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The article evaluates the Mosquito MK4 Multi-Age Anti-Loitering System from Mosquito Loitering Solutions and the Yard Sentinel from Aspectek.

The use of repellents for nematode control has not been established. Leaf extracts of Myrtus communis, an evergreen shrub with wide distribution in the Mediterranean and some other regions, were tested for repellence of second‐stage juveniles (J2s) of Meloidogyne species. Extracts obtained with several solvents and water repelled M. javanica J2s on agar plates, with the 60% methanol extract showing the highest repellent activity. M. hapla J2s were also repelled by the aqueous and 60% methanol extracts. Adding the 60% methanol extract to fluopyram, a chemical J2 attractant, reduced and abolished, respectively, the attraction of M. javanica and M. hapla J2s to it. When the methanolic extract was added near lettuce seedling roots on an agar plate, the number of M. javanica, M. incognita and M. hapla J2s attracted to the root tips was reduced by 70.0%–98.2%, infection rates decreased by 50.1%–95.8% and root length increased by 61.8%–186.7% compared to control seedlings grown on the same plates. When the methanol extract was mixed into the agar plate, the three Meloidogyne species' attraction to and infection of lettuce seedlings was reduced by up to 75.4% and 100%, respectively, and root length increased up to 3.4‐fold. The acetone extract mixed into the agar reduced the attraction of M. javanica J2s to fluopyram but did not affect their repellence by KNO3. The results suggest that M. communis leaf extracts have repellent and infection‐inhibitory activity against Meloidogyne J2, offering potential control means for Meloidogyne species. [ABSTRACT FROM AUTHOR]

Human games are inherently diverse, involving more than mere identity interactions. The diversity of game tasks offers a more authentic explanation in the exploration of social dilemmas. Human behavior is also influenced by conformity, and prosociality is a crucial factor in addressing social dilemmas. This study proposes a generalized prisoner's dilemma model of task diversity that incorporates a conformity-driven interaction. Simulation findings indicate that the diversity of multi-tasks and the path dependence contribute to the flourishing of cooperation in games. Conformity-driven interactions also promote cooperation. However, this promotion effect does not increase linearly, and only appropriate task sizes and suitable proportions of conformity-driven interactions yield optimal results. From a broader group perspective, the interplay of network adaptation, task size, and conformity-driven interaction can form a structure of attractors or repellents. [ABSTRACT FROM AUTHOR]

In this work, the morphology of zirconia, alumina, and silicas was studied, and static sorption of the repellents N, N-diethyl-3-methylbenzamide and ethyl-3-[acetyl(butyl)amino]propionate on these oxides was carried out. ZrO2, Al2O3, and SiO2 phenyl were shown to have high sorption activity to the repellents N, N-diethyl-3-methylbenzamide (239 mg/g for SiO2 phenyl) and ethyl-3-[acetyl(butyl)amino]propionate (251 mg/g for ZrO2). Pointedly, it was found that despite having the largest pore volume and high specific surface area (compared to the other studied oxides), SiO2 C2 has a significantly inferior sorption capacity in respect to other oxides, in particular SiO2 phenyl, which can be explained by the presence of the phenyl group in the latter that has chemical affinity for repellent molecules. Obtained isotherms of SiO2 300 also confirm the low sorption activity towards N, N-diethyl-3-methylbenzamide. The sorption equilibrium for both repellents, in most cases, is described by the Langmuir monomolecular adsorption model. The obtained results suggest that the studied zirconia, alumina, and silica can be used as carrier components of repellents. [ABSTRACT FROM AUTHOR]

Personal protection from mosquito bites is essential for preventing mosquito‐borne diseases. Mosquito repellents are effective methods for preventing mosquito bites. Due to their ease of use and indirect skin contact, mosquito‐repellent stickers loaded with essential oils (EOs) have recently become favoured as novel spatial repellents. To discover active EOs with high spatial repellency, 64 commercial EOs were screened using a modified arm‐in‐cage assay. Four EOs, including nutmeg, melissa, eucalyptus and cinnamon, displayed longer complete protection times (CPTs) of about 60 min. Ten main constituents from the four active EOs were identified by gas chromatography–mass spectrometry (GC–MS), and their spatial repellent activities were further evaluated. 1,8‐Cineole, cinnamaldehyde and citral showed potent repellent activity, with average CPTs of 67.5, 63.8 and 60 min respectively. The interactions of 1,8‐cineole and citral with odorant‐binding protein‐3 (OBP‐3) were studied via molecular docking. Both compounds are docked well in the high hydrophobic pocket and interacted with AealOBP3 through Van der Waals interactions with Phe105, Phe112, Leu114, Met48 and Val50. These natural products provide promising lead fragments for the further development of botanical spatial repellents. [ABSTRACT FROM AUTHOR]

Copyright of Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas is the property of Universidad de Santiago de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is an economically important pest of soft and stone fruit crops. The aim of this study was to identify repellents, formulated in dispensers, which could protect crops from D. suzukii. Fourteen potential repellents were screened against summer‐ and winter‐morph D. suzukii through electroantennography and behavioural bioassays. Repellents effective in the laboratory were tested in polytunnels to determine their efficacy in reducing catches in fruit‐baited traps. Further trials of three potential repellents were conducted to determine the distances over which repellent dispensers could reduce D. suzukii emergence in a strawberry crop. RESULTS: All 14 chemicals screened were detected by the antennae of both D. suzukii morphs. Hexyl acetate and geosmin both elicited a significantly greater corrected EAG response in summer morphs than winter morphs. Summer‐morph D. suzukii were repelled by butyl acetate, ethyl propionate, methyl N,N‐dimethyl anthranilate, geosmin, methyl salicylate, DEET and benzaldehyde at one or more doses test in laboratory bioassays. Winter morphs were repelled by ethyl propionate, methyl anthranilate, methyl N,N‐dimethyl anthranilate, DEET, benzaldehyde and butyl anthranilate at one or more of the doses tested in the laboratory. Ethyl propionate, methyl N,N‐dimethylanthranilate and benzaldehyde repelled both morphs from fruit‐baited traps in polytunnel trapping trials. Ethyl propionate and methyl N,N‐dimethylanthranilate reduced emergence of D. suzukii in a strawberry crop over 3–5 m. CONCLUSIONS: Ethyl propionate and methyl N,N‐dimethylanthranilate may protect strawberry crops against D. suzukii. Future work should test these repellents in combination with attractants in a 'push‐pull' strategy. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Geraniol is a common cosmetic and aroma component since, it is a naturally occurring terpenoid in food plants. When used topically, it mainly serves as a pesticide against mites and ticks, as well as mosquitoes. The majority of research indicates that geraniol is safe for both humans and the environment, while when exposed through the skin or the air, some people experience allergies that are not life-threatening. Some aromatic plants' essential oils include geraniol, a commercially significant terpene alcohol. It is a common component in consumer goods made by the flavour and fragrance industries and is considered one among the most essential compounds in these fields. Geraniol is a natural pest control agent with low toxicity, and it has a nice aroma on top of being insecticidal and repellent. One novel family of cancer chemo preventive medicines may be geraniol. Some vascular effects, anti-inflammatory, anti-oxidant, and antibacterial biological activity have also been studied. [ABSTRACT FROM AUTHOR]

