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1.
J Agric Food Chem ; 72(21): 11949-11957, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38757770

RESUMEN

As the first marketed phenylpyrazole insecticide, fipronil exhibited remarkable broad-spectrum insecticidal activity. However, it poses a significant threat to aquatic organisms and bees due to its high toxicity. Herein, 35 phenylpyrazole derivatives containing a trifluoroethylthio group on the 4 position of the pyrazole ring were designed and synthesized. The predicted physicochemical properties of all of the compounds were within a reasonable range. The biological assay results revealed that compound 7 showed 69.7% lethality against Aedes albopictus (A. albopictus) at the concentration of 0.125 mg/L. Compounds 7, 7g, 8d, and 10j showed superior insecticidal activity for the control of Plutella xylostella (P. xylostella). Notably, compound 7 showed similar insecticidal activity against Aphis craccivora (A. craccivora) compared with fipronil. Potential surface calculation and molecular docking suggested that different lipophilicity and binding models to the Musca domestica (M. domestica) gamma-aminobutyric acid receptors may be responsible for the decreased activity of the tested derivatives. Toxicity tests indicated that compound 8d (LC50 = 14.28 mg/L) induced obviously 14-fold lower toxicity than fipronil (LC50 = 1.05 mg/L) on embryonic-juvenile zebrafish development.


Asunto(s)
Aedes , Diseño de Fármacos , Moscas Domésticas , Insecticidas , Simulación del Acoplamiento Molecular , Pirazoles , Animales , Insecticidas/química , Insecticidas/síntesis química , Insecticidas/farmacología , Pirazoles/química , Pirazoles/farmacología , Pirazoles/síntesis química , Aedes/efectos de los fármacos , Aedes/crecimiento & desarrollo , Relación Estructura-Actividad , Moscas Domésticas/efectos de los fármacos , Moscas Domésticas/crecimiento & desarrollo , Áfidos/efectos de los fármacos , Áfidos/crecimiento & desarrollo , Mariposas Nocturnas/efectos de los fármacos , Mariposas Nocturnas/crecimiento & desarrollo , Estructura Molecular , Proteínas de Insectos/química , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Pez Cebra/embriología
2.
Pestic Biochem Physiol ; 201: 105880, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38685246

RESUMEN

Controlling housefly populations relies on the use of insecticides, which inevitably leads to the development of resistance. A better and more comprehensive understanding of the spatial and temporal distribution of resistance could guide the control of houseflies. However, most studies on housefly resistance in China are scattered and poorly coordinated. We collected resistance data from houseflies in the published literature and from the vector biomonitoring system of the Chinese Center for Disease Control and Prevention. A 5- or 10-year resolution was used to study the temporal dynamics of resistance to five commonly used insecticides: deltamethrin, permethrin, beta-cypermethrin, dichlorvos, and propoxur. ArcGIS was used to visualize their spatial distributions. The correlation between year and resistance coefficient was determined using SPSS 26.0 and RStudio to explore the changes in resistance over the years. A total of 2128 data were included in this study, ranging from 1982 to 2022, based on which we found significant increases in resistance over the past forty years for the five studied insecticides. Among them, pyrethroids had the most strikingly elevated resistance level and were mainly distributed in the northern and southeastern coastal areas. Dichlorvos and propoxur had intermediate increases in resistance, and most of these increases were identified in North China and the Yangtze River. Housefly resistance to commonly used insecticides in China is increasing and spatially heterogeneous. This finding also highlights the necessity of continuous routine surveillance of housefly resistance, which could guide future housefly control operations and slow the development of resistance.


Asunto(s)
Moscas Domésticas , Resistencia a los Insecticidas , Insecticidas , Piretrinas , Moscas Domésticas/efectos de los fármacos , Animales , China , Insecticidas/farmacología , Nitrilos , Permetrina/farmacología , Propoxur
3.
Pestic Biochem Physiol ; 201: 105898, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38685256

