Repellent Agent Research Articles

A Comprehensive Review on Insect Repellent Agents: Medicinal Plants and Synthetic Compounds.

Plant-based repellents have been used for generations as personal protection against mosquitoes. Ethnobotanical studies provide valuable knowledge for developing natural prod-ucts. Commercial repellents with plant-based ingredients are popular, but insufficient studies follow Pesticide Evaluation Scheme WHO guidelines. Further standardized studies are needed to evaluate repellent compounds and develop high-repellency and safe products. Essential Oils (EOs) from aromatic plants have gained popularity as low-risk insecticides due to their low toxicity and short environmental persistence. These plant-derived EOs, produced through steam distillation, have repellent, insecticidal, and growth-reducing effects on various insects. They control phytophagous insects, bite flies, and home and garden insects. US registration is the main hurdle for new EOs. This review explores the use of essential oils from plants as a natural repellent, focusing on their effectiveness and synergistic effects. Essential oils are vol-atile mixtures of hydrocarbons with diverse functional groups, and their effectiveness is linked to monoterpenes and sesquiterpenes. Synergistic effects can improve their effectiveness, and the use of other natural products, like vanillin, can increase protection time. Cymbopogon spp., Ocimum spp., and Eucalyptus spp. are among the most promising plant families.

Extraction and characterization of essential oils from fresh and dry leaves of Pinus elliottii

Essential oils are secondary metabolites whose properties have been studied mainly with emphasis on antimicrobial, biological and pharmaceutical fields, such as antibacterial, antifungal, antiviral, pest control and insect repellents. Essential oils from fresh and dry leaves of Pinus elliottii were extracted by hydrodistillation, chemically characterized and quantified by gas chromatography coupled to a mass spectrometer. The plant leaves were collected in a reforested area in the south of the state of Minas Gerais, Brazil. The two main components in both characterized essential oils were Germacrene D and β-Pinene. In the essential oil from fresh foliage, Germacrene D (47.71%) was the majority component, while in the essential oil from dry foliage, β-Pinene (30.06%) was the majority component. Literature data point that essential oils with large amount of Germacrene D may act as antibacterial and repellent agents. Additionally, literature data also support that essential oils with large amount of β-Pinene exhibit several biological properties, similar to the Germacrene D, in addition with a wide range of medicinal and pharmacological activities. Thus, from our results and with literature data, it is possible to elucidate new potential applications to essential oils from fresh and dry leaves of Pinus elliottii.

Two Lactones Non-toxic to Humans Are Effective Repellents for the German Cockroach.

Lactones are cyclic esters of hydroxy carboxylic acids, present in several fruits and animals consumed by humans. There is evidence that some lactones modify insect behavior. The aim of the present study was to evaluate the repellent effect of four lactones (γ- and δ-nonalactone, and γ- and δ-dodecalactone) in first instar nymphs of the German cockroach, Blattella germanica (Linnaeus). To assess repellency, a nymph was placed on a circle of filter paper, half of which had been treated with lactone dissolved in acetone and the other half with acetone alone. The behavior of the nymph was recorded and the time the nymph spent in each half of the paper was quantified using Ethovision XT 10.1 software. Values of Distribution Coefficient (DC) were calculated: DC = (Tt - TA) / Tt, where Tt is the experimental time and TA is the time the nymph spent in the area treated with the repellent agent. DC can vary between 0 and 1. Values significantly higher than 0.5 indicate repellency. N,N-diethyl-meta-toluamide (DEET) was used as a positive control. DEET, δ- and γ-nonalactone caused repellency as from 77.9µg/cm2, whereas γ- and δ-dodecalactone had a repellent effect starting at 779.0µg/cm2. The values of DC for these concentrations were 0.89 (DEET), 0.86 (γ-nonalactone), 0.87 (δ-nonalactone), 0.83 (γ-dodecalactone), and 0.72 (δ-dodecalactone). To our knowledge, this is the first report of repellency produced by lactones in the German cockroach. This work allowed to identify two lactones that have a repellent effect similar to DEET.