Plasticulture has revolutionised Farming production. In salad cultivation, the snail is the main pest that can cause significant economic losses. The present study focuses on the design of a new industrial mulching material co-extruded separately with three essential oils: cade, turmeric and cumin oil. Experimental tests carried out on a pilot system confirmed the repellent effect against this mollusc and the protection of lettuce weight loss by about 30%. Adhesion tests by Escherichia coli and Pseudomonas aeruginosa demonstrate anti-adhesion properties of 80% when bioactive oils are incorporated into the industrial formulation of the plastic film. Application of the predictive theoretical approach confirms that the adhesion scores cannot be explained by the total adhesion energy and total hydrophobicity energy. This proves that these effects are the result of bioactive activity. This research work offers an innovative, practical and ecologically responsible alternative to protect lettuce crops against nuisances and pests. [ABSTRACT FROM AUTHOR]

While the problem governing Stokes flow about a single particle that is subject to an external force is ill posed in two dimensions (the 'Stokes paradox'), the related problem of two mutually repellent particles is well posed. Motivated by self-assembly phenomena in thin viscous membranes, we consider this problem in the limit of remote particles. Such limits are typically handled in the literature using reflection techniques, which provide successive approximations to the mutual hydrodynamic interactions. Since their starting point is a single particle in an unbounded fluid domain, these techniques are futile in the present two-dimensional problem. We show how this apparent contradiction is resolved via use of singular perturbations. We obtain a two-term approximation for the velocity acquired by circular disks, considering both rigid and free particle surfaces. We also illustrate our perturbation scheme for elliptic disks, deriving a renormalised single-particle velocity. The utility of our asymptotic scheme is illustrated in the general problem of hydrodynamic interaction between a cluster of remote disks. [ABSTRACT FROM AUTHOR]

Introduction: Pear decline (PD) is one of the most devastating diseases of Pyrus communis in Europe and North America. It is caused by the pathogen 'Candidatus Phytoplasma pyri' and transmitted by pear psyllids (Cacopsylla pyri, C. pyricola, and C. pyrisuga). Identifying attractant and repellent volatile organic compounds (VOCs) could improve the development of alternative plant protection measurements like push-pull or attract-and-kill strategies against pear psyllids. Our objective was to investigate which chemical cues of the host plant could influence the host-seeking behavior of pear psyllids, and if cedarwood (CWO) and cinnamon bark (CBO) essential oils could serve as repellents. Results and discussion: Based on the literature, the five most abundant VOCs from pear plants elicited EAG responses in both C. pyri and C. pyrisuga psyllid species. In Y-olfactometer trials, single compounds were not attractive to C. pyri. However, the main compound mixture was attractive to C. pyri and C. pyrisuga females. CWO and CBO were repellent against C. pyri, and when formulated into nanofibers (NF), both were repellent in olfactometer trials. However, CBO nanoformulation was ineffective in masking the odors of pear plants. In a field trial, attractive, repellent CWO and blank formulated NF were inserted in attractive green sticky traps. C. pyri captures in traps with CWO NF were statistically lower than in traps with the attractive mixture. Nevertheless, no statistical differences in the numbers of caught specimens were observed between CWO NF and those captured in green traps baited with blank NF. Transparent traps captured fewer psyllids than green ones. In a second field study with a completed different design (push-and-count design), dispensers filled with CBO were distributed within the plantation, and attractive green sticky traps were placed around the plantation. The numbers of trapped pear psyllids increased significantly in the border of the treated plantation, showing that psyllids were repelled by the EOs in the plantation. Although further field evaluation is needed to assess and improve their effectiveness, our results show that these aromatic compounds, repellent or attractive both in nanoformulations and marking pen dispensers, offer great potential as an environmentally sustainable alternative to currently applied methods for managing pear decline vectors. [ABSTRACT FROM AUTHOR]

The whitefly Bemisia tabaci (Gennadius, 1889) (Hemiptera: Aleyrodidae) is a globally important insect pest, causing extensive damage and losses in horticultural production systems. New natural options are needed to control the whitefly. Ethanol extracts (92) of different organs from 40 plant species of the Yucatan Peninsula were evaluated against B. tabaci in a greenhouse, and an adult repellency index (RI) was determined for leaves and an oviposition deterrence index (ODI) for the extracts. Ethanol extracts at 1% (w/v) after 48 h suppressed the population density of B. tabaci. Leaves of Malpighia glabra L. had the highest repellent activity, causing a decrease in the population density of adults (RI 0.05) and eggs (ODI − 85). Three fractions differing in polarity were obtained by partitioning the ethanol extract of M. glabra, and the hexane fraction had an intermediate RI, but the ODI was not active. LC–UV–HRMS analysis of the fractions showed the presence of syringaresinol, 10-hydroxy-pheophorbide a, pheophorbide a, and lupenone, the first report of these four for this species. Eleven unknown compounds were also detected. This bioprospecting research on botanical extracts from native species of the Yucatan Peninsula enriches our knowledge of potential sources of products for pest management. M. glabra is a promising candidate for further formulation and application studies to control B. tabaci. [ABSTRACT FROM AUTHOR]

In this study, the chemical composition, repellent, and oviposition deterrent effects of five plant essential oils (EOs) extracted from Lantana camara (Verbenaceae), Schinus terebinthifolia (Anacardiaceae), Callistemon viminalis (Myrtaceae), Helichrysum odoratissimum (Asteraceae), and Hyptis suaveolens (Lamiaceae) were evaluated against Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus. When tested at 33.3 µg/cm2, L. camara, S. terebinthifolia, C. viminalis, and H. odoratissimum were effective repellents against Ae. aegypti (89%, 91%, 90%, and 51% repellency, respectively), but they were less repellent against An. gambiae (66%, 86%, 59%, and 49% repellency, respectively). Interestingly, L. camara, S. terebinthifolia, C. viminalis, and H. odoratissimum exhibited 100% repellency against Cx. quinquefasciatus at 33.3 μg/cm2. In time-span bioassays performed at 333 μg/cm2, the EO of L. camara exhibited 100% repellence against Ae. aegypti and An. gambiae for up to 15 min and against Cx. quinquefasciatus for 75 min. The oviposition bioassays revealed that L. camara exhibited the highest activity, showing 85%, 59%, and 89% oviposition deterrence against Ae. aegypti, An. gambiae, and Cx. quinquefasciatus, respectively. The major compounds of L. camara, S. terebinthifolia, and C. viminalis were trans-β-caryophyllene (16.7%), α-pinene (15.5%), and 1,8-cineole (38.1%), respectively. In conclusion, the L. camara and S. terebinthifolia EOs have the potential to be natural mosquito repellents. [ABSTRACT FROM AUTHOR]

