterization, chemical profile and biological properties of essential oils from Chamaemelum nobile (L.) flowers of Morocco: in vitro and in silico studies

IntroductionThis study investigated the antioxidant, antimicrobial, and insecticidal properties of Chamaemelum nobile (L.) essential oil (CN-EO), harvested in Taounate, Morocco. The molecular composition and chemical profile of CN-EO were also characterized.MethodsThe CN-EO was extracted using a Clevenger apparatus. Its chemical composition was analyzed using gas chromatography-mass spectrometry (GC-MS). Antioxidant activity was evaluated using the DPPH assay, while antimicrobial properties were assessed via the disk diffusion method to measure inhibition zones against various bacterial and fungal strains. Insecticidal activity was tested through bioassays to determine insect mortality and repellency rates. Phylogenetic analysis of DNA sequences was conducted to confirm the species identity.ResultsGC-MS analysis identified 24 compounds in CN-EO, with β-Oplopenone (18.66%), Spathulenol (14.90%), and Himachalene (12.47%) as major constituents. CN-EO exhibited strong antioxidant activity (IC50 = 135.8 ± 1.03 μg/mL). Antimicrobial assays revealed inhibition zones of up to 20.67 ± 0.58 mm (Staphylococcus aureus) and antifungal inhibition of 40.42% ± 2.82% against Aspergillus flavus. Insecticidal tests showed total insect mortality at 166 µL/L within 48 h and a 60% repellent effect. Phylogenetic analysis of the DNA sequence revealed a 99.22% similarity with Chamaemelum nobile (L.).ConclusionThese results demonstrate the significant potential of Moroccan CN-EO in phytomedicine. It exhibits a wide range of biological activities and shows great promise as a natural antioxidant, antimicrobial agent, antifungal, and insecticide.

Distinct Impact of Processing on Cross-Order Cry1I Insecticidal Activity

The insecticidal Cry proteins from Bacillus thuringiensis are used in biopesticides or transgenic crops for pest control. The Cry1I protein family has unique characteristics of being produced during the vegetative rather than sporulation phase, its protoxins forming dimers in solution, and exhibiting dual toxicity against lepidopteran and coleopteran pests. The Cry1Ia protoxin undergoes sequential proteolysis from the N- and C-terminal ends, producing intermediate forms with insecticidal activity, while in some cases, the fully processed toxin is inactive. We investigated the oligomerization and toxicity of Cry1Ia intermediate forms generated through trypsinization (T-Int) and larval gut fluid (GF-Int) treatments, as well as the fully trypsinized protein (toxin). Heterologously expressed intermediate forms assembled into oligomers and showed similar toxicity to Cry1Ia protoxin against Ostrinia nubilalis (European corn borer) larvae, while the toxin form was ~30 times less toxic. In contrast, bioassays with Leptinotarsa decemlineata (Colorado potato beetle) larvae did not show significant differences in toxicity among Cry1Ia protoxin, T-Int, GF-Int, and fully processed toxin. These results suggest that the Cry1I mode of action differs by insect order, with N-terminal cleavage affecting toxicity against lepidopteran but not coleopteran larvae. This knowledge is essential for designing pest control strategies using Cry1I insecticidal proteins.

An Investigation into the Biological Activities of Four Lamiaceae Essential Oils Against Thrips flavus, Crops, and Weeds

In recent years, with the increasing awareness of environmental protection and food safety, essential oils (EOs) have gained significant attention as safer and more environmentally friendly alternatives. This study investigated the insecticidal activity of four Lamiaceae EOs (patchouli oil, catnip oil, lavender oil, and mint oil) against Thrips flavus and their effects on crops and weeds. The results show that patchouli oil, catnip oil, and lavender oil exhibited better insecticidal activity, with patchouli oil having the strongest toxicity, with an LC50 value of 0.31 mg/mL. Additionally, catnip oil and lavender oil had significant attractive effects on T. flavus, where lavender oil only had a significant attractive effect on male T. flavus, with an attraction rate of 71.88% (p = 0.03), suggesting that it could be a potential alternative to insect lures. In pot experiments, these EOs demonstrated sustained insecticidal effects and varied impacts on crops. Lavender oil only significantly affected the shoot length of soybeans (Glycine max), while mint oil did not significantly affect the growth of G. max. Finally, we preliminarily analyzed the chemical composition of the EOs to provide insights into their active components. These findings indicate that EOs have potential applications as natural agrochemicals, but further research on their mechanisms and application conditions is required.