RESUMEN

The dinoflagellate Karenia brevis is a causative agent of red tides in the Gulf of Mexico and generates a potent family of structurally related brevetoxins that act via the voltage-sensitive Na+ channel. This project was undertaken to better understand the neurotoxicology and kdr cross-resistance to brevetoxins in house flies by comparing the susceptible aabys strain to ALkdr (kdr) and JPskdr (super-kdr). When injected directly into the hemocoel, larvae exhibited rigid, non-convulsive paralysis consistent with prolongation of sodium channel currents, the known mechanism of action of brevetoxins. In neurophysiological studies, the firing frequency of susceptible larval house fly central nervous system preparations showed a > 200% increase 10 min after treatment with 1 nM brevetoxin-3. This neuroexcitation is consistent with the spastic paralytic response seen after hemocoel injections. Target site mutations in the voltage-sensitive sodium channel of house flies, known to confer knockdown resistance (kdr and super-kdr) against pyrethroids, attenuated the effect of brevetoxin-3 in baseline firing frequency and toxicity assays. The rank order of sensitivity to brevetoxin-3 in both assays was aabys > ALkdr > JPskdr. At the LD50 level, resistance ratios for the knockdown resistance strains were 6.9 for the double mutant (super-kdr) and 2.3 for the single mutant (kdr). The data suggest that knockdown resistance mutations may be one mechanism by which flies survive brevetoxin-3 exposure during red tide events.


Asunto(s)
Moscas Domésticas , Toxinas Marinas , Mutación , Oxocinas , Toxinas Poliéteres , Animales , Oxocinas/farmacología , Moscas Domésticas/genética , Moscas Domésticas/efectos de los fármacos , Larva/efectos de los fármacos , Larva/genética , Dinoflagelados/genética , Dinoflagelados/efectos de los fármacos
4.
Bioorg Chem ; 130: 106258, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36371818

RESUMEN

A number of novel annulated pyrazolopyranopyrimidines were prepared via reaction of iminoether of the corresponding 6-amino-5-cyano-pyrano[2,3-c]pyrazole derivative 1 with different nitrogen nucleophiles. The structure of the synthesized compounds was deduced based on IR, MS, 1H NMR and 13C NMR spectroscopic data. The larvicidal potency of the synthesized compounds against the lab and field strains of Culex pipiens and Musca domestica larvae was evaluated and the structure-activity relationship (SAR) was discussed. The assay revealed that the tested pyranopyrazole derivatives exhibited good larvicidal bio-efficacy whereas iminoether 4 exhibited the highest efficiency, for lab more than field strains of both species. Also, M. domestica larvae were more sensitive to tested compounds than C. pipiens. The field strain showed low resistance ratios to all compounds with only about 2 folds. The inhibitory effects of synthesized molecules on nAChRs were evaluated by molecular docking. Moreover, the cytotoxicity of the newly synthesized compounds against normal human fibroblasts (WI-38) was investigated. The cytotoxic assay showed that derivatives 4 and 5 were not harmful to normal fibroblasts.


Asunto(s)
Culex , Moscas Domésticas , Insecticidas , Pirazoles , Animales , Humanos , Culex/efectos de los fármacos , Culex/metabolismo , Moscas Domésticas/efectos de los fármacos , Moscas Domésticas/metabolismo , Insecticidas/farmacología , Insecticidas/química , Larva , Simulación del Acoplamiento Molecular , Pirazoles/química , Pirazoles/farmacología
5.
Sci Rep ; 11(1): 14209, 2021 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-34244535

RESUMEN

Musca sorbens is a synanthropic filth fly that aggressively attacks people to feed from mucous membranes of the eyes, nose or mouth, from open sores, or from sweat. It has long been suspected that this fly contributes to the transmission of eye infections, particularly trachoma, and recent work has added to the evidence base that M. sorbens is a trachoma vector in Ethiopia. There are few options to control M. sorbens, largely due to a lack of evidence. Space spraying with insecticides is effective, but an environmentally sound and long-term sustainable solution would be better, for example, mass trapping. We tested commercially available and homemade trap types in a pilot (laboratory) study and three field studies. A homemade design, built from a bucket and two empty water bottles, baited with a commercially available lure, The Buzz, was found to be most effective. This trap caught 3848 M. sorbens over 26 trap 'events' (3- or 4-day periods); mean/median per 24 h 43.6 (standard deviation 137.10)/2.25 (IQR 0.25-12.67). The Buzz lure is cheap and effective for 4 weeks, and trap components cheap and locally available. Further studies are needed to understand the impact of this trap on local fly populations and the local transmission of trachoma.