Triatomines are haematophagous insects, some species are vectors of Trypanosoma cruzi, the aetiological agent of Chagas disease. The main strategy for interrupting T. cruzi transmission is to avoid contact of the vector populations with humans. Volatiles from commercial essential oils are excellent candidates to serve as repellents of kissing bugs. We used an exposure device to assess the repellence effect of eight commercial essential oils on Triatoma pallidipennis. The most effective oils were blended and evaluated against T. infestans, T. pallidipennis and Rhodnius prolixus. The blend was also evaluated on parasitised T. pallidipennis. Data were compared with the commercial repellent NN‐diethyl‐3‐methylbenzamide. We recorded the time the insects spent in the proximity of the host and determined if any of the evaluated oils served as kissing bug repellent. We found commercial essential oils and a blend that significantly reduced the time spent in the proximity of the host. The blend was effective for use by human males and females, repelling infected and non‐infected insects. The study of essential oils as repellents of blood‐sucking disease‐vector insects could shed light on the development of new control strategies. [ABSTRACT FROM AUTHOR]

Canine vector-borne diseases (CVBDs) disproportionally affect dogs in the tropics, and some of them are of zoonotic concern. Control strategies should consider several factors, such as pathogen transmission times, vector seasonality, and individual risk factors. Combinations of repellents and fast-killing parasiticides are the first-line strategies for the prevention and control of CVBDs. Further research on transmission-blocking vaccines is needed for planning integrated control approaches against CVBDs. The prevention of canine vector-borne diseases (CVBDs) is pivotal for the health and welfare of dogs as well as for reducing their zoonotic risk to humans. Scientific knowledge gained in recent years contributed to the development of new strategies for the control of these diseases in different social and cultural contexts. Here, we discuss recent advances in the prevention of vector-borne pathogens (VBPs) affecting dogs with a focus on those of zoonotic relevance. [ABSTRACT FROM AUTHOR]

Ticks and tick-borne diseases have gained increasing attention in recent years due to their impact on public health and significant losses in livestock production. The use of synthetic compounds for tick control is becoming problematic, mainly due to the resistance to commercially available products as well as their toxicity. Therefore, new alternative control methods are required. For this purpose, plant-derived extracts may be considered as effective repellents and/or acaricides. The present literature review focuses on studies evaluating the acaricidal and repellent activity of plant-derived extracts and plant secondary metabolites. We also noted recent advances in protein-ligand-docking simulation to examine the possible toxic effect of natural chemical compounds on ticks. In conclusion, plant-derived repellents/acaricides can be effective against ticks, especially in rural areas and livestock farms. [ABSTRACT FROM AUTHOR]

Background: The Lone Star tick, Amblyomma americanum is important to human health because of a variety of pathogenic organisms transmitted to humans during feeding events, which underscores the need to identify novel approaches to prevent tick bites. Thus, the goal of this study was to test natural and synthetic molecules for repellent activity against ticks in spatial, contact and human fingertip bioassays. Methods: The efficacy of essential oils and naturally derived compounds as repellents to Am. americanum nymphs was compared in three different bioassays: contact, spatial and fingertip repellent bioassays. Results: Concentration response curves after contact exposure to 1R-trans-chrysanthemic acid (TCA) indicated a 5.6 μg/cm2 concentration required to repel 50% of ticks (RC50), which was five- and sevenfold more active than DEET and nootkatone, respectively. For contact repellency, the rank order of repellency at 50 μg/cm2 for natural oils was clove > geranium > oregano > cedarwood > thyme > amyris > patchouli > citronella > juniper berry > peppermint > cassia. For spatial bioassays, TCA was approximately twofold more active than DEET and nootkatone at 50 μg/cm2 but was not significantly different at 10 μg/cm2. In spatial assays, thyme and cassia were the most active compounds tested with 100% and 80% ticks repelled within 15 min of exposure respectively and was approximately twofold more effective than DEET at the same concentration. To translate these non-host assays to efficacy when used on the human host, we quantified repellency using a finger-climbing assay. TCA, nootkatone and DEET were equally effective in the fingertip assay, and patchouli oil was the only natural oil that significantly repelled ticks. Conclusions: The differences in repellent potency based on the assay type suggests that the ability to discover active tick repellents suitable for development may be more complicated than with other arthropod species; furthermore, the field delivery mechanism must be considered early in development to ensure translation to field efficacy. TCA, which is naturally derived, is a promising candidate for a tick repellent that has comparable repellency to commercialized tick repellents. [ABSTRACT FROM AUTHOR]

Simple Summary: The negative impact of numerous chemical compounds entering the environment from various anthropogenic sources is one of the reasons for the decline in populations and biodiversity of aboveground invertebrates. Chemical compounds can cause various effects (attracting or repelling) on insects. In laboratory conditions, the motor response of 1802 adult Philonthus decorus Gravenhorst beetles to 40 organic compounds and mixtures of compounds (acids, alcohols, ketones, phenols, aldehydes, aromatic carbohydrates solvents, and vehicle fuels) was revealed. It has been established that females of this rove species are generally less sensitive to odors. Organic acids in most cases were characterized by a repellent (oleic, acetic, oxalic, citric, formic acids) or neutral effect on beetles. The exception was some amino acids that have a moderate attractive effect. Alcohols most often exhibited the properties of moderate repellents or neutral substances for Ph. decorus imagoes. The exceptions were butyl alcohol (strong repellent of females), and methyl alcohol (moderate attractant of females). Aldehydes showed a moderate repellent effect on males and did not affect females. Aromatic hydrocarbons had a weak repellent effect on rove beetles. Organic solvents and fuels exerted no repellent or attractant effects on Ph. decorus. In most cases, they had a moderate repellent or neutral effect on these insects, with the exception of diesel fuel. This type of fuel attracted females. The majority (55%) of the chemical compounds and mixtures of compounds participating in the experiment had no attractant or repellent effect on the staphylinids. The use of organic compounds in different spheres of human activity is accompanied by their influx to and accumulation in the environment. The negative impact of those compounds can be one of the reasons for a decline in populations and biodiversity of aboveground invertebrates. Chemical compounds can potentially cause a variety of effects (attractant or repellent) on insects, including species of the Staphylinidae family. In a laboratory experiment, we identified repellent and attractant influence of 40 organic compounds and mixtures of compounds (acids, alcohols, ketones, phenols, aldehydes, aromatic carbohydrates solvents, and vehicle fuels) on Philonthus decorus Gravenhorst, 1802. The ambulatory responses of the males and females to the same chemical compounds most often varied. A strong repellent activity against both sexes of Ph. decorus was caused by oleic acid, while hexane repelled the males. Acetic acid, 1-butanol, and ammonia solution were found to be strongly repellent against females. A moderate (average) repellent activity towards male Ph. decorus was displayed by organic solvents and fuels, some alcohols (isopropanol, isoamyl alcohol, methanol, ethanol), acids (acetic, formic acid), aromatic carbohydrates (toluene, xylene), and formaldehyde. Female Ph. decorus in general were less sensitive to the odors. The list of repellents with moderate activity against the females was much shorter: solvent 646, white spirit, toluene, isopropanol, isoamyl alcohol, citric and oxalic acids, and glycerol. Moderate attractant activity for Ph. decorus was exhibited by some amino acids, alcohols, and fuel mixes: glycine and L-cysteine (for the males), and phenylalanine, methanol, and diesel fuel (for the females). The rest of the 40 chemical compounds we studied caused no ambulatory responses in Ph. decorus. The difficulties we encountered in the interpretation of the results suggest a need for further experimental studies that would expand the knowledge of the chemoecology of insects. [ABSTRACT FROM AUTHOR]

