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The objective of this study was to evaluate the entomotoxic activity of the hydroalcoholic extract of Eragrostis plana Nees in an experimental model of cockroaches (Nauphoeta cinerea Olivier), for a possible bioinsecticide. For this purpose, aerial parts of E. plana were grounded to obtain the hydroalcoholic extract (EACA), after preparing the concentrations of (0.5; 2.5; 5.0; 12.5; 25.0; 50.0 100.0 μg g-1 per animal) a saline solution was used to control the treatment. To determine the receptors and pathways involved in responses to EACA doses of E. plana, a treatment with the drug octopamine and its inhibitor phentolamine were prepared. The effect of EACA on behavioral activities (grooming) and on cardiac activity were tested. All data were expressed as mean ± standard deviation, being analyzed by the two-way ANOVA test, followed by the Tukey test, considered significant when p<0.05. After carrying out the experiment, it was found that EACA induced a significant effect on leg grooming at all concentrations, except for the concentration of 100 μg g-1 per animal, but the same did not modulate antenna grooming. Regarding the receptors and pathways involved, it was observed that octopamine alone and together with the extract, had a significant effect on leg grooming, while phentolamine, together with the extract, influenced antennae grooming. Regarding the effect of the extract on the semi-isolated heart, it was noticed that the same doses that affected grooming, affected heart rate by decreasing it. At no concentration, at the end of the treatment, there was no recovery of the heart rate. The results point to a direct modulation of octopaminergic and cholinergic pathways in the insect nervous system.

New 1,3,5-trimethylpyrazole-containing malonamide derivatives based on pyflubumide were designed, synthesized, and characterized using 1H-NMR, 13C-NMR, and high-resolution mass spectra (HRMS). The results of preliminary bioassays showed that the target compounds possessed good activities against Tetranychus cinnabarinus, Plutella xylostella, and Aphis craccivora. Most of the target compounds exhibited moderate to good acaricidal activity against Tetranychus cinnabarinus at a concentration of 400 µg/mL, and some showed moderate activity at a concentration of 200 µg/mL; in particular, compounds 8m and 8p exhibited 70.0% mortality. In addition, some of the target compounds exhibited good insecticidal activities against Plutella xylostella at a concentration of 200 µg/mL, especially compounds 8i and 8o, which achieved 100.0% mortality at a concentration of 100 µg/mL. Interestingly, some of the target compounds exhibited potent anti-aphid activity against Aphis craccivora at a concentration of 200 µg/mL; furthermore, compounds 8p and 8q demonstrated 100.0% anti-aphid activity at a concentration of 50 µg/mL. The preliminary analyses of the structure–activity relationships (SAR) indicated that the acaricidal and insecticidal activities varied significantly depending on the type of substituent and substitution pattern, which provides guidance for the further investigation of such structural modifications.

Cyclic peptoids have recently emerged as an important class of bioactive scaffolds with unique conformational properties and excellent metabolic stabilities. In this paper, we describe the design and synthesis of novel cyclic octamer peptoids as simplified isosters of mycotoxin depsipeptides bassianolide, verticilide A1, PF1022A and PF1022B. We also examine their complexing abilities in the presence of sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB) salt and explore their general insecticidal activity. Finally, we discuss the possible relationship between structural features of free and Na+-complexed cyclic octamer peptoids and bioactivities in light of conformational isomerism, a crucial factor affecting cyclic peptoids’ biomimetic potentials.

The insecticidal activity of the Diatomaceous Earth (DE) of Sig was assessed against the Dermestes haemorrhoidalis, which is the main pest affecting wheat stored in Blida, a central region of Algeria and one of the four cereal regions managed by the Algerian Inter-branch Cereals Office (AICO). The formulation was tested at two different doses: 500 and 1000 ppm against adults of the species. The bioassays were carried out in 1-litre glass jars containing soft wheat with an average moisture content of 60% mixed with diatomaceous earth and maintained at 27°C and 70% of humidity. The effectiveness of the treatment was assessed by recording adult mortality after 2, 7 and 14 days. Sig's diatomite showed significant insecticidal activity against Dermestes haemorrhoidalis after only two days of treatment with both doses 500 and 1000 ppm. After 14 days, average mortality was more than 95% even at 500 ppm. Furthermore, electron microscopy of the diatomite particle from Sig (Algeria) reveals the architecture of the frustule. It shows a porous and brittle siliceous shell made largely of diatomite \"skeletons\". This research work allowed getting insights into the mechanism of action of diatomite on the Dermestes haemorrhoidalis. On the other hand, the identification of diatomite of Sig was performed by X-ray diffraction and infrared.