Asunto(s)
Moscas Domésticas/patogenicidad , Insectos Vectores/patogenicidad , Tracoma/parasitología , Tracoma/transmisión , Animales , Etiopía , Ojo/parasitología , Moscas Domésticas/efectos de los fármacos , Humanos , Insectos Vectores/efectos de los fármacos , Insecticidas/farmacología , Odorantes , Tracoma/prevención & control
6.
J Med Entomol ; 58(6): 2338-2348, 2021 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34197608

RESUMEN

The house fly (Musca domestica Linnaeus) is an important disease vector. Insecticide resistance is an obstacle to effective house fly control. Previous studies have demonstrated that point mutations in acetylcholinesterase (Ace), carboxylesterase (MdαE7) and voltage-sensitive sodium channel (Vssc), and over-expression of CYP6D1v1 confer insecticide resistance in the house fly. However, information about the status and underlying mechanisms of insecticide resistance in Kazakhstani house flies is lacking. In this study, we investigated the occurrence of genetic mutations associated with insecticide resistance in field house flies collected at six different locations in southern Kazakhstan. Four mutations (V260L, G342A/V, and F407Y) in Ace and three mutations (G137D and W251L/S) in MdαE7 were detected with appreciable frequencies. Notably, haplotypes carrying triple-loci mutations in Ace and double mutations in MdαE7 were found in Kazakhstan. The L1014H and L1014F mutations in Vssc, and CYP6D1v1 resistance allele were detected at a low frequency in some of the six investigated house fly populations. Phylogenetic analyses of haplotypes supported multiple origins of resistance mutations in Ace and MdαE7. These observations suggest that house flies in southern Kazakhstan may exhibit significant resistance to organophosphates and carbamates. Regular monitoring of insecticide resistance is recommended to achieve effective house fly control by chemical agents in southern Kazakhstan.


Asunto(s)
Moscas Domésticas/genética , Proteínas de Insectos/genética , Resistencia a los Insecticidas/efectos de los fármacos , Insecticidas/farmacología , Mutación , Animales , Carbamatos/farmacología , Moscas Domésticas/efectos de los fármacos , Proteínas de Insectos/metabolismo , Kazajstán , Organofosfatos/farmacología
7.
PLoS One ; 16(4): e0249496, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33831056

RESUMEN

This study was conducted to determine the susceptibility and resistance of some house fly strains of Musca domestica L. to the insect growth regulator insecticides triflumuron and pyriproxyfen in some locations in Riyadh city. Field-collected strains of M. domestica L. from five sites in Riyadh city that represented five slaughterhouse sites where flies spread significantly were tested against triflumuron and pyriproxyfen. Triflumuron LC50 values for the five collected strains ranged from 2.6 to 5.5 ppm, and the resistance factors (RFs) ranged from 13-fold to 27-fold that of the susceptible laboratory strain. Pyriproxyfen LC50 values for the field strains ranged from 0.9 to 1.8 ppm with RFs of 3-fold to 5-fold. These results indicate that pyriproxyfen is an effective insecticide to control house flies and should be used in rotation with other insecticides in the control programs applied by Riyadh municipality.


Asunto(s)
Benzamidas/farmacología , Moscas Domésticas/efectos de los fármacos , Control de Insectos/métodos , Resistencia a los Insecticidas/efectos de los fármacos , Insecticidas/farmacología , Piridinas/farmacología , Animales , Femenino , Arabia Saudita
8.
SAR QSAR Environ Res ; 32(5): 395-410, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33870800

RESUMEN

The fumigant and topical activities exhibited by 27 plant-derived essentials oils (EOs) on adult M. domestica housefly are predicted through the Quantitative Structure-Activity Relationship (QSAR) theory. These molecular structure based calculations are performed on 253 structurally diverse compounds from the EOs, where the number of constituents in each essential oil mixture varies between 2 to 24. A large number of 86,048 non-conformational mixture descriptors are derived as linear combinations of the molecular descriptors of the EO components. Two strategies are compared for the mixture descriptor formulation, which consider or avoid the use of the chemical composition. The multivariable linear regression QSAR models of the present work are useful for fumigant and topical applications, describing predictive parallelisms for the insecticidal activity of the analysed complex mixtures.


Asunto(s)
Moscas Domésticas/efectos de los fármacos , Insecticidas/farmacología , Aceites Volátiles/farmacología , Animales , Fumigación , Repelentes de Insectos/química , Repelentes de Insectos/farmacología , Insecticidas/química , Aceites Volátiles/química , Relación Estructura-Actividad Cuantitativa
9.
Toxins (Basel) ; 13(1)2021 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-33406803

RESUMEN

The Tibellus oblongus spider is an active predator that does not spin webs and remains poorly investigated in terms of venom composition. Here, we present a new toxin, named Tbo-IT2, predicted by cDNA analysis of venom glands transcriptome. The presence of Tbo-IT2 in the venom was confirmed by proteomic analyses using the LC-MS and MS/MS techniques. The distinctive features of Tbo-IT2 are the low similarity of primary structure with known animal toxins and the unusual motif of 10 cysteine residues distribution. Recombinant Tbo-IT2 (rTbo-IT2), produced in E. coli using the thioredoxin fusion protein strategy, was structurally and functionally studied. rTbo-IT2 showed insecticidal activity on larvae of the housefly Musca domestica (LD100 200 µg/g) and no activity on the panel of expressed neuronal receptors and ion channels. The spatial structure of the peptide was determined in a water solution by NMR spectroscopy. The Tbo-IT2 structure is a new example of evolutionary adaptation of a well-known inhibitor cystine knot (ICK) fold to 5 disulfide bonds configuration, which determines additional conformational stability and gives opportunities for insectotoxicity and probably some other interesting features.