N, N‐diethyl‐meta‐toluamide (DEET) has been considered the 'gold standard' for insect repellent use since the 1950s and constitutes most insect repellents on the market. However, conflicting data in the scientific literature and confusing information in the media are at the core of debates about the safety of DEET insect repellents for the protection of children against arthropod bites. The few fatal occurrences involving DEET insect repellents and complications of their use in the pediatric population are typically the result of accidental overdoses or misuse of insect repellents that disregard warnings on product labels. With appropriate application, the safety record of DEET insect repellents continues to be excellent with few side effects. The purpose of this review is to provide a summary of the literature on safety outcomes of DEET insect repellent use in children; outline the pediatric recommendations relating to DEET insect repellents; and provide an overview of EPA‐approved and naturally derived alternatives to DEET that possess low toxicity while providing a similar level of protection to synthetic insect repellents. [ABSTRACT FROM AUTHOR]

Copyright of Glasnik Zastite Bilja is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although N,N-diethyl-3-methylbenzamide (DEET) remains the most effective repellent against mosquitoes and ticks, concerns about skin irritation, rashes, and neurological problems in children have driven the search for natural alternatives. The aim of this research was to develop, manufacture, and test prototype stickers derived from invasive plant species in Europe. These labels contained a coating with encapsulated repellents made from essential oils to protect against mosquito bites and similar blood-sucking insects. Six samples of invasive plant species in Europe such as Japanese knotweed (Fallopia japonica), goldenrod (Solidago gigantea), and black locust (Robinia pseudoacacia) were coated with two essential oil mixtures (of geranium, lavender, and eucalyptus) and were encapsulated on solid carriers for prolonged evaporation. Analysis of the structural properties (weight, thickness, density, and specific volume) were carried out on the coated label samples. Analysis of surface properties (roughness and porosity), capillary absorption, and a comparison of time and evaporation of essential oils were also carried out. Scanning electron microscopy was performed on the samples and the solid carrier with different mixtures of essential oils. The Japanese knotweed sample, coated with a blend of geranium, lavender, and eucalyptus essential oils, showed the highest efficacy and stability. [ABSTRACT FROM AUTHOR]

Superhydrophobic surfaces are often seen as frictionless materials, on which water is highly mobile. Understanding the nature of friction for such water-repellent systems is central to further minimize resistance to motion and energy loss in applications. For slowly moving drops, contact-line friction has been generally considered dominant on slippery superhydrophobic surfaces. Here, we show that this general rule applies only at very low speed. Using a micropipette force sensor in an oscillating mode, we measure the friction of water drops approaching or even equaling zero contact-line friction. We evidence that dissipation then mainly stems from the viscous shearing of the air film (plastron) trapped under the liquid. Because this force is velocity dependent, it can become a serious drag on surfaces that look highly slippery from quasi-static tests. The plastron thickness is found to be the key parameter that enables the control of this special friction, which is useful information for designing the next generation of ultraslippery water-repellent coatings. [ABSTRACT FROM AUTHOR]

The repellent capacity against Sitophilus zeamais and the in vitro inhibition on AChE of 11 essential oils, isolated from six plants of the northern region of Colombia, were assessed using a modified tunnel-type device and the Ellman colorimetric method, respectively. The results were as follows: (i) the degree of repellency (DR) of the EOs against S. zeamais was 20–68% (2 h) and 28–74% (4 h); (ii) the IC50 values on AChE were 5–36 µg/mL; likewise, the %inh. on AChE (1 µg/cm3 per EO) did not show any effect in 91% of the EO tested; (iii) six EOs (Bursera graveolens—bark, B. graveolens—leaves, B. simaruba—bark, Peperomia pellucida—leaves, Piper holtonii (1b*)—leaves, and P. reticulatum—leaves) exhibited a DR (53–74%) ≥ C+ (chlorpyrifos—61%), while all EOs were less active (8–60-fold) on AChE compared to chlorpyrifos (IC50 of 0.59 µg/mL). Based on the ANOVA/linear regression and multivariate analysis of data, some differences/similarities could be established, as well as identifying the most active EOs (five: B. simaruba—bark, Pep. Pellucida—leaves, P. holtonii (1b*)—leaves, B. graveolens—bark, and B. graveolens—leaves). Finally, these EOs were constituted by spathulenol (24%)/β-selinene (18%)/caryophyllene oxide (10%)—B. simaruba; carotol (44%)/dillapiole (21%)—Pep. pellucida; dillapiole (81% confirmed by 1H-/13C-NMR)—P. holtonii; mint furanone derivative (14%)/mint furanone (14%)—B. graveolens—bark; limonene (17%)/carvone (10%)—B. graveolens—leaves. [ABSTRACT FROM AUTHOR]

Bactrocera dorsalis (Diptera: Tephritidae), the primary pest of guava (Psidium guajava), damages numerous horticulture fruits in tropical and subtropical regions. The use of insecticides for the management of this pest adversely affect agro-ecosystem and has environmental consequences. The repellent activity of Salix alba (Willow) bark extract and a Guava oil-based formulation was investigated to protect guava fruit from infestation by the fruit fly, B. dorsalis. In the laboratory experiments, the efficacy of these natural repellents was assessed. Bactrocera dorsalis significantly deterred guava fruit treated with S. alba formulation as compared to the extract alone, which exhibited significant anti-feeding activity, and caused a decline in fecundity rate by 60% and larval mortality rate by 90%. When females were allowed to oviposit on guava fruits in laboratory and field after mating, these flies preferred fruits for oviposition that were not sprayed with S. alba-guava oil formulation. GC-MS analysis showed esters and terpenes as the main components for exhibiting repellent property in S. alba-based formulation. Hence, guava oil formulation of S. alba showed a complete protection of guava fruits against B. dorsalis in the laboratory conditions to control infestation by B. dorsalis. Further research and field trials are warranted to optimize the application methods and assess the long-term effects on crop yield and overall fruit quality. [ABSTRACT FROM AUTHOR]

Starting from a mesoscopic description of cell migration and intraspecific interactions, we obtain by upscaling an effective reaction–diffusion–taxis equation for the cell population density involving spatial nonlocalities in the source term and biasing its motility and growth behavior according to environmental acidity. We prove global existence, uniqueness, and boundedness of a nonnegative solution to a simplified version of the coupled system describing cell and acidity dynamics. A 1D study of pattern formation is performed. Numerical simulations illustrate the qualitative behavior of solutions. [ABSTRACT FROM AUTHOR]