Abstract Background Vector control strategies have predominantly relied on the use of synthetic chemicals, leading to the widespread of resistance among malaria vector populations. This growing resistance has prompted increased interest in alternative control methods, particularly those based on plant-derived essential oils (EOs). The present study investigates the insecticidal efficacy of five essential oils against field populations of Anopheles gambiae sensu lato from Burkina Faso. The objective was also to assess the current distribution and frequency of resistance-conferring mutations within these mosquito populations. Methods Essential oils were extracted from Cymbopogon citratus, Cymbopogon nardus, Eucalyptus camaldulensis, Lippia multiflora, and Ocimum americanum plants by hydrodistillation, and their chemical composition was analyzed by gas chromatography coupled with mass spectrometry (GC–MS). The insecticidal activity of the EOs was evaluated on Anopheles gambiae complex populations collected from fifteen localities, following the WHO tube bioassay protocol. Species identification in Anopheles complex was carried out by PCR. Molecular assays targeting specific resistance genes, particularly the knockdown resistance (kdr) L1014F mutation, were conducted using allele-specific PCR. The KD effect and mortality rates induced by each EO were recorded. Results GC–MS analysis revealed among the 5 EOs samples tested, monoterpenes were the dominant compounds. The KD effects of Cymbopogon citratus, Cymbopogon nardus and Lippia multiflora were more pronounced in all the study areas. The comparative analysis of knockdown times at 50% and 95% (KDT50 and KDT95) highlights significant differences in efficacy between the tested essential oils and permethrin. Overall, the essential oils exhibited significantly lower KDT values than permethrin, indicating a faster and potentially more effective action against Anopheles gambiae populations. Moreover, L. multiflora induced a rate of mortality of 100% in mosquitoes from fifteen localities. Statistical analysis revealed significant differences in mortality rates among the EOs tested. The potent insecticidal activity observed is likely due to the major terpenoid compounds present in these EOs. Among the mosquito populations analyzed, Anopheles arabiensis was predominant and exhibited high phenotypic resistance to pyrethroids in multiple locations. Conclusion The EOs of Cymbopogon citratus, Cymbopogon nardus, and Lippia multiflora could be used as alternatives where pyrethroid resistance in malaria vectors has been established. These findings support the potential integration of these plant-derived oils into environmentally sustainable vector management strategies in Burkina Faso.

Agrotis ipsilon is an important pest of several crops, where it causes damage to various parts of the plant such as stems, roots, leaves and tubers. Due to the growing demand for controlling these pests, there is a constant need for new products as the organisms acquire resistance after continuous contact. And this also generates a demand for bioinsecticides, which normally pose a lower health risk and are less harmful to the environment. Among the plants commonly used as insecticides are neem and rue, which have already been studied for several pests, although never together. This work aimed to determine the insecticidal activity of a natural insecticide derived from a mixture of neem and rue, commonly used in the region of Senhor do Bonfim-BA against A. ipsilon. Four different solutions were prepared, containing a) 20 neem leaves, 10 rue leaves and 5 A. ipsilon caterpillars, b) 20 neem leaves and 10 rue leaves, c) 20 neem leaves and d) 10 rue leaves. Water was tested as control. In the tests carried out, both the mixture popularly used in the region, containing neem, rue, and A. ipsilon caterpillars, as well as the solution containing only neem and rue had good results, killing all caterpillars in 72 hours. Isolated plant extracts did not obtain good results, only delaying the formation of pupae for neem extracts. Therefore, the mixture of Neem and Rue showed good insecticidal potential against A. ipsilon, with much higher activity than its isolated components. Agrotis ipsilon is an important pest of several crops, where it causes damage to various parts of the plant such as stems, roots, leaves and tubers. Due to the growing demand for controlling these pests, there is a constant need for new products as the organisms acquire resistance after continuous contact. And this also generates a demand for bioinsecticides, which normally pose a lower health risk and are less harmful to the environment. Among the plants commonly used as insecticides are neem and rue, which have already been studied for several pests, although never together. This work aimed to determine the insecticidal activity of a natural insecticide derived from a mixture of neem and rue, commonly used in the region of Senhor do Bonfim-BA against A. ipsilon. Four different solutions were prepared, containing a) 20 neem leaves, 10 rue leaves and 5 A. ipsilon caterpillars, b) 20 neem leaves and 10 rue leaves, c) 20 neem leaves and d) 10 rue leaves. Water was tested as control. In the tests carried out, both the mixture popularly used in the region, containing neem, rue, and A. ipsilon caterpillars, as well as the solution containing only neem and rue had good results, killing all caterpillars in 72 hours. Isolated plant extracts did not obtain good results, only delaying the formation of pupae for neem extracts. Therefore, the mixture of Neem and Rue showed good insecticidal potential against A. ipsilon, with much higher activity than its isolated components.

