Ulrich Bernier

United States Department of Agriculture | USDA · Agricultural Research Service (ARS)

BACKGROUND An important component of the biological activity of pyrethroids, when used in disease vector control, is excito‐repellency. In this study, behavioral differences between insecticide susceptible (Orlando) and pyrethroid resistant (Puerto Rico) strains of Aedes aegypti were explored in a round glass arena using fabrics treated with permet...

U.S. military troops are exposed to mosquito-borne pathogens when deployed to endemic regions. Personal protective measures such as permethrin-treated uniforms and dermal repellents are the cornerstones of mosquito-borne disease prevention for the U.S. military. These measures have limitations and additional personal protection tools, such as spati...

To discover new natural materials for insect management, commercially available stored sheep wool was investigated for attractancy to female adult Aedes aegypti mosquitoes. The volatiles from sheep wool were collected by various techniques of headspace (HS) extractions and hydrodistillation. These extracts were analyzed using gas chromatography–mas...

Mosquito-borne illnesses such as malaria and dengue fever continue to cause harm and death to humans on a global scale. Prevention of arthropod bites is one of the most basic defense strategies to prevent the transmission of pathogens, which occurs when an arthropod takes a blood-meal through its bite. Prevention of bites is dependent upon effectiv...

It is important to identify repellents that can provide reliable protection from arthropod biting and prevent arthropod-borne diseases, such as malaria. In the present study, the spatial repellent activity and toxicity of two novel pyridinyl amides (1 and 2) were evaluated against Anopheles albimanus, Anopheles quadrimaculatus, and Anopheles gambia...

The volatile compounds from horse and pony hairs and skin were analyzed to determine bioactive molecules that are kairomones used for host location by blood-feeding diptera. In this study, horse and pony hair samples were extracted with organic solvents (pentane or hexane) and analyzed by gas chromatography mass spectrometry analysis (GC-MS) with c...

Blue tansy essential oil (BTEO) ( Tanacetum annuum L.) was analyzed by GC-MS and GC-FID using two different capillary column stationary phases. Sabinene (14.0%), camphor (13.6%), myrcene (8.0%), β-pinene (7.7%), and chamazulene (6.9%) were the main components using an SE52 column (non-polar). On a polar CW20M phase column, sabinene (15.1%), camphor...

The productivity and survival of managed honey bee colonies is negatively impacted by a diverse array of interacting factors, including exposure to agrochemicals, such as pesticides. This study investigated the use of volatile heterocyclic amine (HCA) compounds as potential short-term repellents that could be employed as feeding deterrents to reduc...

BACKGROUND The compound 2‐((4‐ethyl‐5‐(pyridin‐3‐yl)‐4H‐1,2,4‐triazol‐3‐yl)thio)‐N‐(4‐ethylphenyl) acetamide (VUAA1) is reported to be an odorant receptor co‐receptor (Orco) agonist in insects with potential use as an insect repellent. For this study, the biological activity of VUAA1 was investigated in several bioassays with Aedes aegypti, includi...

The carboxamide N,N-di-ethyl-meta-toluamide (DEET) is the most effective and widely used insect repellent today. However, drawbacks concerning the efficacy and the safety of the repellent have led to efforts to design new classes of insect repellents. Through quantitative structure–activity relationships, chemists have discovered two chemical group...

Aedes aegypti L. (Diptera: Culicidae) is one of the most medically important mosquito species, due to its ability to spread viruses of yellow fever, dengue fever, and Zika in humans. In this study, the insecticidal activity of 17 plant essential oils was evaluated via topical application against two strains of Ae. aegypti mosquito, Orlando (insecti...

BACKGROUND The mosquito, Aedes aegypti (Diptera: Culicidae), is a vector of dengue fever, zika, chikungunya, and yellow fever viruses, and in many areas possesses significant levels of resistance to pyrethroids. Behavioral performance was assessed in 15, 30, and 60 min exposures in a high throughput vapor phase spatial repellency assay to three con...