Synthesis and Insecticidal Activity of 1,2,4-Oxadiazoles Derivates against (Plutella xylostella L.) Diamondback Moth

The diamondback moth (Plutella xylostella) is a cosmopolitan pest known for its destruction of cruciferous plants. Commercial insecticides, such as Decis 25 EC and Azamax, are the main forms of controlling this pest in irrigated systems in the agricultural communities of the city of Garanhuns (northeastern Brazil). However, the difficulty in controlling this pest resides in its high fecundity and short lifecycle, which serve as resistance mechanisms to insecticides. Considering the immediate need to find alternative products to insecticides employed in these agricultural communities, nine 1,2,4-oxadiazoles were synthesized using an easy, mild method with high to moderate yields. The effect of 4-(3-phenyl-1,2,4-oxadiazole-5-yl)-butan-2-one (6a), 4-(3-p-tolyl-1,2,4-oxadiazol-5-yl)-butan-2-one (6c) and (R, S)-3-p-benzylphenyl-1,2,4-oxadiazole-5-yl)-ethanol (7e) and its precursors was assessed against third instar larvae of Plutella xylostella and the results were compared to commercial insecticides available in the communities. Compounds 6a and 6c exhibited the same level of toxicity but were more toxic than compound 7e. All 1,2,4-oxadiazoles exhibited high toxicity. P. xylostella was less susceptible to the commercial insecticides used as the positive controls than the 1,2,4-oxadiazole derivatives. The results demonstrate that the larvae of P. xylostella are highly sensitive to the ring of 1,2,4-oxadiazole, which can be used as a potential insect-control agent. The present study aimed to describe the synthesis and evaluate the insecticidal activity of 4-(3-aryl-1,2,4-oxadiazole-5-yl)-butan-2-one and (R,S)-3-aryl-5-(1-hydroxy-ethyl)-1,2,4-oxadiazole against P. xylostella.

Comparative larvicidal, pupicidal, adulticidal activity of Artemisia nilagirica (C.B. Cl) Pamp extract in controlling Culex quinquefasciatus, Anopheles stephensi, Aedes aegypti and Aedes albopictus.

Vector-borne diseases cause increase in burden, poverty, social liability and death all over the world. Mosquitoes serve as the vector for malaria, dengue, filariasis, yellow fever and also play a major role in transmission of chikungunya and Zika virus. The development of mosquitocidal resistance and associated health problems with the use of synthetic insecticides, have paved the way to control mosquito population by using plant-based botanicals. This study was carried out to evaluate the larvicidal, pupicidal and adulticidal properties of six solvent extracts of Artemisia nilagirica (C.B.Cl) against four infectious vector mosquitoes Anopheles stephensi, Aedes aegypti, Aedes albopictus and Culex quinquefasciatus, by assessing LC50 and LC90 mortality values. Among all six leaf solvent extracts, chloroform extract had higher toxicity (LC50= 127.27ppm and LC90=544.45ppm) against fourth instar larva of C. quinquefasciatus and aqueous extract had lowest lethal effects (LC50=583.33ppm and LC90= 927.27ppm) against fourth instar larva of A. aegypti. Moderate results were found in n- hexane, petroleum ether, methanol and ethanol plant extracts. Phytochemical analysis by GC-MS method confirms presence of significant 12 bioactive compounds like Bi-cyclo (3.1.1) heptanes-2, 4, 6 trimethyl, 3, 7, 11, 15- Tetramethyl-1.2 hexadecan-1-ol, Thiophene, Tetrahydro-2-methyl 1,3 propane diamine and camphor, which were responsible for insecticidal activity. Altogether, current study would serve as an initial step towards replacement of synthetic insecticides to plant- based bio-pesticide against dreadful vector mosquitoes in future.

Nanoscale Metal-Organic Frameworks for the Co-Delivery of Cycloxaprid and Pooled siRNAs to Enhance Control Efficacy in Diaphorina citri.

