Search Results (41)

Green pesticides provide sustainable, biorational alternatives to synthetic pesticides. Sabadilla, Schoenocaulon, store alkaloids in their seeds; veratridine and cevadine are extracted with insecticidal activity. Wild, extant populations of native, N. American, S. texanum, are the focus of this research. The goal of this research was to determine soil constituents; alkaloid levels; quantify reproductive capacity for bulbs/plant, inflorescences/plant, seed capsules/plant, seeds/plant; seed dimensions, 100 seed wt.; standard and saturated salt accelerated aging (SSAA) percent seed germination of open-pollinated, untreated seed. We tested 10 genotypes and derived open-pollinated seed lots from five non-sympatric populations collected in Texas. Soil samples showed variation for all soil characteristics. Organic matter levels and micro-nutrients were low; pH = 7.8–8.2; heavy metals (Al, Cd, Cr, Ni, Pb) were detected. Seeds of S. texanum are smaller than S. officinale, but share appearance, hardness, color and shape. Alkaloid content was ~20% lower than S. officinale. Mean number of bulbs/clump was 2–12 with 1–8 flower stems/plant. Mean 100 seed weight = 0.45 g. No seeds germinated in weeks 1–2 (G1, G2) in standard or SSAA tests. Highest % germination in both tests was in G3–G4, declining precipitously in G5–G6. We establish initial seed germination standards of ≥70% for both standard and SSAA germination tests, based on total or adjusted final % germination of seed lots. Full article

Aphids are major agricultural pests worldwide, causing crop damage both through direct piercing-sucking feeding and the transmission of plant viruses. Their multistage life cycle, unique developmental physiology, plasticity in developing pesticide resistance, and multifaceted interactions with host plants and bacterial endosymbionts make effective control particularly challenging. In this review, we summarize the current toolbox available for aphid control across major crop systems, including chemical pesticides, biological agents, plant resistance, cultural practices, biorational control, and emerging strategies such as RNA interference (RNAi) and symbiosis-targeted approaches. Rather than providing an exhaustive survey of the literature, we draw on conceptual and illustrative studies to critically evaluate the strengths and limitations of each control strategy. Finally, we outline future directions for aphid control, highlighting the potential of modern technologies, such as artificial intelligence (AI), synthetic biology, data-driven analytics, and CRISPR-based genome editing, to expand and improve existing control options. Full article

Drosophila suzukii (Diptera) is a polyphagous fly responsible for a huge loss in production of thin-skinned berries, usually controlled with low-selective synthetic pesticides, which can be toxic for biodiversity and human health. Biorational control of D. suzukii is challenging, despite many known lethal compounds, since most experiments happen in laboratory conditions, and agroecosystems include complex biotic and abiotic variables. Nanoencapsulation rises as an efficient alternative for optimizing pesticide development by protecting active ingredients and increasing selectivity. This review aimed to gather recent (over the last 5 years) research about plant-derived insecticides with the potential to control D. suzukii, examining their toxicity mechanisms and exposure methods, and to identify research gaps and perspectives, especially for nanoproducts. These efforts resulted in the selection of 31 articles, evaluating lethality and behavioral modulation caused by plant-based compounds, which exerted mainly attraction, repellency, and oviposition deterrence. Most studies were carried out under laboratory conditions, mostly testing plants from the Lamiaceae and Asteraceae botanical families, indicating essential oils as potential short-life pesticides against every life stage of D. suzukii, although their physicochemical instability limits field application. There are few studies addressing nano-pesticides for controlling D. suzukii, and these data contribute to botanical prospection for pesticide compounds and point to the development of plant-based nano-pesticides for controlling D. suzukii as a research gap with potential to enable field trials. Full article