Electroantennography (EAG) is a commonly used method to study the olfactory responses of insects, but many behaviorally relevant odorant responses are difficult to evaluate because only a small amount of chemical sample is available in the vapor phase. We have assembled a coupled induction heating-electroantennogram (IH-EAG) system to improve the r...

The adulticidal, larvicidal, and repellent activity of 18 trifluoromethylphenyl amides (TFMPAs) was determined against Aedes aegypti mosquitoes. The compounds studied are the third generation designed from active structures of the previous two generations. N-(3,5-Bis(trifluoromethyl)phenyl)-2-chloroacetamide (8f) and N-(3,5-bis(trifluoromethyl)phen...

Mosquitoes represent one of the most significant threats to human and veterinary health throughout the world. The mosquito Aedes aegypti (L.) is a primary carrier of viruses causing dengue fever, dengue hemorrhagic fever and yellow fever in the tropical and subtropical regions of the world. Personal protection is one method to prevent viral transfe...

This work describes the use of entomological studies combined with in silico models (computer simulations derived from numerical models) to assess the efficacy of a novel device for controlled release of spatial repellents. Controlled Release Devices (CRDs) were tested with different concentrations of metofluthrin and tested against An. quadrimacul...

Trifluoromethylphenyl amides (TFMPAs) were designed and synthesized as potential pesticides were designed and synthesized. Thirty three structures were evaluated for fungicidal activity against three Colletotrichum species using direct bioautography assays. Active compounds were subsequently tested against C. fragariae, C. gloeosporioides, C. acuta...

Background The emergence of mosquitoes that can avoid indoor-deployed interventions, such as treated bed nets and indoor residual spraying, threatens the mainstay of malaria control in Zambia. Furthermore, the requirement for high coverage of these tools poses operational challenges. Spatial repellents are being assessed to supplement these vector...

The increase in insecticide-resistant mosquito populations necessitates the exploration of novel vector control intervention measures. Push-pull strategies have been successful in integrated crop pest management. Through the combinatory use of deterring and attracting stimuli, the abundance of insect pests can be changed in a given area. A push-pul...

Hematophagous arthropods are capable of transmitting human and animal pathogens worldwide. Vector-borne diseases account for 17% of all infectious diseases resulting in 700,000 human deaths annually. Repellents are a primary tool for reducing the impact of biting arthropods on humans and animals. N,N-Diethyl-meta-toluamide (DEET), the most effectiv...

This project focused on the design, synthesis, and testing of trifluoromethylphenyl amides (TFMPAs) as potential mosquitocides and repellents. Fourteen compounds were evaluated for toxicity against larvae and adults of Aedes aegypti. Several compounds were toxic against Aedes aegypti (larval, adult and feeding bioassays) and Drosophila melanogaster...

Background Mosquito mortality has been documented in numerous studies of spatial repellents but the concentration‐dependent toxicity of spatial repellent vapors has not been documented. To address this issue, prallethrin, flumethrin, metofluthrin, transfluthrin, and meperfluthrin were selected for comparative study against Aedes albopictus (Skuse),...

An ethanol extract from Veratrum lobelianum Bernh. rhizomes showed larvicidal activity with LC 50 values of 11.79 ppm and 89.9 ppm against 1 st and 4 th instar larvae, respectively, at 24 h post-treatment. The extract also showed proportion not biting (PNB) value of 0.76 at 100 μg/cm ² against females of Ae . aegypti . Systematic bioassay-guided fr...

Repellent activity of monoterpenoid esters (1-6) with neurotransmitter amino acids (GABA and glycine) was investigated against Aedes aegypti by using a “cloth-patch” assay and compared to reference standard N,N-diethyl-3-methylbenzamide (DEET). Monoterpenoid esters showed repellent activity with minimum effective dosages (MED) in the range of 0.031...

The essential oils (EOs) of Anthemis melampodina (Am) and Anthemis scrobicularis (As) (Asteraceae) were extracted from the aerial parts of the plants by hydrodistillation, and their chemical compositions were analyzed using GC-FID and GC-MS. Fifty-six components representing 85.5% of the oil composition of Anthemis melampdina were identified, and t...