Polyvinyl Butyral Loading with Combined Repellents Showed Effective Protection Against Leech Bites in Diverse Situations.

Background: Leech bites have long been a persistent problem for individuals engaged in outdoor activities, particularly in environments such as moors, jungles, and grasslands. Methods to prevent leech bites are anecdotal and individual, highlighting the need for the development of universal and effective repellent formulations. This study developed a novel approach for repelling leeches using combined repellent agents and a film-forming material (polyvinyl butyral), to enhance efficiency in multi-scenario applications. Material and methods: This study demonstrates that citronellal, icaridin and DDAC (didecyl dimethyl ammonium chloride) showcasing active avoidance and contact toxicity on leeches. the optimized repellent formulation (MSRS, containing citronellal, icaridin and DDAC as repellent agents) enables specific sustained release properties of constituents in both air and water conditions. Results: MSRS could effectively achieve the purposes of "proactive repelling", "contact repelling", and "bite detaching". The effectiveness could last for several hours. Additionally, the hydrophobic polyvinyl butyral membrane reduced the transdermal absorption of repellent agents. Moreover, the formulation is biocompatible and environmentally friendly. Conclusions: This study provides a new feasible strategy for the prevention and removal of leech bites.

Moringa Leaf Powder as Environmentally Friendly Repellent Agent for Controlling the Warehouse Insect Pest for Black Soybean Grain

Black soybean grain (Glycine max L. Merril.) storage is susceptible to insect pests such as Callosobruchus analis (F.), which feeds on soybeans. Steroids/triterpenoids, phenolics, alkaloids, tannins, and terpenoids found in moringa leaf powder can be employed as insect repellents in black soybean grain warehouses. The purpose of this study was to ascertain how applying plant-based insecticides made from powdered moringa leaf will affect the amount of C. analis (F.) that died, the severity of the damage, and the weight loss of black soybean seeds of the Detam 4 Prida varieties. The study took place from August to October 2019 at an elevation of 878 meters above sea level in the Biology Laboratorium of the Agriculture Faculty, University of Winaya Mukti. An experimental design including five treatments and five replications was employed as the research methodology. A was not given any moringa leaf powder; B, C, D, and E each received 0.25, 0.75, and 1 grams of moringa leaf powder, fine powder, and so on. 10 pairs of C. analis (F) per jar were used in each treatment, which involved 100 g of black soybean grain. In the storage of black soybean grain, the percentage of seed damage, weight loss, the number of eggs, larvae, pupae, and images, and mortality of C. analis (F) were all impacted by 0.75 g of moringa leaf powder, according to the findings. According to this research, C. analysis, a warehouse insect pest, is effectively repelled by powdered moringa leaf (F.).

Citrus limon Wastes from Part of the Eastern Cape Province in South Africa: Medicinal, Sustainable Agricultural, and Bio-Resource Potential.

The fruits of Citrus limon are often purchased for their vitamin C-rich juice, while the fruit peel and the tree leaves are discarded as wastes. This study obtained the chemical profiles of the essential oils (EOs) of C. limon wastes (the peel and leaves), evaluated their medicinal value as antioxidants, their potential for sustainable use in agriculture as an insecticide for post-harvest preservation of grains, and their potential as a bioresource in livestock feed formulations. The EOs were isolated from C. limon leaves and peel using a hydro-distillation method on a Clevenger apparatus. The oil constituents were identified using the gas chromatography-mass spectrometry (GC-MS) hyphenated technique. The oils were evaluated for their in vitro antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power methods. An insecticidal study was conducted using contact toxicity, fumigation, and repellence bioassay methods against Sitophilus zeamais (maize weevils). Finally, the predicted income from using lemon peel as an alternative or substitute ingredient for maize in livestock feed formulations was obtained through a conventional simulation method. Chemically, limonene was found to be present in all the EOs analyzed (12-52%), while α-pinene was only found in the fresh leaf and peel oils (13.3% and 10.6%). Caryophyllene oxide was identified as the major component of the dried leaf oil (17.7%). At 20 µg m, the dry peel oil exhibited the highest inhibitory activity (52.41 ± 0.26%) against the DPPH radical, which was comparable to L-ascorbic acid (a standard antioxidant) at 54.25 ± 3.55%. The insecticidal study revealed that the dry peel oil is a better insect repellent (73.33 ± 6.95% at 10 µL) and fumigant (LC50 = 0.17 µL g-1 after 48 h) natural agent compared to the peel oil. Conversely, the dry peel oil showed a better contact activity (LC50 = 1.69 µL g-1) against the maize weevils compared to the dry leaf oil. The simulation study showed the cost of using dry lemon peel as an alternative to maize in livestock feed formulation to be ZAR 2.8 billion, compared against the higher cost of feed formulation with maize, which currently stands at ZAR 24.9 billion. This study has shown that C. limon wastes (the peel and leaves) contain EOs with unique chemical profiles, valuable medicinal properties as free radical scavengers, and considerable insecticidal properties for agricultural use in post-harvest grain preservation, presenting a cost-effective and promising bioresource for livestock feed production.

