Search Results (399)

Aphis gossypii is a major pest that harms crops like industrial tomatoes in Panama. Recent resistance to synthetic insecticides has prompted interest in using plant secondary metabolites as eco-friendly alternatives. While some plants with insecticidal properties are well-known, others remain unexplored but could offer effective solutions. This study aimed to evaluate the insecticidal activity of ethanolic extracts from the stems and leaves of Eschweilera jefensis against nymphs and adults of Aphis gossypii. Extracts were tested at three concentrations (25, 50, and 100 µg/L), with mortality assessed at 24, 48, and 72 h post-application. The LC₅₀ values for the stem extract were 66.5, 36.8, and 31.0 μg/L, and for the leaf extract, they were 37.3, 28.4, and <25 μg/L at 24, 48, and 72 h, respectively. An advanced metabolomic analysis was conducted to identify the active compounds in each extract. This analysis uncovered several pentacyclic triterpenes, which, known for their insecticidal properties, are likely the key bioactive components responsible for the observed effects. Advanced metabolic analyses also revealed that the leaf extract, displaying the strongest insecticidal activity, is primarily composed of friedelene, while the stem extract contains betulin as their key active compounds. Furthermore, 29 known compounds were identified across both extracts, representing the first comprehensive report on the metabolic composition of E. jefensis, which underscores the significance of these findings. Together, these results suggest that E. jefensis extracts could serve as a promising natural alternative to synthetic insecticides for the management and control of A. gossypii. Full article

Staurosporine (STS) was discovered in 1977 by Omura and colleagues during a chemical screening for microbial alkaloids. It was the first indolocarbazole compound isolated from a soil-dwelling bacterium, Streptomyces staurosporeus. STS was also found to have antifungal activity, but its potent protein kinase (PK) inhibitory properties, perhaps the most extensively characterized biochemical feature of STS, were only revealed nearly a decade after its discovery. Thereafter, STS has been studied mainly for its anticancer potential with foreseen applications ranging from biomedical (e.g., antiparasitic) to agricultural (e.g., insecticidal). Interestingly, the recent discovery that STS induces apoptosis in the filamentous fungus Neurospora crassa renewed interest in this molecule as a scaffold for antifungal drug development. Studies in fungi and mammalian cell lines suggest that, in addition to PK inhibition, other modes of action are possible for STS. These may involve the targeting of membrane lipid domains and/or alterations of membrane biophysical properties. Here, the studies on the action of STS and its natural and synthetic derivatives against diverse fungal species, since its discovery to the present day, are critically reviewed and discussed with the aim of highlighting their advantages, limitations to be overcome, conceivable mechanisms of action, and potential as antifungal chemotherapeutic agents. Full article

Botanical insecticides have gained interest due to a rising demand for environmentally friendly pest control methods for stored-product protection. The insecticidal effectiveness of the essential oil (EO) obtained from the oleo-gum-resin of myrrh (Commiphora myrrha (Nees) Engl.), against Prostephanus truncatus (Horn) and Sitophilus zeamais Motschulsky, and the metabolic shifts of the two species, were investigated in this work. A thorough gas chromatography-mass spectrometry (GC-MS) investigation showed that the composition of this EO was dominated by furanosesquiterpenes, specifically, furanoeudesma-1,3-diene and curzerene. Commiphora myrrha EO treatments, especially at 1000 ppm, resulted in high adult mortality for P. truncatus (up to 85.6%), while S. zeamais showed only moderate mortality (up to 25.6%). To investigate the different species-specific effectiveness of the EO, untargeted GC-MS metabolomic profiling was conducted to elucidate the impact of the EO on the metabolism of the insects, with subsequent data analysis employing multivariate, univariate, and network methods. Each species reacts differently to the treatments (myrrh EO versus the synthetic insecticide pirimiphos-methyl (PM)), according to the analysis results. In particular, myrrh EO caused distinct shifts in metabolic pathways that varied between P. truncatus and S. zeamais. Overall, C. myrrha EO exhibits potential as a botanical insecticide, especially against P. truncatus, and it causes metabolic disturbances specific to the species. The results demonstrate the significance of metabolomic technologies in assessing bioinsecticide mechanisms and lend credence to their possible incorporation in integrated pest management methodologies or their contribution to the creation of diagnostic indicators of insecticidal exposure. Full article