Agrotis ipsilon is an important pest of several crops, where it causes damage to various parts of the plant such as stems, roots, leaves and tubers. Due to the growing demand for controlling these pests, there is a constant need for new products as the organisms acquire resistance after continuous contact. And this also generates a demand for bioinsecticides, which normally pose a lower health risk and are less harmful to the environment. Among the plants commonly used as insecticides are neem and rue, which have already been studied for several pests, although never together. This work aimed to determine the insecticidal activity of a natural insecticide derived from a mixture of neem and rue, commonly used in the region of Senhor do Bonfim-BA against A. ipsilon. Four different solutions were prepared, containing a) 20 neem leaves, 10 rue leaves and 5 A. ipsilon caterpillars, b) 20 neem leaves and 10 rue leaves, c) 20 neem leaves and d) 10 rue leaves. Water was tested as control. In the tests carried out, both the mixture popularly used in the region, containing neem, rue, and A. ipsilon caterpillars, as well as the solution containing only neem and rue had good results, killing all caterpillars in 72 hours. Isolated plant extracts did not obtain good results, only delaying the formation of pupae for neem extracts. Therefore, the mixture of Neem and Rue showed good insecticidal potential against A. ipsilon, with much higher activity than its isolated components.

Abstract Excessive use of insecticides has led to resistance of some pathogenic organisms (nematodes, bacteria and fungi), environmental contamination, and the presence of hazardous residues. Therefore, the aim of the present study was to evaluate synthetic metabolites derived from previous studies with edible mushrooms against the soybean weevil Rhyssomatus nigerrimus Fahraeus (Curculonidae) because of the relevance of pest control in an economically important crop. Furthermore, this is one of the first studies where edible fungal molecules are evaluated for the control of these insects. Initially, two in vitro tests (toxic effect and immersion) were evaluated against R. nigerrimus. In these tests, sensitivity and viability were determined in the 2% Tween control in water. For these two tests, the synthetic metabolites pentadecanoic acid (PNA), palmitic acid (PMA), stearic acid (STA), linoleic acid (LNA), β-sitosterol (βT) were evaluated individually as well as in combinations, “the fraction of standards (E1)”. Based on the results obtained, the dip test was selected to evaluate the mixtures of two standards (1. PMA + βT, 2. PMA + PNA, 3. PMA + LNA, 4. PMA + STA, 5. STA + βT, 6. STA + PNA, 7. STA + LNA, 8. PNA + βT, 9. PNA + LNA, 10. LNA + βT), three (1. PNA + βT + LNA, 2. PNA + βT + STA, 3. STA + LNA + PNA and 4. STA + LNA + βT) and four (PNA, βT, LNA and STA). The results showed that the mixture of three standards caused a higher percentage of mortality relative to the control group: l. PNA + βT + LNA and 2. PNA + βT + STA with 54.44 and 48% mortality of R. nigerrimus insects exposed for 15 days. These results show the importance of evaluating mixtures of molecules against R. nigerrimus. Resumo O uso excessivo de inseticidas levou à resistência de alguns organismos patogênicos (nematódeos, bactérias e fungos), à contaminação ambiental e à presença de resíduos perigosos. Portanto, o objetivo do presente estudo foi avaliar a mortalidade de metabólitos sintéticos derivados de estudos anteriores com cogumelos comestíveis contra o gorgulho-da-soja Rhyssomatus nigerrimus Fahraeus (Curculonidae) por causa da relevância do controle de pragas em uma cultura economicamente importante. Além disso, este é um dos primeiros estudos em que as moléculas fúngicas comestíveis são avaliadas para o controle desses insetos. Inicialmente, dois testes in vitro (efeito tóxico e imersão) foram avaliados contra R. nigerrimus. Nesses testes, a sensibilidade e a viabilidade foram determinadas no controle de 2% de Tween na água. Para esses dois testes, os metabólitos sintéticos – ácido pentadecanoico (PNA), ácido palmítico (PMA), ácido esteárico (STA), ácido linoleico (LNA) e β-sitosterol (βT) – foram avaliados individualmente, bem como a combinação dos 5, “a fração de padrões (E1)”. Com base nos resultados obtidos, o teste de imersão foi selecionado para avaliar as misturas de dois padrões (1. PMA + βT, 2. PMA + PNA, 3. PMA + LNA, 4. PMA + STA, 5. STA + βT, 6. STA + PNA, 7. STA + LNA, 8. PNA + βT, 9. PNA + LNA, 10. LNA + βT), três (1. PNA + βT + LNA, 2. PNA + βT + STA, 3. STA + LNA + PNA e 4. STA + LNA + βT) e quatro (PNA, βT, LNA e STA). Os resultados mostraram que a mistura de três padrões foi a com maior porcentagem de mortalidade em relação ao grupo controle, quais sejam, l. PNA + βT + LNA e 2. PNA + βT + STA, com 54,44% e 48% de mortalidade, respectivamente, em uma exposição de 15 dias contra R. nigerrimus. Estes resultados mostram a importância de avaliar as misturas entre moléculas contra R. nigerrimus.