The objective of this investigation was to assess the chemical makeup of essential oil derived from Ptychotis verticillata (PVEO), and to examine its antifungal, insecticidal, and repellent properties. PVEO was extracted through hydrodistillation, and its volatile constituents were analyzed using Headspace Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry. Qualitative and quantitative evaluation of antifungal activity was carried out using the agar diffusion method and the minimum inhibitory concentration (MIC) test against Candida glabrata, Saccharomyces cerevisiae, Aspergillus niger and Penicillium digitatum. We evaluated the repellent potential, as well as the contact and inhalation toxicity of PVEO against Callosobruchus maculatus. The results of the study indicated that the essential oil of P. verticillata was composed mainly of γ-Terpinen (25.86%), ß-Cymene (18.70%) O-Cymen-5-ol (16.78) and a-Pinene (12.13%). PVEO showed potent antifungal activity against all strains tested. The results of insecticidal activity of this essential oil were promising in adult C. maculatus. At a dose of 20 ml · dm-3 of air, EO caused maximum mortality with an LC50 value of 5.64 ml · dm-3 for the inhalation test and 3.4 ml · dm-3 for the contact test. In addition, a significant decrease in the number of eggs laid and adult emergence was observed as EO doses increased, reaching a reduction of around 95% at a dose of 20 ml · dm-3 of air. In terms of repellent activity, PVEO also showed encouraging results. It demonstrated an average repellent activity of around 92 ± 10.95%. Furthermore, molecular docking simulations corroborated the in vitro results and demonstrated that specific p-Menthen-3-one compounds formed more robust hydrogen bonding interactions with the target receptors. These experiments underscore PVEO's effectiveness as a fungicide against the tested fungal strains, demonstrating its role as a bio-insecticide against C. maculatus adults, and its potential as an appealing repellent. This suggests that PVEO could serve as a valuable alternative within integrated pest management strategies. [ABSTRACT FROM AUTHOR]

Mosquito-borne diseases pose significant public health threats worldwide, necessitating effective prevention strategies. Traditional chemical agents used for mosquito bite prevention often carry environmental and health risks. In this review, we explore the potential of graphene-based films as a non-chemical approach for protecting against mosquito bites. The aim of this review is to assess the effectiveness of multilayer graphene films in preventing mosquito bites and to explore their practical implications for public health. Through experimental investigations, researchers found that dry multilayer graphene films effectively block mosquitoes' ability to detect skin or sweat chemicals, thereby preventing mosquito bites. Additionally, these films can serve as physical barriers to the mosquito's feeding mechanism. The findings suggest promising applications of graphene films in protective technologies for human skin and smart fabrics. Graphene's non-toxic nature and ease of application make it an attractive alternative to chemical repellents. Implementing graphene-based films for mosquito bite prevention could potentially reduce the transmission of mosquito-borne diseases, addressing critical public health concerns. In conclusion, this review highlights the potential of graphene films as a non-chemical method for mosquito bite prevention. Future research should focus on evaluating the long-term effectiveness and safety of graphene films, paving the way for the development of innovative technologies that utilize graphene to safeguard against mosquito bites and mitigate the spread of infectious diseases. [ABSTRACT FROM AUTHOR]

The main way to avoid contact with ticks and consequently tick-borne disease is the use of synthetic repellents. The search of new repellent compounds to increase the possibilities of use in strategies controls are necessary. The present study evaluated the repellent activity of two natural terpenes carvacrol and thymol in each one two different formulation (encapsulated and nonencapsulated with yeast cell wall) against the ticks Amblyomma sculptum and Rhipicephalus sanguineus sensu lato nymphs. Nymphs of A. sculptum and R. sanguineus s.l. of a single generation were used. The vertical filter paper repellency assay were performed with different concentration of both terpenes encapsulated and nonencapsulated in yeast cell wall. The repellent concentration 50% (RC50) were calculated to each compound formulation. Both carvacrol and thymol (encapsulated and nonencapsulated), had a repellent activity against A. sculptum and R. sanguineus s.l nymphs. Amblyomma sculptum was more sensitive to nonencapsulated carvacrol (RC50 values: 0.0032 to 0.0082 mg/cm2 after 1 and 15 min) (P < 0.05), while R. sanguineus s.l. was more sensitive to encapsulated carvacrol (RC50 values: 0.00008 to 0.0035 mg/cm2 after 1 and 15 min) (P < 0.05). Among tick species, R. sanguineus s.l. was more sensitive for most compounds than A. sculptum (P < 0.05). Although with distinct repellent activities, carvacrol and thymol encapsulated can be a promising alternative to synthetic repellents against A. sculptum and R. sanguineus s.l. [ABSTRACT FROM AUTHOR]

Amblyomma ticks pose a significant public health threat due to their potential to transmit pathogens associated with rickettsial diseases. (E)-2-octenal, a compound found in donkeys (Equus asinus), exhibits strong repellent properties against Amblyomma sculptum nymphs under laboratory conditions. This study assessed the effectiveness of the (E)-2-octenal in wearable slow-release devices for personal human protection against Amblyomma ticks under natural conditions. Slow-release devices treated with (E)-2-octenal and untreated controls were prepared and tested on two volunteers walking through a tick-infested area in Goiania, Brazil. The experiment was conducted twice daily for three series of 10 days, with each volunteer wearing two devices attached to each leg, one on the ankle and one just above the thigh. Volunteers with control and treated devices exchanged them between rounds. Also, the daily release rate of (E)-2-octenal from the slow-release devices was determined in the laboratory, increasing significantly from 0.77 ± 0.14 µg/day on the first day to 9.93 ± 1.92 µg/day on the 4th day and remaining constant until the 16th day. A total of 5409 ticks were collected from both volunteers. Treated devices resulted in recovering fewer ticks (n = 1,666; 31%) compared to untreated devices (control: n = 3,743; 69%). (E)-2-octenal effectively repelled Amblyomma spp. larvae, A. sculptum adults, and exhibited pronounced repellency against A. dubitatum nymphs and adults. These findings suggest the potential of (E)-2-octenal delivered by wearable slow-release devices as a green-based repellent. Further improvements, however, are necessary to provide better protection for humans against A. sculptum and A. dubitatum in field conditions. [ABSTRACT FROM AUTHOR]

Abstract Background The majority of vector-borne disease cases in the USA are caused by pathogens spread by ticks, most commonly the blacklegged tick, Ixodes scapularis. Personal protection against tick bites, including use of repellents, is the primary defense against tick-borne diseases. Tick repellents registered by the Environmental Protection Agency (EPA) are well documented to be safe as well as effective against ticks. Another group of tick repellent products, 25(b) exempt or minimum risk products, use alternative, mostly botanically derived, active ingredients. These are considered to pose minimal risk to human health and therefore are exempt from EPA registration; efficacy testing is not mandated for these products. Methods We used a finger bioassay to evaluate the repellency against I. scapularis nymphs for 11 formulated 25(b) exempt products together with two positive control DEET-based EPA registered products. Repellency was assessed hourly from 0.5 to 6.5 h after product application. Results The DEET-based products showed ≥ 97% repellency for all examined timepoints. By contrast, an average of 63% of ticks were repelled in the first 1.5 h after application across the 11 25(b) exempt products, and the average fell to 3% repelled between 2.5 and 6.5 h. Ten of the 11 25(b) exempt products showed statistically similar efficacy to DEET-based products at 30 min after application (repellency of 79–97%). However, only four 25(b) exempt products maintained a level of repellency similar to DEET-based products (> 72%) at the 1.5-h mark, and none of these products were effective in repelling ticks at the timepoints from 2.5 to 6.5 h after application. Conclusions Neither the claims on the labels nor specific active ingredients and their concentrations appeared to predict the duration of efficacy we observed for the 25(b) exempt products. These products are not registered with the EPA, so the methods used to determine the application guidelines on their labels are unclear. Consumers should be aware that both the level of efficacy and the duration of repellency may differ among unregulated 25(b) exempt repellent products labeled for use against ticks. We encourage more research on these products and the 25(b) exempt active ingredients they contain to help determine and improve their efficacy as repellents under different conditions. Graphical Abstract