The black bug, Antiteuchus tripterus (Hemiptera: Pentatomidae), is one of the most important pests of cacao in Peru. Its control relies primarily on synthetic insecticides, which negatively impact the environment and the health of cacao farmers. Therefore, the use of natural enemies, such as entomopathogenic fungi, represents a promising and sustainable alternative. In this study, we aimed to characterize entomopathogenic fungal isolates obtained from naturally infected A. tripterus adults in Peru. Using morphological and molecular approaches, we identified the isolates as Purpureocillium takamizusanense. Then, we assessed their pathogenic potential against A. tripterus and identified their functional cell wall groups. To evaluate pathogenicity, A. tripterus nymphs were exposed to serially diluted conidial suspensions (10⁵–10⁹ conidia mL⁻¹; isolate 24M) in both laboratory and field trials. The isolates exhibited conidial viability above 99%. Concentration-mortality bioassays confirmed the lethal effect of P. takamizusanense against A. tripterus nymphs. The LC₅₀ was 1.65 × 10⁶ conidia mL^–1, while the LT₅₀ and LT₉₀ were 3.08 and 7.29 days, respectively. The field mortality rate was about 52%, which can be explained by the influence of the environment. Spectroscopy analyses revealed functional groups including chitin, glucans, lipids, aliphatic chains, and proteins, which may contribute to infection and fungal persistence. This study presents the first record of P. takamizusanense in the Americas and highlights its potential as a biocontrol agent against A. tripterus in cacao plantations. Full article

Cauliflower, a widely cultivated vegetable crop valued for its edible curds, faces a persistent threat from insect pests, which are typically managed using synthetic insecticides. This study evaluated the benefits of intercropping practices as part of an ecological pest management strategy in cauliflower cultivation during the winter seasons of 2017–18 and 2021–22. Nine insect pests belonging to six families of three orders were recorded. The calendula intercropping system (IS) consistently showed the lowest infestation by Plutella xylostella and Pieris brassicae/plant. Calendula IS had attracted the highest numbers of syrphids, Cotesia glomerata, Diaeretiella rapae, Cotesia vestalis, and coccinellids such as Coccinella septempunctata and Cheilomenes sexmaculata. In candytuft IS, a strong tri-trophic interaction between the flower and D. rapae significantly reduced aphid populations, for each additional D. rapae, aphid numbers decreased by 48.53 in 2018. The marigold IS recorded the highest Shannon diversity index in 2021–22. The longest adult survival of C. septempunctata (8.67 ± 3.35 days), in the absence of aphids was recorded on candytuft flowers. The total sugars and protein in flowers positively influenced the longevity of the adult coccinellid beetles (R²-40.42 and 20.79%, respectively). Calendula intercropping yielded the highest revenue return of Indian rupee (₹) 11.33 per INR 1 invested, compared to the cauliflower monocrop (1.58). These findings demonstrate that, intercropping and habitat manipulation can enhance ecological pest control and reduce the dependence on synthetic chemicals. Full article