Asunto(s)
Venenos de Araña/química , Arañas/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN Complementario , Regulación de la Expresión Génica , Moscas Domésticas/efectos de los fármacos , Larva/efectos de los fármacos , Conformación Proteica , Pliegue de Proteína , Proteómica , Transcriptoma
10.
Nat Prod Res ; 35(9): 1566-1571, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-31507220

RESUMEN

Coumarin (2H-1-benzopyran-2-one) is a phenolic compound derived from the shikimate pathway and synthesized by various medicinal and aromatic plants as parent molecule of a large group of secondary metabolites, namely coumarins. Its main utilization is as fixative in perfumes and flavour enhancer. Given its role as phytoalexin and phagodepression activity, herein we evaluated for the first time its efficacy against several insect species: the green peach aphid, Myzus persicae, the moth Spodoptera littoralis, the housefly, Musca domestica and the filariasis vector Culex quinquefasciatus. Two non-target species were also included in our toxicity evaluation experiments: the ladybug Harmonia axyridis and the earthworm Eisenia fetida. Results highlighted remarkable selectivity of coumarin, being highly toxic to M. persicae aphids (LC50(90) values of 1.3(1.9) mg L-1) and friendly to natural enemies of aphids as well as soil invertebrates.


Asunto(s)
Áfidos/efectos de los fármacos , Cumarinas/toxicidad , Animales , Culex/efectos de los fármacos , Moscas Domésticas/efectos de los fármacos , Concentración 50 Inhibidora , Insecticidas/toxicidad , Larva/efectos de los fármacos , Mariposas Nocturnas/efectos de los fármacos , Extractos Vegetales/química , Semillas/química , Spodoptera/efectos de los fármacos , Pruebas de Toxicidad
11.
Food Chem Toxicol ; 147: 111899, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33279675

RESUMEN

Pesticides are used to control and combat insects and pests in the agricultural sector, households, and public health programs. The frequent and disorderly use of these pesticides may lead to variety of undesired effects. Therefore, natural products have many advantages over to synthetic compounds to be used as insecticides. The goal of this study was to find natural products with insecticidal potential against Musca domestica and Mythimna separata. To achieve this goal, we developed predictive QSAR models using MuDRA, PLS, and RF approaches and performed virtual screening of 117 natural products. As a result of QSAR modeling, we formulated the recommendations regarding physico-chemical characteristics for promising compounds active against Musca domestica and Mythimna separata. Homology models were successfully built for both species and molecular docking of QSAR hits vs known insecticides allowed us to prioritize twenty-two compounds against Musca domestica and six against Mythimna separata. Our results suggest that pimarane diterpenes, abietanes diterpenes, dimeric diterpenes and scopadulane diterpenes obtained from aerial parts of species of the genus Calceolaria (Calceolariaceae: Scrophulariaceae) can be considered as potential insecticidal.


Asunto(s)
Dípteros/efectos de los fármacos , Diterpenos/química , Diterpenos/farmacología , Insecticidas/farmacología , Animales , Diseño de Fármacos , Moscas Domésticas/efectos de los fármacos , Modelos Biológicos , Estructura Molecular , Relación Estructura-Actividad Cuantitativa , Scrophulariaceae/química , Sensibilidad y Especificidad
12.
J Agric Food Chem ; 68(50): 15005-15014, 2020 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-33269911