In the present work, fruits of Prangos platychlaena Boiss. ex Tchihat. ssp. platychlaena (Apiaceae) collected from eastern (sample A) and central (sample B) parts of Turkey were subjected to hydrodistillation to yield essential oils (EOs). The chemical composition of P. platychlaena ssp. platychlaena fruit oil was analyzed by gas chromatography–fla...

Hematophagous arthropods are capable of transmitting human and animal pathogens worldwide. Vector-borne diseases account for 17% of all infectious diseases resulting in 700,000 human deaths annually. Repellents are a primary tool for reducing the impact of biting arthropods on humans and animals. N,N-Diethyl-meta-toluamide (DEET), the most effectiv...

Emerging insecticide resistance is a major issue for vector control. It decreases the effectiveness of insecticides, thereby requiring greater quantities for comparable control with a net increase in risk of disease resurgence, product cost, and damage risk to the ecosystem. Pyrethroid resistance has been documented in Puerto Rican populations of A...

Percent bite protection by treatment type and mosquito strain for all replicates combined in the blood-feeding bioassays. (PDF)

Abbott corrected percent mortaility by treatment type and mosquito strain for all replicates combined in the topical toxicity bioassays. (PDF)

Host derived chemical cues are an important aspect of arthropod attraction to potential hosts. Host cues that act over longer distances include CO2, heat, and water vapor, while cues such as volatile organic compounds (VOCs) act over closer distances. Domestic dogs are important hosts for disease cycles that include dog heartworm disease vectored b...

The oregano, Origanum onites L., essential oil (EO) was tested in laboratory behavioural bioassays for repellent activity against Amblyomma americanum (L.) and Aedes aegypti (L.). The O. onites EO was characterised using GC-FID and GC-MS. Carvacrol (75.70%), linalool (9.0%), p-cymene (4.33%) and thymol (1.9%) were the most abundant compounds. At a...

Mosquitoes, such as Aedes aegypti and Anopheles gambiae, are important vectors of human diseases. Fluralaner, a recently introduced parasiticide, was evaluated as a mosquitocide in this study. On Ae. aegypti and An. gambiae fourth-instar larvae, fluralaner had 24-h LC50 (lethal concentration for 50% mortality) values of 1.8 ppb and 0.4 ppb, respect...

Repellents prevent mosquito bites and help reduce mosquito-borne disease, a global public health issue. Laboratory-based repellent bioassays predict the ability of compounds to deter mosquito feeding, but the variety of repellent bioassays and statistical analysis methods makes it difficult to compare results across methodologies. The most realisti...

Mosquito surveillance in remote areas with limited access to canisters of CO2 or dry ice will benefit from an effective alternative CO2 source, such as the natural production of CO2 from yeast fermentation. In this study, we investigate differences in mosquito capture rates from the Centers for Disease Control and Prevention (CDC) light traps baite...

A new mesembrine-type alkaloid, named sarniensine, was isolated together with tazettine, lycorine, the main alkaloid, and3-epimacronine from Nerine sarniensis, with the last two produced for the first time by this plant. This Amaryllidaceae, which is indigenous of South Africa, was investigated for its alkaloid content because the organic extract o...

The essential oil (EO) of the aerial parts of Rhanterium epapposum Oliv. (Asteraceae), was obtained by hydrodistillation. The oil was subsequently analyzed both by GC-FID and GC-MS, simultaneously. Forty-five components representing 99.2% of the oil composition were identified. The most abundant compounds were camphene (38.5%), myrcene (17.5%), lim...

The essential oil (EO) of Lantana montevidensis (Spreng.) Briq. (L. Sellowiana Link & Otto) was investigated for its chemical composition and mosquito repellent activity. The essential oil obtained by hydrodistillation of aerial plant parts was analyzed by GC-FID and GC-MS. The major constituents were β-elemene (22.0%), β-caryophyllene (20.1%), and...