Human-biting ticks threaten public health in the United States. Registration by the Environmental Protection Agency of products to kill host-seeking ticks or repel ticks contacting humans is indicative of their safety and effectiveness. Unregulated minimum risk products, exempt from Environmental Protection Agency registration and often based on botanical oils, are proliferating in the marketplace, but there is concern about their effectiveness to kill and repel ticks. Evaluations of such products are limited in the published literature. A review showed considerable variability among minimum risk products to kill host-seeking blacklegged ticks, with effectiveness similar to chemical pesticide products for some minimum risk products but minimal impact on the ticks for other products. Evaluations of minimum risk tick repellents have typically focused on individual active ingredients rather than formulated products, which often combine multiple active ingredients. Consumers should be aware that effectiveness to kill and repel ticks can differ among unregulated minimum risk products.

Ticks are blood-sucking parasites and occur all over the world, especially in humid and subhumid nations such as India. They are very important vectors of many economically important livestock diseases, such as Anaplasma spp., Babesia spp., and Theileria spp. Ticks were collected from organized and unorganized cattle farms situated in and around Mhow. The initially collected samples of ticks (≤200) were washed in tap water and identified as Rhipicephalus microplus. The study was carried out from June 2021 to May 2022. Ticks were treated with 0.625, 1.25, 2.50, 5, and 10% oil of Azadirachta indica in both the adult immersion test and larval immersion test. All the concentrations were prepared with absolute ethanol. In the present study, fipronil was used as a positive control using various concentrations (x/8, x/4, x/2, x, and 2x) and was prepared in distilled water. The LC50 values against fipronil were observed as 1.03 and 1.12 ppm for adults and larvae, respectively. Results of the study showed that the oil of Azadirachta indica was responsible for the mortality of adults (LC50 = 2.70%) and larval stages (LC50 = 1.27%) at all the concentrations used. Furthermore, it was observed that this oil was also responsible for the inhibition of oviposition and had excellent repellent activity at 10% concentration. Based on the study, we can conclude that the oil of A. indica can be used in an integrated tick management system to reduce the tick burden on animals. [ABSTRACT FROM AUTHOR]

Larvicidal, ovicidal, and repellent activities of the essential oil extracted by hydrodistillation from the leaves of the endemic Ethiopian plant Leucas stachydiformis (Hochst. ex Benth.) Briq were investigated against Anopheles arabiensis, the dominant malaria vector species in Ethiopia with the objective of searching for a plant-based malaria vector control strategy from medicinal plants. The larvicidal effect was tested against the fourth instar An. arabiensis wild larvae whilst freshly laid ova of An. arabiensis were used to determine the ovicidal activity of the essential oil at concentrations ranging from 6.25 to 400 ppm. Concentrations of 41.6–366.7 µg/cm2 were used to evaluate the repellent activity of the essential oil on 3–5 days old adult female An. arabiensis. The oil composition of L. stachydiformis was also analyzed using GC-MS. The study revealed that the oil possesses the highest larvicidal activity at 400 ppm and 200 ppm after 24 h and 48 h of treatment. LC50 values for the fourth larval instar after 24 h and 48 h of treatment were 43.4 ppm and 34.2 ppm, respectively. After 72 h of exposure, the oil displayed 100% ovicidal activity at 400 ppm with an IH50 value of 32.2 ppm. In the repellency test, at concentrations of 366.7, 133.3, and 41.6 µg/cm2, the oil gave a total percentage protection of 67.9 ± 4.2%, 37.2 ± 2.8%, and 32 ± 2.2%, respectively, for 4 h. The highest concentration (366.7 µg/cm2) gave 100% protection up to 90 min. GC-MS analysis of the oil revealed the presence of 24 compounds representing 90.34% of the total oil with caryophyllene oxide, germacrene D, and trans-caryophyllene constituting more than 50% of its components. Results of the present study suggest that the essential oil of L. stachydiformis has the potential to be used for the control of An. arabiensis mosquitoes. [ABSTRACT FROM AUTHOR]

Mosquitoes of the genera Aedes, Anopheles and Culex vector a wide range of pathogens seriously affecting humans and livestock on a global scale. Over-reliance on insecticides and repellents has driven research into alternative, naturally-derived compounds to fulfil the same objectives. Steam distilled extracts of four plants with strong, yet attractive, volatile profiles were initially assessed for repellency in a dual-port olfactometer using Aedes aegypti as the model species. Picea sitchensis was found to be the most repellent, proving comparable to leading products when applied at 100% (p = 1.000). Key components of conifer-derived volatile profiles were then screened via electroantennography before those components eliciting an electrophysiological response were assayed individually in the olfactometer; according to WHO protocol. The most promising 5 were selected for reductive analyses to produce an optimised semiochemical blend. This combination, and a further two variations of the blend, were then progressed to a multi-species analysis using the BG-test whereby bite-attempt frequency on hands was assessed under different repellent treatments; assays were compared between Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus. Efficacy was found against all three species, although it was found that Ae. aegypti was the most susceptible to the repellent, with An. gambiae being the least. Here, a novel, naturally-derived blend is presented with weak spatial repellency, as confirmed in laboratory assays. Further work will be required to assess the full extent of the potential of the products, both in terms of field application and species screening; however, the success of the products developed demonstrate that plant metabolites have great capacity for use in the repellent sector; both to improve upon known compounds and to reduce the usage of toxic products currently on the market. [ABSTRACT FROM AUTHOR]

The current study aimed to evaluate the presence of chemical variations in essential oils (EOs) extracted from Artemisia scoparia growing at different altitudes and to reveal their antibacterial, mosquito larvicidal, and repellent activity. The gas chromatographic–mass spectrometric analysis of A. scoparia EOs revealed that the major compounds were capillene (9.6–31.8%), methyleugenol (0.2–26.6%), β-myrcene (1.9–21.4%), γ-terpinene (1.5–19.4%), trans-β-caryophyllene (0.8–12.4%), and eugenol (0.1–9.1%). The EO of A. scoparia collected from the city of Attock at low elevation was the most active against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa bacteria (minimum inhibitory concentration of 156–1250 µg/mL) and showed the best mosquito larvicidal activity (LC50, 55.3 mg/L). The EOs of A. scoparia collected from the high-altitude areas of Abbottabad and Swat were the most repellent for females of Ae. aegypti and exhibited repellency for 120 min and 165 min, respectively. The results of the study reveal that different climatic conditions and altitudes have significant effects on the chemical compositions and the biological activity of essential oils extracted from the same species. [ABSTRACT FROM AUTHOR]