Mix design optimisation of self-sealing concrete containing microcapsules with polyurethane shell and water repellent cargo

Despite the robust ability of microcapsules (MIC) to break and release agent for healing/sealing efficacy, the reduction of concrete strength has been a major issue when using MIC. In this study, the optimisation of concrete mix design was initiated with employing three main parameters: MIC size (56, 93 μm), MIC dosage (0, 3, 6% by weight of cement) and water-cement (w/c) ratio (0.40, 0.50, 0.60). The used microcapsules consisted of water repellent agent core acting as a sealing agent and polyurethane as the shell material. Results confirmed the MIC dosage as the most significant factor affecting the mechanical properties, while no significant effect on the MIC size. Further, the MIC effect can be reduced by changing the concrete mix design from low to high w/c. The sealing efficiency of concrete was remarkably improved with the inclusion of MIC and a good bond between the capsules and concrete matrix was attained.

Rational design and discovery of novel oxalate-like derivatives as aphid-repellent candidates based on odorant-binding protein 3

Odorant-binding protein (OBP) is a potential target for developing insect repellent agents. In this study, twelve novel oxalate-like derivatives containing an isoprene chain were designed and synthesized based on the binding cavity of Acyrthosiphon pisum OBP3 (ApisOBP3). All oxalate-like derivatives showed excellent binding affinity to ApisOBP3 (Ki = 2–10 μM) and repellent activity against A. pisum (repellent rate: 44–62 %) and Myzus persicae (M. persicae, repellent rate: 49–66 %). Moreover, these oxalate-like derivatives were accidentally found to have good binding ability to another transport protein ApisOBP7 (Ki = 4–24 μM). Among them, compound 5b showed good stability and was identified as the most promising compound with good binding affinity to ApisOBP3 (Ki = 2.53 μM) and ApisOBP7 (Ki = 6.00 μM) as well as the highest repellent rate against A. pisum and M. persicae (above 60 %). The introduction of a unique oxalate skeleton in compound 5b significantly promoted its binding to ApisOBP3 by hydrophobic and electrostatic interactions, as verified by the MM/GBSA method. This study proved the feasibility of rational design of novel aphid repellent agents targeting aphid OBPs.

A Review on the Comparative Analysis of Synthetic Insect Repellents and Essential Oil Based Sustained-release Insect Repellent Formulations