Mango fruits are one of the strategic fruit crops in different countries that are attacked by several serious pests such as Cryptoblabes gnidiella and Scirtothrips mangiferae. Natural extracts, especially essential oils, provide several promising insecticide agents to control different insects as an alternative to synthetic insecticides. Using Clevenger-type hydrodistillation, the essential oils of five thyme plants—Thymus vulgaris, Origanum vulgare, Thymus argenteus, Thymus citriodorus, and Origanum syriacum—from Saudi Arabia and Egypt were extracted, and GC/MS analysis was performed. In addition, some chemical parameters of the five species were determined, such as chlorophyll a, chlorophyll b, β-carotene, total antioxidant capacity, total phenols, and total flavonoids. Two compounds, thymol and carvacrol, were identified in T. vulgaris and O. vulgare at ratios of 69.45 and 64.82%, respectively. These major compounds were isolated and identified using ¹H NMR analysis. The insecticidal potentials of the five essential oils and their pure isolated compounds were evaluated on C. gnidiella and S. mangiferae on mango inflorescences. The results showed that T. vulgaris and O. vulgare oils were the most potent against C. gnidiella (LC₅₀, 183.33 and 164.68 ppm, respectively) and S. mangiferae (18.93 and 16.93 ppm, respectively). Thymol and carvacrol had the highest effect on both insects. Furthermore, the effect of thymol and carvacrol at LC₅₀ values on some biochemical parameters of C. gnidiella was determined. Therefore, thymol and carvacrol from Thymus species are promising compounds that could be used as insecticides against the harmful insects C. gnidiella and S. mangiferae on mango inflorescences. Full article

The fall armyworm, Spodoptera frugiperda, is a long-distance migratory pest, which invaded the African continent in 2016, causing enormous losses to agricultural crops, especially maize. Synthetic insecticides are primarily used for managing S. frugiperda, but they leave residues on human food and animal feed and also cause environmental hazards. We evaluated the crude ethanolic extract of Piper guineense fruits for contact toxicity on S. frugiperda larvae and determined the lethal concentration (LC₅₀) of the extract. Additionally, we conducted an electrophysiological (EAG) experiment to determine the responses of adult S. frugiperda males and females to P. guineense and determined whether the extract influenced mating, oviposition, and repellence to the adult female. We found that P. guineense extract caused significantly higher mortality to S. frugiperda larvae than an ethanol control. Electrophysiologically, we observed significantly higher responses to the extract than the control, with some variations in response between the sexes. A wind tunnel experiment revealed that females moved more towards the control than towards the extract. Taken together, our results confirm that P. guineense extract is effective against S. frugiperda larvae and adults. Future research should explore the responses of S. frugiperda to P. guineense extract on a field scale. Full article

Eurydema ventralis Kolenati, 1846 (Hemiptera: Pentatomidae), commonly known as the cabbage stink bug, is an increasingly important pest in Brassicaceae crops across Europe, including Slovenia. This review provides a comprehensive synthesis of current knowledge on the taxonomy, biology, distribution, and economic impact of Eurydema ventralis, with a focus on cabbage (Brassica oleracea L. var. capitata) cultivation. Various monitoring and population assessment methods are discussed as foundational tools for implementing integrated pest management (IPM). The focus of this study is on the available control strategies, including chemical, biological, cultural, and mechanical approaches. While synthetic insecticides remain a commonly used option, their environmental impact, potential for resistance development, and non-target effects raise concerns. Increasing research attention is being given to biological control agents, such as egg parasitoids, generalist predators (e.g., Coccinellidae, Carabidae, Nabidae), and entomopathogenic fungi. These agents show considerable promise but are not being fully utilized at present. A further review of cultural practices and mechanical control methods is also undertaken for their role in reducing pest populations. The compatibility of different strategies within an IPM framework is examined in detail. In conclusion, this review identifies existing knowledge gaps and puts forward a number of recommendations for future research directions. The purpose of these recommendations is to support the development of more sustainable and ecological pest management solutions for E. ventralis in cabbage cultivation. Full article