Recently, ornamental plants in urban and unmanaged landscapes were found to be infected with several plant viruses transmitted by Brevipalpus mites. The main purpose of this research was to identify suitable tools for managing Brevipalpus yothersi in these environments by evaluating the efficacy, persistence, and rainfastness of selected biorational pesticides, as well as their compatibility with the predatory mite Amblyseius largoensis. We found that horticultural oils (i.e., petroleum distillates with varying levels of refinement, marketed as mineral or paraffinic oils) and Beauveria bassiana (Strain GHA) suppressed all developmental stages of B. yothersi at levels comparable to spirodiclofen, a commonly used acaricide for controlling B. yothersi. The paraffinic oil provided the best overall performance across the rainfastness, residuality, and greenhouse evaluations. This food-grade horticultural oil is exempt from residue tolerances and could be readily adopted for B. yothersi control in urban landscapes. Paraffinic oil had adverse effects on predatory mites. However, predator populations recovered after paraffinic oil application, and the combined treatment of paraffinic oil + A. largoensis ultimately provided better control than either the predators or the oil alone. When properly applied, horticultural oils provide a practical option for controlling populations of viruliferous Brevipalpus mites in urban and unmanaged landscapes. Full article

Controlling banana aphid (Pentalonia nigronervosa) vectors of banana bunchy-top disease is crucial for integrated disease management. Synthetic insecticides, though effective in aphid control, pose health and environmental risks. Biorational pesticides (including botanicals and soaps) are safer alternatives. This study screened four fresh and fermented aqueous plant extracts (chili pepper, garlic, neem, and peppermint) and three soaps (bathing, laundry bar, and liquid soap) singly or in mixtures against banana aphids through in vitro and in vivo experiments. Aphid-inoculated banana leaf-blade disks were used for the in vitro studies over 96 h. Potted plantlets were used for the in vivo studies over eight weeks. Applying these preparations resulted in significant (p ≤ 0.05) aphid mortality (28.6 to 100%) compared to the water control (3.3%) at 96 h post-spray (hps). In vitro, a single application of nimbecidine^® (Azadirachtin 0.03%), garlic, chili-pepper botanicals, insecticidal, and bathing soap caused >50% mortality at 96 hps. Mixed applications of chili pepper, garlic-based, and neem botanicals with soap caused >70% mortality at 96 hps in vitro. Binary mixtures of neem oil, garlic, fermented garlic, or fermented peppermint with insecticidal soap, and neem oil with bar soap, were promising in vivo, reducing the aphid populations to <20/plant compared to the control, which had >200 aphids after week 8. However, these potential preparations incurred a higher cost (USD 1.30/banana mat) compared to the synthetic pesticide (USD 0.022/mat). Thus, biorational mixtures have a potential to effectively control banana aphids. Full article

The objective of this study is to evaluate the effects of botanical oils on the mortality of the phytophagous mite Tetranychus urticae, the predatory mite Amblyseius swirskii, and on gas exchange in papaya seedlings. Two vegetable oils (soybean and corn), two essential oils (lavender and oregano), a synthetic pesticide (abamectin), and a control (water) were evaluated on papaya seedlings infested with T. urticae. In laboratory assays, within the first day after application, abamectin caused 100% mortality of T. urticae adults, followed closely by soybean (96%), corn (94.7%), and lavender (94.7%) oils. In A. swirskii, abamectin caused 100% mortality within 24 h; at 72 h, corn and lavender oils reached 96%, while oregano oil caused the least mortality (67.3%). In field trials, both abamectin and botanical oils statistically reduced eggs per leaf 24 h after application relative to the control, and a similar pattern was observed for nymphs 48 h after treatment. Botanical oils equaled abamectin in T. urticae adult suppression by 72 h, and soybean caused complete adult mortality by day 14. Regarding gas exchange, abamectin significantly affected the photosynthesis and transpiration processes. Thus, botanical oils represent viable biorational options for managing T. urticae in papaya, with lower ecological and physiological costs than abamectin. Full article