The necessity of developing insect repellents with highly effective sustained release properties has attracted more attention due to the vast spread of arthropod-borne diseases such as dengue and malaria, which must be controlled with proper measures, and also due to the devastating damage caused by severe infestation of insect pests on crops and stored food. Natural and synthetic insect repellents are used against insect vectors and insect pests. Topical insect repellent formulations should be less toxic, less irritant, and less skin permeable. Irrespective of the type and form of the repellent, the mechanism of action depends on the formation of a vapour barrier/ odour barrier, that would deviate the insect from reaching the host. Synthetic insect repellents are highly efficient but due to their high toxicity, degradation resistance, and bio accumulation, they raise environmental and ecological issues. Due to the adverse effects caused by synthetic insect repellents, more attention is given to insect repellents consisting of natural products.Essential oils are among the widely used natural insect repellents available due to their biocompatibility and non-toxicity. High volatility of essential oils is the major problem that hampers the application of essential oils as insect repellent agents. The high volatility that reduces the length of application, and its activity can be successfully addressed by the formulation of slow-release insect repellent composites by incorporating essential oils into adsorbing or encapsulating matrices. Zeolites, montmorillonite, β-cyclodextrin, polymeric materials, and electrospun nanomaterials are commonly used to develop slow-release formulations with essential oils. Among these, polymeric microcapsules are the most extensively studied and developed slow-release insect repellent systems that are based on natural and synthetic active compounds.
 Key words: Formulation, Insects, Microcapsules, Repellents, Zeolite

Comparative analysis of repellent products for dogs in the conditions of farms of the Ararat valley of Armenia

The article presents the results of a comparative analysis of the clinical efficacy of repellent agents in various forms in the climatic and natural conditions of the Ararat Valley of the Republic of Armenia, during the period of maximum seasonal and daily activity of blood-sucking diptera insects. In the period from June 14 to June 19, 2023, the repellent effect of the veterinary medicinal product RolfClub 3D (RolfClub 3D), in the form of drops on the withers for dogs, and the repellent collar Francodex against insects was studied. The experiment involved 38 clinically healthy dogs aged 1 to 10 years, of both sexes. During the examination of animals, we did not register any complications in the form of inflammatory processes on the skin and the general condition of the studied animals after the use of the funds. In the recommended doses in dogs, the drug did not cause undesirable side effects, specific toxic effects and effects on the central nervous system. The experiment confirmed the repellent effect of veterinary drugs in the form of drops on the withers of RolfClub 3D and a Francodex insect collar applied to dogs individually, once, during the prevention of bites of diptera flying insects according to the presented doses, rules and application techniques, showed high efficiency of the repellent effect in the conditions of farms of the Ararat Valley for 3 days.

Insecticidal activity and repellent potential of ocimum gratissimum on tribolium castaneum

Background: Using botanicals for pest control has become very popular in recent years in sub-Saharan Africa and other parts of the world. These botanicals are recognized to offer protection against insect pests thanks to the natural components inherent in them. Some of these chemicals may work independently or in concert to create a desired result that lead to health challenge. Objectives: This study was aimed at evaluating the toxicity and repellent potential of Ocimum gratissimum on Tribolium castaneum. Methodology: The different concentrations 20% (200 mg/mL), 10% (100 mg/mL), 5% (50 mg/mL), 2.5% (25 mg/mL), and 1.25% (12.5mg/mL) of the oil extracts including control with acetone only were selected and tested to determine the LD50 value and LD90 value. Repellent activity contained in the essential oil was done using standard method. Result: Mortality increased in accordance with increase in concentration of O. gratissimum. The highest and lowest doses of O. gratissimum, 200 mg/ml and 12.5 mg/ml (P<0.05, P=0.009), caused mortalities of 90% and 43.3% respectively. The log-probit regression analysis showed that the LD50 and LD90 for this plant extract were 18.60 mg/mL and 175.99 mg/mL respectively. Conclusion: The present study has evidently shown that O.gratissimum oil have insecticidal activity. O.gratissimum oil extract also serve as good toxicant and repellent agents in the treatment of Tribolium castaneum during storage.

Novel production of macrocapsules for self-sealing mortar specimens using stereolithographic 3D printers

The use of capsule-based technology for self-sealing and self-healing cementitious systems has been extensively investigated for both macro- and microencapsulated additions. In this study, macrocapsules, produced using a novel technique were characterised and compared, evaluating mechanical triggering, bonding with the cementitious matrix, and self-sealing efficiency upon integration into cementitious mortar specimens. Macrocapsules containing a commercially available water repellent agent were produced in two ways. Stereolithographic additive manufacturing (3D printing) was used to produce novel rigid acrylate macrocapsules as well as alumina ones. Cementitious macrocapsules produced with a rolling technique were also used as a comparison. The capsules were characterised in terms of watertightness, water uptake, and shell morphology. Following this, the capsules were integrated into cement mortar prisms and subjected to controlled cracking by three-point bending to evaluate the triggering and subsequent self-sealing effect. The results highlighted influential process parameters that can be optimised and explored for further capsule-based self-sealing in structural applications.