RNA pesticides have emerged as a promising alternative to conventional chemical pesticides due to their high specificity and minimal environmental impact. However, the instability of RNA molecules in the environment and the challenges associated with their effective delivery to target pests limit their broader application. This study addresses these challenges by developing a dual delivery system using chitosan (CS) and Metal-Organic Frameworks (MOFs) to enhance the delivery and efficacy of double-stranded RNA (dsRNA) and cycloxaprid against Diaphorina citri, a vector of citrus greening disease. The CS-MOF nanoparticles were synthesized and characterized using scanning electron microscopy (SEM) and dynamic light scattering (DLS). Insect bioassays demonstrated that the codelivery system significantly improved insecticidal activity, achieving over 80% mortality in D. citri within 2 days. The results indicate that the encapsulation of dsRNA within MOFs enhances its stability, while the controlled release properties of the nanoparticles improve the efficacy of cycloxaprid. This novel approach shows great potential in overcoming the limitations of RNA pesticides and offers a sustainable solution for pest management in agriculture. Future research should optimize the delivery system, conduct field trials, and explore its applicability to other agricultural pests.

Computer-aided design of novel anthranilic diamides containing fluorinated alkoxy groups as potential ryanodine receptor insecticides.

Increasing the diversity of lead compounds has been shown to enhance the efficacy of diamide insecticides. Fifty novel compounds were precisely designed and synthesized utilizing fragment-based assembly and virtual screening coupling. The median lethal concentration (LC50) values of compounds X-30 and X-40 against Mythimna separata were 0.09 and 0.08 mg L-1, respectively, which are lower than that of chlorantraniliprole (CHL, 0.11 mg L-1). Notably, compounds X-10, X-18, X-25, X-32 and X-43 had corresponding LC50 values of 2.0 × 10-4, 5.0 × 10-4, 6.0 × 10-4, 9.0 × 10-4 and 7.0 × 10-4 mg L-1 against Plutella xylostella, respectively. The best compound X-10 exhibited five-fold greater efficacy than CHL (1.0 × 10-3 mg L-1). The LC50 values of compounds X-21, X-29, and X-40 against Spodoptera frugiperda were 0.27, 0.26 and 0.25 mg L-1, respectively, which are slightly lower than that of CHL (0.33 mg L-1). In the case of Ostrinia furnacalis, compound X-43 showed good efficacy with LC50 values comparable to those of CHL (1.38 versus 1.57 mg L-1). Calcium imaging experiments demonstrated that X-21 acted on S. frugiperda ryanodine receptors. Furthermore, this series of compounds showed safety toward nontarget mammals compared to CHL. The introduction of fluorinated alkoxy groups at the 3-position of the pyrazole ring leads to good insecticidal activity and improved insect selectivity. © 2025 Society of Chemical Industry.

Two Birds with One Stone: Eco‐Friendly Nano‐Formulation Endows a Commercial Fungicide with Excellent Insecticidal Activity

AbstractThe development of multi‐action pesticides presents significant advantages, including cost‐effectiveness, reduced application frequency, enhanced resistance management, and minimized environmental impact. Despite its efficacy in targeting chitin synthase in both fungi and insects, the insecticidal performance of polyoxin B remains limited. To overcome this limitation, a novel nano‐formulation, polyoxin B@ZTS is developed, utilizing agricultural byproducts, tea saponin, and zein. This formulation features a small particle size, high leaf deposition efficiency, and excellent dispersion properties. Leveraging a disulfide bond system, polyoxin B@ZTS is designed to respond to the intracellular reducing environment, enabling controlled release of polyoxin B. Remarkably, the nano‐formulation facilitates the penetration of physiological barriers, achieving equivalent insecticidal and fungicidal efficacy to polyoxin B at only one‐fifth of the dosage. This work highlights the potential of eco‐friendly, cost‐effective, and multifunctional nano‐pesticides, providing a compelling solution for sustainable agricultural practices and demonstrating broad applicability in integrated pest and disease management.