This paper focuses on the impact of mosquito biting bias on the success of malaria intervention strategies. The initial model is developed considering the existence of symptomatic and asymptomatic humans, as well as vector bias. The model is then analyzed to demonstrate how the malaria-endemic equilibrium always exists and is globally asymptotically stable if the basic reproduction number is larger than one. On the other hand, malaria will always go extinct in the population if the basic reproduction number is less than one. For intervention analysis, the model is extended by considering mosquito repellent and hospitalization as control strategies. The control reproduction number is shown analytically. Using the Pontryagin maximum principle, we characterize our optimal control problem. Several scenarios are conducted to observe the dynamics of control variables under different circumstances. We found that the intervention of mosquito repellent and hospitalization together is the most cost-effective strategy to reduce the spread of malaria. Furthermore, we have shown that the more biased the vector attracted to infected individuals, the higher the cost needed to implement the control strategy. [ABSTRACT FROM AUTHOR]

Developing a safe and potent repellent of mosquitoes applicable to human skins is an effective measure against the spread of mosquito-borne diseases. Recently, we have identified that hydrophobic solutions such as low viscosity polydimethylsiloxane (L-PDMS) spread on a human skin prevent mosquitoes from staying on and biting it. This is likely due to the ability of L-PDMS in wetting mosquito legs and exerting a capillary force from which the mosquitoes attempt to escape. Here we show three additional functions of L-PDMS that can contribute to repel Aedes albopictus, by combining physicochemical analysis and behavioral assays in both an arm cage and a virtual flight arena. First, L-PDMS, when mixed with topical repellents and applied on a human skin, enhances the effect of topical repellents in reducing mosquito bites by efficiently transferring them to mosquito legs upon contact. Second, L-PDMS applied to mosquito tarsi compromises visual object tracking during flight, exerting an influence outlasting the contact. Finally, L-PDMS applied to mosquito tarsi acts as an aversive reinforcer in associative learning, making mosquitoes avoid the conditioned odor. These results uncover a multifaceted potential of L-PDMS in altering a sequence of mosquito behaviors from biting a human skin, visual object tracking following takeoff, to the response to an odor linked with L-PDMS. [ABSTRACT FROM AUTHOR]

In this article, we study the Cauchy problem of the chemotaxis-Navier–Stokes system with the consumption and production of chemosignals with a logistic source. The parameters χ ≠ 0 ,   ξ ≠ 0 ,   λ > 0 and μ > 0 . The system is a model that involves double chemosignals; one is an attractant consumed by the cells themselves, and the other is an attractant or a repellent produced by the cells themselves. We prove the global-in-time existence and uniqueness of the weak solution to the system for a large class of initial data on the whole space R 2 . [ABSTRACT FROM AUTHOR]

Tomato leaf miner (Tuta absoluta) is a notoriously invasive pest that has spread from South America to over 110 countries worldwide and poses a significant threat to the global tomato industry. Adverse effects associated with the overuse of chemical insecticides have prompted researchers to seek ecologically-based management options, such as using secondary plants. However, research on the repellent plants of T. absoluta is missing. In this study, we assessed the potential of nine commonly reported repellent plants. Rosmarinus officinalis was found to exhibit a significant repellent effect against T. absoluta. We quantified the volatile organic compounds (VOCs) in R. officinalis, and further determined the repellent effects of the specific VOCs. The plant R. officinalis and the VOC eucalyptol delayed the developmental period of T. absoluta and decreased the egg-hatching rate. By running cage and greenhouse experiments, we confirmed that R. officinalis and eucalyptol reduced the damage caused by T. absoluta via antixenosis (i.e. reduced number of eggs laid). Our results showed the important function of R. officinalis and its VOCs in controlling T. absoluta, guiding the use of repellent plants as a key component of Integrated Pest Management packages. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this paper is to improve understanding of the spatial relationship of the built environment (BE) with urban gun crime and how the influence of environmental features varies across geographic location and socioeconomic context. Specifically, we analyze associations between incidents of reported firearms violence and distance to built environment features, accounting for neighborhood socio-economic status. Methods: This study compares reported crime data with the outputs from a Monte Carlo Simulation using the Network Cross-K Function for Stochastic Spatial Events on street networks. Where data is available, we examine ten features—transit stations, universities/colleges, convenience stores, gas stations, liquor licenses, alcohol outlets, tobacco retailers, lodging, restaurants, and schools—across diverse metropolitan areas to uncover features that exert "attractive" or "repellent" influence on firearms violence. We present results from four U.S. cities and examine how results vary by socio-economic status of census tracts. Results: Attractive features include tobacco retailers in Pittsburgh, hotels/motels, alcohol outlets, and restaurants in New Orleans, and rail transit stations in Los Angeles. We uncover localized attractive and repellent relationships within the lowest and highest socio-economic areas. We also identify several firearms crime repellents, including universities/colleges and public/private schools. Conclusions: We find that attractors vary by city and socio-economic status, indicating that the unique underlying environmental context of each city facilitates firearms crime differently. [ABSTRACT FROM AUTHOR]

The brown planthopper (Nilaparvata lugens, BPH), white-backed planthopper (Sogatella furcifera, WBPH) and small brown planthopper (Laodelphax striatellus, SBPH) are three serious pests in the rice cultivation of Asia. Using plant extracts or their derived compounds to control rice planthoppers could be sustainable, as they are reliable sources of bio-pesticide. In this study, we evaluated the repellency of eighteen plant ethanolic extracts and their derived compounds against these planthoppers. Our results indicated that ethanolic extracts from Litsea cubeba, Zanthoxylum bungeanum, Piper nigrum, Curcuma longa, and Cinnamomum camphora possessed repellency effects on female adults and nymphs of BPH. The petroleum ether fractions of L. cubeba, Z. bungeanum, and C. longa ethanolic extracts, the ethyl acetate fractions of P. nigrum ethanolic extracts were analyzed with GC–MS. Based on earlier reports and our GC–MS analysis, nine compounds derived from the above ethanolic extracts were selected to screen their repellency to BPH in H-tube olfactometer. Two effective compounds, 1-(2-hydroxy-4, 6-dimethoxyphenyl)-ethanone (xanthoxyline) and caryophyllene oxide, were chosen to investigate their repellency on three species of rice planthoppers. The two compounds showed significant repellency to BPH, WBPH and SBPH under laboratory and greenhouse conditions at 10–1000 ppm. Field experiments showed that the releasers which contained 1000 ppm xanthoxyline or caryophyllene oxide suppressed the planthoppers population significantly. Additionally, xanthoxyline and caryophyllene oxide showed no adverse effect on the predator, Cyrtorhinus lividipennis, in the laboratory and field conditions. These results may contribute to the IPM program for the development of green planthoppers repellents applied in the rice field. [ABSTRACT FROM AUTHOR]