ATP-binding cassette (ABC) transporters, a large class of transmembrane proteins, are widely found in organisms and play an important role in the transport of xenobiotics. Insect ABC transporters are involved in insecticide detoxification and Bacillus thuringiensis (Bt) toxin perforation. The complete ABC transporter is composed of two hydrophobic transmembrane domains (TMDs) and two nucleotide binding domains (NBDs). Conformational changes that are needed for their action are mediated by ATP hydrolysis. According to the similarity among their sequences and organization of conserved ATP-binding cassette domains, insect ABC transporters have been divided into eight subfamilies (ABCA–ABCH). This review describes the functions and mechanisms of ABC transporters in insecticide detoxification, plant toxic secondary metabolites transport and insecticidal activity of Bt toxin. With improved understanding of the role and mechanisms of ABC transporter in resistance to insecticides and Bt toxins, we can identify valuable target sites for developing new strategies to control pests and manage resistance and achieve green pest control.

Eucalyptus globulus essential oil (EGEO) is considered as a potential source of bioactive compounds with significant biological activity. The aim of this study was to analyze the chemical composition of EGEO, in vitro and in situ antimicrobial activity, antibiofilm activity, antioxidant activity, and insecticidal activity. The chemical composition was identified using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The main components of EGEO were 1,8-cineole (63.1%), p-cimene (7.7%), a-pinene (7.3%), and a-limonene (6.9%). Up to 99.2% of monoterpenes were present. The antioxidant potential of essential oil and results indicate that 10 μL of this sample can neutralize 55.44 ± 0.99% of ABTS•+, which is equivalent to 3.22 ± 0.01 TEAC. Antimicrobial activity was determined via two methods: disk diffusion and minimum inhibitory concentration. The best antimicrobial activity was shown against C. albicans (14.00 ± 1.00 mm) and microscopic fungi (11.00 ± 0.00 mm–12.33 ± 0.58 mm). The minimum inhibitory concentration showed the best results against C. tropicalis (MIC 50 2.93 µL/mL, MIC 90 3.17 µL/mL). The antibiofilm activity of EGEO against biofilm-forming P. flourescens was also confirmed in this study. The antimicrobial activity in situ, i.e., in the vapor phase, was significantly stronger than in the contact application. Insecticidal activity was also tested and at concentrations of 100%, 50%, and 25%; the EGEO killed 100% of O. lavaterae individuals. EGEO was comprehensively investigated in this study and information regarding the biological activities and chemical composition of the essential oil of Eucalyptus globulus was expanded.