A water-distilled essential oil (EO) from the aerial parts of Pimpinella cypria Boiss. (Apiaceae), an endemic species in northern Cyprus, was analyzed by GCFID and GC-MS. Forty-five compounds were identified in the oil, which comprised 81.7% of the total composition. The compound classes in the oil were oxygenated sesquiterpenes (33.9%), sesquiterp...

Acorus species are rich in secondary compounds and possess high contents of essential oils in their rhizomes. We report on the isolation, characterization and antifungal and pesticidal activity of essential oil and eleven compounds obtained from A. tatarinowii Schott. and A. calamus L. Five of the compounds had weak antifungal activity against the...

Natural products are an ideal source of chemicals for topical application to human skin, and can be a means of personal protection from the bites of mosquitoes and other arthropods. This report covers a diverse array of natural compounds, and includes descriptions of observed correlations between chemical properties and repellency. Repellent effica...

The global field protection (GFP) was developed to protect and optimize pest management resources integrating satellite images for precise field demarcation with physical models of controlled release devices of pesticides to protect large fields. The GFP was implemented using a graphical user interface to aid the end-user to select location and def...

A detailed analysis of Prangos pabularia Lindl. (Apiaceae) fruit oil was performed by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Bicyclogermacrene (21%), (Z)-β-ocimene (19%), α-humulene (8%), α-pinene (8%) and spathulenol (6%) were the main constituents of the oil. One compound with 1.8% at RI 3420 remained uniden...

Cuticular hydrocarbons of 2 species of tsetse flies were examined for differences between populations by GC/MS. Differences were minimal between populations of the same species. Proposed structures of likely sex pheromones for these species was speculated upon.

Mosquito-borne pathogens affect millions of people worldwide. This work describes a new method to deliver spatial repellents. Functional microdispensers (FMDs) were designed to deliver spatial repellents against mosquitoes. In vivo trials showed that FMDs protect human subjects against mosquitoes by reducing 70-90% of bites received, with a protect...

Synthesis of chalcones and 2-pyrazoline derivatives has been an active field of research due to the established pharmacological effects of these compounds. In this study, a series of chalcone (1a–i), 2-pyrazoline-1-carbothioamides (2a–i), and 2-pyrazoline-1-carboxamide derivatives (3a–g) were synthesized and screened for their potential pesticide a...

Functional Micro-Dispensers (FMDs) based on Micro-Electro-Mechanical-Systems (MEMS) were designed to deliver spatial repellents that reduce the ability of mosquitoes to feed on humans. FMDs were integrated with fabrics as functional materials for protection against mosquito bites. The use of MEMS devices provide an unprecedented control over the re...

The increase in insecticide resistant mosquito populations necessitates the exploration of novel vector control intervention measures. Push-pull strategies for insect control have been successful when used in integrated crop pest management. Through the combinatory use of deterring and attracting stimuli, the abundance of insect pests can be change...

The attraction of female Aedes aegypti to single compounds and binary compositions containing L-lactic acid and an additional saturated compound from a set of ketones, sulfides, and chloroalkanes was studied using a triple-cage dual-port olfactometer. These chemical classes were studied because of their structural relation to acetone, dimethyl disu...

The essential oils from the flower, leaf, and stem of Echinophora lamondiana B.Yildiz et Z.Bahcecioglu were analyzed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. In total, 41, 37, and 44 compounds were identified, which accounted for 98.0, 99.1, and 97.0% of flower, leaf, and stem essential oils, respec...

Caryopteris ×clandonensis A. Simmonds ex C. H. Curtis 'Durio' Pink Chablis™, (Lamiaceae) a pink-flowered cultivar distinctive among the typically blue-flowered cultivars of bluebeard, is valued as a small, deciduous shrub in the landscape for its mounded growth habit, showy flower display in summer, and attractiveness to insect pollinators. As part...

Mosquitoes of various species mate in swarms comprised of tens of thousands of flying males. In this study, we examined Aedes aegypti swarming behavior and identified associated chemical cues. Novel evidence is provided that Ae. aegypti females aggregate by means of olfactory cues, such as aggregation pheromones. Isolation of Ae. aegypti aggregatio...