Industrial hemp (Cannabis sativa subsp. sativa L.) is an emerging crop in Florida, generating $445 million in 2024. However, it is highly susceptible to acarine pests, including spider mites (Tetranychidae), broad mites (Tarsonemidae), and russet mites (Eriophyidae). Management options are limited due to a few federally registered products approved by the Florida Department of Agriculture and Consumer Services (FDACS-DPI). Laboratory bioassays were conducted on hemp leaf discs infested with Tetranychus urticae, T. gloveri, Polyphagotarsonemus latus, or Aculops cannabicola, and treated with biorational pesticides (citric acid, rosemary, thyme, sesame, garlic, and mineral oil) at maximum label rates. Citric acid and garlic oil were most efficacious against T. urticae, while garlic and thyme oils were most efficacious against the other species, causing over 80% mortality. Greenhouse trials confirmed the efficacy of citric acid and garlic oil against T. urticae, achieving 60–80% mortality within 24 h. Predatory mites (Amblyseius swirskii, A. andersoni, Neoseiulus californicus, Galendromus occidentalis) were evaluated against A. cannabicola, with A. swirskii showing the highest predation (≈20 adults/24 h) and reproduction. Compatibility tests indicated thyme and garlic oils did not significantly affect A. swirskii survival (>70% alive after 24 h). These findings support integrated pest management strategies for hemp acarine pests. Full article

Integrated pest management (IPM) in tomato (Solanum lycopersicum L.) on the Ecuadorian coast represents a critical challenge, given that pest persistence has led producers to abandon the crop, generating significant losses. This study compared pest population fluctuations in greenhouse and open field conditions under realistic management conditions and free infestation, considering the influence of environmental factors and applications of biorational, semisynthetic, and synthetic pesticides. In open fields, infestations were high and sustained, exceeding treatment thresholds, while in greenhouses, levels were lower, attributable to the protection of the aphid netting. Product efficacy depended on the pest and the level of infestation: Azadirachta indica, Bacillus thuringiensis, and Beauveria bassiana were effective in low infestations; spinetoram and abamectin reached efficacies between 80 and 100% in moderate infestations; neonicotinoids had variable efficacy, ranging from 47.8% to 89.9%. Since the system determines the type of pest and the level of infestation, monitoring becomes a key tool for timely decision-making. The findings show that the greenhouse limits the entry of the main pest, Prodiplosis longifila. While it does not prevent the presence of smaller pests, such as thrips and white mites, the combination of physical barriers and low-toxicity pesticides significantly reduces populations, minimizing the number of applications and the use of more toxic insecticides. The proposed strategy provides solid evidence for the effective implementation of a greenhouse to reduce pest pressure and promote IPM in protected coastal systems in Ecuador. Full article

Acalitus simplex is an eriophyoid mite pest of the ornamental plant Ruellia simplex. Acalitus simplex compromises the esthetics of R. simplex by inducing erinea formation. Management practices for A. simplex are currently lacking. This study assessed the potential of commercial biorational (citric acid, potassium salt of fatty acids, garlic, thyme, and mineral oil) and conventional (abamectin, fenpyroximate, bifenthrin, spiromesifen) pesticides under laboratory conditions, using two types of spray applications: (A) curative, after erinea formation, and (B) prophylactic, before erinea formation. In the curative application, abamectin, garlic oil, and mineral oil were most effective; in the prophylactic application, abamectin and mineral oil showed the highest efficacies. Abamectin and mineral oil were further tested under greenhouse conditions. Both treatments effectively controlled A. simplex by preventing erinea formation over a four-week post-application period, regardless of the application type. At the end of the experiment, mites were extracted from R. simplex plants. In the curative application, significantly fewer mites were extracted from abamectin and mineral oil treatments than in the control. In the prophylactic application, mites were absent in abamectin and mineral oil treatments but present in the control. Abamectin and mineral oil can be used to manage A. simplex in landscapes. Full article