Salvia connivens Methanolic Extract Against Spodoptera frugiperda and Tenebrio molitor and Its Effect on Poecilia reticulata and Danio rerio

Spodoptera frugiperda (Lepidoptera: Noctuidae) and Tenebrio molitor (Coleoptera: Tenebrionidae) are two prominent pests of maize and its stored grains, respectively. Botanical pesticides have been proposed as an alternative for their management. This study evaluated the insecticidal activity of Salvia connivens (Lamiaceae) methanolic extract and rosmarinic acid against S. frugiperda and T. molitor by adding them to an artificial diet, as well as their ecotoxicological effects on Poecilia reticulata (Cyprinodontiformes: Poeciliidae) and Danio rerio (Cypriniformes: Danionidae) through acute toxicity tests. The methanolic extract showed higher mortality activity against S. frugiperda (LC50 = 874.28 ppm) than against T. molitor (LC50 = 1856.94 ppm) and was non-toxic to fish. Rosmarinic acid, the most abundant compound in the extract (80.45 mg g−1), showed higher activity against S. frugiperda (LC50 = 176.81 ppm). This compound did not cause a toxic effect on adult P. reticulata at the tested concentrations. However, in P. reticulata fingerlings and D. rerio adults, it was non-toxic, except in D. rerio embryos, where it was slightly toxic. These findings suggest that S. connivens methanolic extract has potential as a botanical product for the management of S. frugiperda and T. molitor with low ecotoxicological impact, while rosmarinic acid may be a useful compound for the management of S. frugiperda.

Behavioral Profiling in Zebrafish Identifies Insecticide-Related Compounds.

Pesticides, including insecticides, are indispensable for large-scale agriculture. Modulating chloride ion channels has proven highly successful as a mode of action (MoA) for insect management. Identifying new ligands for these channels affords opportunities for the potential development of new insecticide products. We discovered an unexpected behavioral response in larval zebrafish exposed to endosulfan, a γ-aminobutyric acid (GABA)-gated chloride channel modulator. At low concentrations, endosulfan increased zebrafish motor activity under strobing blue or green light stimuli. Using this distinct behavioral phenotype as a proxy for similar modes of action, we screened over 9,000 compounds and identified several structurally diverse hits that phenocopied endosulfan's effects in vivo. Nine selected hits were tested in an in vitro GABA receptor (GABAR) oocyte assay, confirming that certain compounds block Drosophila GABAR activation. Subsequent in vivo insect assays revealed that one of these GABAR antagonists showed insecticidal activity against the Western corn rootworm (Diabrotica virgifera virgifera), which is a commercially important pest of corn. Our findings demonstrate a new approach for identifying GABAR-targeting insecticides through behavior-based screening in zebrafish.

Discovery of Novel Neonicotinoids with Conjugated Diene Enabled by Cascade Allylation/Isomerization Synthetic Methodology.

As one of the most significant insecticides, neonicotinoids have played a pivotal role in crop protection and public sanitation. However, the high resistance and bee toxicity of neonicotinoid insecticides have attracted considerable attention. Herein, a series of neonicotinoid compounds with conjugated diene moieties were synthesized through the cascade allylation/isomerization reaction. Most of the target compounds exhibited excellent insecticidal activities against Aphis craccivora, and some compounds exhibited good insecticidal activities against Mythimna separata. In particular, compound A15 showed outstanding insecticidal activity against A. craccivora (LC50 = 0.15 mg/L), which was superior to that of imidacloprid (LC50 = 0.36 mg/L). In addition, this candidate exhibited minimal cross-resistance to imidacloprid. The acute contact toxicity tests on Apis mellifera suggested that compound A15 was 10 times less toxic than imidacloprid. Electrophysiological experiments and molecular docking studies indicated that compound A15 exerted its insecticidal effects by interfering with nicotinic acetylcholine receptors. This work identifies a novel conjugated diene neonicotinoid candidate with significant potential for further development.

Evaluating the potential of Kalanchoe pinnata, Piper amalago amalago, and other botanicals as economical insecticidal synergists against Anopheles gambiae