RESUMEN

To control the development of resistance to conventional insecticides acting as γ-aminobutyric acid (GABA) receptor antagonists (e.g., fipronil), new GABAergic 5,5-disubstituted 4,5-dihydropyrazolo[1,5-a]quinazolines were designed via a scaffold-hopping strategy and synthesized with a facile method. Among the 50 target compounds obtained, compounds 5a, 5b, 7a, and 7g showed excellent insecticidal activities against a susceptible strain of Plutella xylostella (LC50 values ranging from 1.03 to 1.44 µg/mL), which were superior to that of fipronil (LC50 = 3.02 µg/mL). Remarkably, the insecticidal activity of compound 5a was 64-fold better than that of fipronil against the field population of fipronil-resistant P. xylostella. Electrophysiological studies against the housefly GABA receptor heterologously expressed in Xenopus oocytes indicated that compound 5a could act as a potent GABA receptor antagonist, and IC50 was calculated to be 32.5 nM. Molecular docking showed that the binding poses of compound 5a with the housefly GABA receptor can be different compared to fipronil, which explains the effectiveness of compound 5a against fipronil-resistant insects. These findings have suggested compound 5a as a lead compound for a novel GABA receptor antagonist controlling field-resistant insects and provided a basis for further design, structural modification, and development of 4,5-dihydropyrazolo[1,5-a]quinazoline motifs as new insecticidal GABA receptor antagonists.


Asunto(s)
Antagonistas del GABA/química , Antagonistas del GABA/farmacología , Moscas Domésticas/efectos de los fármacos , Proteínas de Insectos/antagonistas & inhibidores , Insecticidas/síntesis química , Insecticidas/farmacología , Quinazolinas/química , Quinazolinas/farmacología , Animales , Diseño de Fármacos , Moscas Domésticas/química , Moscas Domésticas/genética , Moscas Domésticas/metabolismo , Proteínas de Insectos/química , Proteínas de Insectos/metabolismo , Insecticidas/química , Simulación del Acoplamiento Molecular , Receptores de GABA/química , Receptores de GABA/metabolismo
13.
J Insect Sci ; 20(6)2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-33135745

RESUMEN

Veterinary and medical entomologists who are involved in research on pest control often need to perform dose-response bioassays and analyze the results. This article is meant as a beginner's guide for doing this and includes instructions for using the free program R for the analyses. The bioassays and analyses are described using previously unpublished data from bioassays on house flies, Musca domestica Linnaeus (Diptera: Muscidae), but can be used on a wide range of pest species. Flies were exposed topically to beta-cyfluthrin, a pyrethroid, or exposed to spinosad or spinetoram in sugar to encourage consumption. LD50 values for beta-cyfluthrin in a susceptible strain were similar regardless of whether mortality was assessed at 24 or 48 h, consistent with it being a relatively quick-acting insecticide. Based on LC50 values, spinetoram was about twice as toxic as spinosad in a susceptible strain, suggesting a benefit to formulating spinetoram for house fly control, although spinetoram was no more toxic than spinosad for a pyrethroid-resistant strain. Results were consistent with previous reports of spinosad exhibiting little cross-resistance. For both spinosad and spinetoram, LC50 values were not greatly different between the pyrethroid-resistant strain and the susceptible strain.


Asunto(s)
Moscas Domésticas/efectos de los fármacos , Insecticidas/farmacología , Macrólidos/farmacología , Nitrilos/farmacología , Piretrinas/farmacología , Animales , Bioensayo , Combinación de Medicamentos , Femenino
14.
Pestic Biochem Physiol ; 168: 104648, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32711758

RESUMEN

The house fly, Musca domestica L. (Diptera: Muscidae), is an insect pest of public health and veterinary importance. Spiromesifen is a new chemistry insecticide widely used for the management of sucking insect pests of vegetables and crops. In the present study, assessment of resistance risk and fitness costs associated with spiromesifen resistance in M. domestica was studied. Moreover, stability of resistance to spiromesifen and other tested insecticides (fipronil, spinosad, and bifenthrin) was evaluated in the spiromesifen-selected-strain (SPIRO-SEL-POP). After 7-generations of selection with spiromesifen, SPIRO-SEL-POP developed 108.76-fold resistance compared with the unselected strain (UNSEL-POP). The estimated value of realized heritability was 0.59 for spiromesifen resistance. Due to withdrawal of spiromesifen selection for five generations (F6-F10) on SPIRO-SEL-POP, a decline in LC50 values against spiromesifen, spinosad and bifenthrin was 0.16, 0.14 and 0.13-folds, respectively. In biological trait experiments, larval weight of Cross1 (SPIRO-SEL-POP♀ × UNSEL-POP♂) and SPIRO-SEL-POP was significantly lower than that of Cross2 (SPIRO-SEL-POP♂ × UNSEL-POP♀) and UNSEL-POP. Pupal weight of SPIRO-SEL-POP was higher when compared with Cross1 while it was similar to that of Cross2 and UNSEL-POP. Adult emergence rate of UNSEL-POP was higher than Cross1, but similar to the Cross2 and SPIRO-SEL-POP. The SPIRO-SEL-POP and Cross1 showed the lowest relative fitness when compared with USEL-POP and Cross2. Intrinsic rate of natural increase of SPIRO-SEL-POP was much lower than that of UNSEL-POP and Cross2 followed by Cross1. The SPIRO-SEL-POP exhibited lower biotic potential when compared with UNSEL-POP and Cross2 but similar to Cross1. Fecundity and hatching rates were lower in SPIRO-SEL-POP compared to UNSEL-POP. It could be concluded that spiromesifen resistance in M. domestica comes with a cost and is instable. Therefore, spiromesifen rotation with other insecticides and withdraw of its usage for some period could help to sustain its efficacy by delaying the development of resistance.