Santolina chamaecyparissus L. (cotton-lavender) is receiving increasing attention due to its potential for modern medicine and is considered both a functional food and nutraceutical. In this work, the phytochemical profile of its flower hydromethanolic extract was investigated by gas chromatography–mass spectrometry, and its applications as a biorational for crop protection were explored against Neocosmospora spp., both in vitro and in planta. The phytochemical profiling analysis identified several terpene groups. Among sesquiterpenoids, which constituted the major fraction (50.4%), compounds featuring cedrane skeleton (8-cedren-13-ol), aromadendrene skeleton (such as (−)-spathulenol, ledol, alloaromadendrene oxide, epiglobulol, and alloaromadendrene), hydroazulene skeleton (ledene oxide, isoledene, and 1,2,3,3a,8,8a-hexahydro-2,2,8-trimethyl-,(3aα,8β,8aα)-5,6-azulenedimethanol), or copaane skeleton (cis-α-copaene-8-ol) were predominant. Additional sesquiterpenoids included longiborneol and longifolene. The monoterpenoid fraction (1.51%) was represented by eucalyptol, (+)-4-carene, endoborneol, and 7-norbornenol. In vitro tests against N. falciformis and N. keratoplastica, two emerging soil phytopathogens, resulted in effective concentration EC₉₀ values of 984.4 and 728.6 μg·mL⁻¹, respectively. A higher dose (3000 μg·mL⁻¹) was nonetheless required to achieve full protection in the in planta tests conducted on zucchini (Cucurbita pepo L.) cv. ‘Diamant F1’ and tomato (Solanum lycopersicum L.) cv. ‘Optima F1’ plants inoculated with N. falciformis by root dipping. The reported data indicate an antimicrobial activity comparable to that of fosetyl-Al and higher than that of azoxystrobin conventional fungicides, thus making the flower extract a promising bioactive product for organic farming and expanding S. chamaecyparissus potential applications. Full article

The pepper weevil (Anthonomus eugenii) is a major pest that causes significant economic damage to several species and cultivars of pepper, including jalapeño (Capsicum annuum var. jalapeño). Protecting pepper crops from this pest often necessitates the use of chemical insecticides. To enhance control measures and mitigate the risk of insecticide resistance in the pepper weevil, this study focused on determining the optimal timing and application intervals of thiamethoxam and isocycloseram and assessed the effectiveness of rotating these pesticides with biorational insecticides. The effectiveness of various spray intervals for thiamethoxam and isocycloseram, starting at the bloom stage and one week post-bloom, was also assessed on the management of pepper weevils. The spray intervals for each insecticide included foliar applications weekly, every two weeks, every three weeks initiated at the blooming stage, and every two weeks beginning one week after blooming. The application of thiamethoxam and isocycloseram starting at bloom at one-week (7.3 ± 0.9 and 0.6 ± 0.4) and two-week (7.3 ± 0.9 and 0.7 ± 0.2) intervals significantly reduced the number of pepper weevil-infested buds compared to the untreated control (18.3 ± 2.5 and 1.7 ± 0.2). Isocycloseram starting at bloom and rotated with azadirachtin + pyrethrins as well as isocycloseram rotated with azadirachtin + pyrethrins and thiamethoxam on a weekly basis had the lowest number of pepper weevil-infested buds, flowers, and fruits and higher marketable yield. These findings suggest that adopting foliar applications weekly or every two weeks starting at bloom, as well as the rotation of thiamethoxam and isocycloseram with biorational insecticides, can effectively reduce pepper weevil infestation and increase pepper yield. Full article

Mosquito control still relies heavily on synthetic molecules, which can lead to the selection of resistant populations and undesirable environmental problems. This study described the preparation of a nanoparticle of the plant-derived molecule, β-myrcene, with chitosan, and the assessment of its toxicity against larvae of the yellow fever mosquito, Aedes aegypti. By producing fluorescent chitosan nanoparticles, we were able to observe their distribution in the digestive tract of larvae of Ae. aegypti. Chitosan-based nanoparticles containing β-myrcene (238 mg/L) could kill 100% of the larvae tested, whereas the blank control (i.e., the nanoparticle without β-myrcene) showed no larvicidal activity. The chitosan nanoparticles with β-myrcene had a zeta potential of +15 mV and a hydrodynamic diameter ranging from 30 to 2800 nm. The blank control, without β-myrcene, had a zeta potential of +26 mV and a diameter of 30 to 830 nm. Fluorescence analysis showed that the nanoparticles were efficiently absorbed and distributed in the digestive tract organs of the Ae. aegypti larvae. In short, our results reinforce the benefits of using chitosan to carry molecules of plant-derived-molecules, such as β-myrcene, in mosquito control, suggesting a broad internal distribution that contributes to their toxicity. Full article