Simple Summary: The old-world sand fly, Phlebotomus papatasi (Scopoli 1786), is a major vector of Leishmania major, the predominant pathogen responsible for zoonotic cutaneous leishmaniasis in the Middle East, North Africa, Southern Europe, and Central Asia. DEET and other synthetic insect repellents have been used for personal protection against sand fly bites. However, the frequent use of DEET repellent raised concerns in regards to skin sensitivity, toxicity, and unpleasant odor. There are increasing efforts to evaluate natural products for use in developing more effective organic sand fly repellents. This paper reports the results of a laboratory study on several plant essential oils and saturated fatty acids concerning their repellency against female sand flies. A static air repellency assay was used to measure the responses of sand flies to test materials. The sand fly repellency of each test material was compared with those achieved by commercial repellent DEET and IR35353 at the same test concentration. The study identified two of the tested essential oils as effective spatial repellents at reduced concentrations compared to those of DEET, and two saturated fatty acids were found to produce significant sand fly mortality. The results from this study establish the foundation for developing more effective natural sand fly repellent products. The sand fly, Phlebotomus papatasi (Scopoli, 1786), is a major vector for Leishmania major in the Middle East, which has impacted human health and US military operations in the area, demonstrating the need to develop effective sand fly control and repellent options. Here, we report the results of spatial repellency and avoidance experiments in a static air olfactometer using the female P. papatasi testing essential oils of Lippia graveolens (Mexican oregano), Pimenta dioica (allspice), Amyris balsamifera (amyris), Nepeta cataria (catnip), Mentha piperita (peppermint), and Melaleuca alternifolia (tea tree); the 9–12 carbon saturated fatty acids (nonanoic acid, decanoic acid, undecanoic acid, and dodecanoic acid); and the synthetic repellents DEET and IR3535. The materials applied at 1% exhibited varying activity levels but were not significantly different in mean repellency and avoidance from DEET and IR3535, except in regards to nonanoic acid. Some materials, particularly nonanoic and undecanoic acids, produced sand fly mortality. The observed trends in mean repellency over exposure time included the following: (1) P. dioica oil, M. alternifolia oil, decanoic acid, undecanoic acid, DEET, and IR3535 exhibited increasing mean repellency over time; (2) oils of N. cataria, A. balsamifera, M. piperita, and dodecanoic acid exhibited relatively constant mean repellency over time; and (3) L. graveolens oil and nonanoic acid exhibited a general decrease in mean repellent activity over time. These studies identified the essential oils of N. cataria and A. balsamifera as effective spatial repellents at reduced concentrations compared to those of DEET. Additional research is required to elucidate the modes of action and potential synergism of repellents and essential oil components for enhanced repellency activity. [ABSTRACT FROM AUTHOR]

Further range expansion of invasive animal species can be prevented by controlling their behavior. Acoustic repellent is a promising approach to deter problematic animals from ecologically sensitive areas. To develop an acoustic repellent system for a green anole that was introduced to the Ogasawara islands in Japan, this study evaluated the deterrent effect of (1) a pattern sound of machine noise and (2) a mixture of artificial and biologically relevant sounds. We created a sound level gradient inside a small experimental cage in a laboratory setting and measured whether green anoles avoided the vicinity of a speaker. In approximately 80% of cases, both the pattern machine sound and the mixture sounds prevented green anoles from stepping into the vicinity of a speaker (<24 cm). The mixture sounds maintained the deterrent effect at a middle distance from a speaker (<72 cm), whereas the pattern machine sound did not work as a strong acoustic repellent at this distance. These results imply that the mixing of biotic and abiotic sounds can improve the effective range of acoustic repellent for green anoles. However, several shortcomings of the acoustic repellent system were also highlighted. Since a green anole is an insectivore predator, our findings will contribute to protecting endangered native insect fauna from the predation of non‐native lizard species. [ABSTRACT FROM AUTHOR]

BACKGROUND: The push–pull strategy is considered as a promising eco‐friendly method for pest management. Plant volatile organic compounds (PVOCs) act as semiochemicals constitute the key factor in implementing this strategy. Benzyl alcohol and geraniol, as functional PVOCs, were reported to regulate insect behavior, showing the potential application in pest control. Using geraniol as lead, a geraniol derivative 5i with fine repellent activity was discovered in our previous work. In order to explore novel, eco‐friendly aphid control agents, a series of benzyl geranate derivatives was designed and synthesized using 5i as the lead and benzyl alcohol as the active fragment. RESULTS: Benzyl alcohol was firstly evaluated to have repellent activity to Acyrthosiphon pisum. Based on this repellent fragment, a series of novel benzyl geranate derivatives was rationally designed and synthesized using a scaffold‐hopping strategy. Among them, compound T9, with a binding affinity (Kd = 0.43 μm) and a substantial repellency of 64.7% against A. pisum, is the most promising compound. Molecule docking showed that hydrophobic and hydrogen‐bonding interactions substantially influenced the binding affinity of compounds with ApisOBP9. Additionally, T9 exhibited low‐toxicity to honeybees and ladybugs. CONCLUSION: Using a simple scaffold‐hopping strategy combined with active fragment benzyl alcohol, a new derivative T9, with high aphid‐repellency and low‐toxicity to nontarget organisms, can be considered as a novel potential eco‐friendly aphid control agent for sustainable agriculture. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: The bites and blood sucking of bed bugs (Cimex spp.) (Hemiptera: Cimicidae) pose a serious threat to human physical and mental health. Application of an effective repellent can prevent or reduce bed bug bites. Previous studies on repellent screening mainly focused on Cimex lectularius L. In this study, we investigated the repellent effect of two safe food additives, ethyl anthranilate (EA) and butyl anthranilate (BA), against Cimex hemipterus (F.), and also explored the role of antennae and mouthparts on C. hemipterus perception of repellents. RESULTS: Both EA and BA had a strong repellent effect against tropical bed bugs and their repellency was similar or lower than that of N,N‐diethyl‐3‐methyl benzoyl amide, depending on whether or not a CO2 source was present. EA had higher repellency than BA and exhibited repellency to C. hemipterus for 3 days when a CO2 source was present. C. hemipterus avoided resting on 20% EA‐ and BA‐treated harborages. Applying 20% EA and BA on rabbit skin significantly reduced the blood intake of C. hemipterus within 2 h. C. hemipterus could perceive EA and BA after their antennae or mouthparts or both antennae and mouthparts were removed. CONCLUSION: Both EA and BA had strong repellency against C. hemipterus, with EA being more repellent. Ablation of antennae and mouthparts did not affect the perception of EA and BA by C. hemipterus. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In order to improve the mosquito repellent and water repellent properties of cotton fabrics, finishing agents for mosquito repellent and fluorine-free water repellent agent were applied to cotton fabrics using pad-dry method. The properties of cotton fabric before and after finishing including water contact angle, repellency, antifouling, mechanical property, air permeability, washing resistance, surface micro-morphology and infrared spectrum were tested. The results indicated that the fabric treated by mosquito repellent and hydrophobic finishing has excellent properties, the water contact angle was 148° and repellent rate was 75%.Additionally, the breaking strength of the finished fabric was improved 64.6%.It is considered that the modified fabric shows better mosquito repellent and hydrophobic property. [ABSTRACT FROM AUTHOR]

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