This study aims to evaluate the insecticidal activity of four bacterial strains against M. cerasi under both laboratory and field conditions, in order to provide a more sustainable and eco-friendly alternative to chemical insecticides. Four environmentally friendly bacterial strains were evaluated for their potential as biocontrol agents: Brevibacillus brevis (FD-1), Bacillus cereus (FD-63), Bacillus thuringiensis subsp. kenyae (FDP-8), and Bacillus thuringiensis subsp. kurstaki (FDP-41). Experiments were conducted under both controlled laboratory and field conditions. Data showed that mortality rates ranged from 33.33% to 93.33% under controlled conditions and from 13.33% to 50% under field conditions over the 96 h period. B. thuringiensis subsp. kurstaki (FDP-41) and B. thuringiensis subsp. kenyae (FDP-8) were the most effective bacterial strains against the aphids in controlled conditions. The percentage of mortality related to these applications was 93.33% and 80% in 96 h under laboratory conditions. However, the effectiveness of B. thuringiensis subsp. kurstaki (FDP-41) was 50% at 96 h in the field. These findings suggest that B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. kenyae hold significant potential as biological control agents against M. cerasi. Additionally, FDP-41 showed the lowest LT₅₀ value of 25.37 h in the laboratory and 86.40 h in the field. This indicates a much more rapid and potent effect on M. cerasi compared to other strains. As a result, it was concluded that these bacterial strains may be used successfully as biocontrol agents in the biological control of M. cerasi. Their successful use could reduce reliance on synthetic insecticides, thereby minimizing pesticide residues on crops and contributing to safer agricultural production and environmental sustainability. Full article

In this study, we investigated the insecticidal potential of Eucalyptus globulus Labill. and Cymbopogon citratus Stapf essential oils (EOs), both alone and in synergistic blends with their primary active compounds, against adult houseflies (Musca domestica L.). Toxicity assessments were also conducted on non-target organisms—dwarf honeybees (Apis florea Fabricius) and guppies (Poecilia reticulata Peters)—to evaluate environmental safety. All binary EO mixtures demonstrated superior efficacy compared to individual EOs and the synthetic pyrethroid α-cypermethrin (1% positive control). The most potent formulation, combining 2.5% (v/v) geranial with 2.5% (v/v) E. globulus EO, exhibited a synergistic effect, achieving complete fly mortality (LT₅₀: 0.06 h). This mixture’s mortality index significantly exceeded those of single-component formulations, with a mortality index of 0.22, confirming greater toxicity to flies than α-cypermethrin. Importantly, all the tested EOs and their blends were non-toxic to honeybees and guppies; in comparison, α-cypermethrin caused significant harm. These findings highlight the 2.5% (v/v) geranial + 2.5% (v/v) E. globulus EO blend as a highly effective and environmentally friendly alternative to conventional insecticides. Further research is recommended to optimize its formulation for practical use in sustainable fly management. Full article

The Tuta absoluta species represents a significant threat to solanaceous crops globally and has developed resistance to conventional synthetic insecticides. This study investigated the insecticidal properties of essential oils (EOs) from Melaleuca alternifolia and Eucalyptus staigeriana against T. absoluta using the age-stage, two-sex life table methodology. Initially, the EOs of M. alternifolia and E. staigeriana were chemically characterized by gas chromatography (GC) techniques. In this analysis, we identified 19 compounds in M. alternifolia essential oil, with terpinen-4-ol, γ-terpinene, and α-terpinene as the predominant constituents. Eucalyptus staigeriana essential oil contained 25 identified compounds, predominantly limonene, terpinolene, geranial, and neral. Essential oils were dissolved in acetone and applied topically to larval stages. Both treatments significantly reduced pest longevity and adversely affected key demographic parameters. Melaleuca alternifolia treatment resulted in a substantial decrease in the intrinsic rate of population increase, indicating potential for population suppression. These findings support the potential application of M. alternifolia and E. staigeriana EOs as biological control agents against T. absoluta in integrated pest management programs. Full article