Tomatoes are one of the predominant vegetable crops grown throughout the year in Tamil Nadu, India. Their perishable nature and resource-intensive cultivation make them susceptible to biotic stress. The damage caused by invasive insect pests, bacterial wilt during the rainy season, and viral diseases are major yield-limiting factors, and the farmers mostly depend on calendar-based insecticide applications for insect pest and disease management in tomatoes. The desired tomato hybrids grafted onto bacterial wilt-resistant eggplant rootstocks offer protection against bacterial wilt during the rainy season. The integrated pest and disease management (IPDM) practices consist of resistant grafted tomato seedlings (wild eggplant rootstocks EG 203 and TS 03), bioinoculants (Bacillus subtilis + Trichoderma asperellum + Purpureocillium lilacinum), pheromone traps (Phthorimaea absoluta and Helicoverpa armigera), botanicals (azadirachtin), microbial pesticides (Bacillus thuringiensis, Metarhizium anisopliae, and Beauveria bassiana), and bio-rationals, which were evaluated in four locations in two major tomato-growing tracts of Tamil Nadu. The results revealed that the treatment EG 203 eggplant rootstock-grafted tomato along with IPDM practices performed better across all experimental locations than the other treatment combinations viz., TS 03 eggplant rootstock-grafted tomato + IPDM, tomato + IPDM, grafted tomato + farmers’ practice and tomato + farmers’ practice. The EG 203-grafted tomato recorded a higher yield than the farmers’ practice with significantly superior biometric parameters. The treatment of EG 203-grafted tomato and IPDM practices can be adopted for safer tomato production by enabling a reduction in pesticide applications while enhancing productivity. Full article

Green mould, caused by Trichoderma aggressivum, is one of the major fungal diseases of button mushrooms. The main problems in chemical disease control include a lack of effective agents, the occurrence of pathogen resistance to pesticides, and the harmful impact on the environment. In an attempt to find a solution, the interaction between two beneficial microorganisms, Bacillus amyloliquefaciens B-241 (an antifungal agent) and Streptomyces flavovirens A06 (a yield stimulant), was investigated in vivo. The synergy factor (SF) was calculated as a ratio between the observed and expected impact on the yield or efficacy of disease suppression after artificial inoculation with T. aggressivum. The highest control of T. aggressivum was achieved by joint application of the two beneficial microorganisms. The additive interaction between microorganisms in efficacy against the pathogen was revealed. The largest yield was obtained in mushroom beds sprayed with the two beneficial microorganisms combined (B-241 80% and A06 20%). Regarding the impact on the yield, synergistic interaction between the two microorganisms was confirmed (SFs were 1.62 or 1.52). The introduction of optimized microbial combinations could create new possibilities for biorational edible mushroom protection, with improved yield and quality and reduced risks to human health and the environment. Full article

The γ-aminobutyric acid (GABA) receptors play pivotal roles in the transmission of neuronal information in the nervous system of insects, which has led these proteins to be targeted by synthetic and natural products. Here, we assessed the insecticidal potential of the essential oil of Pectis brevipedunculata (Gardner) Sch. Bip., a neotropical Asteraceae plant used in traditional medicine, for controlling Drosophila suzukii (Matsumura) adults by feeding exposure. By using in silico approaches, we disentangle the contribution of GABA receptors and other potential neuronal targets (e.g., acetylcholinesterase, glutathione-S-transferases) in insects that may explain the essential oil differential activities against D. suzukii and two essential pollinator bees (Apis mellifera Linnaeus and Partamona helleri Friese). Neral (26.7%) and geranial (33.9%) were the main essential oil components which killed D. suzukii with an estimated median lethal concentration (LC₅₀) of 2.25 µL/mL. Both pollinator forager bee species, which would likely contact this compound in the field, were more tolerant to the essential oil and did not have their diet consumptions affected by the essential oil. Based on the molecular predictions for the three potential targets and the essential oil main components, a higher affinity of interaction with the GABA receptors of D. suzukii (geranial −6.2 kcal/mol; neral −5.8 kcal/mol) in relation to A. mellifera (geranial −5.2 kcal/mol; neral −4.9 kcal/mol) would contribute to explaining the difference in toxicities observed in the bioassays. Collectively, our findings indicated the involvement of GABA receptors in the potential of P. brevipedunculata essential oil as an alternative tool for controlling D. suzukii. Full article