Novel Essential Oils Blend as a Repellent and Toxic Agent against Disease-Transmitting Mosquitoes

Bio-insecticidal research has focused on long-term vector control using essential oils (EOs). This study examined the larvicidal, oviposition-deterrent, and repellent properties of five medicinal herb-based EO formulations (EOFs) on mosquitoes that are vectors of dengue, filariasis, and malaria. EOFs were significantly more toxic to the larvae and pupae of Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti with LC50 = 9.23, 12.85, and 14.46 ppm, as well with 10.22, 11.39, and 12.81 ppm, with oviposition active indexes of −0.84, −0.95, and −0.92, respectively. Oviposition-deterrent repellence was found in 91.39%, 94.83%, and 96.09%. EOs and N, N-Diethyl-3-methylbenzamide (DEET) were prepared at various concentrations for time duration repellent bioassays (6.25–100 ppm). Ae. aegypti, An. stephensi, and Cx. quinquefasciatus were monitored for 300, 270, and 180 min, respectively. At 100 ppm, EOs and DEET had comparable repellence in terms of test durations. EOF’s primary components d-limonene (12.9%), 2,6-octadienal, 3,7-dimethyl, (Z) (12.2%), acetic acid, phenylmethyl ester (19.6%), verbenol (7.6%), and benzyl benzoate (17.4%) may be combined to make a mosquito larvicidal and repellant equivalent to synthetic repellent lotions. In the molecular dynamics simulations, limonene (−6.1 kcal/mol) and benzyl benzoate (−7.5 kcal/mol) had a positive chemical association with DEET (−6.3 kcal/mol) and interacted with the OBP binding pocket with high affinity and stability. This research will help local herbal product manufacturers and the cosmetics industry in developing 100% herbal insect repellent products to combat mosquito-borne diseases, including dengue, malaria, and filariasis.

The influence of material characteristics and environmental circumstances on the efficiency of water repellent treatments of historic facades

Water repellents are widely applied directly to the outer surfaces of existing buildings to increase the hydrophobicity of porous materials. Research on the efficiency of water repellent treatment under practical approaches and environmental circumstances are limited. This study aims to examine the hydrophobic efficiency of a siloxane-based water repellent solvent on different materials (natural stone, brick and lime mortar) using the practical application approach of spraying, and to determine how material characteristics and application conditions affect the water repellent agent’s efficiency.Spray-treated samples demonstrate comparable hydrophobic efficiency to those capillary absorbed samples, though absorb less active agent during treatment. Application temperature and relative humidity have little effect on water repellent efficiency. Moreover, the critical coverage amount for different material varied. Lime mortar and limestone's hydrophobic performance is less effective than that on brick and sandstone due to their chemical components and pore structure.

Effect of Protein Repellent Addition to Self-Healing Experimental Resin Composite on Microcosm Biofilm and Cytotoxicity

Purpose: To investigate the effect of addition of MPC protein repellent agent to selfhealingexperimental resin composite on the self-healing efficacy, microcosm biofilmand the cytoxicity. Material and Methods: Polyurea formaldehyde microcapsuleswere synthesized by Insitu Polymerization Technique. MPC and the microcapsules areadded to the prepared experimental resin composite with different MPC concentrations.Protein repellence essay was examined by the Micro bicinchoninic Acid method.Biofilm models formed of streptococcus mutans growth was prepared and visualized byconfocal laser electron microscope to investigate the live \ dead assay over the studiedspecimens. The cytotoxicity of the specimens was examined via SRB assay. Fracturetoughness was examined using universal testing machine till fracture. Self-healingefficacy is evaluated. Results: In protein deposition, it was found that the 0%MPChas the highest value while the least value was found in the 10% group. In live/dead bacterial assay, it was found that the 0%MPC has the highest living bacterialvalue and the lowest dead bacterial value while the 7.5% group has the lowest livingbacterial value and the highest dead bacterial value. In the mechanical evaluation,the virgin fracture toughness, the highest facture toughness was found in the controlspecimens while the least fracture toughness was found in 10% group, the selfhealingefficacy results showed that the highest self-healing value was found in the0%MPC while the least self-healing efficacy value was found in the control group.Conclusion: Innovative self-healing composite with protein repellence give rise fora great variety of dental biomaterials with more promising results and long clinicalserviceability