BackgroundSynergists reduce insecticide metabolism in mosquitoes by competing with insecticides for the active sites of metabolic enzymes, such as cytochrome P450s (CYPs). This increases the availability of the insecticide at its specific target site. The combination of both insecticides and synergists increases the toxicity of the mixture. Given the demonstrated resistance to the classical insecticides in numerous Anopheles spp., the use of synergists is becoming increasingly pertinent. Tropical plants synthesize diverse phytochemicals, presenting a repository of potential synergists.MethodsExtracts prepared from medicinal plants found in Jamaica were screened against recombinant Anopheles gambiae CYP6M2 and CYP6P3, and Anopheles funestus CYP6P9a, CYPs associated with anopheline resistance to pyrethroids and several other insecticide classes. The toxicity of these extracts alone or as synergists, was evaluated using bottle bioassays with the insecticide permethrin. RNA sequencing and in silico modelling were used to determine the mode of action of the extracts.ResultsAqueous extracts of Piper amalago var. amalago inhibited CYP6P9a, CYP6M2, and CYP6P3 with IC50s of 2.61 ± 0.17, 4.3 ± 0.42, and 5.84 ± 0.42 μg/ml, respectively, while extracts of Kalanchoe pinnata, inhibited CYP6M2 with an IC50 of 3.52 ± 0.68 μg/ml. Ethanol extracts of P. amalago var. amalago and K. pinnata displayed dose-dependent insecticidal activity against An. gambiae, with LD50s of 368.42 and 282.37 ng/mosquito, respectively. Additionally, An. gambiae pretreated with K. pinnata (dose: 1.43 μg/mosquito) demonstrated increased susceptibility (83.19 ± 6.14%) to permethrin in a bottle bioassay at 30 min compared to the permethrin only treatment (0% mortality). RNA sequencing demonstrated gene modulation for CYP genes in anopheline mosquitoes exposed to 715 ng of ethanolic plant extract at 24 h. In silico modelling showed good binding affinity between CYPs and the plants’ secondary metabolites.ConclusionThis study demonstrates that extracts from P. amalago var. amalago and K. pinnata, with inhibitory properties, IC50 < 6.95 μg/ml, against recombinant anopheline CYPs may be developed as natural synergists against anopheline mosquitoes. Novel synergists can help to overcome metabolic resistance to insecticides, which is increasingly reported in malaria vectors.Graphical

Evaluation of hesperidin as a potential larvicide against Culex pipiens with computational prediction of its mode of action via molecular docking

Hesperidin, a natural flavanone glycoside predominantly found in citrus fruits, has gained attention for its wide-ranging biological activities, including potential insecticidal properties. Culex pipiens, commonly known as the northern house mosquito, is a major vector of several human pathogens, such as the West Nile virus and filariasis, making it a key target in the fight against vector-borne diseases. In this study, we evaluated the larvicidal activity of Hesperidin against Culex pipiens larvae, assessing its potential as an alternative to chemical insecticides. Hesperidin demonstrated potent larvicidal effects, with a lethal concentration 50 (LC50) of 570.3 ± 0.04 µg/mL, outperforming the conventional insecticide Chlorpyrifos 588.3 ± 0.28 µg/mL in efficacy. Molecular docking simulations revealed a strong binding affinity between Hesperidin and crucial neuroreceptors in Culex pipiens, particularly acetylcholinesterase (AChE), a key enzyme involved in nerve signal transmission. The interaction between Hesperidin’s hydroxyl groups and the AChE enzyme’s active site suggests that AChE inhibition is the primary mechanism driving Hesperidin’s insecticidal action. These findings position Hesperidin as a promising, environmentally friendly alternative to synthetic insecticides. However, further research is needed to assess its toxicity to non-target organisms and optimize its formulation for broader application in mosquito control.

Design, synthesis and insecticidal activities of novel m-diamide compounds containing n-propyl group

Design, synthesis and insecticidal activities of novel m-diamide compounds containing n-propyl group

Antibacterial, Antibiofilm Activity of Cymbopogon citrates L. Essential oil Leaves Extract and assessment of its effect on fimA and papC Genes against Escherichia coli Isolate