Asunto(s)
Moscas Domésticas/efectos de los fármacos , Insecticidas/farmacología , Muscidae/efectos de los fármacos , Compuestos de Espiro , Animales , Resistencia a los Insecticidas/efectos de los fármacos
15.
Acta Trop ; 210: 105620, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32649995

RESUMEN

Housefly, Musca (M) domestica L. (Diptera: Muscidae) is a pervasive insect that transmits a variety of pathogens to humans and livestock. Although numerous synthetic pesticides are available to combat houseflies, their ecological and toxicological concerns have led to the exploration of natural products as safer alternatives. The present work was designed to develop an essential oil based controlled-release evaporating tablet (EO-CRT) and investigate its repellency against M. domestica. This study assesses the toxicological impacts of the EO-CRT following its sub-chronic inhalation exposure. Briefly, repellent activity of fourteen essential oils viz. lemon grass, bergamot, mentha, basil, camphor, lavender, clove, patchouli, rosemary, cinnamon, eucalyptus, citronella, jasmine and wild turmeric against M. domestica were screened using the 'Y'-tube olfactometer. The synergistic activity of the best four oils, under preliminary screening, were further evaluated by double and triple blending. The best combination of three oils were finalized for optimization with 17-run, 3-factor, 3-level Box-Behnken design. This was then employed to construct polynomial models and predict the best optimized formulation EO-CRT. EO-CRT was characterized by Differential Scanning Calorimetry (DSC) and Gas Chromatography-Mass Spectroscopy (GC-MS). The efficacy of the EO-CRT against M. domestica was assessed by attraction and repellent assay. Chest X-ray, histopathology and scanning electron microscopy of the exposed lung was performed to study EO-CRT's sub-chronic toxicity on Wistar rats. The EO-CRT showed slow release up to a period of 10 days at room temperature, exhibited 100% repellency (%Error=1.237) against M. domestica and was found to possess all the characteristics of an ideal formulation. Sub-chronic toxicity study further revealed the non-toxic nature of the EO-CRT. Thus, our study provides an assurance that the formulated EO-CRT could be effective not only in repelling the nuisance pest, M. domestica, in human dwellings, but also in minimizing the mechanical transmission of pathogens by it.


Asunto(s)
Moscas Domésticas/efectos de los fármacos , Repelentes de Insectos/farmacología , Aceites Volátiles/farmacología , Animales , Preparaciones de Acción Retardada/farmacología , Femenino , Masculino , Aceites Volátiles/toxicidad , Ratas , Ratas Wistar , Comprimidos/farmacología
16.
J Med Entomol ; 57(6): 1843-1851, 2020 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-32516402

RESUMEN

Insecticide resistance in pest populations is an increasing problem in both urban and rural settings caused by over-application of insecticides and lack of rotation among chemical classes. The house fly (Musca domestica L.) is a cosmopolitan fly species implicated in the transmission of numerous pathogens, and which can be extremely pestiferous when present in high numbers. The evolution of insecticide resistance has long been documented in house flies, with resistance reported to all major insecticide classes. House fly resistance to imidacloprid, the most widely used neonicotinoid insecticide available for fly control, has been selected for in field populations through both physiological and behavioral resistance mechanisms. In the current study, house flies collected from a southern California dairy were selectively bred for behavioral resistance to imidacloprid, without increasing the physiological resistance profile of the selected flies. Flies were also successfully selected for behavioral susceptibility to imidacloprid. The rapid selection for either behavioral resistance or behavioral susceptibility suggests that inheritable alleles conferring behavioral resistance were already present in the wild-type fly population collected from the dairy site. The methods used for the specific selection of behavioral resistance (or susceptibility) in the fly population will be useful for further studies on the specific mechanisms conferring this resistance. House fly behavioral resistance was further investigated using behavioral observation and feeding preference assays, with resistance determined to be both contact-dependent and specific to the insecticide (imidacloprid) rather than to a non-insecticidal component of a bait matrix as previously documented.