Effect of Protein Repellent Addition to Self-Healing Experimental Resin Composite on Microcosm Biofilm and Cytotoxicity

Purpose: To investigate the effect of addition of MPC protein repellent agent to selfhealingexperimental resin composite on the self-healing efficacy, microcosm biofilmand the cytoxicity. Material and Methods: Polyurea formaldehyde microcapsuleswere synthesized by Insitu Polymerization Technique. MPC and the microcapsules areadded to the prepared experimental resin composite with different MPC concentrations.Protein repellence essay was examined by the Micro bicinchoninic Acid method.Biofilm models formed of streptococcus mutans growth was prepared and visualized byconfocal laser electron microscope to investigate the live \ dead assay over the studiedspecimens. The cytotoxicity of the specimens was examined via SRB assay. Fracturetoughness was examined using universal testing machine till fracture. Self-healingefficacy is evaluated. Results: In protein deposition, it was found that the 0%MPChas the highest value while the least value was found in the 10% group. In live/dead bacterial assay, it was found that the 0%MPC has the highest living bacterialvalue and the lowest dead bacterial value while the 7.5% group has the lowest livingbacterial value and the highest dead bacterial value. In the mechanical evaluation,the virgin fracture toughness, the highest facture toughness was found in the controlspecimens while the least fracture toughness was found in 10% group, the selfhealingefficacy results showed that the highest self-healing value was found in the0%MPC while the least self-healing efficacy value was found in the control group.Conclusion: Innovative self-healing composite with protein repellence give rise fora great variety of dental biomaterials with more promising results and long clinicalserviceability

Liquid-liquid chromatography separation of hemp terpenes with repellent properties against Hyalomma marginatum: A multi-methodological approach

Tick-borne diseases raise serious health concerns for both humans and animals. Tick control and disease prevention largely depend on synthetic acaricides and repellents, often incriminated for high toxicity. To find alternative, safe, and efficient agents against ticks, research on plant-based volatile terpenes constitutes a promising direction. This study aimed to separate and identify hemp flower compounds with repellent properties against Hyalomma marginatum (Acari: Ixodidae). Produced by supercritical CO2 extraction under different pressure (100–110 bar) and temperature (40–60 °C) conditions, the hemp extracts were tested in a moving object bioassay. The extract with the highest repellent power was further subjected to batch liquid-liquid chromatography (LLC). The biphasic solvent system (n-heptane/methanol/acetonitrile 10/5/10, v/v/v) for separating the major hemp terpenes was selected by combining the COSMO-RS-based distribution coefficient screening with experimental validation. Bisabolol (>99%), caryophyllene oxide (>98%), and caryophyllene/humulene (3.5/1, w/w, >95% purity) were thus isolated and assessed in the H. marginatum bioassay. The activity of bisabolol (20% w/w in hexane) was comparable to the synthetic repellent DEET at the same concentration. For the large-scale purification of bisabolol, trapping multiple dual mode, a semi-continuous flow-reversal LLC operating mode, was proposed and evaluated. Bisabolol was obtained with a solvent consumption 2.6-times lower and productivity 2.7-times higher than the batch process. In conclusion, using a multi-methodological computer-aided approach, bisabolol was efficiently identified and isolated as a good tick repellent agent from hemp flowers.

Volatile metabolites from new cultivars of catnip and oregano as potential antibacterial and insect repellent agents.