The use of chemical pesticides in agriculture has led to the development of resistant pest populations, posing a challenge to long-term pest management. This review aims to evaluate the scientific literature on the individual and combined use of baculoviruses with conventional chemical and biological insecticides to combat Plutella xylostella, Spodoptera exigua, and Spodoptera frugiperda in broccoli, tomato, and maize crops. Notable findings include that both individual Plutella xylostella nucleopolyhedrovirus (PxNPV) and the combination of Plutella xylostella granulovirus (PxGV) and azadirachtin at a low dose effectively control Plutella xylostella; both combinations of Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) with emamectin benzoate and chlorfenapyr reduced resistance in Spodoptera exigua and increased the efficacy of the insecticides; and the combination of Spodoptera frugiperda nucleopolyhedrovirus (SfMNPV) and spinetoram is effective against Spodoptera frugiperda. Integrating baculoviruses into pest management strategies offers a promising approach to mitigate the adverse effects of chemical pesticides, such as resistance development, health risks, and environmental damage. However, there remains a broad spectrum of research opportunities regarding the use of baculoviruses in agriculture. Full article

Tomato crops are treated with high concentrations of synthetic fertilizers and insecticides to increase yields, but the careless use of these chemicals harms the environment and human health and affects plant pathogen resistance. The effect of foliar spray of three concentrations of chitosan (500, 1000, and 2000 mg L⁻¹) on plant growth, yield, fruit quality, and physiological performance in two tomato varieties (Floradade and Candela F1) was studied. Physiological traits such as photosynthesis, chlorophyll content, and leaf area index of the plants were positively affected by chitosan, an effective compound that biostimulates growth, with increases in biomass of organs with respect to the control treatment. Chitosan also improved tomato quality, such as increases in polyphenols, antioxidant capacity, flavonoids, carotenoids, vitamin C, and total soluble solids in both tomato varieties. Finally, yield increased by 76.4% and 65.4% in Floradade and Candela F1, respectively. The responses of tomato plants to chitosan application were different depending on the variety evaluated, indicating a differential response to the biostimulant. The use of chitosan in agriculture is a tool that has no negative effects on plants and the environment and can increase the productive capacity of tomato plants. Full article

The mosquito Aedes aegypti is the vector responsible for the transmission of important arboviruses such as dengue fever, Chikungunya, Zika virus, and yellow fever. These diseases affect millions of people and exert impacts on healthcare systems throughout the world. Given the increasing resistance to synthetic insecticides, essential oils from plants constitute an ecologically viable alternative for the control of this vector. The aim of the present study was to investigate the larvicidal activity of the essential oil (EO), aqueous extract, rutin, and hydrolate from the leaves of Myrciaria floribunda against Aedes aegypti larvae in the initial L4 stage. The yield of EO was 0.47%. Thirty-seven chemical constituents were identified and quantified using chromatographic methods. The major constituents were (E)-caryophyllene (27.35%), 1,8-cineole (11.25%), β-selinene (4.92%), and α-muurolene (4.92%). In the larvicidal tests, the lethal concentration (LC₅₀) was 201.73 ppm for the essential oil, 15.85% for the aqueous extract, and 22.46 ppm for rutin. The hydrolate had no larvicidal activity. The compounds that exhibited larvicidal activity against Aedes aegypti constitute a promising option for the development of natural formulations to diminish the propagation of this vector. Full article

Megalurothrips usitatus is a global pest damaged legume crops, particularly cowpea (Vigna unguiculata). This study aimed to determine the chemical composition of lemongrass essential oil (LEO) and its insecticidal activity against the insect pest M. usitatus. The composition of lemongrass essential oil was analyzed using Gas Chromatography Mass Spectrometry (GC-MS). D-limonene, Neral, and Citral were found to constitute over 30% of the essential oil. LEO exhibited higher insecticidal toxicity than the individual pure components. Based on our results, the optimal formulation of LEO emulsifiable concentrates (ECs) was identified, and their insecticidal activity was further investigated. The mortality rate induced by the LEO did not significantly differ from that of the emamectin benzoate (EB) formulation but was lower than that of spinosad (SP). Additionally, LEO was shown to act as a synergist when combined with EB for controlling M. usitatus. This research offers an alternative strategy for controlling M. usitatus and reducing the reliance on synthetic pesticides. Full article