Background: Escherichia coli, sometimes known as E. coli, is a gram-negative bacterium that is typically present in people's intestinal flora. Some forms of E. coli can cause sickness, while the majority of these types are benign and aid in digestion. By creating biofilms, bacteria are able to defend themselves against mechanical, chemical, and biological assaults, giving them exceptional survival benefits. The scented medicinal grass known as lemon grass belongs to the Cymbopogon genus. Lemongrass essential oils include bioactive phytoconstituents that have a wide range of therapeutic benefits, including antibacterial, anticancer, antioxidant, insecticidal, and antimalarial actions. Methods: The aim of this study is to evaluating the antibacterial activity of (C. citrates) essential oil leaves extract and assessment of its effect on fimA and papC genes in E. coli. Gas chromatography and mass spectrometry analyses of the C. citrates essential oil extract. Forty-eight isolates of E. coli from different sources such as (urine, blood and stool. the diagnosis was confirmed using VITEK-2. The experiments use in this study is (Antibiotic susceptibility test, Disc diffusion method, Total phenolic content, Determination of Minimum Inhibitory Concentration (MIC) of C. citrates L. m biofilm formation and Genetic analysis). Results: The objective of this study is to assess the antibacterial and antibiofilm properties of extracts derived from the leaves of C. citrates and the effect on gene expression of fimA and papC genes after treatment with sub-MIC of C. citrates leaves extracts. Conclusion: The finding of this study showed that (90%) of the isolates had FimA while PapC was present in (60%) of the total isolates. The gene expression revealed that there was a decrease in the expression of Fim A and PapC genes.

Compounds Involved in the Invasive Characteristics of Lantana camara.

Lantana camara L. is native to tropical America and has naturalized in many other tropical, subtropical, and temperate regions in Asia, Africa, Oceania, North and South America, and Europe. L. camara infests diverse habitats with a wide range of climatic factors, and its population increases aggressively as one of the world's 100 worst invasive alien species. Its infestation reduces species diversity and abundance in the natural ecosystems and reduces agricultural production. The life history characteristics of L. camara, such as its high reproductive ability and high adaptive ability to various environmental conditions, may contribute to its ability to infest and increase its population. Possible evidence of the compounds involved in the defense functions of L. camara against natural enemies, such as herbivore mammals and insects, parasitic nematodes, pathogenic fungi and bacteria, and the allelochemicals involved in its allelopathy against neighboring competitive plant species, have accumulated in the literature over three decades. Lantadenes A and B, oleanonic acid, and icterogenin are highly toxic to herbivore mammals, and β-humulene, isoledene, α-copaene thymol, and hexadecanoic acid have high insecticidal activity. β-Caryophyllene and cis-3-hexen-1-ol may function as herbivore-induced plant volatiles which are involved in sending warning signals to undamaged tissues and the next plants of the same species. Farnesol and farnesal may interrupt insect juvenile hormone biosynthesis and cause abnormal metamorphosis of insects. Several triterpenes, such as lantanolic acid, lantoic acid, pomolic acid, camarin, lantacin, camarinin, ursolic acid, and oleanonic acid, have demonstrated nematocidal activity. Lantadene A, β-caryophyllene, germacrene-D, β-curcumene, eicosapentaenoic acid, and loliolide may possess antimicrobial activity. Allelochemicals, such as caffeic acid, ferulic acid, salicylic acid, α-resorcylic acid, p-hydroxybenzoic acid, vanillic acid, unbelliferone, and quercetin, including lantadenes A and B and β-caryophyllene, suppress the germination and growth of neighboring plant species. These compounds may be involved in the defense functions and allelopathy and may contribute to L. camara's ability to infest and to expand its population as an invasive plant species in new habitats. This is the first review to focus on how compounds enhance the invasive characteristics of L. camara.

Synthesis and Insecticidal/Fungicidal Activities of Triazone Derivatives Containing Acylhydrazone Moieties.

A series of novel triazone derivatives containing aldehyde hydrazone or ketone hydrazone moieties were designed, synthesized and their biological activities were investigated against Aphis craccivora, Culex pipiens pallens, Helicoverpa armigera, Ostrinia nubilalis, Mythimna separata and 14 Kinds of fungi. Most of the aldehyde hydrazone exhibited excellent insecticidal activities against A. craccivora. In particular, the aphicidal activities of compounds 3t (35%) and 3w (30%) were equivalent to pymetrozine (30%) at 5 mg/kg. The aphicidal activities of derivatives 3p, 3u, 3y, 5g, 5i, 5l, 5q and 5u against C. pipiens pallens were higher than that of pymetrozine. Compound 3u (100%) exhibited good larvicidal activities against C. pipiens pallens at 0.25 mg/kg. Most derivatives exhibited broad-spectrum fungicidal activities against 14 kinds of plant fungi at 50 mg/kg. Thirty-nine compounds exhibited a more than 50% inhibition rate against Physalospora piricola. Compounds 3h, 3t and 3w were expected to be the leading structure for the development of new triazone insecticides agents.