Asunto(s)
Moscas Domésticas/efectos de los fármacos , Control de Insectos , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Neonicotinoides/farmacología , Nitrocompuestos/farmacología , Selección Genética/fisiología , Animales , Femenino , Moscas Domésticas/genética , Moscas Domésticas/fisiología , Masculino
17.
Sci Rep ; 10(1): 8400, 2020 05 21.
Artículo en Inglés | MEDLINE | ID: mdl-32439946

RESUMEN

Two unique housefly strains, PSS and N-PRS (near-isogenic line with the PSS), were used to clarify the mechanisms associated with propoxur resistance in the housefly, Musca domestica. The propoxur-selected resistant (N-PRS) strain exhibited >1035-fold resistance to propoxur and 1.70-, 12.06-, 4.28-, 57.76-, and 57.54-fold cross-resistance to beta-cypermethrin, deltamethrin, bifenthrin, phoxim, and azamethiphos, respectively, compared to the susceptible (PSS) strain. We purified acetylcholinesterase (AChE) from the N-PRS and PSS strains using a procainamide affinity column and characterized the AChE. The sensitivity of AChE to propoxur based on the bimolecular rate constant (Ki) was approximately 100-fold higher in the PSS strain compared to the N-PRS strain. The cDNA encoding Mdace from both the N-PRS strain and the PSS strain were cloned and sequenced using RT-PCR. The cDNA was 2073 nucleotides long and encoded a protein of 691 amino acids. A total of four single nucleotide polymorphisms (SNPs), I162M, V260L, G342A, and F407Y, were present in the region of the active site of AChE from the N-PRS strain. The transcription level and DNA copy number of Mdace were significantly higher in the resistant strain than in the susceptible strain. These results indicated that mutations combined with the up-regulation of Mdace might be essential in the housefly resistance to propoxur.


Asunto(s)
Acetilcolinesterasa/genética , Moscas Domésticas/efectos de los fármacos , Proteínas de Insectos/genética , Resistencia a los Insecticidas/efectos de los fármacos , Insecticidas/farmacología , Propoxur/farmacología , Acetilcolinesterasa/metabolismo , Animales , Inhibidores de la Colinesterasa/farmacología , Regulación Enzimológica de la Expresión Génica , Moscas Domésticas/genética , Proteínas de Insectos/metabolismo , Resistencia a los Insecticidas/genética , Mutación , Polimorfismo de Nucleótido Simple
18.
Food Chem Toxicol ; 138: 111203, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32074491

RESUMEN

Thymus alternans and Teucrium montanum subsp. jailae are medicinal and aromatic plants, typical of Slovakian flora, producing bioactive essential oils. In the present study, we evaluated the insecticidal potential of the essential oils, obtained by hydrodistillation from the plant aerial parts and analysed by GC-MS, as insecticidal agents. For the purpose, they were assayed against three insect species acting as agricultural pests or vectors of medical relevance, such as the common housefly, Musca domestica L., the lymphatic filariasis vector, Culex quinquefasciatus and the Egyptian cotton leafworm Spodoptera littoralis; α-cypermethrin was tested as positive control. The two essential oils exhibited a different chemical profile, with monoterpenes and sesquiterpenes being the main fractions in the essential oils from Th. alternans and T. montanum subsp. jailae, respectively. Insecticidal tests showed that the T. montanum essential oil was effective against S. littoralis (LD50(90) = 56.7 (170.0) µg larva-1) and Cx. quinquefasciatus larvae (LC50(90) = 180.5 (268.7) mg L-1), whereas T. alternans essential oil displayed good toxicity against M. domestica adults (LD50(90) = 103.7 (223.9) µg adult-1). Overall, our results add useful knowledge about the potential of Slovakian flora as a source of botanicals for the eco-friendly management of insect pests and vectors.