Unique volatile pyrethroids and a method for repelling and/or killing insects involving treating an object or area with an insect repelling effective amount or insect killing effective amount of at least one unique volatile pyrethroid and optionally a carrier. Also a method for repelling and/or killing insects involving treating an object or area w...

Recently, vector-borne diseases have been resurging in endemic areas and expanding their geographic range into nonendemic areas. Such changes have refocused attention to the potential for major public health events, as naïve populations are exposed to these pathogens. Personal topical repellents, recommended by the United States Centers for Disease...

The essential oil of Haplophyllum tuberculatum was prepared by hydrodistillation of the fresh flowering aerial parts of the plant collected from Saudi Arabia. The oil was subsequently analyzed by GC and GC-MS. Thirty seven compounds, accounting for 96.4 % of the oil composition were identified. The major components were trans-p-menth-2-en-1-ol (19....

In this study, Angelica dahurica and Angelica pubescentis rot essential oils were investigated as pest management perspective and root samples were also analyzed genetically using the nuclear ribosomal internal transcribed spacer (ITS) region as a DNA barcode marker. Angelica pubescentis root essential oil demonstrated moderate antifungal activity...

Aedes aegypti L. is the major vector for dengue and yellow fever. In order to discover plant based mosquito repellents, the n-hexane, ethyl acetate extracts and essential oils from the flowers of German chamomile (Matricaria chamomilla L.), Roman chamomile (Chamaemelum nobile L.) and Juhua (Chrysanthemum morifolium Ramat.) were screened for the rep...

Caryopteris x clandonensis (Lamiaceae), a hybrid of C. incana and C. mongolica, is a popular landscape shrub for USDA hardiness zones 5 to 9 with mildly aromatic foliage and violet to deep-blue flowers in later summer. The cultivar Durio is novel in producing pink flowers. Essential oil of C. ×clandonensis 'Durio' was evaluated as part of a larger...

Mosquitoes are vectors for many pathogens that cause human diseases including dengue fever, yellow fever and malaria. In an effort to discover new plant based products, essential oils from the flower, leaf and stem of Echinophoralamondiana B.Yildiz et Z.Bahcecioglu were screened for their larvicidal and repellent activity against mosquitoes. Only l...

In traditional vector surveillance systems, adult mosquito density and the rate of mosquito-human host contact are estimated from the mosquito numbers captured in mechanical traps. But the design of the traps, their placement in the habitat and operating time, microclimate, and other environmental factors bias mosquito responses such that trapped m...

The essential oil from aerial parts of Ruta chalepensis L. (Sapindales: Rutaceae) was obtained by hydrodistillation, and its chemical profile was identified using gas chromatography and gas chromatography-mass spectrometry. Compounds, 2-undecanone (43.2%), 2-nonanone (27.9%), and 2-nonyl acetate (10.6%) were the major constituents of the oil. Bitin...

Molecular field topology analysis, scaffold hopping, and molecular docking were used as complementary computational tools for the design of repellents for Aedes aegypti, the insect vector for yellow fever, chikungunya, and dengue fever. A large number of analogues were evaluated by virtual screening with Glide molecular docking software. This produ...

Aedes aegypti (L.) is a primary vector that transmits pathogens that cause yellow and dengue fevers. Better products are needed to prevent bites from these insects and therefore reduce the risk of disease transmission to humans and other animals. Mosquito repellents play a major role in reducing bites and therefore mitigating transmission of mosqui...

Twenty trifluoromethylphenyl amides were synthesized and evaluated as fungicides and as mosquito toxicants and repellents. Against Aedes aegypti larvae, N-(2,6-dichloro-4-(trifluoromethyl)phenyl)-3,5-dinitrobenzamide (1e) was the most toxic compound (24h LC50 1940nM), while against adults N-(2,6-dichloro-4-(trifluoromethyl)phenyl)-2,2,2-trifluoroac...