Plant based natural products have been widely used as antibacterial and insect repellent agents globally. Because of growing resistance in bacterial plant pathogens and urban pests to current methods of control, combined with the long- and short-term negative impact of certain chemical controls in humans, non-target organisms, and the environment, finding alternative methods is necessary to prevent and/or mitigate losses caused by these pathogens and pests. The antibacterial and insect repellent activities of essential oils of novel cultivars of catnip (Nepeta cataria L. cv. CR9) and oregano (Origanum vulgare L. cv. Pierre) rich in the terpenes nepetalactone and carvacrol, respectively, were evaluated using the agar well diffusion assay and petri dish repellency assay. The essential oils exhibit moderate to high antibacterial activity against three plant pathogens, Pseudomonas cichorii, Pseudomonas syringae and Xanthomonas perforans of economic interest and the individual essential oils, their mixtures and carvacrol possess strong insect repellent activity against the common bed bug (Cimex lectularius L.), an urban pest of major significance to public health. In this study, the essential oils of catnip and oregano were determined to be promising candidates for further evaluation and development as antibacterial agents and plant-based insect repellents with applications in agriculture and urban pest management.

A GABA Receptor Modulator and Semiochemical Compounds Evidenced Using Volatolomics as Candidate Markers of Chronic Exposure to Fipronil in Apis mellifera

Among the various "omics" approaches that can be used in toxicology, volatolomics is in full development. A volatolomic study was carried out on soil bacteria to validate the proof of concept, and this approach was implemented in a new model organism: the honeybee Apis mellifera. Emerging bees raised in the laboratory in pain-type cages were used. Volatolomics analysis was performed on cuticles, fat bodies, and adhering tissues (abdomens without the digestive tract), after 14 and 21 days of chronic exposure to 0.5 and 1 µg/L of fipronil, corresponding to sublethal doses. The VOCs analysis was processed using an HS-SPME/GC-MS method. A total of 281 features were extracted and tentatively identified. No significant effect of fipronil on the volatolome could be observed after 14 days of chronic exposure. Mainly after 21 days of exposure, a volatolome deviation appeared. The study of this deviation highlighted 11 VOCs whose signal abundances evolved during the experiment. Interestingly, the volatolomics approach revealed a VOC (2,6-dimethylcyclohexanol) that could act on GABA receptor activity (the fipronil target) and VOCs associated with semiochemical activities (pheromones, repellent agents, and compounds related to the Nasonov gland) leading to a potential impact on bee behavior.

Fabrication of multifunctional cotton fabrics dyed with Coptis chinensis extract

Low dye exhaustion and poor colorfastness of cotton fabrics dyed with natural dyes were the inevitable issues, which may potentially limit their application in textile industries. Hence, there is great demand for improving dyeing performance of natural dyes to expand their application. This work presents a facile and efficient way to improve dye exhaustion and color fastness of cotton fabrics dyed with Coptis chinensis ( C. chinensis ) extract through fabric pretreatment and aftertreatment processes. The cotton fabrics were firstly treated with critic acid (CA) to increase their capacity of anionic sites. Enhanced effect of water repellent agent as the aftertreatment chemical, which was applied to improve washing fastness of dyed fabrics, was evaluated. The color characteristics, color fastness and functionalities of dyed fabrics were also assessed. The results indicated that pretreated cotton fabrics displayed higher color strength than the untreated fabrics. Additionally, the dyed fabrics treated with water repellent agents showed better washing fastness. The antibacterial activity of dyed fabric was increased up to 98% and the ultraviolet protection factor (UPF) value reached 349.69. What’s more, the dyed fabrics also exhibited excellent wrinkle resistance and waterproof property. The integration of antibacterial, antiultraviolet, antiwrinkle and waterproof properties in the cotton fabrics dyed with C. chinensis extract was a meaningful achievement, which exhibited great potential application in medical textile and garment. • Simultaneous dyeing and functional finishing were achieved by using C. chinensis extract. • Pretreatment of cotton fabrics with CA was beneficial for enhancing color strength. • Aftertreatment of dyed cotton fabrics with water repellent agent improve washing colorfastness. • The dyed cotton fabrics exhibit excellent multifunctional properties.