Asunto(s)
Insecticidas/farmacología , Aceites Volátiles/farmacología , Plantas Medicinales/química , Teucrium/química , Thymus (Planta)/química , Animales , Culex/efectos de los fármacos , Culex/metabolismo , Femenino , Cromatografía de Gases y Espectrometría de Masas , Moscas Domésticas/efectos de los fármacos , Moscas Domésticas/metabolismo , Insecticidas/análisis , Larva/efectos de los fármacos , Larva/metabolismo , Monoterpenos/análisis , Monoterpenos/farmacología , Aceites Volátiles/análisis , Piretrinas/análisis , Piretrinas/farmacología , Sesquiterpenos/análisis , Sesquiterpenos/farmacología , Eslovaquia , Spodoptera/efectos de los fármacos , Spodoptera/metabolismo
19.
Food Chem Toxicol ; 138: 111184, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32061727

RESUMEN

Marsh rosemary (Ledum palustre, Ericaceae) has been widely used in the traditional medicine of various regions worldwide, and as insect repellent. Little is known on its essential oil insecticidal potential. This study explored the insecticidal effects of the essential oil obtained from L. palustre growing in Poland on selected insect pests and vectors. GC-MS analysis evidenced an uncommon chemotype characterized by ascaridole (35.3% as sum of cis-ascaridole and isoascaridole) and p-cymene (25.5%). The essential oil was effective against Culex quinquefasciatus, Spodoptera littoralis and Musca domestica, showing LC50/LD50 of 66.6 mg L-1, 117.2 µg larva-1 and 61.4 µg adult-1, respectively. It was not toxic to non-target Eisenia fetida earthworms and moderately toxic to Daphnia magna microcrustaceans, over the positive control α-cypermethrin. The essential oil cytotoxicity on human keratinocytes and fibroblasts showed high IC50 values (71.3 and 84.4 µg mL-1, respectively). Comet assay data highlighted no DNA damages. Based on our findings, this essential oil, characterized by the ascaridole/p-cymene chemotype, could be a candidate for the formulation of botanical insecticides; large-scale production of green insecticides by this rare species may be assured by ex situ cultivation and biotechnological techniques.


Asunto(s)
Monoterpenos Ciclohexánicos/farmacología , Insecticidas/farmacología , Aceites Volátiles/farmacología , Peróxidos/farmacología , Rosmarinus/química , Animales , Línea Celular , Ensayo Cometa , Culex/efectos de los fármacos , Culicidae/efectos de los fármacos , Monoterpenos Ciclohexánicos/análisis , Cimenos/análisis , Cimenos/farmacología , Daphnia/efectos de los fármacos , Moscas Domésticas/efectos de los fármacos , Humanos , Repelentes de Insectos/análisis , Repelentes de Insectos/farmacología , Insecticidas/análisis , Queratinocitos/citología , Queratinocitos/efectos de los fármacos , Larva/efectos de los fármacos , Mosquitos Vectores/efectos de los fármacos , Mariposas Nocturnas/efectos de los fármacos , Aceites Volátiles/análisis , Oligoquetos/efectos de los fármacos , Peróxidos/análisis , Polonia , Piretrinas/análisis , Piretrinas/farmacología , Spodoptera/efectos de los fármacos
20.
Int J Biol Macromol ; 150: 141-151, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32045613

RESUMEN

Toll-like receptors (TLRs) are the earliest reported pathogen recognition receptors (PRRs), and these receptors play pivotal roles in the innate immune system. Systematic studies of TLR family at the genome-wide level are important to understand its functions but are currently lacking in the insect lineage. Here, 6 TLR genes were identified and characterized in housefly (Musca domestica). The TLR genes of housefly were classified into five families according to the phylogenetic analysis of insect TLRs. The domain organization analyses indicated that the TLRs were composed by three major components: a leucine-rich repeat (LRR) domain, a transmembrane region (TM) and a Toll/interleukin-1 receptor (TIR) domain. Primary and tertiary structure analysis showed that the ectodomains of arthropod TLRs were longer than that of other phyla or classes. The mRNA expression levels of all 6 TLRs downregulated in the resistant housefly strain. Moreover, the expression levels of 6 TLRs varied between tissue and gender. Additionally, the 3D structures of the TIR domain were highly conserved during evolution. Collectively, these results help elucidate the crucial roles of TLRs in the immune response of housefly and provide a foundation for further understanding of innate immunity of the housefly.


Asunto(s)
Genoma de los Insectos , Genómica , Moscas Domésticas/efectos de los fármacos , Moscas Domésticas/genética , Resistencia a los Insecticidas/genética , Receptores Toll-Like/genética , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Evolución Molecular , Femenino , Genómica/métodos , Moscas Domésticas/metabolismo , Inmunidad Innata , Masculino , Modelos Moleculares , Familia de Multigenes , Especificidad de Órganos/genética , Filogenia , Conformación Proteica , Dominios y Motivos de Interacción de Proteínas , Mapeo de Interacción de Proteínas , Mapas de Interacción de Proteínas , Factores Sexuales , Receptores Toll-Like/química
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